diff third_party/sqlite3/autosetup/proj.tcl @ 167:589bab390fb4

[ThirdParty] Added sqlite3 to the third_party.
author MrJuneJune <me@mrjunejune.com>
date Mon, 19 Jan 2026 16:28:45 -0800
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/sqlite3/autosetup/proj.tcl	Mon Jan 19 16:28:45 2026 -0800
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+########################################################################
+# 2024 September 25
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#  * May you do good and not evil.
+#  * May you find forgiveness for yourself and forgive others.
+#  * May you share freely, never taking more than you give.
+#
+
+#
+# ----- @module proj.tcl -----
+# @section Project-agnostic Helper APIs
+#
+
+#
+# Routines for Steve Bennett's autosetup which are common to trees
+# managed in and around the umbrella of the SQLite project.
+#
+# The intent is that these routines be relatively generic, independent
+# of a given project.
+#
+# For practical purposes, the copy of this file hosted in the SQLite
+# project is the "canonical" one:
+#
+# https://sqlite.org/src/file/autosetup/proj.tcl
+#
+# This file was initially derived from one used in the libfossil
+# project, authored by the same person who ported it here, and this is
+# noted here only as an indication that there are no licensing issues
+# despite this code having a handful of near-twins running around a
+# handful of third-party source trees.
+#
+# Design notes:
+#
+# - Symbols with _ separators are intended for internal use within
+#   this file, and are not part of the API which auto.def files should
+#   rely on. Symbols with - separators are public APIs.
+#
+# - By and large, autosetup prefers to update global state with the
+#   results of feature checks, e.g. whether the compiler supports flag
+#   --X.  In this developer's opinion that (A) causes more confusion
+#   than it solves[^1] and (B) adds an unnecessary layer of "voodoo"
+#   between the autosetup user and its internals. This module, in
+#   contrast, instead injects the results of its own tests into
+#   well-defined variables and leaves the integration of those values
+#   to the caller's discretion.
+#
+# [1]: As an example: testing for the -rpath flag, using
+# cc-check-flags, can break later checks which use
+# [cc-check-function-in-lib ...] because the resulting -rpath flag
+# implicitly becomes part of those tests. In the case of an rpath
+# test, downstream tests may not like the $prefix/lib path added by
+# the rpath test. To avoid such problems, we avoid (intentionally)
+# updating global state via feature tests.
+#
+
+#
+# $proj__Config is an internal-use-only array for storing whatever generic
+# internal stuff we need stored.
+#
+array set ::proj__Config [subst {
+  self-tests [get-env proj.self-tests 0]
+  verbose-assert [get-env proj.assert-verbose 0]
+  isatty [isatty? stdout]
+}]
+
+#
+# List of dot-in files to filter in the final stages of
+# configuration. Some configuration steps may append to this.  Each
+# one in this list which exists will trigger the generation of a
+# file with that same name, minus the ".in", in the build directory
+# (which differ from the source dir in out-of-tree builds).
+#
+# See: proj-dot-ins-append and proj-dot-ins-process
+#
+set ::proj__Config(dot-in-files) [list]
+
+#
+# @proj-warn msg
+#
+# Emits a warning message to stderr. All args are appended with a
+# space between each.
+#
+proc proj-warn {args} {
+  show-notices
+  puts stderr [join [list "WARNING:" \[ [proj-scope 1] \]: {*}$args] " "]
+}
+
+
+#
+# Internal impl of [proj-fatal] and [proj-error]. It must be called
+# using tailcall.
+#
+proc proj__faterr {failMode args} {
+  show-notices
+  set lvl 1
+  while {"-up" eq [lindex $args 0]} {
+    set args [lassign $args -]
+    incr lvl
+  }
+  if {$failMode} {
+    puts stderr [join [list "FATAL:" \[ [proj-scope $lvl] \]: {*}$args]]
+    exit 1
+  } else {
+    error [join [list in \[ [proj-scope $lvl] \]: {*}$args]]
+  }
+}
+
+#
+# @proj-fatal ?-up...? msg...
+#
+# Emits an error message to stderr and exits with non-0. All args are
+# appended with a space between each.
+#
+# The calling scope's name is used in the error message. To instead
+# use the name of a call higher up in the stack, use -up once for each
+# additional level.
+#
+proc proj-fatal {args} {
+  tailcall proj__faterr 1 {*}$args
+}
+
+#
+# @proj-error ?-up...? msg...
+#
+# Works like proj-fatal but uses [error] intead of [exit].
+#
+proc proj-error {args} {
+  tailcall proj__faterr 0 {*}$args
+}
+
+#
+# @proj-assert script ?message?
+#
+# Kind of like a C assert: if uplevel of [list expr $script] is false,
+# a fatal error is triggered. The error message, by default, includes
+# the body of the failed assertion, but if $msg is set then that is
+# used instead.
+#
+proc proj-assert {script {msg ""}} {
+  if {1 eq $::proj__Config(verbose-assert)} {
+    msg-result [proj-bold "asserting: $script"]
+  }
+  if {![uplevel 1 [list expr $script]]} {
+    if {"" eq $msg} {
+      set msg $script
+    }
+    tailcall proj__faterr 1 "Assertion failed:" $msg
+  }
+}
+
+#
+# @proj-bold str
+#
+# If this function believes that the current console might support
+# ANSI escape sequences then this returns $str wrapped in a sequence
+# to bold that text, else it returns $str as-is.
+#
+proc proj-bold {args} {
+  if {$::autosetup(iswin) || !$::proj__Config(isatty)} {
+    return [join $args]
+  }
+  return "\033\[1m${args}\033\[0m"
+}
+
+#
+# @proj-indented-notice ?-error? ?-notice? msg
+#
+# Takes a multi-line message and emits it with consistent indentation.
+# It does not perform any line-wrapping of its own. Which output
+# routine it uses depends on its flags, defaulting to msg-result.
+# For -error and -notice it uses user-notice.
+#
+# If the -notice flag it used then it emits using [user-notice], which
+# means its rendering will (A) go to stderr and (B) be delayed until
+# the next time autosetup goes to output a message.
+#
+# If the -error flag is provided then it renders the message
+# immediately to stderr and then exits.
+#
+# If neither -notice nor -error are used, the message will be sent to
+# stdout without delay.
+#
+proc proj-indented-notice {args} {
+  set fErr ""
+  set outFunc "msg-result"
+  while {[llength $args] > 1} {
+    switch -exact -- [lindex $args 0] {
+      -error  {
+        set args [lassign $args fErr]
+        set outFunc "user-notice"
+      }
+      -notice {
+        set args [lassign $args -]
+        set outFunc "user-notice"
+      }
+      default {
+        break
+      }
+    }
+  }
+  set lines [split [join $args] \n]
+  foreach line $lines {
+    set line [string trimleft $line]
+    if {"" eq $line} {
+      $outFunc $line
+    } else {
+      $outFunc "    $line"
+    }
+  }
+  if {"" ne $fErr} {
+    show-notices
+    exit 1
+  }
+}
+
+#
+# @proj-is-cross-compiling
+#
+# Returns 1 if cross-compiling, else 0.
+#
+proc proj-is-cross-compiling {} {
+  expr {[get-define host] ne [get-define build]}
+}
+
+#
+# @proj-strip-hash-comments value
+#
+# Expects to receive string input, which it splits on newlines, strips
+# out any lines which begin with any number of whitespace followed by
+# a '#', and returns a value containing the [append]ed results of each
+# remaining line with a \n between each. It does not strip out
+# comments which appear after the first non-whitespace character.
+#
+proc proj-strip-hash-comments {val} {
+  set x {}
+  foreach line [split $val \n] {
+    if {![string match "#*" [string trimleft $line]]} {
+      append x $line \n
+    }
+  }
+  return $x
+}
+
+#
+# @proj-cflags-without-werror
+#
+# Fetches [define $var], strips out any -Werror entries, and returns
+# the new value. This is intended for temporarily stripping -Werror
+# from CFLAGS or CPPFLAGS within the scope of a [define-push] block.
+#
+proc proj-cflags-without-werror {{var CFLAGS}} {
+  set rv {}
+  foreach f [get-define $var ""] {
+    switch -exact -- $f {
+      -Werror {}
+      default { lappend rv $f }
+    }
+  }
+  join $rv " "
+}
+
+#
+# @proj-check-function-in-lib
+#
+# A proxy for cc-check-function-in-lib with the following differences:
+#
+# - Does not make any global changes to the LIBS define.
+#
+# - Strips out the -Werror flag from CFLAGS before running the test,
+#   as these feature tests will often fail if -Werror is used.
+#
+# Returns the result of cc-check-function-in-lib (i.e. true or false).
+# The resulting linker flags are stored in the [define] named
+# lib_${function}.
+#
+proc proj-check-function-in-lib {function libs {otherlibs {}}} {
+  set found 0
+  define-push {LIBS CFLAGS} {
+    #puts "CFLAGS before=[get-define CFLAGS]"
+    define CFLAGS [proj-cflags-without-werror]
+    #puts "CFLAGS after =[get-define CFLAGS]"
+    set found [cc-check-function-in-lib $function $libs $otherlibs]
+  }
+  return $found
+}
+
+#
+# @proj-search-for-header-dir ?-dirs LIST? ?-subdirs LIST? header
+#
+# Searches for $header in a combination of dirs and subdirs, specified
+# by the -dirs {LIST} and -subdirs {LIST} flags (each of which have
+# sane defaults). Returns either the first matching dir or an empty
+# string.  The return value does not contain the filename part.
+#
+proc proj-search-for-header-dir {header args} {
+  set subdirs {include}
+  set dirs {/usr /usr/local /mingw}
+# Debatable:
+#  if {![proj-is-cross-compiling]} {
+#    lappend dirs [get-define prefix]
+#  }
+  while {[llength $args]} {
+    switch -exact -- [lindex $args 0] {
+      -dirs     { set args [lassign $args - dirs] }
+      -subdirs  { set args [lassign $args - subdirs] }
+      default   {
+        proj-error "Unhandled argument: $args"
+      }
+    }
+  }
+  foreach dir $dirs {
+    foreach sub $subdirs {
+      if {[file exists $dir/$sub/$header]} {
+        return "$dir/$sub"
+      }
+    }
+  }
+  return ""
+}
+
+#
+# @proj-find-executable-path ?-v? binaryName
+#
+# Works similarly to autosetup's [find-executable-path $binName] but:
+#
+# - If the first arg is -v, it's verbose about searching, else it's quiet.
+#
+# Returns the full path to the result or an empty string.
+#
+proc proj-find-executable-path {args} {
+  set binName $args
+  set verbose 0
+  if {[lindex $args 0] eq "-v"} {
+    set verbose 1
+    set args [lassign $args - binName]
+    msg-checking "Looking for $binName ... "
+  }
+  set check [find-executable-path $binName]
+  if {$verbose} {
+    if {"" eq $check} {
+      msg-result "not found"
+    } else {
+      msg-result $check
+    }
+  }
+  return $check
+}
+
+#
+# @proj-bin-define binName ?defName?
