DrSocalkwe3n/luajit
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x86/x64: Call external symbols directly from interpreter code.

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Except for ELF/x86 PIC, where it's easier to use wrappers.
This commit is contained in:
Mike Pall
2014-12-08 01:58:05 +01:00
parent f49c61a277
commit e03df1e339
7 changed files with 43 additions and 18 deletions
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1
src/host/buildvm.c
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@@ -179,6 +179,7 @@ static int build_code(BuildCtx *ctx)
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;

1
src/host/buildvm.h
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@@ -82,6 +82,7 @@ typedef struct BuildCtx {
const char *beginsym;
/* Strings generated by DynASM. */
const char *const *globnames;
const char *const *extnames;
const char *dasm_ident;
const char *dasm_arch;
/* Relocations. */

23
src/host/buildvm_asm.c
View File

@@ -51,8 +51,8 @@ static const char *const jccnames[] = {
"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,
/* Emit x86/x64 text relocations. */
static void emit_asm_reloc_text(BuildCtx *ctx, uint8_t *cp, int n,
const char *sym)
{
const char *opname = NULL;
@@ -71,6 +71,20 @@ err:
exit(1);
}
emit_asm_bytes(ctx, cp, n);
if (strncmp(sym+(*sym == '_'), LABEL_PREFIX, sizeof(LABEL_PREFIX)-1)) {
/* Various fixups for external symbols outside of our binary. */
if (ctx->mode == BUILD_elfasm) {
if (LJ_32)
fprintf(ctx->fp, "#if __PIC__\n\t%s lj_wrap_%s\n#else\n", opname, sym);
fprintf(ctx->fp, "\t%s %s@PLT\n", opname, sym);
if (LJ_32)
fprintf(ctx->fp, "#endif\n");
return;
} else if (LJ_32 && ctx->mode == BUILD_machasm) {
fprintf(ctx->fp, "\t%s L%s$stub\n", opname, sym);
return;
}
}
fprintf(ctx->fp, "\t%s %s\n", opname, sym);
}
#else
@@ -254,8 +268,9 @@ void emit_asm(BuildCtx *ctx)
BuildReloc *r = &ctx->reloc[rel];
int n = r->ofs - ofs;
#if LJ_TARGET_X86ORX64
if (ctx->mode == BUILD_machasm && r->type != 0) {
emit_asm_reloc_mach(ctx, ctx->code+ofs, n, ctx->relocsym[r->sym]);
if (r->type != 0 &&
(ctx->mode == BUILD_elfasm || ctx->mode == BUILD_machasm)) {
emit_asm_reloc_text(ctx, ctx->code+ofs, n, ctx->relocsym[r->sym]);
} else {
emit_asm_bytes(ctx, ctx->code+ofs, n);
emit_asm_reloc(ctx, r->type, ctx->relocsym[r->sym]);