Refactor buildvm symbol generation.

Fixes Windows and OSX builds with LUAJIT_DISABLE_JIT.

8 files changed, 203 insertions, 324 deletions

diff --git a/src/buildvm.c b/src/buildvm.c
index dd0cbcc6..1b4d6928 100644
--- a/src/buildvm.c
+++ b/src/buildvm.c
@@ -101,6 +101,33 @@ static void emit_raw(BuildCtx *ctx)
 
 /* -- 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 ? "_" : "";
+#else
+  const char *symprefix = ctx->mode != BUILD_elfasm ? "_" : "";
+#endif
+  sprintf(name, "%s%s%s", symprefix, prefix, suffix);
+  p = strchr(name, '@');
+  if (p) {
+    if (!LJ_64 && (ctx->mode == BUILD_coffasm || ctx->mode == BUILD_peobj))
+      name[0] = '@';
+    else
+      *p = '\0';
+  }
+  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)
 {
@@ -108,32 +135,38 @@ static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type)
     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 = idx;
+  ctx->reloc[ctx->nreloc].sym = relocmap[idx];
   ctx->reloc[ctx->nreloc].type = type;
   ctx->nreloc++;
   return 0;  /* Encode symbol offset of 0. */
 }
 
 /* Naive insertion sort. Performance doesn't matter here. */
-static void perm_insert(int *perm, int32_t *ofs, int i)
+static void sym_insert(BuildCtx *ctx, int32_t ofs,
+                       const char *prefix, const char *suffix)
 {
-  perm[i] = i;
+  ptrdiff_t i = ctx->nsym++;
   while (i > 0) {
-    int a = perm[i-1];
-    int b = perm[i];
-    if (ofs[a] <= ofs[b]) break;
-    perm[i] = a;
-    perm[i-1] = b;
+    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, j;
+  int i;
 
   /* Initialize DynASM structures. */
   ctx->nglob = GLOB__MAX;
@@ -141,8 +174,10 @@ static int build_code(BuildCtx *ctx)
   memset(ctx->glob, 0, ctx->nglob*sizeof(void *));
   ctx->nreloc = 0;
 
-  ctx->extnames = extnames;
   ctx->globnames = globnames;
+  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;
@@ -160,37 +195,41 @@ static int build_code(BuildCtx *ctx)
   ctx->code = (uint8_t *)malloc(ctx->codesz);
   if ((status = dasm_encode(Dst, (void *)ctx->code))) return status;
 
-  /* Allocate the symbol offset and permutation tables. */
-  ctx->nsym = ctx->npc + ctx->nglob;
-  ctx->perm = (int *)malloc((ctx->nsym+1)*sizeof(int *));
-  ctx->sym_ofs = (int32_t *)malloc((ctx->nsym+1)*sizeof(int32_t));
+  /* 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 n = dasm_getpclabel(Dst, i);
-    if (n < 0) return 0x22000000|i;
-    ctx->sym_ofs[i] = n;
-    perm_insert(ctx->perm, ctx->sym_ofs, i);
+    int32_t ofs = dasm_getpclabel(Dst, i);
+    if (ofs < 0) return 0x22000000|i;
+    ctx->bc_ofs[i] = ofs;
+#if !LJ_HASJIT
+    if (!(i == BC_JFORI || i == BC_JFORL || i == BC_JITERL || i == BC_JLOOP ||
+          i == BC_IFORL || i == BC_IITERL || i == BC_ILOOP))
+#endif
+      sym_insert(ctx, ofs, LABEL_PREFIX_BC, bc_names[i]);
   }
 
   /* Collect the globals (named labels). */
-  for (j = 0; j < ctx->nglob; j++, i++) {
-    const char *gl = globnames[j];
+  for (i = 0; i < ctx->nglob; i++) {
+    const char *gl = globnames[i];
     int len = (int)strlen(gl);
-    if (!ctx->glob[j]) {
+    if (!ctx->glob[i]) {
       fprintf(stderr, "Error: undefined global %s\n", gl);
       exit(2);
     }
-    if (len >= 2 && gl[len-2] == '_' && gl[len-1] == 'Z')
-      ctx->sym_ofs[i] = -1;  /* Skip the _Z symbols. */
-    else
-      ctx->sym_ofs[i] = (int32_t)((uint8_t *)(ctx->glob[j]) - ctx->code);
-    perm_insert(ctx->perm, ctx->sym_ofs, i);
+    /* 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. */
-  ctx->sym_ofs[i] = (int32_t)ctx->codesz;
-  perm_insert(ctx->perm, ctx->sym_ofs, i);
+  sym_insert(ctx, (int32_t)ctx->codesz, "", "");
+  ctx->nsym--;
 
   dasm_free(Dst);
 
