1 files changed, 220 insertions, 0 deletions

diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c
new file mode 100644
index 00000000..e6972bd5
--- /dev/null
+++ b/src/buildvm_asm.c
@@ -0,0 +1,220 @@
+/*
+** LuaJIT VM builder: Assembler source code emitter.
+** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#include "buildvm.h"
+#include "lj_bc.h"
+
+/* ------------------------------------------------------------------------ */
+
+/* Emit bytes piecewise as assembler text. */
+static void emit_asm_bytes(BuildCtx *ctx, uint8_t *p, int n)
+{
+  int i;
+  for (i = 0; i < n; i++) {
+    if ((i & 15) == 0)
+      fprintf(ctx->fp, "\t.byte %d", p[i]);
+    else
+      fprintf(ctx->fp, ",%d", p[i]);
+    if ((i & 15) == 15) putc('\n', ctx->fp);
+  }
+  if ((n & 15) != 0) putc('\n', ctx->fp);
+}
+
+/* Emit relocation */
+static void emit_asm_reloc(BuildCtx *ctx, BuildReloc *r)
+{
+  const char *sym = ctx->extnames[r->sym];
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+    if (r->type)
+      fprintf(ctx->fp, "\t.long %s-.-4\n", sym);
+    else
+      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);
+    if (r->type)
+      fprintf(ctx->fp, "\t.long _%s-.-4\n", sym);
+    else
+      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);
+    break;
+  }
+}
+
+static const char *const jccnames[] = {
+  "jo", "jno", "jb", "jnb", "jz", "jnz", "jbe", "ja",
+  "js", "jns", "jpe", "jpo", "jl", "jge", "jle", "jg"
+};
+
+/* Emit relocation for the incredibly stupid OSX assembler. */
+static void emit_asm_reloc_mach(BuildCtx *ctx, uint8_t *cp, int n,
+                                const char *sym)
+{
+  const char *opname = NULL;
+  if (--n < 0) goto err;
+  if (cp[n] == 0xe8) {
+    opname = "call";
+  } else if (cp[n] == 0xe9) {
+    opname = "jmp";
+  } else if (cp[n] >= 0x80 && cp[n] <= 0x8f && n > 0 && cp[n-1] == 0x0f) {
+    opname = jccnames[cp[n]-0x80];
+    n--;
+  } else {
+err:
+    fprintf(stderr, "Error: unsupported opcode for %s symbol relocation.\n",
+            sym);
+    exit(1);
+  }
+  emit_asm_bytes(ctx, cp, n);
+  if (!strncmp(sym, LABEL_PREFIX, sizeof(LABEL_PREFIX)-1))
+    fprintf(ctx->fp, "\t%s _%s\n", opname, sym);
+  else
+    fprintf(ctx->fp, "\t%s _" LABEL_PREFIX "wrapper_%s\n", opname, sym);
+}
+
+/* Emit an assembler label. */
+static void emit_asm_label(BuildCtx *ctx, const char *name, int size, int isfunc)
+{
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+    fprintf(ctx->fp,
+      "\n\t.globl %s\n"
+      "\t.hidden %s\n"
+      "\t.type %s, @%s\n"
+      "\t.size %s, %d\n"
+      "%s:\n",
+      name, name, name, isfunc ? "function" : "object", name, size, name);
+    break;
+  case BUILD_coffasm:
+    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);
+    break;
+  case BUILD_machasm:
+    fprintf(ctx->fp,
+      "\n\t.private_extern _%s\n"
+      "_%s:\n", name, name);
+    break;
+  default:
+    break;
+  }
+}
+
+/* Emit alignment. */
+static void emit_asm_align(BuildCtx *ctx, int bits)
+{
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+  case BUILD_coffasm:
+    fprintf(ctx->fp, "\t.p2align %d\n", bits);
+    break;
+  case BUILD_machasm:
+    fprintf(ctx->fp, "\t.align %d\n", bits);
+    break;
+  default:
+    break;
+  }
+}
+
+/* ------------------------------------------------------------------------ */
+
+/* Emit assembler source code. */
+void emit_asm(BuildCtx *ctx)
+{
+  char name[80];
+  int32_t prev;
+  int i, pi, rel;
+
+  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, 1);
+  if (ctx->mode == BUILD_elfasm)
+    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) {
+      sprintf(name, LABEL_PREFIX "%s", ctx->globnames[pi-ctx->npc]);
+      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, LABEL_PREFIX_BC "%s", bc_names[pi]);
+      emit_asm_label(ctx, name, size, 1);
+    }
+    while (rel < ctx->nreloc && ctx->reloc[rel].ofs < stop) {
+      int n = ctx->reloc[rel].ofs - prev;
+      if (ctx->mode == BUILD_machasm && ctx->reloc[rel].type != 0) {
+        emit_asm_reloc_mach(ctx, ctx->code+prev, n,
+                            ctx->extnames[ctx->reloc[rel].sym]);
+      } else {
+        emit_asm_bytes(ctx, ctx->code+prev, n);
+        emit_asm_reloc(ctx, &ctx->reloc[rel]);
+      }
+      prev += n+4;
+      rel++;
+    }
+    emit_asm_bytes(ctx, ctx->code+prev, stop-prev);
+    prev = next;
+    pi = ni;
+  }
+
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+    fprintf(ctx->fp, "\n\t.section .rodata\n");
+    break;
+  case BUILD_coffasm:
+    fprintf(ctx->fp, "\n\t.section .rdata,\"dr\"\n");
+    break;
+  case BUILD_machasm:
+    fprintf(ctx->fp, "\n\t.const\n");
+    break;
+  default:
+    break;
+  }
+  emit_asm_align(ctx, 5);
+
+  emit_asm_label(ctx, LABEL_OP_OFS, 2*ctx->npc, 0);
+  for (i = 0; i < ctx->npc; i++)
+    fprintf(ctx->fp, "\t.short %d\n", ctx->sym_ofs[i]);
+
+  fprintf(ctx->fp, "\n");
+  switch (ctx->mode) {
+  case BUILD_elfasm:
+    fprintf(ctx->fp, "\t.section .note.GNU-stack,\"\",@progbits\n");
+    /* fallthrough */
+  case BUILD_coffasm:
+    fprintf(ctx->fp, "\t.ident \"%s\"\n", ctx->dasm_ident);
+    break;
+  case BUILD_machasm:
+    fprintf(ctx->fp,
+      "\t.cstring\n"
+      "\t.ascii \"%s\\0\"\n", ctx->dasm_ident);
+    break;
+  default:
+    break;
+  }
+  fprintf(ctx->fp, "\n");
+}
+