+#
+# Uses [proj-find-executable-path $binName] to (verbosely) search for
+# a binary, sets a define (see below) to the result, and returns the
+# result (an empty string if not found).
+#
+# The define'd name is: If $defName is not empty, it is used as-is. If
+# $defName is empty then "BIN_X" is used, where X is the upper-case
+# form of $binName with any '-' characters replaced with '_'.
+#
+proc proj-bin-define {binName {defName {}}} {
+  set check [proj-find-executable-path -v $binName]
+  if {"" eq $defName} {
+    set defName "BIN_[string toupper [string map {- _} $binName]]"
+  }
+  define $defName $check
+  return $check
+}
+
+#
+# @proj-first-bin-of bin...
+#
+# Looks for the first binary found of the names passed to this
+# function.  If a match is found, the full path to that binary is
+# returned, else "" is returned.
+#
+# Despite using cc-path-progs to do the search, this function clears
+# any define'd name that function stores for the result (because the
+# caller has no sensible way of knowing which [define] name it has
+# unless they pass only a single argument).
+#
+proc proj-first-bin-of {args} {
+  set rc ""
+  foreach b $args {
+    set u [string toupper $b]
+    # Note that cc-path-progs defines $u to "false" if it finds no
+    # match.
+    if {[cc-path-progs $b]} {
+      set rc [get-define $u]
+    }
+    undefine $u
+    if {"" ne $rc} break
+  }
+  return $rc
+}
+
+#
+# @proj-opt-was-provided key
+#
+# Returns 1 if the user specifically provided the given configure flag
+# or if it was specifically set using proj-opt-set, else 0. This can
+# be used to distinguish between options which have a default value
+# and those which were explicitly provided by the user, even if the
+# latter is done in a way which uses the default value.
+#
+# For example, with a configure flag defined like:
+#
+#   { foo-bar:=baz => {its help text} }
+#
+# This function will, when passed foo-bar, return 1 only if the user
+# passes --foo-bar to configure, even if that invocation would resolve
+# to the default value of baz. If the user does not explicitly pass in
+# --foo-bar (with or without a value) then this returns 0.
+#
+# Calling [proj-opt-set] is, for purposes of the above, equivalent to
+# explicitly passing in the flag.
+#
+# Note: unlike most functions which deal with configure --flags, this
+# one does not validate that $key refers to a pre-defined flag. i.e.
+# it accepts arbitrary keys, even those not defined via an [options]
+# call. [proj-opt-set] manipulates the internal list of flags, such
+# that new options set via that function will cause this function to
+# return true. (That's an unintended and unavoidable side-effect, not
+# specifically a feature which should be made use of.)
+#
+proc proj-opt-was-provided {key} {
+  dict exists $::autosetup(optset) $key
+}
+
+#
+# @proj-opt-set flag ?val?
+#
+# Force-set autosetup option $flag to $val. The value can be fetched
+# later with [opt-val], [opt-bool], and friends.
+#
+# Returns $val.
+#
+proc proj-opt-set {flag {val 1}} {
+  if {$flag ni $::autosetup(options)} {
+    # We have to add this to autosetup(options) or else future calls
+    # to [opt-bool $flag] will fail validation of $flag.
+    lappend ::autosetup(options) $flag
+  }
+  dict set ::autosetup(optset) $flag $val
+  return $val
+}
+
+#
+# @proj-opt-exists flag
+#
+# Returns 1 if the given flag has been defined as a legal configure
+# option, else returns 0. Options set via proj-opt-set "exist" for
+# this purpose even if they were not defined via autosetup's
+# [options] function.
+#
+proc proj-opt-exists {flag} {
+  expr {$flag in $::autosetup(options)};
+}
+
+#
+# @proj-val-truthy val
+#
+# Returns 1 if $val appears to be a truthy value, else returns
+# 0. Truthy values are any of {1 on true yes enabled}
+#
+proc proj-val-truthy {val} {
+  expr {$val in {1 on true yes enabled}}
+}
+
+#
+# @proj-opt-truthy flag
+#
+# Returns 1 if [opt-val $flag] appears to be a truthy value or
+# [opt-bool $flag] is true. See proj-val-truthy.
+#
+proc proj-opt-truthy {flag} {
+  if {[proj-val-truthy [opt-val $flag]]} { return 1 }
+  set rc 0
+  catch {
+    # opt-bool will throw if $flag is not a known boolean flag
+    set rc [opt-bool $flag]
+  }
+  return $rc
+}
+
+#
+# @proj-if-opt-truthy boolFlag thenScript ?elseScript?
+#
+# If [proj-opt-truthy $flag] is true, eval $then, else eval $else.
+#
+proc proj-if-opt-truthy {boolFlag thenScript {elseScript {}}} {
+  if {[proj-opt-truthy $boolFlag]} {
+    uplevel 1 $thenScript
+  } else {
+    uplevel 1 $elseScript
+  }
+}
+
+#
+# @proj-define-for-opt flag def ?msg? ?iftrue? ?iffalse?
+#
+# If [proj-opt-truthy $flag] then [define $def $iftrue] else [define
+# $def $iffalse]. If $msg is not empty, output [msg-checking $msg] and
+# a [msg-results ...] which corresponds to the result. Returns 1 if
+# the opt-truthy check passes, else 0.
+#
+proc proj-define-for-opt {flag def {msg ""} {iftrue 1} {iffalse 0}} {
+  if {"" ne $msg} {
+    msg-checking "$msg "
+  }
+  set rcMsg ""
+  set rc 0
+  if {[proj-opt-truthy $flag]} {
+    define $def $iftrue
+    set rc 1
+  } else {
+    define $def $iffalse
+  }
+  switch -- [proj-val-truthy [get-define $def]] {
+    0 { set rcMsg no }
+    1 { set rcMsg yes }
+  }
+  if {"" ne $msg} {
+    msg-result $rcMsg
+  }
+  return $rc
+}
+
+#
+# @proj-opt-define-bool ?-v? optName defName ?descr?
+#
+# Checks [proj-opt-truthy $optName] and calls [define $defName X]
+# where X is 0 for false and 1 for true. $descr is an optional
+# [msg-checking] argument which defaults to $defName. Returns X.
+#
+# If args[0] is -v then the boolean semantics are inverted: if
+# the option is set, it gets define'd to 0, else 1. Returns the
+# define'd value.
+#
+proc proj-opt-define-bool {args} {
+  set invert 0
+  if {[lindex $args 0] eq "-v"} {
+    incr invert
+    lassign $args - optName defName descr
+  } else {
+    lassign $args optName defName descr
+  }
+  if {"" eq $descr} {
+    set descr $defName
+  }
+  #puts "optName=$optName defName=$defName descr=$descr"
+  set rc 0
+  msg-checking "[join $descr] ... "
+  set rc [proj-opt-truthy $optName]
+  if {$invert} {
+    set rc [expr {!$rc}]
+  }
+  msg-result [string map {0 no 1 yes} $rc]
+  define $defName $rc
+  return $rc
+}
+
+#
+# @proj-check-module-loader
+#
+# Check for module-loading APIs (libdl/libltdl)...
+#
+# Looks for libltdl or dlopen(), the latter either in -ldl or built in
+# to libc (as it is on some platforms). Returns 1 if found, else
+# 0. Either way, it `define`'s:
+#
+#  - HAVE_LIBLTDL to 1 or 0 if libltdl is found/not found
+#  - HAVE_LIBDL to 1 or 0 if dlopen() is found/not found
+#  - LDFLAGS_MODULE_LOADER one of ("-lltdl", "-ldl", or ""), noting
+#    that -ldl may legally be empty on some platforms even if
+#    HAVE_LIBDL is true (indicating that dlopen() is available without
+#    extra link flags). LDFLAGS_MODULE_LOADER also gets "-rdynamic" appended
+#    to it because otherwise trying to open DLLs will result in undefined
+#    symbol errors.
+#
+# Note that if it finds LIBLTDL it does not look for LIBDL, so will
+# report only that is has LIBLTDL.
+#
+proc proj-check-module-loader {} {
+  msg-checking "Looking for module-loader APIs... "
+  if {99 ne [get-define LDFLAGS_MODULE_LOADER 99]} {
+    if {1 eq [get-define HAVE_LIBLTDL 0]} {
+      msg-result "(cached) libltdl"
+      return 1
+    } elseif {1 eq [get-define HAVE_LIBDL 0]} {
+      msg-result "(cached) libdl"
+      return 1
+    }
+    # else: wha???
+  }
+  set HAVE_LIBLTDL 0
+  set HAVE_LIBDL 0
+  set LDFLAGS_MODULE_LOADER ""
+  set rc 0
+  puts "" ;# cosmetic kludge for cc-check-XXX
+  if {[cc-check-includes ltdl.h] && [cc-check-function-in-lib lt_dlopen ltdl]} {
+    set HAVE_LIBLTDL 1
+    set LDFLAGS_MODULE_LOADER "-lltdl -rdynamic"
+    msg-result " - Got libltdl."
+    set rc 1
+  } elseif {[cc-with {-includes dlfcn.h} {
+    cctest -link 1 -declare "extern char* dlerror(void);" -code "dlerror();"}]} {
+    msg-result " - This system can use dlopen() without -ldl."
+    set HAVE_LIBDL 1
+    set LDFLAGS_MODULE_LOADER ""
+    set rc 1
+  } elseif {[cc-check-includes dlfcn.h]} {
+    set HAVE_LIBDL 1
+    set rc 1
+    if {[cc-check-function-in-lib dlopen dl]} {
+      msg-result " - dlopen() needs libdl."
+      set LDFLAGS_MODULE_LOADER "-ldl -rdynamic"
+    } else {
+      msg-result " - dlopen() not found in libdl. Assuming dlopen() is built-in."
+      set LDFLAGS_MODULE_LOADER "-rdynamic"
+    }
+  }
+  define HAVE_LIBLTDL $HAVE_LIBLTDL
+  define HAVE_LIBDL $HAVE_LIBDL
+  define LDFLAGS_MODULE_LOADER $LDFLAGS_MODULE_LOADER
+  return $rc
+}
+
+#
+# @proj-no-check-module-loader
+#
+# Sets all flags which would be set by proj-check-module-loader to
+# empty/falsy values, as if those checks had failed to find a module
+# loader. Intended to be called in place of that function when
+# a module loader is explicitly not desired.
+#
+proc proj-no-check-module-loader {} {
+  define HAVE_LIBDL 0
+  define HAVE_LIBLTDL 0
+  define LDFLAGS_MODULE_LOADER ""
+}
+
+#
+# @proj-file-content ?-trim? filename
+#
+# Opens the given file, reads all of its content, and returns it.  If
+# the first arg is -trim, the contents of the file named by the second
+# argument are trimmed before returning them.
+#
+proc proj-file-content {args} {
+  set trim 0
+  set fname $args
+  if {"-trim" eq [lindex $args 0]} {
+    set trim 1
+    lassign $args - fname
+  }
+  set fp [open $fname rb]
+  set rc [read $fp]
+  close $fp
+  if {$trim} { return [string trim $rc] }
+  return $rc
+}
+
+#
+# @proj-file-conent filename
+#
+# Returns the contents of the given file as an array of lines, with
+# the EOL stripped from each input line.