@@ -260,7 +299,7 @@ static void emit_bcdef(BuildCtx *ctx)
   for (i = 0; i < ctx->npc; i++) {
     if (i != 0)
       fprintf(ctx->fp, ",\n");
-    fprintf(ctx->fp, "%d", ctx->sym_ofs[i]);
+    fprintf(ctx->fp, "%d", ctx->bc_ofs[i]);
   }
 }
 
diff --git a/src/buildvm.h b/src/buildvm.h
index 6d242207..41038dd6 100644
--- a/src/buildvm.h
+++ b/src/buildvm.h
@@ -34,9 +34,6 @@
 #define LABEL_PREFIX_LIBCF      LABEL_PREFIX "lib_cf_"
 #define LABEL_PREFIX_LIBINIT    LABEL_PREFIX "lib_init_"
 
-/* Extra labels. */
-#define LABEL_ASM_BEGIN         LABEL_PREFIX "vm_asm_begin"
-
 /* Forward declaration. */
 struct dasm_State;
 
@@ -66,6 +63,11 @@ typedef struct BuildReloc {
   int type;
 } BuildReloc;
 
+typedef struct BuildSym {
+  const char *name;
+  int32_t ofs;
+} BuildSym;
+
 /* Build context structure. */
 typedef struct BuildCtx {
   /* DynASM state pointer. Should be first member. */
@@ -78,12 +80,13 @@ typedef struct BuildCtx {
   /* Code and symbols generated by DynASM. */
   uint8_t *code;
   size_t codesz;
-  int npc, nglob, nsym, nreloc;
+  int npc, nglob, nsym, nreloc, nrelocsym;
   void **glob;
-  int *perm;
-  int32_t *sym_ofs;
+  BuildSym *sym;
+  const char **relocsym;
+  int32_t *bc_ofs;
+  const char *beginsym;
   /* Strings generated by DynASM. */
-  const char *const *extnames;
   const char *const *globnames;
   const char *dasm_ident;
   const char *dasm_arch;
diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c
index b135b864..1898f0d5 100644
--- a/src/buildvm_asm.c
+++ b/src/buildvm_asm.c
@@ -123,74 +123,33 @@ static void emit_asm_align(BuildCtx *ctx, int bits)
 /* Emit assembler source code. */
 void emit_asm(BuildCtx *ctx)
 {
-  char name[80];
-  int32_t prev;
-  int i, pi, rel;
-#if LJ_64
-  const char *symprefix = ctx->mode == BUILD_machasm ? "_" : "";
-  int keepfc = 0;
-#else
-  const char *symprefix = ctx->mode != BUILD_elfasm ? "_" : "";
-  /* Keep fastcall suffix for COFF on WIN32. */
-  int keepfc = (ctx->mode == BUILD_coffasm);
-#endif
+  int i, rel;
 
   fprintf(ctx->fp, "\t.file \"buildvm_%s.dasc\"\n", ctx->dasm_arch);
   fprintf(ctx->fp, "\t.text\n");
   emit_asm_align(ctx, 4);
 
-  sprintf(name, "%s" LABEL_ASM_BEGIN, symprefix);
-  emit_asm_label(ctx, name, 0, 0);
+  emit_asm_label(ctx, ctx->beginsym, 0, 0);
   if (ctx->mode != BUILD_machasm)
     fprintf(ctx->fp, ".Lbegin:\n");
 
