Add support of asm label for functions.

Add support for asm labels for functions, that is the ability to rename
a function at assembly level with __asm__ ("newname") appended in
function declaration.

libtcc.c

@@ -72,6 +72,12 @@ ST_DATA void *rt_prog_main;
 #endif /* ALL_IN_ONE */
 
 /********************************************************/
+#ifndef CONFIG_TCC_ASM_LABEL
+ST_FUNC void asm_label_instr(CString *)
+{
+    error("inline asm() not supported");
+}
+#endif
 #ifndef CONFIG_TCC_ASM
 ST_FUNC void asm_instr(void)
 {
@@ -436,7 +442,10 @@ ST_FUNC void put_extern_sym2(Sym *sym, Section *section,
     }
 
     if (!sym->c) {
-        name = get_tok_str(sym->v, NULL);
+        if (sym->a)
+          name = get_tok_str(sym->a, NULL);
+        else
+          name = get_tok_str(sym->v, NULL);
 #ifdef CONFIG_TCC_BCHECK
         if (tcc_state->do_bounds_check) {
             char buf[32];

tcc.h

@@ -118,6 +118,7 @@
 #if !defined(TCC_TARGET_ARM) && !defined(TCC_TARGET_C67)
 #define CONFIG_TCC_ASM
 #endif
+#define CONFIG_TCC_ASM_LABEL
 
 /* object format selection */
 #if defined(TCC_TARGET_C67)
@@ -211,6 +212,7 @@ typedef struct SValue {
 /* symbol management */
 typedef struct Sym {
     int v;    /* symbol token */
+    int a;    /* asm symbol token */
     long r;    /* associated register */
     union {
         long c;    /* associated number */
@@ -1189,6 +1191,7 @@ ST_FUNC int tcc_load_coff(TCCState * s1, int fd);
 
 /* ------------ tccasm.c ------------ */
 ST_FUNC void asm_instr(void);
+ST_FUNC void asm_label_instr(CString *);
 ST_FUNC void asm_global_instr(void);
 
 #ifdef CONFIG_TCC_ASM

tccasm.c

@@ -18,6 +18,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#ifdef CONFIG_TCC_ASM
+
 #include "tcc.h"
 
 ST_FUNC int asm_get_local_label_name(TCCState *s1, unsigned int n)
@@ -991,6 +993,8 @@ static void parse_asm_operands(ASMOperand *operands, int *nb_operands_ptr,
     }
 }
 
+#endif
+
 static void parse_asm_str(CString *astr)
 {
     skip('(');
@@ -1006,6 +1010,20 @@ static void parse_asm_str(CString *astr)
     cstr_ccat(astr, '\0');
 }
 
+/* Parse an asm label and return the label
+ * Don't forget to free the CString in the caller! */
+static void asm_label_instr(CString *astr)
+{
+    next();
+    parse_asm_str(astr);
+    skip(')');
+#ifdef ASM_DEBUG
+    printf("asm_alias: \"%s\"\n", (char *)astr->data);
+#endif
+}
+
+#ifdef CONFIG_TCC_ASM
+
 /* parse the GCC asm() instruction */
 ST_FUNC void asm_instr(void)
 {
@@ -1136,3 +1154,5 @@ ST_FUNC void asm_global_instr(void)
 
     cstr_free(&astr);
 }
+
+#endif

tccgen.c

@@ -136,6 +136,7 @@ ST_FUNC Sym *sym_push2(Sym **ps, int v, int t, long c)
 {
     Sym *s;
     s = sym_malloc();
+    s->a = 0;
     s->v = v;
     s->type.t = t;
     s->type.ref = NULL;
@@ -368,6 +369,8 @@ static Sym *external_sym(int v, CType *type, int r)
     if (!s) {
         /* push forward reference */
         s = sym_push(v, type, r | VT_CONST | VT_SYM, 0);
+        if (type && type->ref && type->ref->a)
+            s->a = type->ref->a;
         s->type.t |= VT_EXTERN;
     } else if (s->type.ref == func_old_type.ref) {
         s->type.ref = type->ref;
@@ -2996,6 +2999,8 @@ static void post_type(CType *type, AttributeDef *ad)
     CType pt;
 
     if (tok == '(') {
+        TokenSym *ts = NULL;
+
         /* function declaration */
         next();
         l = 0;
@@ -3051,10 +3056,19 @@ static void post_type(CType *type, AttributeDef *ad)
         /* NOTE: const is ignored in returned type as it has a special
            meaning in gcc / C++ */
         type->t &= ~(VT_STORAGE | VT_CONSTANT); 
+        if (tok == TOK_ASM1 || tok == TOK_ASM2 || tok == TOK_ASM3) {
+          CString astr;
+
+          asm_label_instr(&astr);
+          ts = tok_alloc(astr.data, strlen(astr.data));
+          cstr_free(&astr);
+        }
         post_type(type, ad);
         /* we push a anonymous symbol which will contain the function prototype */
         ad->func_args = arg_size;
         s = sym_push(SYM_FIELD, type, INT_ATTR(ad), l);
+        if (ts != NULL)
+          s->a = ts->tok;
         s->next = first;
         type->t = t1 | VT_FUNC;
         type->ref = s;
@@ -5228,7 +5242,10 @@ static void gen_function(Sym *sym)
     ind = cur_text_section->data_offset;
     /* NOTE: we patch the symbol size later */
     put_extern_sym(sym, cur_text_section, ind, 0);
-    funcname = get_tok_str(sym->v, NULL);
+    if (sym->a)
+      funcname = get_tok_str(sym->a, NULL);
+    else
+      funcname = get_tok_str(sym->v, NULL);
     func_ind = ind;
     /* put debug symbol */
     if (tcc_state->do_debug)
@@ -5308,6 +5325,12 @@ ST_FUNC void decl(int l)
     Sym *sym;
     AttributeDef ad;
     
+    /* 
+     *  type.ref must be either a valid reference or NULL for external_sym to
+     *  work. As type = btype is executed before external_sym is call, setting
+     *  btype.ref to 0 is enough.
+     */
+    btype.ref = 0;
     while (1) {
         if (!parse_btype(&btype, &ad)) {
             /* skip redundant ';' */