+#
+proc proj-file-content-list {fname} {
+  set fp [open $fname rb]
+  set rc {}
+  while { [gets $fp line] >= 0 } {
+    lappend rc $line
+  }
+  close $fp
+  return $rc
+}
+
+#
+# @proj-file-write ?-ro? fname content
+#
+# Works like autosetup's [writefile] but explicitly uses binary mode
+# to avoid EOL translation on Windows. If $fname already exists, it is
+# overwritten, even if it's flagged as read-only.
+#
+proc proj-file-write {args} {
+  if {"-ro" eq [lindex $args 0]} {
+    lassign $args ro fname content
+  } else {
+    set ro ""
+    lassign $args fname content
+  }
+  file delete -force -- $fname; # in case it's read-only
+  set f [open $fname wb]
+  puts -nonewline $f $content
+  close $f
+  if {"" ne $ro} {
+    catch {
+      exec chmod -w $fname
+      #file attributes -w $fname; #jimtcl has no 'attributes'
+    }
+  }
+}
+
+#
+# @proj-check-compile-commands ?-assume-for-clang? ?configFlag?
+#
+# Checks the compiler for compile_commands.json support. If
+# $configFlag is not empty then it is assumed to be the name of an
+# autosetup boolean config which controls whether to run/skip this
+# check.
+#
+# If -assume-for-clang is provided and $configFlag is not empty and CC
+# matches *clang* and no --$configFlag was explicitly provided to the
+# configure script then behave as if --$configFlag had been provided.
+# To disable that assumption, either don't pass -assume-for-clang or
+# pass --$configFlag=0 to the configure script. (The reason for this
+# behavior is that clang supports compile-commands but some other
+# compilers report false positives with these tests.)
+#
+# Returns 1 if supported, else 0, and defines HAVE_COMPILE_COMMANDS to
+# that value. Defines MAKE_COMPILATION_DB to "yes" if supported, "no"
+# if not. The use of MAKE_COMPILATION_DB is deprecated/discouraged:
+# HAVE_COMPILE_COMMANDS is preferred.
+#
+# ACHTUNG: this test has a long history of false positive results
+# because of compilers reacting differently to the -MJ flag.  Because
+# of this, it is recommended that this support be an opt-in feature,
+# rather than an on-by-default default one. That is: in the
+# configure script define the option as
+# {--the-flag-name=0 => {Enable ....}}
+#
+proc proj-check-compile-commands {args} {
+  set i 0
+  set configFlag {}
+  set fAssumeForClang 0
+  set doAssume 0
+  msg-checking "compile_commands.json support... "
+  if {"-assume-for-clang" eq [lindex $args 0]} {
+    lassign $args - configFlag
+    incr fAssumeForClang
+  } elseif {1 == [llength $args]} {
+    lassign $args configFlag
+  } else {
+    proj-error "Invalid arguments"
+  }
+  if {1 == $fAssumeForClang && "" ne $configFlag} {
+    if {[string match *clang* [get-define CC]]
+        && ![proj-opt-was-provided $configFlag]
+        && ![proj-opt-truthy $configFlag]} {
+      proj-indented-notice [subst -nocommands -nobackslashes {
+        CC appears to be clang, so assuming that --$configFlag is likely
+        to work. To disable this assumption use --$configFlag=0.}]
+      incr doAssume
+    }
+  }
+  if {!$doAssume && "" ne $configFlag && ![proj-opt-truthy $configFlag]} {
+    msg-result "check disabled. Use --${configFlag} to enable it."
+    define HAVE_COMPILE_COMMANDS 0
+    define MAKE_COMPILATION_DB no
+    return 0
+  } else {
+    if {[cctest -lang c -cflags {/dev/null -MJ} -source {}]} {
+      # This test reportedly incorrectly succeeds on one of
+      # Martin G.'s older systems. drh also reports a false
+      # positive on an unspecified older Mac system.
+      msg-result "compiler supports -MJ. Assuming it's useful for compile_commands.json"
+      define MAKE_COMPILATION_DB yes; # deprecated
+      define HAVE_COMPILE_COMMANDS 1
+      return 1
+    } else {
+      msg-result "compiler does not support compile_commands.json"
+      define MAKE_COMPILATION_DB no
+      define HAVE_COMPILE_COMMANDS 0
+      return 0
+    }
+  }
+}
+
+#
+# @proj-touch filename
+#
+# Runs the 'touch' external command on one or more files, ignoring any
+# errors.
+#
+proc proj-touch {filename} {
+  catch { exec touch {*}$filename }
+}
+
+#
+# @proj-make-from-dot-in ?-touch? infile ?outfile?
+#
+# Uses [make-template] to create makefile(-like) file(s) $outfile from
+# $infile but explicitly makes the output read-only, to avoid
+# inadvertent editing (who, me?).
+#
+# If $outfile is empty then:
+#
+# - If $infile is a 2-element list, it is assumed to be an in/out pair,
+#   and $outfile is set from the 2nd entry in that list. Else...
+#
+# - $outfile is set to $infile stripped of its extension.
+#
+# If the first argument is -touch then the generated file is touched
+# to update its timestamp. This can be used as a workaround for
+# cases where (A) autosetup does not update the file because it was
+# not really modified and (B) the file *really* needs to be updated to
+# please the build process.
+#
+# Failures when running chmod or touch are silently ignored.
+#
+proc proj-make-from-dot-in {args} {
+  set fIn ""
+  set fOut ""
+  set touch 0
+  if {[lindex $args 0] eq "-touch"} {
+    set touch 1
+    lassign $args - fIn fOut
+  } else {
+    lassign $args fIn fOut
+  }
+  if {"" eq $fOut} {
+    if {[llength $fIn]>1} {
+      lassign $fIn fIn fOut
+    } else {
+      set fOut [file rootname $fIn]
+    }
+  }
+  #puts "filenames=$filename"
+  if {[file exists $fOut]} {
+    catch { exec chmod u+w $fOut }
+  }
+  #puts "making template: $fIn ==> $fOut"
+  #define-push {top_srcdir} {
+    #puts "--- $fIn $fOut top_srcdir=[get-define top_srcdir]"
+    make-template $fIn $fOut
+    #puts "--- $fIn $fOut top_srcdir=[get-define top_srcdir]"
+    # make-template modifies top_srcdir
+  #}
+  if {$touch} {
+    proj-touch $fOut
+  }
+  catch {
+    exec chmod -w $fOut
+    #file attributes -w $f; #jimtcl has no 'attributes'
+  }
+}
+
+#
+# @proj-check-profile-flag ?flagname?
+#
+# Checks for the boolean configure option named by $flagname. If set,
+# it checks if $CC seems to refer to gcc. If it does (or appears to)
+# then it defines CC_PROFILE_FLAG to "-pg" and returns 1, else it
+# defines CC_PROFILE_FLAG to "" and returns 0.
+#
+# Note that the resulting flag must be added to both CFLAGS and
+# LDFLAGS in order for binaries to be able to generate "gmon.out".  In
+# order to avoid potential problems with escaping, space-containing
+# tokens, and interfering with autosetup's use of these vars, this
+# routine does not directly modify CFLAGS or LDFLAGS.
+#
+proc proj-check-profile-flag {{flagname profile}} {
+  #puts "flagname=$flagname ?[proj-opt-truthy $flagname]?"
+  if {[proj-opt-truthy $flagname]} {
+    set CC [get-define CC]
+    regsub {.*ccache *} $CC "" CC
+    # ^^^ if CC="ccache gcc" then [exec] treats "ccache gcc" as a
+    # single binary name and fails. So strip any leading ccache part
+    # for this purpose.
+    if { ![catch { exec $CC --version } msg]} {
+      if {[string first gcc $CC] != -1} {
+        define CC_PROFILE_FLAG "-pg"
+        return 1
+      }
+    }
+  }
+  define CC_PROFILE_FLAG ""
+  return 0
+}
+
+#
+# @proj-looks-like-windows ?key?
+#
+# Returns 1 if this appears to be a Windows environment (MinGw,
+# Cygwin, MSys), else returns 0. The optional argument is the name of
+# an autosetup define which contains platform name info, defaulting to
+# "host" (meaning, somewhat counterintuitively, the target system, not
+# the current host). The other legal value is "build" (the build
+# machine, i.e. the local host). If $key == "build" then some
+# additional checks may be performed which are not applicable when
+# $key == "host".
+#
+proc proj-looks-like-windows {{key host}} {
+  global autosetup
+  switch -glob -- [get-define $key] {
+    *-*-ming* - *-*-cygwin - *-*-msys - *windows* {
+      return 1
+    }
+  }
+  if {$key eq "build"} {
+    # These apply only to the local OS, not a cross-compilation target,
+    # as the above check potentially can.
+    if {$::autosetup(iswin)} { return 1 }
+    if {[find-an-executable cygpath] ne "" || $::tcl_platform(os) eq "Windows NT"} {
+      return 1
+    }
+  }
+  return 0
+}
+
+#
+# @proj-looks-like-mac ?key?
+#
+# Looks at either the 'host' (==compilation target platform) or
+# 'build' (==the being-built-on platform) define value and returns if
+# if that value seems to indicate that it represents a Mac platform,
+# else returns 0.
+#
+proc proj-looks-like-mac {{key host}} {
+  switch -glob -- [get-define $key] {
+    *-*-darwin* {
+      # https://sqlite.org/forum/forumpost/7b218c3c9f207646
+      # There's at least one Linux out there which matches *apple*.
+      return 1
+    }
+    default {
+      return 0
+    }
+  }
+}
+
+#
+# @proj-exe-extension
+#
+# Checks autosetup's "host" and "build" defines to see if the build
+# host and target are Windows-esque (Cygwin, MinGW, MSys). If the
+# build environment is then BUILD_EXEEXT is [define]'d to ".exe", else
+# "". If the target, a.k.a. "host", is then TARGET_EXEEXT is
+# [define]'d to ".exe", else "".
+#
+proc proj-exe-extension {} {
+  set rH ""
+  set rB ""
+  if {[proj-looks-like-windows host]} {
+    set rH ".exe"
+  }
+  if {[proj-looks-like-windows build]} {
+    set rB ".exe"
+  }
+  define BUILD_EXEEXT $rB
+  define TARGET_EXEEXT $rH
+}
+
+#
+# @proj-dll-extension
+#
+# Works like proj-exe-extension except that it defines BUILD_DLLEXT
+# and TARGET_DLLEXT to one of (.so, ,dll, .dylib).
+#
+# Trivia: for .dylib files, the linker needs the -dynamiclib flag
+# instead of -shared.
+#
+proc proj-dll-extension {} {
+  set inner {{key} {
+    if {[proj-looks-like-mac $key]} {
+      return ".dylib"
+    }
+    if {[proj-looks-like-windows $key]} {
+      return ".dll"
+    }
+    return ".so"
+  }}
+  define BUILD_DLLEXT [apply $inner build]
+  define TARGET_DLLEXT [apply $inner host]
+}
+
+#
+# @proj-lib-extension
+#
+# Static-library counterpart of proj-dll-extension. Defines
+# BUILD_LIBEXT and TARGET_LIBEXT to the conventional static library
+# extension for the being-built-on resp. the target platform.
