Integrate MinGW build with DWARF2 exception handling.

Only works with DWARF2-enabled GCC 4.x (not the default MinGW GCC).
Fix fastcall symbol names for COFF assembler output.
Add DWARF2 unwind info to COFF assembler output.
Use COFF assembler mode for MinGW builds.
Always enable the DWARF2 handler if compiled with GCC.

1 files changed, 33 insertions, 27 deletions

diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c
index bd835ebc..2d0ba3b5 100644
--- a/src/buildvm_asm.c
+++ b/src/buildvm_asm.c
@@ -33,14 +33,14 @@ static void emit_asm_reloc(BuildCtx *ctx, int type, const char *sym)
       fprintf(ctx->fp, "\t.long %s\n", sym);
     break;
   case BUILD_coffasm:
-    fprintf(ctx->fp, "\t.def _%s; .scl 3; .type 32; .endef\n", sym);
+    fprintf(ctx->fp, "\t.def %s; .scl 3; .type 32; .endef\n", sym);
     if (type)
-      fprintf(ctx->fp, "\t.long _%s-.-4\n", sym);
+      fprintf(ctx->fp, "\t.long %s-.-4\n", sym);
     else
-      fprintf(ctx->fp, "\t.long _%s\n", sym);
+      fprintf(ctx->fp, "\t.long %s\n", sym);
     break;
   default:  /* BUILD_machasm for relative relocations handled below. */
-    fprintf(ctx->fp, "\t.long _%s\n", sym);
+    fprintf(ctx->fp, "\t.long %s\n", sym);
     break;
   }
 }
@@ -70,7 +70,7 @@ err:
     exit(1);
   }
   emit_asm_bytes(ctx, cp, n);
-  fprintf(ctx->fp, "\t%s _%s\n", opname, sym);
+  fprintf(ctx->fp, "\t%s %s\n", opname, sym);
 }
 
 /* Emit an assembler label. */
@@ -87,15 +87,15 @@ static void emit_asm_label(BuildCtx *ctx, const char *name, int size, int isfunc
       name, name, name, isfunc ? "function" : "object", name, size, name);
     break;
   case BUILD_coffasm:
-    fprintf(ctx->fp, "\n\t.globl _%s\n", name);
+    fprintf(ctx->fp, "\n\t.globl %s\n", name);
     if (isfunc)
-      fprintf(ctx->fp, "\t.def _%s; .scl 3; .type 32; .endef\n", name);
-    fprintf(ctx->fp, "_%s:\n", name);
+      fprintf(ctx->fp, "\t.def %s; .scl 3; .type 32; .endef\n", name);
+    fprintf(ctx->fp, "%s:\n", name);
     break;
   case BUILD_machasm:
     fprintf(ctx->fp,
-      "\n\t.private_extern _%s\n"
-      "_%s:\n", name, name);
+      "\n\t.private_extern %s\n"
+      "%s:\n", name, name);
     break;
   default:
     break;
@@ -126,13 +126,22 @@ 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
 
   fprintf(ctx->fp, "\t.file \"buildvm_%s.dasc\"\n", ctx->dasm_arch);
   fprintf(ctx->fp, "\t.text\n");
   emit_asm_align(ctx, 4);
 
-  emit_asm_label(ctx, LABEL_ASM_BEGIN, 0, 0);
-  if (ctx->mode == BUILD_elfasm)
+  sprintf(name, "%s" LABEL_ASM_BEGIN, symprefix);
+  emit_asm_label(ctx, name, 0, 0);
+  if (ctx->mode != BUILD_machasm)
     fprintf(ctx->fp, ".Lbegin:\n");
 
   i = 0;
@@ -148,10 +157,10 @@ void emit_asm(BuildCtx *ctx)
     int32_t stop = next;
     if (pi >= ctx->npc) {
       char *p;
-      sprintf(name, LABEL_PREFIX "%s", ctx->globnames[pi-ctx->npc]);
-      /* Always strip fastcall suffix. Wrong for (unused) COFF on Win32. */
+      sprintf(name, "%s" LABEL_PREFIX "%s", symprefix,
+              ctx->globnames[pi-ctx->npc]);
       p = strchr(name, '@');
-      if (p) *p = '\0';
+      if (p) { if (keepfc) name[0] = '@'; else *p = '\0'; }
       emit_asm_label(ctx, name, size, 1);
 #if LJ_HASJIT
     } else {
@@ -160,25 +169,21 @@ void emit_asm(BuildCtx *ctx)
                  pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL ||
                  pi == BC_ILOOP)) {
 #endif
-      sprintf(name, LABEL_PREFIX_BC "%s", bc_names[pi]);
+      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) {
       BuildReloc *r = &ctx->reloc[rel];
       int n = r->ofs - prev;
-      const char *sym = ctx->extnames[r->sym];
-      const char *p = strchr(sym, '@');
-      if (p) {
-        /* Always strip fastcall suffix. Wrong for (unused) COFF on Win32. */
-        strncpy(name, sym, p-sym);
-        name[p-sym] = '\0';
-        sym = name;
-      }
+      char *p;
+      sprintf(name, "%s%s", symprefix, ctx->extnames[r->sym]);
+      p = strchr(name, '@');
+      if (p) { if (keepfc) name[0] = '@'; else *p = '\0'; }
       if (ctx->mode == BUILD_machasm && r->type != 0) {
-        emit_asm_reloc_mach(ctx, ctx->code+prev, n, sym);
+        emit_asm_reloc_mach(ctx, ctx->code+prev, n, name);
       } else {
         emit_asm_bytes(ctx, ctx->code+prev, n);
-        emit_asm_reloc(ctx, r->type, sym);
+        emit_asm_reloc(ctx, r->type, name);
       }
       prev += n+4;
       rel++;
@@ -203,7 +208,8 @@ void emit_asm(BuildCtx *ctx)
   }
   emit_asm_align(ctx, 5);
 
-  emit_asm_label(ctx, LABEL_OP_OFS, 2*ctx->npc, 0);
+  sprintf(name, "%s" LABEL_OP_OFS, symprefix);
+  emit_asm_label(ctx, name, 2*ctx->npc, 0);
   for (i = 0; i < ctx->npc; i++)
     fprintf(ctx->fp, "\t.short %d\n", ctx->sym_ofs[i]);