-  i = 0;
-  do {
-    pi = ctx->perm[i++];
-    prev = ctx->sym_ofs[pi];
-  } while (prev < 0);  /* Skip the _Z symbols. */
-
-  for (rel = 0; i <= ctx->nsym; i++) {
-    int ni = ctx->perm[i];
-    int32_t next = ctx->sym_ofs[ni];
-    int size = (int)(next - prev);
-    int32_t stop = next;
-    if (pi >= ctx->npc) {
-      char *p;
-      sprintf(name, "%s" LABEL_PREFIX "%s", symprefix,
-              ctx->globnames[pi-ctx->npc]);
-      p = strchr(name, '@');
-      if (p) { if (keepfc) name[0] = '@'; else *p = '\0'; }
-      emit_asm_label(ctx, name, size, 1);
-#if LJ_HASJIT
-    } else {
-#else
-    } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                 pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
-                 pi == BC_ILOOP)) {
-#endif
-      sprintf(name, "%s" LABEL_PREFIX_BC "%s", symprefix, bc_names[pi]);
-      emit_asm_label(ctx, name, size, 1);
-    }
-    while (rel < ctx->nreloc && ctx->reloc[rel].ofs < stop) {
+  for (i = rel = 0; i < ctx->nsym; i++) {
+    int32_t ofs = ctx->sym[i].ofs;
+    int32_t next = ctx->sym[i+1].ofs;
+    emit_asm_label(ctx, ctx->sym[i].name, next - ofs, 1);
+    while (rel < ctx->nreloc && ctx->reloc[rel].ofs < next) {
       BuildReloc *r = &ctx->reloc[rel];
-      int n = r->ofs - prev;
-      char *p;
-      sprintf(name, "%s%s", symprefix, ctx->extnames[r->sym]);
-      p = strchr(name, '@');
-      if (p) { if (keepfc) name[0] = '@'; else *p = '\0'; }
+      int n = r->ofs - ofs;
       if (ctx->mode == BUILD_machasm && r->type != 0) {
-        emit_asm_reloc_mach(ctx, ctx->code+prev, n, name);
+        emit_asm_reloc_mach(ctx, ctx->code+ofs, n, ctx->relocsym[r->sym]);
       } else {
-        emit_asm_bytes(ctx, ctx->code+prev, n);
-        emit_asm_reloc(ctx, r->type, name);
+        emit_asm_bytes(ctx, ctx->code+ofs, n);
+        emit_asm_reloc(ctx, r->type, ctx->relocsym[r->sym]);
       }
-      prev += n+4;
+      ofs += n+4;
       rel++;
     }
-    emit_asm_bytes(ctx, ctx->code+prev, stop-prev);
-    prev = next;
-    pi = ni;
+    emit_asm_bytes(ctx, ctx->code+ofs, next-ofs);
   }
 
   fprintf(ctx->fp, "\n");
diff --git a/src/buildvm_peobj.c b/src/buildvm_peobj.c
index 2ff274f9..4cde6e00 100644
--- a/src/buildvm_peobj.c
+++ b/src/buildvm_peobj.c
@@ -84,14 +84,11 @@ typedef struct PEsymaux {
 #define PEOBJ_ARCH_TARGET       0x014c
 #define PEOBJ_RELOC_REL32       0x14  /* MS: REL32, GNU: DISP32. */
 #define PEOBJ_RELOC_DIR32       0x06
-#define PEOBJ_SYM_PREFIX        "_"
-#define PEOBJ_SYMF_PREFIX       "@"
 #elif LJ_TARGET_X64
 #define PEOBJ_ARCH_TARGET       0x8664
 #define PEOBJ_RELOC_REL32       0x04  /* MS: REL32, GNU: DISP32. */
 #define PEOBJ_RELOC_DIR32       0x02
 #define PEOBJ_RELOC_ADDR32NB    0x03
-#define PEOBJ_SYM_PREFIX        ""
 #endif
 
 /* Section numbers (0-based). */
@@ -164,18 +161,13 @@ static void emit_peobj_sym_sect(BuildCtx *ctx, PEsection *pesect, int sect)
   owrite(ctx, &aux, PEOBJ_SYM_SIZE);
 }
 
-#define emit_peobj_sym_func(ctx, name, ofs) \
-  emit_peobj_sym(ctx, name, (uint32_t)(ofs), \
-                 PEOBJ_SECT_TEXT, PEOBJ_TYPE_FUNC, PEOBJ_SCL_EXTERN)
-
 /* Emit Windows PE object file. */
 void emit_peobj(BuildCtx *ctx)
 {
   PEheader pehdr;
   PEsection pesect[PEOBJ_NSECTIONS];
-  int nzsym, relocsyms;
   uint32_t sofs;
-  int i;
+  int i, nrsym;
   union { uint8_t b; uint32_t u; } host_endian;
 
   host_endian.u = 1;
@@ -230,16 +222,11 @@ void emit_peobj(BuildCtx *ctx)
 