+#
+proc proj-lib-extension {} {
+  set inner {{key} {
+    switch -glob -- [get-define $key] {
+      *-*-ming* - *-*-cygwin - *-*-msys {
+        return ".a"
+        # ^^^ this was ".lib" until 2025-02-07. See
+        # https://sqlite.org/forum/forumpost/02db2d4240
+      }
+      default {
+        return ".a"
+      }
+    }
+  }}
+  define BUILD_LIBEXT [apply $inner build]
+  define TARGET_LIBEXT [apply $inner host]
+}
+
+#
+# @proj-file-extensions
+#
+# Calls all of the proj-*-extension functions.
+#
+proc proj-file-extensions {} {
+  proj-exe-extension
+  proj-dll-extension
+  proj-lib-extension
+}
+
+#
+# @proj-affirm-files-exist ?-v? filename...
+#
+# Expects a list of file names. If any one of them does not exist in
+# the filesystem, it fails fatally with an informative message.
+# Returns the last file name it checks. If the first argument is -v
+# then it emits msg-checking/msg-result messages for each file.
+#
+proc proj-affirm-files-exist {args} {
+  set rc ""
+  set verbose 0
+  if {[lindex $args 0] eq "-v"} {
+    set verbose 1
+    set args [lrange $args 1 end]
+  }
+  foreach f $args {
+    if {$verbose} { msg-checking "Looking for $f ... " }
+    if {![file exists $f]} {
+      user-error "not found: $f"
+    }
+    if {$verbose} { msg-result "" }
+    set rc $f
+  }
+  return rc
+}
+
+#
+# @proj-check-emsdk
+#
+# Emscripten is used for doing in-tree builds of web-based WASM stuff,
+# as opposed to WASI-based WASM or WASM binaries we import from other
+# places. This is only set up for Unix-style OSes and is untested
+# anywhere but Linux. Requires that the --with-emsdk flag be
+# registered with autosetup.
+#
+# It looks for the SDK in the location specified by --with-emsdk.
+# Values of "" or "auto" mean to check for the environment var EMSDK
+# (which gets set by the emsdk_env.sh script from the SDK) or that
+# same var passed to configure.
+#
+# If the given directory is found, it expects to find emsdk_env.sh in
+# that directory, as well as the emcc compiler somewhere under there.
+#
+# If the --with-emsdk[=DIR] flag is explicitly provided and the SDK is
+# not found then a fatal error is generated, otherwise failure to find
+# the SDK is not fatal.
+#
+# Defines the following:
+#
+# - HAVE_EMSDK = 0 or 1 (this function's return value)
+# - EMSDK_HOME = "" or top dir of the emsdk
+# - EMSDK_ENV_SH = "" or $EMSDK_HOME/emsdk_env.sh
+# - BIN_EMCC = "" or $EMSDK_HOME/upstream/emscripten/emcc
+#
+# Returns 1 if EMSDK_ENV_SH is found, else 0.  If EMSDK_HOME is not empty
+# but BIN_EMCC is then emcc was not found in the EMSDK_HOME, in which
+# case we have to rely on the fact that sourcing $EMSDK_ENV_SH from a
+# shell will add emcc to the $PATH.
+#
+proc proj-check-emsdk {} {
+  set emsdkHome [opt-val with-emsdk]
+  define EMSDK_HOME ""
+  define EMSDK_ENV_SH ""
+  define BIN_EMCC ""
+  set hadValue [llength $emsdkHome]
+  msg-checking "Emscripten SDK? "
+  if {$emsdkHome in {"" "auto"}} {
+    # Check the environment. $EMSDK gets set by sourcing emsdk_env.sh.
+    set emsdkHome [get-env EMSDK ""]
+  }
+  set rc 0
+  if {$emsdkHome ne ""} {
+    define EMSDK_HOME $emsdkHome
+    set emsdkEnv "$emsdkHome/emsdk_env.sh"
+    if {[file exists $emsdkEnv]} {
+      msg-result "$emsdkHome"
+      define EMSDK_ENV_SH $emsdkEnv
+      set rc 1
+      set emcc "$emsdkHome/upstream/emscripten/emcc"
+      if {[file exists $emcc]} {
+        define BIN_EMCC $emcc
+      }
+    } else {
+      msg-result "emsdk_env.sh not found in $emsdkHome"
+    }
+  } else {
+    msg-result "not found"
+  }
+  if {$hadValue && 0 == $rc} {
+    # Fail if it was explicitly requested but not found
+    proj-fatal "Cannot find the Emscripten SDK"
+  }
+  define HAVE_EMSDK $rc
+  return $rc
+}
+
+#
+# @proj-cc-check-Wl-flag ?flag ?args??
+#
+# Checks whether the given linker flag (and optional arguments) can be
+# passed from the compiler to the linker using one of these formats:
+#
+# - -Wl,flag[,arg1[,...argN]]
+# - -Wl,flag -Wl,arg1 ...-Wl,argN
+#
+# If so, that flag string is returned, else an empty string is
+# returned.
+#
+proc proj-cc-check-Wl-flag {args} {
+  cc-with {-link 1} {
+    # Try -Wl,flag,...args
+    set fli "-Wl"
+    foreach f $args { append fli ",$f" }
+    if {[cc-check-flags $fli]} {
+      return $fli
+    }
+    # Try -Wl,flag -Wl,arg1 ...-Wl,argN
+    set fli ""
+    foreach f $args { append fli "-Wl,$f " }
+    if {[cc-check-flags $fli]} {
+      return [string trim $fli]
+    }
+    return ""
+  }
+}
+
+#
+# @proj-check-rpath
+#
+# Tries various approaches to handling the -rpath link-time
+# flag. Defines LDFLAGS_RPATH to that/those flag(s) or an empty
+# string. Returns 1 if it finds an option, else 0.
+#
+# By default, the rpath is set to $prefix/lib. However, if either of
+# --exec-prefix=... or --libdir=...  are explicitly passed to
+# configure then [get-define libdir] is used (noting that it derives
+# from exec-prefix by default).
+#
+proc proj-check-rpath {} {
+  if {[proj-opt-was-provided libdir]
+      || [proj-opt-was-provided exec-prefix]} {
+    set lp "[get-define libdir]"
+  } else {
+    set lp "[get-define prefix]/lib"
+  }
+  # If we _don't_ use cc-with {} here (to avoid updating the global
+  # CFLAGS or LIBS or whatever it is that cc-check-flags updates) then
+  # downstream tests may fail because the resulting rpath gets
+  # implicitly injected into them.
+  cc-with {-link 1} {
+    if {[cc-check-flags "-rpath $lp"]} {
+      define LDFLAGS_RPATH "-rpath $lp"
+    } else {
+      set wl [proj-cc-check-Wl-flag -rpath $lp]
+      if {"" eq $wl} {
+        set wl [proj-cc-check-Wl-flag -R$lp]
+      }
+      if {"" eq $wl} {
+        # HP-UX: https://sqlite.org/forum/forumpost/d80ecdaddd
+        set wl [proj-cc-check-Wl-flag +b $lp]
+      }
+      define LDFLAGS_RPATH $wl
+    }
+  }
+  expr {"" ne [get-define LDFLAGS_RPATH]}
+}
+
+#
+# @proj-check-soname ?libname?
+#
+# Checks whether CC supports the -Wl,-soname,lib... flag. If so, it
+# returns 1 and defines LDFLAGS_SONAME_PREFIX to the flag's prefix, to
+# which the client would need to append "libwhatever.N".  If not, it
+# returns 0 and defines LDFLAGS_SONAME_PREFIX to an empty string.
+#
+# The libname argument is only for purposes of running the flag
+# compatibility test, and is not included in the resulting
+# LDFLAGS_SONAME_PREFIX. It is provided so that clients may
+# potentially avoid some end-user confusion by using their own lib's
+# name here (which shows up in the "checking..." output).
+#
+proc proj-check-soname {{libname "libfoo.so.0"}} {
+  cc-with {-link 1} {
+    if {[cc-check-flags "-Wl,-soname,${libname}"]} {
+      define LDFLAGS_SONAME_PREFIX "-Wl,-soname,"
+      return 1
+    } elseif {[cc-check-flags "-Wl,+h,${libname}"]} {
+      # HP-UX: https://sqlite.org/forum/forumpost/d80ecdaddd
+      define LDFLAGS_SONAME_PREFIX "-Wl,+h,"
+      return 1
+    } else {
+      define LDFLAGS_SONAME_PREFIX ""
+      return 0
+    }
+  }
+}
+
+#
+# @proj-check-fsanitize ?list-of-opts?
+#
+# Checks whether CC supports -fsanitize=X, where X is each entry of
+# the given list of flags. If any of those flags are supported, it
+# returns the string "-fsanitize=X..." where X... is a comma-separated
+# list of all flags from the original set which are supported. If none
+# of the given options are supported then it returns an empty string.
+#
+# Example:
+#
+#  set f [proj-check-fsanitize {address bounds-check just-testing}]
+#
+# Will, on many systems, resolve to "-fsanitize=address,bounds-check",
+# but may also resolve to "-fsanitize=address".
+#
+proc proj-check-fsanitize {{opts {address bounds-strict}}} {
+  set sup {}
+  foreach opt $opts {
+    # -nooutput is used because -fsanitize=hwaddress will otherwise
+    # pass this test on x86_64, but then warn at build time that
+    # "hwaddress is not supported for this target".
+    cc-with {-nooutput 1} {
+      if {[cc-check-flags "-fsanitize=$opt"]} {
+        lappend sup $opt
+      }
+    }
+  }
+  if {[llength $sup] > 0} {
+    return "-fsanitize=[join $sup ,]"
+  }
+  return ""
+}
+
+#
+# Internal helper for proj-dump-defs-json. Expects to be passed a
+# [define] name and the variadic $args which are passed to
+# proj-dump-defs-json. If it finds a pattern match for the given
+# $name in the various $args, it returns the type flag for that $name,
+# e.g. "-str" or "-bare", else returns an empty string.
+#
+proc proj-defs-type_ {name spec} {
+  foreach {type patterns} $spec {
+    foreach pattern $patterns {
+      if {[string match $pattern $name]} {
+        return $type
+      }
+    }
+  }
+  return ""
+}
+
+#
+# Internal helper for proj-defs-format_: returns a JSON-ish quoted
+# form of the given string-type values. It only performs the most
+# basic of escaping. The input must not contain any control
+# characters.
+#
+proc proj-quote-str_ {value} {
+  return \"[string map [list \\ \\\\ \" \\\"] $value]\"
+}
+
+#
+# An internal impl detail of proj-dump-defs-json. Requires a data
+# type specifier, as used by make-config-header, and a value. Returns
+# the formatted value or the value $::proj__Config(defs-skip) if the caller
+# should skip emitting that value.
