--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/host/buildvm.c	Thu Jan 22 20:10:30 2026 -0800
@@ -0,0 +1,529 @@
+/*
+** LuaJIT VM builder.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+**
+** This is a tool to build the hand-tuned assembler code required for
+** LuaJIT's bytecode interpreter. It supports a variety of output formats
+** to feed different toolchains (see usage() below).
+**
+** This tool is not particularly optimized because it's only used while
+** _building_ LuaJIT. There's no point in distributing or installing it.
+** Only the object code generated by this tool is linked into LuaJIT.
+**
+** Caveat: some memory is not free'd, error handling is lazy.
+** It's a one-shot tool -- any effort fixing this would be wasted.
+*/
+
+#include "buildvm.h"
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_bc.h"
+#if LJ_HASJIT
+#include "lj_ir.h"
+#include "lj_ircall.h"
+#endif
+#include "lj_frame.h"
+#include "lj_dispatch.h"
+#if LJ_HASFFI
+#include "lj_ctype.h"
+#include "lj_ccall.h"
+#endif
+#include "luajit.h"
+
+#if defined(_WIN32)
+#include <fcntl.h>
+#include <io.h>
+#endif
+
+/* ------------------------------------------------------------------------ */
+
+/* DynASM glue definitions. */
+#define Dst		ctx
+#define Dst_DECL	BuildCtx *ctx
+#define Dst_REF		(ctx->D)
+#define DASM_CHECKS	1
+
+#include "../dynasm/dasm_proto.h"
+
+/* Glue macros for DynASM. */
+static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type);
+
+#define DASM_EXTERN(ctx, addr, idx, type) \
+  collect_reloc(ctx, addr, idx, type)
+
+/* ------------------------------------------------------------------------ */
+
+/* Avoid trouble if cross-compiling for an x86 target. Speed doesn't matter. */
+#define DASM_ALIGNED_WRITES	1
+
+/* Embed architecture-specific DynASM encoder. */
+#if LJ_TARGET_X86ORX64
+#include "../dynasm/dasm_x86.h"
+#elif LJ_TARGET_ARM
+#include "../dynasm/dasm_arm.h"
+#elif LJ_TARGET_ARM64
+#include "../dynasm/dasm_arm64.h"
+#elif LJ_TARGET_PPC
+#include "../dynasm/dasm_ppc.h"
+#elif LJ_TARGET_MIPS
+#include "../dynasm/dasm_mips.h"
+#else
+#error "No support for this architecture (yet)"
+#endif
+
+/* Embed generated architecture-specific backend. */
+#include "buildvm_arch.h"
+
+/* ------------------------------------------------------------------------ */
+
+void owrite(BuildCtx *ctx, const void *ptr, size_t sz)
+{
+  if (fwrite(ptr, 1, sz, ctx->fp) != sz) {
+    fprintf(stderr, "Error: cannot write to output file: %s\n",
+	    strerror(errno));
+    exit(1);
+  }
+}
+
+/* ------------------------------------------------------------------------ */
+
+/* Emit code as raw bytes. Only used for DynASM debugging. */
+static void emit_raw(BuildCtx *ctx)
+{
+  owrite(ctx, ctx->code, ctx->codesz);
+}
+
+/* -- Build machine code -------------------------------------------------- */
+
+static const char *sym_decorate(BuildCtx *ctx,
+				const char *prefix, const char *suffix)
+{
+  char name[256];
+  char *p;
+#if LJ_64
+  const char *symprefix = ctx->mode == BUILD_machasm ? "_" : "";
+#elif LJ_TARGET_XBOX360
+  const char *symprefix = "";
+#else
+  const char *symprefix = ctx->mode != BUILD_elfasm ? "_" : "";
+#endif
+  sprintf(name, "%s%s%s", symprefix, prefix, suffix);
+  p = strchr(name, '@');
+  if (p) {
+#if LJ_TARGET_X86ORX64
+    if (!LJ_64 && (ctx->mode == BUILD_coffasm || ctx->mode == BUILD_peobj))
+      name[0] = name[1] == 'R' ? '_' : '@';  /* Just for _RtlUnwind@16. */
+    else