   /* Compute the size of the symbol table:
   ** @feat.00 + nsections*2
-  ** + asm_start + (nsyms-nzsym)
-  ** + relocsyms
+  ** + asm_start + nsym
+  ** + nrsym
   */
-  /* Skip _Z syms. */
-  for (nzsym = 0; ctx->sym_ofs[ctx->perm[nzsym]] < 0; nzsym++) ;
-  for (relocsyms = 0; ctx->extnames[relocsyms]; relocsyms++) ;
-  pehdr.nsyms = 1+PEOBJ_NSECTIONS*2 + 1+(ctx->nsym-nzsym) + relocsyms;
-#if !LJ_HASJIT
-  pehdr.nsyms -= 11;  /* See below, removes [IJ]* opcode symbols. */
-#endif
+  nrsym = ctx->nrelocsym;
+  pehdr.nsyms = 1+PEOBJ_NSECTIONS*2 + 1+ctx->nsym + nrsym;
 #if LJ_TARGET_X64
   pehdr.nsyms += 1;  /* Symbol for lj_err_unwind_win64. */
 #endif
@@ -264,13 +251,13 @@ void emit_peobj(BuildCtx *ctx)
     PEreloc reloc;
     pdata[0] = 0; pdata[1] = (uint32_t)ctx->codesz; pdata[2] = 0;
     owrite(ctx, &pdata, sizeof(pdata));
-    reloc.vaddr = 0; reloc.symidx = 1+2+relocsyms+2+2+1;
+    reloc.vaddr = 0; reloc.symidx = 1+2+nrsym+2+2+1;
     reloc.type = PEOBJ_RELOC_ADDR32NB;
     owrite(ctx, &reloc, PEOBJ_RELOC_SIZE);
-    reloc.vaddr = 4; reloc.symidx = 1+2+relocsyms+2+2+1;
+    reloc.vaddr = 4; reloc.symidx = 1+2+nrsym+2+2+1;
     reloc.type = PEOBJ_RELOC_ADDR32NB;
     owrite(ctx, &reloc, PEOBJ_RELOC_SIZE);
-    reloc.vaddr = 8; reloc.symidx = 1+2+relocsyms+2;
+    reloc.vaddr = 8; reloc.symidx = 1+2+nrsym+2;
     reloc.type = PEOBJ_RELOC_ADDR32NB;
     owrite(ctx, &reloc, PEOBJ_RELOC_SIZE);
   }
@@ -287,7 +274,7 @@ void emit_peobj(BuildCtx *ctx)
     xdata[7] = 0;  /* Alignment. */
     xdata[8] = xdata[9] = 0;  /* Relocated address of exception handler. */
     owrite(ctx, &xdata, sizeof(xdata));
-    reloc.vaddr = sizeof(xdata)-4; reloc.symidx = 1+2+relocsyms+2+2;
+    reloc.vaddr = sizeof(xdata)-4; reloc.symidx = 1+2+nrsym+2+2;
     reloc.type = PEOBJ_RELOC_ADDR32NB;
     owrite(ctx, &reloc, PEOBJ_RELOC_SIZE);
   }
@@ -299,69 +286,28 @@ void emit_peobj(BuildCtx *ctx)
   /* Write symbol table. */
   strtab = NULL;  /* 1st pass: collect string sizes. */
   for (;;) {
-    char name[80];
-
     strtabofs = 4;
     /* Mark as SafeSEH compliant. */
     emit_peobj_sym(ctx, "@feat.00", 1,
                    PEOBJ_SECT_ABS, PEOBJ_TYPE_NULL, PEOBJ_SCL_STATIC);
 
     emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_TEXT);
-    for (i = 0; ctx->extnames[i]; i++) {
-      const char *sym = ctx->extnames[i];
-      const char *p = strchr(sym, '@');
-      if (p) {
-#ifdef PEOBJ_SYMF_PREFIX
-        sprintf(name, PEOBJ_SYMF_PREFIX "%s", sym);
-#else
-        strncpy(name, sym, p-sym);
-        name[p-sym] = '\0';
-#endif
-      } else {
-        sprintf(name, PEOBJ_SYM_PREFIX "%s", sym);
-      }
-      emit_peobj_sym(ctx, name, 0,
+    for (i = 0; i < nrsym; i++)
+      emit_peobj_sym(ctx, ctx->relocsym[i], 0,
                      PEOBJ_SECT_UNDEF, PEOBJ_TYPE_FUNC, PEOBJ_SCL_EXTERN);
-    }
 
 #if LJ_TARGET_X64
     emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_PDATA);
     emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_XDATA);
-    emit_peobj_sym(ctx, PEOBJ_SYM_PREFIX "lj_err_unwind_win64", 0,
+    emit_peobj_sym(ctx, "lj_err_unwind_win64", 0,
                    PEOBJ_SECT_UNDEF, PEOBJ_TYPE_FUNC, PEOBJ_SCL_EXTERN);
 #endif
 