+#
+set ::proj__Config(defs-skip) "-proj-defs-format_ sentinel"
+proc proj-defs-format_ {type value} {
+  switch -exact -- $type {
+    -bare {
+      # Just output the value unchanged
+    }
+    -none {
+      set value $::proj__Config(defs-skip)
+    }
+    -str {
+      set value [proj-quote-str_ $value]
+    }
+    -auto {
+      # Automatically determine the type
+      if {![string is integer -strict $value]} {
+        set value [proj-quote-str_ $value]
+      }
+    }
+    -array {
+      set ar {}
+      foreach v $value {
+        set v [proj-defs-format_ -auto $v]
+        if {$::proj__Config(defs-skip) ne $v} {
+          lappend ar $v
+        }
+      }
+      set value "\[ [join $ar {, }] \]"
+    }
+    "" {
+      set value $::proj__Config(defs-skip)
+    }
+    default {
+      proj-fatal "Unknown type in proj-dump-defs-json: $type"
+    }
+  }
+  return $value
+}
+
+#
+# @proj-dump-defs-json outfile ...flags
+#
+# This function works almost identically to autosetup's
+# make-config-header but emits its output in JSON form. It is not a
+# fully-functional JSON emitter, and will emit broken JSON for
+# complicated outputs, but should be sufficient for purposes of
+# emitting most configure vars (numbers and simple strings).
+#
+# In addition to the formatting flags supported by make-config-header,
+# it also supports:
+#
+#  -array {patterns...}
+#
+# Any defines matching the given patterns will be treated as a list of
+# values, each of which will be formatted as if it were in an -auto {...}
+# set, and the define will be emitted to JSON in the form:
+#
+#  "ITS_NAME": [ "value1", ...valueN ]
+#
+# Achtung: if a given -array pattern contains values which themselves
+# contains spaces...
+#
+#   define-append foo {"-DFOO=bar baz" -DBAR="baz barre"}
+#
+# will lead to:
+#
+#  ["-DFOO=bar baz", "-DBAR=\"baz", "barre\""]
+#
+# Neither is especially satisfactory (and the second is useless), and
+# handling of such values is subject to change if any such values ever
+# _really_ need to be processed by our source trees.
+#
+proc proj-dump-defs-json {file args} {
+  file mkdir [file dirname $file]
+  set lines {}
+  lappend args -bare {SIZEOF_* HAVE_DECL_*} -auto HAVE_*
+  foreach n [lsort [dict keys [all-defines]]] {
+    set type [proj-defs-type_ $n $args]
+    set value [proj-defs-format_ $type [get-define $n]]
+    if {$::proj__Config(defs-skip) ne $value} {
+      lappend lines "\"$n\": ${value}"
+    }
+  }
+  set buf {}
+  lappend buf [join $lines ",\n"]
+  write-if-changed $file $buf {
+    msg-result "Created $file"
+  }
+}
+
+#
+# @proj-xfer-option-aliases map
+#
+# Expects a list of pairs of configure flags which have been
+# registered with autosetup, in this form:
+#
+#  { alias1 => canonical1
+#    aliasN => canonicalN ... }
+#
+# The names must not have their leading -- part and must be in the
+# form which autosetup will expect for passing to [opt-val NAME] and
+# friends.
+#
+# Comment lines are permitted in the input.
+#
+# For each pair of ALIAS and CANONICAL, if --ALIAS is provided but
+# --CANONICAL is not, the value of the former is copied to the
+# latter. If --ALIAS is not provided, this is a no-op. If both have
+# explicitly been provided a fatal usage error is triggered.
+#
+# Motivation: autosetup enables "hidden aliases" in [options] lists,
+# and elides the aliases from --help output but does no further
+# handling of them. For example, when --alias is a hidden alias of
+# --canonical and a user passes --alias=X, [opt-val canonical] returns
+# no value. i.e. the script must check both [opt-val alias] and
+# [opt-val canonical].  The intent here is that this function be
+# passed such mappings immediately after [options] is called, to carry
+# over any values from hidden aliases into their canonical names, such
+# that [opt-value canonical] will return X if --alias=X is passed to
+# configure.
+#
+# That said: autosetup's [opt-str] does support alias forms, but it
+# requires that the caller know all possible aliases. It's simpler, in
+# terms of options handling, if there's only a single canonical name
+# which each down-stream call of [opt-...] has to know.
+#
+proc proj-xfer-options-aliases {mapping} {
+  foreach {hidden - canonical} [proj-strip-hash-comments $mapping] {
+    if {[proj-opt-was-provided $hidden]} {
+      if {[proj-opt-was-provided $canonical]} {
+        proj-fatal "both --$canonical and its alias --$hidden were used. Use only one or the other."
+      } else {
+        proj-opt-set $canonical [opt-val $hidden]
+      }
+    }
+  }
+}
+
+#
+# Arguable/debatable...
+#
+# When _not_ cross-compiling and CC_FOR_BUILD is _not_ explicitly
+# specified, force CC_FOR_BUILD to be the same as CC, so that:
+#
+# ./configure CC=clang
+#
+# will use CC_FOR_BUILD=clang, instead of cc, for building in-tree
+# tools. This is based off of an email discussion and is thought to
+# be likely to cause less confusion than seeing 'cc' invocations
+# when when the user passes CC=clang.
+#
+# Sidebar: if we do this before the cc package is installed, it gets
+# reverted by that package. Ergo, the cc package init will tell the
+# user "Build C compiler...cc" shortly before we tell them otherwise.
+#
+proc proj-redefine-cc-for-build {} {
+  if {![proj-is-cross-compiling]
+      && [get-define CC] ne [get-define CC_FOR_BUILD]
+      && "nope" eq [get-env CC_FOR_BUILD "nope"]} {
+    user-notice "Re-defining CC_FOR_BUILD to CC=[get-define CC]. To avoid this, explicitly pass CC_FOR_BUILD=..."
+    define CC_FOR_BUILD [get-define CC]
+  }
+}
+
+#
+# @proj-which-linenoise headerFile
+#
+# Attempts to determine whether the given linenoise header file is of
+# the "antirez" or "msteveb" flavor. It returns 2 for msteveb, else 1
+# (it does not validate that the header otherwise contains the
+# linenoise API).
+#
+proc proj-which-linenoise {dotH} {
+  set srcHeader [proj-file-content $dotH]
+  if {[string match *userdata* $srcHeader]} {
+    return 2
+  } else {
+    return 1
+  }
+}
+
+#
+# @proj-remap-autoconf-dir-vars
+#
+# "Re-map" the autoconf-conventional --XYZdir flags into something
+# which is more easily overridable from a make invocation.
+#
+# Based off of notes in <https://sqlite.org/forum/forumpost/00d12a41f7>.
+#
+# Consider:
+#
+# $ ./configure --prefix=/foo
+# $ make install prefix=/blah
+#
+# In that make invocation, $(libdir) would, at make-time, normally be
+# hard-coded to /foo/lib, rather than /blah/lib. That happens because
+# autosetup exports conventional $prefix-based values for the numerous
+# autoconfig-compatible XYZdir vars at configure-time.  What we would
+# normally want, however, is that --libdir derives from the make-time
+# $(prefix).  The distinction between configure-time and make-time is
+# the significant factor there.
+#
+# This function attempts to reconcile those vars in such a way that
+# they will derive, at make-time, from $(prefix) in a conventional
+# manner unless they are explicitly overridden at configure-time, in
+# which case those overrides takes precedence.
+#
+# Each autoconf-relvant --XYZ flag which is explicitly passed to
+# configure is exported as-is, as are those which default to some
+# top-level system directory, e.g. /etc or /var.  All which derive
+# from either $prefix or $exec_prefix are exported in the form of a
+# Makefile var reference, e.g.  libdir=${exec_prefix}/lib. Ergo, if
+# --exec-prefix=FOO is passed to configure, libdir will still derive,
+# at make-time, from whatever exec_prefix is passed to make, and will
+# use FOO if exec_prefix is not overridden at make-time.  Without this
+# post-processing, libdir would be cemented in as FOO/lib at
+# configure-time, so could be tedious to override properly via a make
+# invocation.
+#
+proc proj-remap-autoconf-dir-vars {} {
+  set prefix [get-define prefix]
+  set exec_prefix [get-define exec_prefix $prefix]
+  # The following var derefs must be formulated such that they are
+  # legal for use in (A) makefiles, (B) pkgconfig files, and (C) TCL's
+  # [subst] command.  i.e. they must use the form ${X}.
+  foreach {flag makeVar makeDeref} {
+    exec-prefix     exec_prefix    ${prefix}
+    datadir         datadir        ${prefix}/share
+    mandir          mandir         ${datadir}/man
+    includedir      includedir     ${prefix}/include
+    bindir          bindir         ${exec_prefix}/bin
+    libdir          libdir         ${exec_prefix}/lib
+    sbindir         sbindir        ${exec_prefix}/sbin
+    sysconfdir      sysconfdir     /etc
+    sharedstatedir  sharedstatedir ${prefix}/com
+    localstatedir   localstatedir  /var
+    runstatedir     runstatedir    /run
+    infodir         infodir        ${datadir}/info
+    libexecdir      libexecdir     ${exec_prefix}/libexec
+  } {
+    if {[proj-opt-was-provided $flag]} {
+      define $makeVar [join [opt-val $flag]]
+    } else {
+      define $makeVar [join $makeDeref]
+    }
+    # Maintenance reminder: the [join] call is to avoid {braces}
+    # around the output when someone passes in,
+    # e.g. --libdir=\${prefix}/foo/bar. Debian's SQLite package build
+    # script does that.
+  }
+}
+
+#
+# @proj-env-file flag ?default?
+#
+# If a file named .env-$flag exists, this function returns a
+# trimmed copy of its contents, else it returns $dflt. The intended
+# usage is that things like developer-specific CFLAGS preferences can
+# be stored in .env-CFLAGS.
+#
+proc proj-env-file {flag {dflt ""}} {
+  set fn ".env-${flag}"
+  if {[file readable $fn]} {
+    return [proj-file-content -trim $fn]
+  }
+  return $dflt
+}
+
+#
+# @proj-get-env var ?default?
+#
+# Extracts the value of "environment" variable $var from the first of
+# the following places where it's defined:
+#
+# - Passed to configure as $var=...
+# - Exists as an environment variable
+# - A file named .env-$var (see [proj-env-file])
+#
+# If none of those are set, $dflt is returned.
+#
+proc proj-get-env {var {dflt ""}} {
+  get-env $var [proj-env-file $var $dflt]
+}
+
+#
+# @proj-scope ?lvl?
+#
+# Returns the name of the _calling_ proc from ($lvl + 1) levels up the
+# call stack (where the caller's level will be 1 up from _this_
+# call). If $lvl would resolve to global scope "global scope" is
+# returned and if it would be negative then a string indicating such
+# is returned (as opposed to throwing an error).
+#
+proc proj-scope {{lvl 0}} {
+  #uplevel [expr {$lvl + 1}] {lindex [info level 0] 0}
+  set ilvl [info level]
+  set offset [expr {$ilvl  - $lvl - 1}]
+  if { $offset < 0} {
+    return "invalid scope ($offset)"
+  } elseif { $offset == 0} {
+    return "global scope"
+  } else {
+    return [lindex [info level $offset] 0]
+  }
+}
+
+#
+# Deprecated name of [proj-scope].