+      *p = '\0';
+#elif LJ_TARGET_PPC && !LJ_TARGET_CONSOLE
+    /* Keep @plt etc. */
+#else
+    *p = '\0';
+#endif
+  }
+  p = (char *)malloc(strlen(name)+1);  /* MSVC doesn't like strdup. */
+  strcpy(p, name);
+  return p;
+}
+
+#define NRELOCSYM	(sizeof(extnames)/sizeof(extnames[0])-1)
+
+static int relocmap[NRELOCSYM];
+
+/* Collect external relocations. */
+static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type)
+{
+  if (ctx->nreloc >= BUILD_MAX_RELOC) {
+    fprintf(stderr, "Error: too many relocations, increase BUILD_MAX_RELOC.\n");
+    exit(1);
+  }
+  if (relocmap[idx] < 0) {
+    relocmap[idx] = ctx->nrelocsym;
+    ctx->relocsym[ctx->nrelocsym] = sym_decorate(ctx, "", extnames[idx]);
+    ctx->nrelocsym++;
+  }
+  ctx->reloc[ctx->nreloc].ofs = (int32_t)(addr - ctx->code);
+  ctx->reloc[ctx->nreloc].sym = relocmap[idx];
+  ctx->reloc[ctx->nreloc].type = type;
+  ctx->nreloc++;
+#if LJ_TARGET_XBOX360
+  return (int)(ctx->code - addr) + 4;  /* Encode symbol offset of .text. */
+#else
+  return 0;  /* Encode symbol offset of 0. */
+#endif
+}
+
+/* Naive insertion sort. Performance doesn't matter here. */
+static void sym_insert(BuildCtx *ctx, int32_t ofs,
+		       const char *prefix, const char *suffix)
+{
+  ptrdiff_t i = ctx->nsym++;
+  while (i > 0) {
+    if (ctx->sym[i-1].ofs <= ofs)
+      break;
+    ctx->sym[i] = ctx->sym[i-1];
+    i--;
+  }
+  ctx->sym[i].ofs = ofs;
+  ctx->sym[i].name = sym_decorate(ctx, prefix, suffix);
+}
+
+/* Build the machine code. */
+static int build_code(BuildCtx *ctx)
+{
+  int status;
+  int i;
+
+  /* Initialize DynASM structures. */
+  ctx->nglob = GLOB__MAX;
+  ctx->glob = (void **)malloc(ctx->nglob*sizeof(void *));
+  memset(ctx->glob, 0, ctx->nglob*sizeof(void *));
+  ctx->nreloc = 0;
+
+  ctx->globnames = globnames;
+  ctx->extnames = extnames;
+  ctx->relocsym = (const char **)malloc(NRELOCSYM*sizeof(const char *));
+  ctx->nrelocsym = 0;
+  for (i = 0; i < (int)NRELOCSYM; i++) relocmap[i] = -1;
+
+  ctx->dasm_ident = DASM_IDENT;
+  ctx->dasm_arch = DASM_ARCH;
+
+  dasm_init(Dst, DASM_MAXSECTION);
+  dasm_setupglobal(Dst, ctx->glob, ctx->nglob);
+  dasm_setup(Dst, build_actionlist);
+
+  /* Call arch-specific backend to emit the code. */
+  ctx->npc = build_backend(ctx);
+
+  /* Finalize the code. */
+  (void)dasm_checkstep(Dst, -1);
+  if ((status = dasm_link(Dst, &ctx->codesz))) return status;
+  ctx->code = (uint8_t *)malloc(ctx->codesz);
+  if ((status = dasm_encode(Dst, (void *)ctx->code))) return status;
+
+  /* Allocate symbol table and bytecode offsets. */
+  ctx->beginsym = sym_decorate(ctx, "", LABEL_PREFIX "vm_asm_begin");
+  ctx->sym = (BuildSym *)malloc((ctx->npc+ctx->nglob+1)*sizeof(BuildSym));
+  ctx->nsym = 0;
+  ctx->bc_ofs = (int32_t *)malloc(ctx->npc*sizeof(int32_t));
+
+  /* Collect the opcodes (PC labels). */
+  for (i = 0; i < ctx->npc; i++) {
+    int32_t ofs = dasm_getpclabel(Dst, i);
+    if (ofs < 0) return 0x22000000|i;
+    ctx->bc_ofs[i] = ofs;
+    if ((LJ_HASJIT ||
+	 !(i == BC_JFORI || i == BC_JFORL || i == BC_JITERL || i == BC_JLOOP ||
+	   i == BC_IFORL || i == BC_IITERL || i == BC_ILOOP)) &&
+	(LJ_HASFFI || i != BC_KCDATA))
+      sym_insert(ctx, ofs, LABEL_PREFIX_BC, bc_names[i]);
+  }
+
+  /* Collect the globals (named labels). */
+  for (i = 0; i < ctx->nglob; i++) {
+    const char *gl = globnames[i];
+    int len = (int)strlen(gl);
+    if (!ctx->glob[i]) {
+      fprintf(stderr, "Error: undefined global %s\n", gl);