-    emit_peobj_sym(ctx, PEOBJ_SYM_PREFIX LABEL_ASM_BEGIN, 0,
+    emit_peobj_sym(ctx, ctx->beginsym, 0,
                    PEOBJ_SECT_TEXT, PEOBJ_TYPE_NULL, PEOBJ_SCL_EXTERN);
-    for (i = nzsym; i < ctx->nsym; i++) {
-      int pi = ctx->perm[i];
-      if (pi >= ctx->npc) {
-        const char *sym = ctx->globnames[pi-ctx->npc];
-        const char *p = strchr(sym, '@');
-        if (p) {
-#ifdef PEOBJ_SYMF_PREFIX
-          sprintf(name, PEOBJ_SYMF_PREFIX LABEL_PREFIX "%s", sym);
-#else
-          sprintf(name, LABEL_PREFIX "%s", sym);
-          name[(p-sym)+sizeof(LABEL_PREFIX)-1] = '\0';
-#endif
-        } else {
-          sprintf(name, PEOBJ_SYM_PREFIX LABEL_PREFIX "%s", sym);
-        }
-        emit_peobj_sym_func(ctx, name, ctx->sym_ofs[pi]);
-#if LJ_HASJIT
-      } else {
-#else
-      } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                   pi == BC_JLOOP || pi == BC_JFUNCF || pi == BC_JFUNCV ||
-                   pi == BC_IFORL || pi == BC_IITERL || pi == BC_ILOOP ||
-                   pi == BC_IFUNCF || pi == BC_IFUNCV)) {
-#endif
-        sprintf(name, PEOBJ_SYM_PREFIX LABEL_PREFIX_BC "%s",
-                bc_names[pi]);
-        emit_peobj_sym_func(ctx, name, ctx->sym_ofs[pi]);
-      }
-    }
+    for (i = 0; i < ctx->nsym; i++)
+      emit_peobj_sym(ctx, ctx->sym[i].name, (uint32_t)ctx->sym[i].ofs,
+                     PEOBJ_SECT_TEXT, PEOBJ_TYPE_FUNC, PEOBJ_SCL_EXTERN);
 
     emit_peobj_sym_sect(ctx, pesect, PEOBJ_SECT_RDATA_Z);
 