+#
+proc proj-current-scope {{lvl 0}} {
+  puts stderr \
+    "Deprecated proj-current-scope called from [proj-scope 1]. Use proj-scope instead."
+  proj-scope [incr lvl]
+}
+
+#
+# Converts parts of tclConfig.sh to autosetup [define]s.
+#
+# Expects to be passed the name of a value tclConfig.sh or an empty
+# string.  It converts certain parts of that file's contents to
+# [define]s (see the code for the whole list). If $tclConfigSh is an
+# empty string then it [define]s the various vars as empty strings.
+#
+proc proj-tclConfig-sh-to-autosetup {tclConfigSh} {
+  set shBody {}
+  set tclVars {
+    TCL_INCLUDE_SPEC
+    TCL_LIBS
+    TCL_LIB_SPEC
+    TCL_STUB_LIB_SPEC
+    TCL_EXEC_PREFIX
+    TCL_PREFIX
+    TCL_VERSION
+    TCL_MAJOR_VERSION
+    TCL_MINOR_VERSION
+    TCL_PACKAGE_PATH
+    TCL_PATCH_LEVEL
+    TCL_SHLIB_SUFFIX
+  }
+  # Build a small shell script which proxies the $tclVars from
+  # $tclConfigSh into autosetup code...
+  lappend shBody "if test x = \"x${tclConfigSh}\"; then"
+  foreach v $tclVars {
+    lappend shBody "$v= ;"
+  }
+  lappend shBody "else . \"${tclConfigSh}\"; fi"
+  foreach v $tclVars {
+    lappend shBody "echo define $v {\$$v} ;"
+  }
+  lappend shBody "exit"
+  set shBody [join $shBody "\n"]
+  #puts "shBody=$shBody\n"; exit
+  eval [exec echo $shBody | sh]
+}
+
+#
+# @proj-tweak-default-env-dirs
+#
+# This function is not useful before [use system] is called to set up
+# --prefix and friends. It should be called as soon after [use system]
+# as feasible.
+#
+# For certain target environments, if --prefix is _not_ passed in by
+# the user, set the prefix to an environment-specific default. For
+# such environments its does [define prefix ...]  and [proj-opt-set
+# prefix ...], but it does not process vars derived from the prefix,
+# e.g. exec-prefix. To do so it is generally necessary to also call
+# proj-remap-autoconf-dir-vars late in the config process (immediately
+# before ".in" files are filtered).
+#
+# Similar modifications may be made for --mandir.
+#
+# Returns >0 if it modifies the environment, else 0.
+#
+proc proj-tweak-default-env-dirs {} {
+  set rc 0
+  switch -glob -- [get-define host] {
+    *-haiku {
+      if {![proj-opt-was-provided prefix]} {
+        set hdir /boot/home/config/non-packaged
+        proj-opt-set prefix $hdir
+        define prefix $hdir
+        incr rc
+      }
+      if {![proj-opt-was-provided mandir]} {
+        set hdir /boot/system/documentation/man
+        proj-opt-set mandir $hdir
+        define mandir $hdir
+        incr rc
+      }
+    }
+  }
+  return $rc
+}
+
+#
+# @proj-dot-ins-append file ?fileOut ?postProcessScript??
+#
+# Queues up an autosetup [make-template]-style file to be processed
+# at a later time using [proj-dot-ins-process].
+#
+# $file is the input file. If $fileOut is empty then this function
+# derives $fileOut from $file, stripping both its directory and
+# extension parts. i.e. it defaults to writing the output to the
+# current directory (typically $::autosetup(builddir)).
+#
+# If $postProcessScript is not empty then, during
+# [proj-dot-ins-process], it will be eval'd immediately after
+# processing the file. In the context of that script, the vars
+# $dotInsIn and $dotInsOut will be set to the input and output file
+# names.  This can be used, for example, to make the output file
+# executable or perform validation on its contents:
+#
+##  proj-dot-ins-append my.sh.in my.sh {
+##    catch {exec chmod u+x $dotInsOut}
+##  }
+#
+# See [proj-dot-ins-process], [proj-dot-ins-list]
+#
+proc proj-dot-ins-append {fileIn args} {
+  set srcdir $::autosetup(srcdir)
+  switch -exact -- [llength $args] {
+    0 {
+      lappend fileIn [file rootname [file tail $fileIn]] ""
+    }
+    1 {
+      lappend fileIn [join $args] ""
+    }
+    2 {
+      lappend fileIn {*}$args
+    }
+    default {
+      proj-fatal "Too many arguments: $fileIn $args"
+    }
+  }
+  #puts "******* [proj-scope]: adding [llength $fileIn]-length item: $fileIn"
+  lappend ::proj__Config(dot-in-files) $fileIn
+}
+
+#
+# @proj-dot-ins-list
+#
+# Returns the current list of [proj-dot-ins-append]'d files, noting
+# that each entry is a 3-element list of (inputFileName,
+# outputFileName, postProcessScript).
+#
+proc proj-dot-ins-list {} {
+  return $::proj__Config(dot-in-files)
+}
+
+#
+# @proj-dot-ins-process ?-touch? ?-validate? ?-clear?
+#
+# Each file which has previously been passed to [proj-dot-ins-append]
+# is processed, with its passing its in-file out-file names to
+# [proj-make-from-dot-in].
+#
+# The intent is that a project accumulate any number of files to
+# filter and delay their actual filtering until the last stage of the
+# configure script, calling this function at that time.
+#
+# Optional flags:
+#
+# -touch: gets passed on to [proj-make-from-dot-in]
+#
+# -validate: after processing each file, before running the file's
+#  associated script, if any, it runs the file through
+#  proj-validate-no-unresolved-ats, erroring out if that does.
+#
+# -clear: after processing, empty the dot-ins list. This effectively
+#  makes proj-dot-ins-append available for re-use.
+#
+proc proj-dot-ins-process {args} {
+  proj-parse-flags args flags {
+    -touch   "" {return "-touch"}
+    -clear    0 {expr 1}
+    -validate 0 {expr 1}
+  }
+  #puts "args=$args"; parray flags
+  if {[llength $args] > 0} {
+    error "Invalid argument to [proj-scope]: $args"
+  }
+  foreach f $::proj__Config(dot-in-files) {
+    proj-assert {3==[llength $f]} \
+      "Expecting proj-dot-ins-list to be stored in 3-entry lists. Got: $f"
+    lassign $f fIn fOut fScript
+    #puts "DOING $fIn  ==> $fOut"
+    proj-make-from-dot-in {*}$flags(-touch) $fIn $fOut
+    if {$flags(-validate)} {
+      proj-validate-no-unresolved-ats $fOut
+    }
+    if {"" ne $fScript} {
+      uplevel 1 [join [list set dotInsIn $fIn \; \
+                         set dotInsOut $fOut \; \
+                         eval \{${fScript}\} \; \
+                         unset dotInsIn dotInsOut]]
+    }
+  }
+  if {$flags(-clear)} {
+    set ::proj__Config(dot-in-files) [list]
+  }
+}
+
+#
+# @proj-validate-no-unresolved-ats filenames...
+#
+# For each filename given to it, it validates that the file has no
+# unresolved @VAR@ references. If it finds any, it produces an error
+# with location information.
+#
+# Exception: if a filename matches the pattern {*[Mm]ake*} AND a given
+# line begins with a # (not including leading whitespace) then that
+# line is ignored for purposes of this validation. The intent is that
+# @VAR@ inside of makefile comments should not (necessarily) cause
+# validation to fail, as it's sometimes convenient to comment out
+# sections during development of a configure script and its
+# corresponding makefile(s).
+#
+proc proj-validate-no-unresolved-ats {args} {
+  foreach f $args {
+    set lnno 1
+    set isMake [string match {*[Mm]ake*} $f]
+    foreach line [proj-file-content-list $f] {
+      if {!$isMake || ![string match "#*" [string trimleft $line]]} {
+        if {[regexp {(@[A-Za-z0-9_\.]+@)} $line match]} {
+          error "Unresolved reference to $match at line $lnno of $f"
+        }
+      }
+      incr lnno
+    }
+  }
+}
+
+#
+# @proj-first-file-found tgtVar fileList
+#
+# Searches $fileList for an existing file. If one is found, its name
+# is assigned to tgtVar and 1 is returned, else tgtVar is set to ""
+# and 0 is returned.
+#
+proc proj-first-file-found {tgtVar fileList} {
+  upvar $tgtVar tgt
+  foreach f $fileList {
+    if {[file exists $f]} {
+      set tgt $f
+      return 1
+    }
+  }
+  set tgt ""
+  return 0
+}
+
+#
+# Defines $defName to contain makefile recipe commands for re-running
+# the configure script with its current set of $::argv flags.  This
+# can be used to automatically reconfigure.
+#
+proc proj-setup-autoreconfig {defName} {
+  define $defName \
+    [join [list \
+             cd \"$::autosetup(builddir)\" \
+             && [get-define AUTOREMAKE "error - missing @AUTOREMAKE@"]]]
+}
+
+#
+# @prop-append-to defineName args...
+#
+# A proxy for Autosetup's [define-append]. Appends all non-empty $args
+# to [define-append $defineName].
+#
+proc proj-define-append {defineName args} {
+  foreach a $args {
+    if {"" ne $a} {
+      define-append $defineName {*}$a
+    }
+  }
+}
+
+#
+# @prod-define-amend ?-p|-prepend? ?-d|-define? defineName args...
+#
+# A proxy for Autosetup's [define-append].
+#
+# Appends all non-empty $args to the define named by $defineName.  If
+# one of (-p | -prepend) are used it instead prepends them, in their
+# given order, to $defineName.
+#
+# If -define is used then each argument is assumed to be a [define]'d
+# flag and [get-define X ""] is used to fetch it.
+#
+# Re. linker flags: typically, -lXYZ flags need to be in "reverse"
+# order, with each -lY resolving symbols for -lX's to its left. This
+# order is largely historical, and not relevant on all environments,
+# but it is technically correct and still relevant on some
+# environments.
+#
+# See: proj-append-to
+#
+proc proj-define-amend {args} {
+  set defName ""
+  set prepend 0
+  set isdefs 0
+  set xargs [list]
+  foreach arg $args {
+    switch -exact -- $arg {
+      "" {}
+      -p - -prepend { incr prepend }
+      -d - -define  { incr isdefs }
+      default {
+        if {"" eq $defName} {
+          set defName $arg
+        } else {
+          lappend xargs $arg
+        }
+      }
+    }
+  }
+  if {"" eq $defName} {
+    proj-error "Missing defineName argument in call from [proj-scope 1]"
+  }
+  if {$isdefs} {
+    set args $xargs
+    set xargs [list]
+    foreach arg $args {
+      lappend xargs [get-define $arg ""]
+    }
+    set args $xargs
+  }
+#  puts "**** args=$args"
+#  puts "**** xargs=$xargs"
+
+  set args $xargs
+  if {$prepend} {
+    lappend args {*}[get-define $defName ""]
+    define $defName [join $args]; # join to eliminate {} entries
+  } else {
+    proj-define-append $defName {*}$args
+  }
+}
+
+#
+# @proj-define-to-cflag ?-list? ?-quote? ?-zero-undef? defineName...