+      exit(2);
+    }
+    /* Skip the _Z symbols. */
+    if (!(len >= 2 && gl[len-2] == '_' && gl[len-1] == 'Z'))
+      sym_insert(ctx, (int32_t)((uint8_t *)(ctx->glob[i]) - ctx->code),
+		 LABEL_PREFIX, globnames[i]);
+  }
+
+  /* Close the address range. */
+  sym_insert(ctx, (int32_t)ctx->codesz, "", "");
+  ctx->nsym--;
+
+  dasm_free(Dst);
+
+  return 0;
+}
+
+/* -- Generate VM enums --------------------------------------------------- */
+
+const char *const bc_names[] = {
+#define BCNAME(name, ma, mb, mc, mt)       #name,
+BCDEF(BCNAME)
+#undef BCNAME
+  NULL
+};
+
+#if LJ_HASJIT
+const char *const ir_names[] = {
+#define IRNAME(name, m, m1, m2)	#name,
+IRDEF(IRNAME)
+#undef IRNAME
+  NULL
+};
+
+const char *const irt_names[] = {
+#define IRTNAME(name, size)	#name,
+IRTDEF(IRTNAME)
+#undef IRTNAME
+  NULL
+};
+
+const char *const irfpm_names[] = {
+#define FPMNAME(name)		#name,
+IRFPMDEF(FPMNAME)
+#undef FPMNAME
+  NULL
+};
+
+const char *const irfield_names[] = {
+#define FLNAME(name, ofs)	#name,
+IRFLDEF(FLNAME)
+#undef FLNAME
+  NULL
+};
+
+const char *const ircall_names[] = {
+#define IRCALLNAME(cond, name, nargs, kind, type, flags)	#name,
+IRCALLDEF(IRCALLNAME)
+#undef IRCALLNAME
+  NULL
+};
+
+static const char *const trace_errors[] = {
+#define TREDEF(name, msg)	msg,
+#include "lj_traceerr.h"
+  NULL
+};
+#endif
+
+#if LJ_HASJIT
+static const char *lower(char *buf, const char *s)
+{
+  char *p = buf;
+  while (*s) {
+    *p++ = (*s >= 'A' && *s <= 'Z') ? *s+0x20 : *s;
+    s++;
+  }
+  *p = '\0';
+  return buf;
+}
+#endif
+
+/* Emit C source code for bytecode-related definitions. */
+static void emit_bcdef(BuildCtx *ctx)
+{
+  int i;
+  fprintf(ctx->fp, "/* This is a generated file. DO NOT EDIT! */\n\n");
+  fprintf(ctx->fp, "LJ_DATADEF const uint16_t lj_bc_ofs[] = {\n");
+  for (i = 0; i < ctx->npc; i++) {
+    if (i != 0)
+      fprintf(ctx->fp, ",\n");
+    fprintf(ctx->fp, "%d", ctx->bc_ofs[i]);
+  }
+}
+
+/* Emit VM definitions as Lua code for debug modules. */
+static void emit_vmdef(BuildCtx *ctx)
+{
+#if LJ_HASJIT
+  char buf[80];
+#endif
+  int i;
+  fprintf(ctx->fp, "-- This is a generated file. DO NOT EDIT!\n\n");
+  fprintf(ctx->fp, "assert(require(\"jit\").version == \"%s\", \"LuaJIT core/library version mismatch\")\n\n", LUAJIT_VERSION);
+  fprintf(ctx->fp, "return {\n\n");
+
+  fprintf(ctx->fp, "bcnames = \"");
+  for (i = 0; bc_names[i]; i++) fprintf(ctx->fp, "%-6s", bc_names[i]);
+  fprintf(ctx->fp, "\",\n\n");
+
+#if LJ_HASJIT
+  fprintf(ctx->fp, "irnames = \"");
+  for (i = 0; ir_names[i]; i++) fprintf(ctx->fp, "%-6s", ir_names[i]);
+  fprintf(ctx->fp, "\",\n\n");
+
+  fprintf(ctx->fp, "irfpm = { [0]=");
+  for (i = 0; irfpm_names[i]; i++)
+    fprintf(ctx->fp, "\"%s\", ", lower(buf, irfpm_names[i]));
+  fprintf(ctx->fp, "},\n\n");
+
+  fprintf(ctx->fp, "irfield = { [0]=");
+  for (i = 0; irfield_names[i]; i++) {
+    char *p;
+    lower(buf, irfield_names[i]);
+    p = strchr(buf, '_');
+    if (p) *p = '.';
+    fprintf(ctx->fp, "\"%s\", ", buf);
+  }
+  fprintf(ctx->fp, "},\n\n");
+
+  fprintf(ctx->fp, "ircall = {\n[0]=");
+  for (i = 0; ircall_names[i]; i++)
+    fprintf(ctx->fp, "\"%s\",\n", ircall_names[i]);
+  fprintf(ctx->fp, "},\n\n");
+
+  fprintf(ctx->fp, "traceerr = {\n[0]=");
+  for (i = 0; trace_errors[i]; i++)
+    fprintf(ctx->fp, "\"%s\",\n", trace_errors[i]);
+  fprintf(ctx->fp, "},\n\n");
+#endif
+}
+
+/* -- Argument parsing ---------------------------------------------------- */