diff --git a/src/buildvm_x64.h b/src/buildvm_x64.h
index b8d8f60a..747253fd 100644
--- a/src/buildvm_x64.h
+++ b/src/buildvm_x64.h
@@ -2403,50 +2403,33 @@ static void emit_asm_debug(BuildCtx *ctx)
         "\t.align " BSZPTR "\n"
         "LECIEX:\n\n");
     for (i = 0; i < ctx->nsym; i++) {
-      int pi = ctx->perm[i];
-      int ni = ctx->perm[i+1];
-      int size = ctx->sym_ofs[ni] - ctx->sym_ofs[pi];
-      if (ctx->sym_ofs[pi] >= 0 && size > 0) {
-        char name[80];
-        if (pi >= ctx->npc) {
-          char *p;
-          sprintf(name, "_" LABEL_PREFIX "%s", ctx->globnames[pi - ctx->npc]);
-          p = strchr(name, '@'); if (p) *p = '\0';
-#if LJ_HASJIT
-        } else {
-#else
-        } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                     pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
-                     pi == BC_ILOOP)) {
-#endif
-          sprintf(name, "_" LABEL_PREFIX_BC "%s", bc_names[pi]);
-        }
-        fprintf(ctx->fp,
-            "%s.eh:\n"
-            "LSFDE%d:\n"
-            "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
-            "\t.long L$set$%d\n"
-            "LASFDE%d:\n"
-            "\t.long LASFDE%d-EH_frame1\n"
-            "\t.long %s-.\n"
-            "\t.long %d\n"
-            "\t.byte 0\n"                       /* augmentation length */
-            "\t.byte 0xe\n\t.byte %d\n"         /* def_cfa_offset */
+      const char *name = ctx->sym[i].name;
+      int32_t size = ctx->sym[i+1].ofs - ctx->sym[i].ofs;
+      fprintf(ctx->fp,
+          "%s.eh:\n"
+          "LSFDE%d:\n"
+          "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
+          "\t.long L$set$%d\n"
+          "LASFDE%d:\n"
+          "\t.long LASFDE%d-EH_frame1\n"
+          "\t.long %s-.\n"
+          "\t.long %d\n"
+          "\t.byte 0\n"                 /* augmentation length */
+          "\t.byte 0xe\n\t.byte %d\n"           /* def_cfa_offset */
 #if LJ_64
-            "\t.byte 0x86\n\t.byte 0x2\n"       /* offset rbp */
-            "\t.byte 0x83\n\t.byte 0x3\n"       /* offset rbx */
-            "\t.byte 0x8f\n\t.byte 0x4\n"       /* offset r15 */
-            "\t.byte 0x8e\n\t.byte 0x5\n"       /* offset r14 */
+          "\t.byte 0x86\n\t.byte 0x2\n" /* offset rbp */
+          "\t.byte 0x83\n\t.byte 0x3\n" /* offset rbx */
+          "\t.byte 0x8f\n\t.byte 0x4\n" /* offset r15 */
+          "\t.byte 0x8e\n\t.byte 0x5\n" /* offset r14 */
 #else
-            "\t.byte 0x84\n\t.byte 0x2\n"       /* offset ebp (4 for MACH-O)*/
-            "\t.byte 0x87\n\t.byte 0x3\n"       /* offset edi */
-            "\t.byte 0x86\n\t.byte 0x4\n"       /* offset esi */
-            "\t.byte 0x83\n\t.byte 0x5\n"       /* offset ebx */
+          "\t.byte 0x84\n\t.byte 0x2\n" /* offset ebp (4 for MACH-O)*/
+          "\t.byte 0x87\n\t.byte 0x3\n" /* offset edi */
+          "\t.byte 0x86\n\t.byte 0x4\n" /* offset esi */
+          "\t.byte 0x83\n\t.byte 0x5\n" /* offset ebx */
 #endif
-            "\t.align " BSZPTR "\n"
-            "LEFDE%d:\n\n",
-            name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
-      }
+          "\t.align " BSZPTR "\n"
+          "LEFDE%d:\n\n",
+          name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
     }
 #if LJ_64
     fprintf(ctx->fp, "\t.subsections_via_symbols\n");
diff --git a/src/buildvm_x64win.h b/src/buildvm_x64win.h
index 7876c9b3..b5cc4679 100644
--- a/src/buildvm_x64win.h
+++ b/src/buildvm_x64win.h
@@ -2404,50 +2404,33 @@ static void emit_asm_debug(BuildCtx *ctx)
         "\t.align " BSZPTR "\n"
         "LECIEX:\n\n");
     for (i = 0; i < ctx->nsym; i++) {
-      int pi = ctx->perm[i];
-      int ni = ctx->perm[i+1];
-      int size = ctx->sym_ofs[ni] - ctx->sym_ofs[pi];
-      if (ctx->sym_ofs[pi] >= 0 && size > 0) {
-        char name[80];
-        if (pi >= ctx->npc) {
-          char *p;
-          sprintf(name, "_" LABEL_PREFIX "%s", ctx->globnames[pi - ctx->npc]);
-          p = strchr(name, '@'); if (p) *p = '\0';
-#if LJ_HASJIT
-        } else {
-#else
-        } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                     pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
-                     pi == BC_ILOOP)) {
-#endif
-          sprintf(name, "_" LABEL_PREFIX_BC "%s", bc_names[pi]);
-        }
-        fprintf(ctx->fp,
-            "%s.eh:\n"
-            "LSFDE%d:\n"
-            "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