+#
+# Treat each argument as the name of a [define] and renders it like a
+# CFLAGS value in one of the following forms:
+#
+#  -D$name
+#  -D$name=integer   (strict integer matches only)
+#  '-D$name=value'   (without -quote)
+#  '-D$name="value"' (with -quote)
+#
+# It treats integers as numbers and everything else as a quoted
+# string, noting that it does not handle strings which themselves
+# contain quotes.
+#
+# The -zero-undef flag causes no -D to be emitted for integer values
+# of 0.
+#
+# By default it returns the result as string of all -D... flags,
+# but if passed the -list flag it will return a list of the
+# individual CFLAGS.
+#
+proc proj-define-to-cflag {args} {
+  set rv {}
+  proj-parse-flags args flags {
+    -list       0 {expr 1}
+    -quote      0 {expr 1}
+    -zero-undef 0 {expr 1}
+  }
+  foreach d $args {
+    set v [get-define $d ""]
+    set li {}
+    if {"" eq $d} {
+      set v "-D${d}"
+    } elseif {[string is integer -strict $v]} {
+      if {!$flags(-zero-undef) || $v ne "0"} {
+        set v "-D${d}=$v"
+      }
+    } elseif {$flags(-quote)} {
+      set v "'-D${d}=\"$v\"'"
+    } else {
+      set v "'-D${d}=$v'"
+    }
+    lappend rv $v
+  }
+  expr {$flags(-list) ? $rv : [join $rv]}
+}
+
+
+if {0} {
+  # Turns out that autosetup's [options-add] essentially does exactly
+  # this...
+
+  # A list of lists of Autosetup [options]-format --flags definitions.
+  # Append to this using [proj-options-add] and use
+  # [proj-options-combine] to merge them into a single list for passing
+  # to [options].
+  #
+  set ::proj__Config(extra-options) {}
+
+  # @proj-options-add list
+  #
+  # Adds a list of options to the pending --flag processing.  It must be
+  # in the format used by Autosetup's [options] function.
+  #
+  # This will have no useful effect if called from after [options]
+  # is called.
+  #
+  # Use [proj-options-combine] to get a combined list of all added
+  # options.
+  #
+  # PS: when writing this i wasn't aware of autosetup's [options-add],
+  # works quite similarly. Only the timing is different.
+  proc proj-options-add {list} {
+    lappend ::proj__Config(extra-options) $list
+  }
+
+  # @proj-options-combine list1 ?...listN?
+  #
+  # Expects each argument to be a list of options compatible with
+  # autosetup's [options] function. This function concatenates the
+  # contents of each list into a new top-level list, stripping the outer
+  # list part of each argument, and returning that list
+  #
+  # If passed no arguments, it uses the list generated by calls to
+  # [proj-options-add].
+  proc proj-options-combine {args} {
+    set rv [list]
+    if {0 == [llength $args]} {
+      set args $::proj__Config(extra-options)
+    }
+    foreach e $args {
+      lappend rv {*}$e
+    }
+    return $rv
+  }
+}; # proj-options-*
+
+# Internal cache for use via proj-cache-*.
+array set proj__Cache {}
+
+#
+# @proj-cache-key arg {addLevel 0}
+#
+# Helper to generate cache keys for [proj-cache-*].
+#
+# $addLevel should almost always be 0.
+#
+# Returns a cache key for the given argument:
+#
+#   integer: relative call stack levels to get the scope name of for
+#   use as a key. [proj-scope [expr {1 + $arg + addLevel}]] is
+#   then used to generate the key. i.e. the default of 0 uses the
+#   calling scope's name as the key.
+#
+#   Anything else: returned as-is
+#
+proc proj-cache-key {arg {addLevel 0}} {
+  if {[string is integer -strict $arg]} {
+    return [proj-scope [expr {$arg + $addLevel + 1}]]
+  }
+  return $arg
+}
+
+#
+# @proj-cache-set ?-key KEY? ?-level 0? value
+#
+# Sets a feature-check cache entry with the given key.
+#
+# See proj-cache-key for -key's and -level's semantics, noting that
+# this function adds one to -level for purposes of that call.
+proc proj-cache-set {args} {
+  proj-parse-flags args flags {
+    -key => 0
+    -level => 0
+  }
+  lassign $args val
+  set key [proj-cache-key $flags(-key) [expr {1 + $flags(-level)}]]
+  #puts "** fcheck set $key = $val"
+  set ::proj__Cache($key) $val
+}
+
+#
+# @proj-cache-remove ?key? ?addLevel?
+#
+# Removes an entry from the proj-cache.
+proc proj-cache-remove {{key 0} {addLevel 0}} {
+  set key [proj-cache-key $key [expr {1 + $addLevel}]]
+  set rv ""
+  if {[info exists ::proj__Cache($key)]} {
+    set rv $::proj__Cache($key)
+    unset ::proj__Cache($key)
+  }
+  return $rv;
+}
+
+#
+# @proj-cache-check ?-key KEY? ?-level LEVEL? tgtVarName
+#
+# Checks for a feature-check cache entry with the given key.
+#
+# If the feature-check cache has a matching entry then this function
+# assigns its value to tgtVar and returns 1, else it assigns tgtVar to
+# "" and returns 0.
+#
+# See proj-cache-key for $key's and $addLevel's semantics, noting that
+# this function adds one to $addLevel for purposes of that call.
+proc proj-cache-check {args} {
+  proj-parse-flags args flags {
+    -key => 0
+    -level => 0
+  }
+  lassign $args tgtVar
+  upvar $tgtVar tgt
+  set rc 0
+  set key [proj-cache-key $flags(-key) [expr {1 + $flags(-level)}]]
+  #puts "** fcheck get key=$key"
+  if {[info exists ::proj__Cache($key)]} {
+    set tgt $::proj__Cache($key)
+    incr rc
+  } else {
+    set tgt ""
+  }
+  return $rc
+}
+
+#
+# @proj-coalesce ...args
+#
+# Returns the first argument which is not empty (eq ""), or an empty
+# string on no match.
+proc proj-coalesce {args} {
+  foreach arg $args {
+    if {"" ne $arg} {
+      return $arg
+    }
+  }
+  return ""
+}
+
+#
+# @proj-parse-flags argvListName targetArrayName {prototype}
+#
+# A helper to parse flags from proc argument lists.
+#
+# The first argument is the name of a var holding the args to
+# parse. It will be overwritten, possibly with a smaller list.
+#
+# The second argument is the name of an array variable to create in
+# the caller's scope.
+#
+# The third argument, $prototype, is a description of how to handle
+# the flags. Each entry in that list must be in one of the
+# following forms:
+#
+#   -flag  defaultValue ?-literal|-call|-apply?
+#                       script|number|incr|proc-name|{apply $aLambda}
+#
+#   -flag* ...as above...
+#
+#   -flag  => defaultValue ?-call proc-name-and-args|-apply lambdaExpr?
+#
+#   -flag* => ...as above...
+#
+#   :PRAGMA
+#
+# The first two forms represents a basic flag with no associated
+# following argument. The third and fourth forms, called arg-consuming
+# flags, extract the value from the following argument in $argvName
+# (pneumonic: => points to the next argument.). The :PRAGMA form
+# offers a way to configure certain aspects of this call.
+#
+# If $argv contains any given flag from $prototype, its default value
+# is overridden depending on several factors:
+#
+#  - If the -literal flag is used, or the flag's script is a number,
+#    value is used verbatim.
+#
+#  - Else if the -call flag is used, the argument must be a proc name
+#    and any leading arguments, e.g. {apply $myLambda}.  The proc is passed
+#    the (flag, value) as arguments (non-consuming flags will get
+#    passed the flag's current/starting value and consuming flags will
+#    get the next argument).  Its result becomes the result of the
+#    flag.
+#
+#  - Else if -apply X is used, it's effectively shorthand for -call
+#    {apply X}. Its argument may either be a $lambaRef or a {{f v}
+#    {body}} construct.
+#
+#  - Else if $script is one of the following values, it is treated as
+#    the result of...
+#
+#    - incr: increments the current value of the flag.
+#
+#  - Else $script is eval'd to get its result value. That result
+#    becomes the new flag value for $tgtArrayName(-flag). This
+#    function intercepts [return $val] from eval'ing $script.  Any
+#    empty script will result in the flag having "" assigned to it.
+#
+# Unless the -flag has a trailing asterisk, e.g. -flag*, this function
+# assumes that each flag is unique, and using a flag more than once
+# causes an error to be triggered. the -flag* forms works similarly
+# except that may appear in $argv any number of times:
+#
+#  - For non-arg-consuming flags, each invocation of -flag causes the
+#    result of $script to overwrite the previous value. e.g. so
+#    {-flag* {x} {incr foo}} has a default value of x, but passing in
+#    -flag twice would change it to the result of incrementing foo
+#    twice. This form can be used to implement, e.g., increasing
+#    verbosity levels by passing -verbose multiple times.
+#
+#  - For arg-consuming flags, the given flag starts with value X, but
+#    if the flag is provided in $argv, the default is cleared, then
+#    each instance of -flag causes its value to be appended to the
+#    result, so {-flag* => {a b c}} defaults to {a b c}, but passing
+#    in -flag y -flag z would change it to {y z}, not {a b c y z}..
+#
+# By default, the args list is only inspected until the first argument
+# which is not described by $prototype. i.e. the first "non-flag" (not
+# counting values consumed for flags defined like -flag => default).
+# The :all-flags pragma (see below) can modify this behavior.
+#
+# If a "--" flag is encountered, no more arguments are inspected as
+# flags unless the :all-flags pragma (see below) is in effect. The
+# first instance of "--" is removed from the target result list but
+# all remaining instances of "--" are are passed through.
+#
+# Any argvName entries not described in $prototype are considered to
+# be "non-flags" for purposes of this function, even if they
+# ostensibly look like flags.
+#
+# Returns the number of flags it processed in $argvName, not counting
+# "--".
+#
+# Example:
+#
+## set args [list -foo -bar {blah} -z 8 9 10 -theEnd]
+## proj-parse-flags args flags {
+##   -foo    0  {expr 1}
+##   -bar    => 0
+##   -no-baz 1  {return 0}
+##   -z 0 2
+## }
+#
+# After that $flags would contain {-foo 1 -bar {blah} -no-baz 1 -z 2}
+# and $args would be {8 9 10 -theEnd}.
+#
+# Pragmas:
+#
+# Passing :PRAGMAS to this function may modify how it works. The
+# following pragmas are supported (note the leading ":"):
+#
+#   :all-flags indicates that the whole input list should be scanned,
+#   not stopping at the first non-flag or "--".