+
+/* Build mode names. */
+static const char *const modenames[] = {
+#define BUILDNAME(name)		#name,
+BUILDDEF(BUILDNAME)
+#undef BUILDNAME
+  NULL
+};
+
+/* Print usage information and exit. */
+static void usage(void)
+{
+  int i;
+  fprintf(stderr, LUAJIT_VERSION " VM builder.\n");
+  fprintf(stderr, LUAJIT_COPYRIGHT ", " LUAJIT_URL "\n");
+  fprintf(stderr, "Target architecture: " LJ_ARCH_NAME "\n\n");
+  fprintf(stderr, "Usage: buildvm -m mode [-o outfile] [infiles...]\n\n");
+  fprintf(stderr, "Available modes:\n");
+  for (i = 0; i < BUILD__MAX; i++)
+    fprintf(stderr, "  %s\n", modenames[i]);
+  exit(1);
+}
+
+/* Parse the output mode name. */
+static BuildMode parsemode(const char *mode)
+{
+  int i;
+  for (i = 0; modenames[i]; i++)
+    if (!strcmp(mode, modenames[i]))
+      return (BuildMode)i;
+  usage();
+  return (BuildMode)-1;
+}
+
+/* Parse arguments. */
+static void parseargs(BuildCtx *ctx, char **argv)
+{
+  const char *a;
+  int i;
+  ctx->mode = (BuildMode)-1;
+  ctx->outname = "-";
+  for (i = 1; (a = argv[i]) != NULL; i++) {
+    if (a[0] != '-')
+      break;
+    switch (a[1]) {
+    case '-':
+      if (a[2]) goto err;
+      i++;
+      goto ok;
+    case '\0':
+      goto ok;
+    case 'm':
+      i++;
+      if (a[2] || argv[i] == NULL) goto err;
+      ctx->mode = parsemode(argv[i]);
+      break;
+    case 'o':
+      i++;
+      if (a[2] || argv[i] == NULL) goto err;
+      ctx->outname = argv[i];
+      break;
+    default: err:
+      usage();
+      break;
+    }
+  }
+ok:
+  ctx->args = argv+i;
+  if (ctx->mode == (BuildMode)-1) goto err;
+}
+
+int main(int argc, char **argv)
+{
+  BuildCtx ctx_;
+  BuildCtx *ctx = &ctx_;
+  int status, binmode;
+
+  if (sizeof(void *) != 4*LJ_32+8*LJ_64) {
+    fprintf(stderr,"Error: pointer size mismatch in cross-build.\n");
+    fprintf(stderr,"Try: make HOST_CC=\"gcc -m32\" CROSS=...\n\n");
+    return 1;
+  }
+
+  UNUSED(argc);
+  parseargs(ctx, argv);
+
+  if ((status = build_code(ctx))) {
+    fprintf(stderr,"Error: DASM error %08x\n", status);
+    return 1;
+  }
+
+  switch (ctx->mode) {
+  case BUILD_peobj:
+  case BUILD_raw:
+    binmode = 1;
+    break;
+  default:
+    binmode = 0;
+    break;
+  }
+
+  if (ctx->outname[0] == '-' && ctx->outname[1] == '\0') {
+    ctx->fp = stdout;
+#if defined(_WIN32)
+    if (binmode)
+      _setmode(_fileno(stdout), _O_BINARY);  /* Yuck. */
+#endif
+  } else if (!(ctx->fp = fopen(ctx->outname, binmode ? "wb" : "w"))) {
+    fprintf(stderr, "Error: cannot open output file '%s': %s\n",
+	    ctx->outname, strerror(errno));
+    exit(1);
+  }
+
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+  case BUILD_coffasm:
+  case BUILD_machasm:
+    emit_asm(ctx);
+    emit_asm_debug(ctx);
+    break;
+  case BUILD_peobj:
+    emit_peobj(ctx);
+    break;
+  case BUILD_raw:
+    emit_raw(ctx);
+    break;
+  case BUILD_bcdef:
+    emit_bcdef(ctx);
+    emit_lib(ctx);
+    break;
+  case BUILD_vmdef:
+    emit_vmdef(ctx);
+    emit_lib(ctx);
+    fprintf(ctx->fp, "}\n\n");
+    break;
+  case BUILD_ffdef:
+  case BUILD_libdef:
+  case BUILD_recdef:
+    emit_lib(ctx);
+    break;
+  case BUILD_folddef:
+    emit_fold(ctx);
+    break;
+  default:
+    break;
+  }
+
+  fflush(ctx->fp);
+  if (ferror(ctx->fp)) {
+    fprintf(stderr, "Error: cannot write to output file: %s\n",
+	    strerror(errno));
+    exit(1);
+  }
+  fclose(ctx->fp);
+
+  return 0;
+}
+