-            "\t.long L$set$%d\n"
-            "LASFDE%d:\n"
-            "\t.long LASFDE%d-EH_frame1\n"
-            "\t.long %s-.\n"
-            "\t.long %d\n"
-            "\t.byte 0\n"                       /* augmentation length */
-            "\t.byte 0xe\n\t.byte %d\n"         /* def_cfa_offset */
+      const char *name = ctx->sym[i].name;
+      int32_t size = ctx->sym[i+1].ofs - ctx->sym[i].ofs;
+      fprintf(ctx->fp,
+          "%s.eh:\n"
+          "LSFDE%d:\n"
+          "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
+          "\t.long L$set$%d\n"
+          "LASFDE%d:\n"
+          "\t.long LASFDE%d-EH_frame1\n"
+          "\t.long %s-.\n"
+          "\t.long %d\n"
+          "\t.byte 0\n"                 /* augmentation length */
+          "\t.byte 0xe\n\t.byte %d\n"           /* def_cfa_offset */
 #if LJ_64
-            "\t.byte 0x86\n\t.byte 0x2\n"       /* offset rbp */
-            "\t.byte 0x83\n\t.byte 0x3\n"       /* offset rbx */
-            "\t.byte 0x8f\n\t.byte 0x4\n"       /* offset r15 */
-            "\t.byte 0x8e\n\t.byte 0x5\n"       /* offset r14 */
+          "\t.byte 0x86\n\t.byte 0x2\n" /* offset rbp */
+          "\t.byte 0x83\n\t.byte 0x3\n" /* offset rbx */
+          "\t.byte 0x8f\n\t.byte 0x4\n" /* offset r15 */
+          "\t.byte 0x8e\n\t.byte 0x5\n" /* offset r14 */
 #else
-            "\t.byte 0x84\n\t.byte 0x2\n"       /* offset ebp (4 for MACH-O)*/
-            "\t.byte 0x87\n\t.byte 0x3\n"       /* offset edi */
-            "\t.byte 0x86\n\t.byte 0x4\n"       /* offset esi */
-            "\t.byte 0x83\n\t.byte 0x5\n"       /* offset ebx */
+          "\t.byte 0x84\n\t.byte 0x2\n" /* offset ebp (4 for MACH-O)*/
+          "\t.byte 0x87\n\t.byte 0x3\n" /* offset edi */
+          "\t.byte 0x86\n\t.byte 0x4\n" /* offset esi */
+          "\t.byte 0x83\n\t.byte 0x5\n" /* offset ebx */
 #endif
-            "\t.align " BSZPTR "\n"
-            "LEFDE%d:\n\n",
-            name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
-      }
+          "\t.align " BSZPTR "\n"
+          "LEFDE%d:\n\n",
+          name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
     }
 #if LJ_64
     fprintf(ctx->fp, "\t.subsections_via_symbols\n");
diff --git a/src/buildvm_x86.dasc b/src/buildvm_x86.dasc
index e0a70daa..579e39da 100644
--- a/src/buildvm_x86.dasc
+++ b/src/buildvm_x86.dasc
@@ -5133,50 +5133,33 @@ static void emit_asm_debug(BuildCtx *ctx)
         "\t.align " BSZPTR "\n"
         "LECIEX:\n\n");
     for (i = 0; i < ctx->nsym; i++) {
-      int pi = ctx->perm[i];
-      int ni = ctx->perm[i+1];
-      int size = ctx->sym_ofs[ni] - ctx->sym_ofs[pi];
-      if (ctx->sym_ofs[pi] >= 0 && size > 0) {
-        char name[80];
-        if (pi >= ctx->npc) {
-          char *p;
-          sprintf(name, "_" LABEL_PREFIX "%s", ctx->globnames[pi - ctx->npc]);
-          p = strchr(name, '@'); if (p) *p = '\0';
-#if LJ_HASJIT
-        } else {
-#else
-        } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                     pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
-                     pi == BC_ILOOP)) {
-#endif
-          sprintf(name, "_" LABEL_PREFIX_BC "%s", bc_names[pi]);
-        }
-        fprintf(ctx->fp,
-            "%s.eh:\n"
-            "LSFDE%d:\n"
-            "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
-            "\t.long L$set$%d\n"
-            "LASFDE%d:\n"
-            "\t.long LASFDE%d-EH_frame1\n"
-            "\t.long %s-.\n"
-            "\t.long %d\n"
-            "\t.byte 0\n"                       /* augmentation length */
-            "\t.byte 0xe\n\t.byte %d\n"         /* def_cfa_offset */
+      const char *name = ctx->sym[i].name;
+      int32_t size = ctx->sym[i+1].ofs - ctx->sym[i].ofs;
+      fprintf(ctx->fp,
+          "%s.eh:\n"
+          "LSFDE%d:\n"
+          "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
+          "\t.long L$set$%d\n"
+          "LASFDE%d:\n"
+          "\t.long LASFDE%d-EH_frame1\n"
+          "\t.long %s-.\n"
+          "\t.long %d\n"
+          "\t.byte 0\n"                 /* augmentation length */
+          "\t.byte 0xe\n\t.byte %d\n"           /* def_cfa_offset */
 #if LJ_64
-            "\t.byte 0x86\n\t.byte 0x2\n"       /* offset rbp */
-            "\t.byte 0x83\n\t.byte 0x3\n"       /* offset rbx */
-            "\t.byte 0x8f\n\t.byte 0x4\n"       /* offset r15 */
-            "\t.byte 0x8e\n\t.byte 0x5\n"       /* offset r14 */