+#
+proc proj-parse-flags {argvName tgtArrayName prototype} {
+  upvar $argvName argv
+  upvar $tgtArrayName outFlags
+  array set flags {}; # staging area
+  array set blob {}; # holds markers for various per-key state and options
+  set incrSkip 1; # 1 if we stop at the first non-flag, else 0
+  # Parse $prototype for flag definitions...
+  set n [llength $prototype]
+  set checkProtoFlag {
+    #puts "**** checkProtoFlag #$i of $n k=$k fv=$fv"
+    switch -exact -- $fv {
+      -literal {
+        proj-assert {![info exists blob(${k}.consumes)]}
+        set blob(${k}.script) [list expr [lindex $prototype [incr i]]]
+      }
+      -apply {
+        set fv [lindex $prototype [incr i]]
+        if {2 == [llength $fv]} {
+          # Treat this as a lambda literal
+          set fv [list $fv]
+        }
+        lappend blob(${k}.call) "apply $fv"
+      }
+      -call {
+        # arg is either a proc name or {apply $aLambda}
+        set fv [lindex $prototype [incr i]]
+        lappend blob(${k}.call) $fv
+      }
+      default {
+        proj-assert {![info exists blob(${k}.consumes)]}
+        set blob(${k}.script) $fv
+      }
+    }
+    if {$i >= $n} {
+      proj-error -up "[proj-scope]: Missing argument for $k flag"
+    }
+  }
+  for {set i 0} {$i < $n} {incr i} {
+    set k [lindex $prototype $i]
+    #puts "**** #$i of $n k=$k"
+
+    # Check for :PRAGMA...
+    switch -exact -- $k {
+      :all-flags {
+        set incrSkip 0
+        continue
+      }
+    }
+
+    proj-assert {[string match -* $k]} \
+      "Invalid argument: $k"
+
+    if {[string match {*\*} $k]} {
+      # Re-map -foo* to -foo and flag -foo as a repeatable flag
+      set k [string map {* ""} $k]
+      incr blob(${k}.multi)
+    }
+
+    if {[info exists flags($k)]} {
+      proj-error -up "[proj-scope]: Duplicated prototype for flag $k"
+    }
+
+    switch -exact -- [lindex $prototype [expr {$i + 1}]] {
+      => {
+        # -flag => DFLT ?-subflag arg?
+        incr i 2
+        if {$i >= $n} {
+          proj-error -up "[proj-scope]: Missing argument for $k => flag"
+        }
+        incr blob(${k}.consumes)
+        set vi [lindex $prototype $i]
+        if {$vi in {-apply -call}} {
+          proj-error -up "[proj-scope]: Missing default value for $k flag"
+        } else {
+          set fv [lindex $prototype [expr {$i + 1}]]
+          if {$fv in {-apply -call}} {
+            incr i
+            eval $checkProtoFlag
+          }
+        }
+      }
+      default {
+        # -flag VALUE ?flag? SCRIPT
+        set vi [lindex $prototype [incr i]]
+        set fv [lindex $prototype [incr i]]
+        eval $checkProtoFlag
+      }
+    }
+    #puts "**** #$i of $n k=$k vi=$vi"
+    set flags($k) $vi
+  }
+  #puts "-- flags"; parray flags
+  #puts "-- blob"; parray blob
+  set rc 0
+  set rv {}; # staging area for the target argv value
+  set skipMode 0
+  set n [llength $argv]
+  # Now look for those flags in $argv...
+  for {set i 0} {$i < $n} {incr i} {
+    set arg [lindex $argv $i]
+    #puts "-- [proj-scope] arg=$arg"
+    if {$skipMode} {
+      lappend rv $arg
+    } elseif {"--" eq $arg} {
+      # "--" is the conventional way to end processing of args
+      if {[incr blob(--)] > 1} {
+        # Elide only the first one
+        lappend rv $arg
+      }
+      incr skipMode $incrSkip
+    } elseif {[info exists flags($arg)]} {
+      # A known flag...
+      set isMulti [info exists blob(${arg}.multi)]
+      incr blob(${arg}.seen)
+      if {1 < $blob(${arg}.seen) && !$isMulti} {
+        proj-error -up [proj-scope] "$arg flag was used multiple times"
+      }
+      set vMode 0; # 0=as-is, 1=eval, 2=call
+      set isConsuming [info exists blob(${arg}.consumes)]
+      if {$isConsuming} {
+        incr i
+        if {$i >= $n} {
+          proj-error -up [proj-scope] "is missing argument for $arg flag"
+        }
+        set vv [lindex $argv $i]
+      } elseif {[info exists blob(${arg}.script)]} {
+        set vMode 1
+        set vv $blob(${arg}.script)
+      } else {
+        set vv $flags($arg)
+      }
+
+      if {[info exists blob(${arg}.call)]} {
+        set vMode 2
+        set vv [concat {*}$blob(${arg}.call) $arg $vv]
+      } elseif {$isConsuming} {
+        proj-assert {!$vMode}
+        # fall through
+      } elseif {"" eq $vv || [string is double -strict $vv]} {
+        set vMode 0
+      } elseif {$vv in {incr}} {
+        set vMode 0
+        switch -exact $vv {
+          incr {
+            set xx $flags($k); incr xx; set vv $xx; unset xx
+          }
+          default {
+            proj-error "Unhandled \$vv value $vv"
+          }
+        }
+      } else {
+        set vv [list eval $vv]
+        set vMode 1
+      }
+      if {$vMode} {
+        set code [catch [list uplevel 1 $vv] vv xopt]
+        if {$code ni {0 2}} {
+          return {*}$xopt $vv
+        }
+      }
+      if {$isConsuming && $isMulti} {
+        if {1 == $blob(${arg}.seen)} {
+          # On the first hit, overwrite the default with a new list.
+          set flags($arg) [list $vv]
+        } else {
+          # On subsequent hits, append to the list.
+          lappend flags($arg) $vv
+        }
+      } else {
+        set flags($arg) $vv
+      }
+      incr rc
+    } else {
+      # Non-flag
+      incr skipMode $incrSkip
+      lappend rv $arg
+    }
+  }
+  set argv $rv
+  array set outFlags [array get flags]
+  #puts "-- rv=$rv argv=$argv flags="; parray flags
+  return $rc
+}; # proj-parse-flags
+
+#
+# Older (deprecated) name of proj-parse-flags.
+#
+proc proj-parse-simple-flags {args} {
+  tailcall proj-parse-flags {*}$args
+}
+
+if {$::proj__Config(self-tests)} {
+  set __ova $::proj__Config(verbose-assert);
+  set ::proj__Config(verbose-assert) 1
+  puts "Running [info script] self-tests..."
+  # proj-cache...
+  apply {{} {
+    #proj-warn "Test code for proj-cache"
+    proj-assert {![proj-cache-check -key here check]}
+    proj-assert {"here" eq [proj-cache-key here]}
+    proj-assert {"" eq $check}
+    proj-cache-set -key here thevalue
+    proj-assert {[proj-cache-check -key here check]}
+    proj-assert {"thevalue" eq $check}
+
+    proj-assert {![proj-cache-check check]}
+    #puts "*** key = ([proj-cache-key 0])"
+    proj-assert {"" eq $check}
+    proj-cache-set abc
+    proj-assert {[proj-cache-check check]}
+    proj-assert {"abc" eq $check}
+
+    #parray ::proj__Cache;
+    proj-assert {"" ne [proj-cache-remove]}
+    proj-assert {![proj-cache-check check]}
+    proj-assert {"" eq [proj-cache-remove]}
+    proj-assert {"" eq $check}
+  }}
+
+  # proj-parse-flags ...
+  apply {{} {
+    set foo 3
+    set argv {-a "hi - world" -b -b -b -- -a {bye bye} -- -d -D c -a "" --}
+    proj-parse-flags argv flags {
+      :all-flags
+      -a* => "gets overwritten"
+      -b* 7 {incr foo}
+      -d 1 0
+      -D 0 1
+    }
+
+    #puts "-- argv = $argv"; parray flags;
+    proj-assert {"-- c --" eq $argv}
+    proj-assert {$flags(-a) eq "{hi - world} {bye bye} {}"}
+    proj-assert {$foo == 6}
+    proj-assert {$flags(-b) eq $foo}
+    proj-assert {$flags(-d) == 0}
+    proj-assert {$flags(-D) == 1}
+    set foo 0
+    foreach x $flags(-a) {
+      proj-assert {$x in {{hi - world} {bye bye} {}}}
+      incr foo
+    }
+    proj-assert {3 == $foo}
+
+    set argv {-a {hi world} -b -maybe -- -a {bye bye} -- -b c --}
+    set foo 0
+    proj-parse-flags argv flags {
+      -a => "aaa"
+      -b 0 {incr foo}
+      -maybe no -literal yes
+    }
+    #parray flags; puts "--- argv = $argv"
+    proj-assert {"-a {bye bye} -- -b c --" eq $argv}
+    proj-assert {$flags(-a) eq "hi world"}
+    proj-assert {1 == $flags(-b)}
+    proj-assert {"yes" eq $flags(-maybe)}
+
+    set argv {-f -g -a aaa -M -M -M -L -H -A AAA a b c}
+    set foo 0
+    set myLambda {{flag val} {
+      proj-assert {$flag in {-f -g -M}}
+      #puts "myLambda flag=$flag val=$val"
+      incr val
+    }}
+    proc myNonLambda {flag val} {
+      proj-assert {$flag in {-A -a}}
+      #puts "myNonLambda flag=$flag val=$val"
+      concat $val $val
+    }
+    proj-parse-flags argv flags {
+      -f 0 -call {apply $myLambda}
+      -g 2 -apply $myLambda
+      -h 3 -apply $myLambda
+      -H 30 33
+      -a => aAAAa -apply {{f v} {
+        set v
+      }}
+      -A => AaaaA -call myNonLambda
+      -B => 17 -call myNonLambda
+      -M* 0 -apply $myLambda
+      -L "" -literal $myLambda
+    }
+    rename myNonLambda ""
+    #puts "--- argv = $argv"; parray flags
+    proj-assert {$flags(-f) == 1}
+    proj-assert {$flags(-g) == 3}
+    proj-assert {$flags(-h) == 3}
+    proj-assert {$flags(-H) == 33}
+    proj-assert {$flags(-a) == {aaa}}
+    proj-assert {$flags(-A) eq "AAA AAA"}
+    proj-assert {$flags(-B) == 17}
+    proj-assert {$flags(-M) == 3}
+    proj-assert {$flags(-L) eq $myLambda}
+
+    set argv {-touch -validate}
+    proj-parse-flags argv flags {
+      -touch "" {return "-touch"}
+      -validate 0 1
+    }
+    #puts "----- argv = $argv"; parray flags
+    proj-assert {$flags(-touch) eq "-touch"}
+    proj-assert {$flags(-validate) == 1}
+    proj-assert {$argv eq {}}
+
+    set argv {-i -i -i}
+    proj-parse-flags argv flags {
+      -i* 0 incr
+    }
+    proj-assert {3 == $flags(-i)}
+  }}
+  set ::proj__Config(verbose-assert) $__ova
+  unset __ova
+  puts "Done running [info script] self-tests."
+}; # proj- API self-tests