+          "\t.byte 0x86\n\t.byte 0x2\n" /* offset rbp */
+          "\t.byte 0x83\n\t.byte 0x3\n" /* offset rbx */
+          "\t.byte 0x8f\n\t.byte 0x4\n" /* offset r15 */
+          "\t.byte 0x8e\n\t.byte 0x5\n" /* offset r14 */
 #else
-            "\t.byte 0x84\n\t.byte 0x2\n"       /* offset ebp (4 for MACH-O)*/
-            "\t.byte 0x87\n\t.byte 0x3\n"       /* offset edi */
-            "\t.byte 0x86\n\t.byte 0x4\n"       /* offset esi */
-            "\t.byte 0x83\n\t.byte 0x5\n"       /* offset ebx */
+          "\t.byte 0x84\n\t.byte 0x2\n" /* offset ebp (4 for MACH-O)*/
+          "\t.byte 0x87\n\t.byte 0x3\n" /* offset edi */
+          "\t.byte 0x86\n\t.byte 0x4\n" /* offset esi */
+          "\t.byte 0x83\n\t.byte 0x5\n" /* offset ebx */
 #endif
-            "\t.align " BSZPTR "\n"
-            "LEFDE%d:\n\n",
-            name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
-      }
+          "\t.align " BSZPTR "\n"
+          "LEFDE%d:\n\n",
+          name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
     }
 #if LJ_64
     fprintf(ctx->fp, "\t.subsections_via_symbols\n");
diff --git a/src/buildvm_x86.h b/src/buildvm_x86.h
index fec4d3f9..c36e2aa5 100644
--- a/src/buildvm_x86.h
+++ b/src/buildvm_x86.h
@@ -2529,50 +2529,33 @@ static void emit_asm_debug(BuildCtx *ctx)
         "\t.align " BSZPTR "\n"
         "LECIEX:\n\n");
     for (i = 0; i < ctx->nsym; i++) {
-      int pi = ctx->perm[i];
-      int ni = ctx->perm[i+1];
-      int size = ctx->sym_ofs[ni] - ctx->sym_ofs[pi];
-      if (ctx->sym_ofs[pi] >= 0 && size > 0) {
-        char name[80];
-        if (pi >= ctx->npc) {
-          char *p;
-          sprintf(name, "_" LABEL_PREFIX "%s", ctx->globnames[pi - ctx->npc]);
-          p = strchr(name, '@'); if (p) *p = '\0';
-#if LJ_HASJIT
-        } else {
-#else
-        } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL ||
-                     pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
-                     pi == BC_ILOOP)) {
-#endif
-          sprintf(name, "_" LABEL_PREFIX_BC "%s", bc_names[pi]);
-        }
-        fprintf(ctx->fp,
-            "%s.eh:\n"
-            "LSFDE%d:\n"
-            "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
-            "\t.long L$set$%d\n"
-            "LASFDE%d:\n"
-            "\t.long LASFDE%d-EH_frame1\n"
-            "\t.long %s-.\n"
-            "\t.long %d\n"
-            "\t.byte 0\n"                       /* augmentation length */
-            "\t.byte 0xe\n\t.byte %d\n"         /* def_cfa_offset */
+      const char *name = ctx->sym[i].name;
+      int32_t size = ctx->sym[i+1].ofs - ctx->sym[i].ofs;
+      fprintf(ctx->fp,
+          "%s.eh:\n"
+          "LSFDE%d:\n"
+          "\t.set L$set$%d,LEFDE%d-LASFDE%d\n"
+          "\t.long L$set$%d\n"
+          "LASFDE%d:\n"
+          "\t.long LASFDE%d-EH_frame1\n"
+          "\t.long %s-.\n"
+          "\t.long %d\n"
+          "\t.byte 0\n"                 /* augmentation length */
+          "\t.byte 0xe\n\t.byte %d\n"           /* def_cfa_offset */
 #if LJ_64
-            "\t.byte 0x86\n\t.byte 0x2\n"       /* offset rbp */
-            "\t.byte 0x83\n\t.byte 0x3\n"       /* offset rbx */
-            "\t.byte 0x8f\n\t.byte 0x4\n"       /* offset r15 */
-            "\t.byte 0x8e\n\t.byte 0x5\n"       /* offset r14 */
+          "\t.byte 0x86\n\t.byte 0x2\n" /* offset rbp */
+          "\t.byte 0x83\n\t.byte 0x3\n" /* offset rbx */
+          "\t.byte 0x8f\n\t.byte 0x4\n" /* offset r15 */
+          "\t.byte 0x8e\n\t.byte 0x5\n" /* offset r14 */
 #else
-            "\t.byte 0x84\n\t.byte 0x2\n"       /* offset ebp (4 for MACH-O)*/
-            "\t.byte 0x87\n\t.byte 0x3\n"       /* offset edi */
-            "\t.byte 0x86\n\t.byte 0x4\n"       /* offset esi */
-            "\t.byte 0x83\n\t.byte 0x5\n"       /* offset ebx */
+          "\t.byte 0x84\n\t.byte 0x2\n" /* offset ebp (4 for MACH-O)*/
+          "\t.byte 0x87\n\t.byte 0x3\n" /* offset edi */
+          "\t.byte 0x86\n\t.byte 0x4\n" /* offset esi */
+          "\t.byte 0x83\n\t.byte 0x5\n" /* offset ebx */
 #endif
-            "\t.align " BSZPTR "\n"
-            "LEFDE%d:\n\n",
-            name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
-      }
+          "\t.align " BSZPTR "\n"
+          "LEFDE%d:\n\n",
+          name, i, i, i, i, i, i, i, name, size, CFRAME_SIZE, i);
     }
 #if LJ_64
     fprintf(ctx->fp, "\t.subsections_via_symbols\n");