tccpp: fix bug in handling of recursive macros

3 files changed, 47 insertions, 2 deletions

diff --git a/tcc.h b/tcc.h
index 7d42607..a3a9c78 100644
--- a/tcc.h
+++ b/tcc.h
@@ -683,6 +683,7 @@ struct TCCState {
 #define TOK_DOTS     0xcc /* three dots */
 #define TOK_SHR      0xcd /* unsigned shift right */
 #define TOK_PPNUM    0xce /* preprocessor number */
+#define TOK_NOSUBST  0xcf /* means following token has already been pp'd */
 
 #define TOK_SHL   0x01 /* shift left */
 #define TOK_SAR   0x02 /* signed shift right */
diff --git a/tccpp.c b/tccpp.c
index c461ff8..27f9870 100644
--- a/tccpp.c
+++ b/tccpp.c
@@ -2797,7 +2797,8 @@ static inline int *macro_twosharps(const int *macro_str)
         if (tok == TOK_TWOSHARPS)
             continue;
         while (*ptr == TOK_TWOSHARPS) {
-            t = *++ptr;
+            do { t = *++ptr; } while (t == TOK_NOSUBST);
+            
             if (t && t != TOK_TWOSHARPS) {
                 TOK_GET(&t, &ptr, &cval);
 
@@ -2856,11 +2857,20 @@ static void macro_subst(TokenString *tok_str, Sym **nested_list,
         TOK_GET(&t, &ptr, &cval);
         if (t == 0)
             break;
+        if (t == TOK_NOSUBST) {
+            /* following token has already been subst'd. just copy it on */
+            tok_str_add2(tok_str, TOK_NOSUBST, NULL);
+            TOK_GET(&t, &ptr, &cval);
+            goto no_subst;
+        }
         s = define_find(t);
         if (s != NULL) {
             /* if nested substitution, do nothing */
-            if (sym_find2(*nested_list, t))
+            if (sym_find2(*nested_list, t)) {
+                /* and mark it as TOK_NOSUBST, so it doesn't get subst'd again */
+                tok_str_add2(tok_str, TOK_NOSUBST, NULL);
                 goto no_subst;
+            }
             ml.p = macro_ptr;
             if (can_read_stream)
                 ml.prev = *can_read_stream, *can_read_stream = &ml;
@@ -2928,6 +2938,9 @@ ST_FUNC void next(void)
                 macro_ptr = NULL;
             }
             goto redo;
+        } else if (tok == TOK_NOSUBST) {
+            /* discard preprocessor's nosubst markers */
+            goto redo;
         }
     }
     
diff --git a/tests/tcctest.c b/tests/tcctest.c
index 0128957..f62983d 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -45,6 +45,7 @@
 void string_test();
 void expr_test();
 void macro_test();
+void recursive_macro_test();
 void scope_test();
 void forward_test();
 void funcptr_test();
@@ -281,6 +282,35 @@ comment
     TEST2();
 }
 
+
+static void print_num(char *fn, int line, int num) {
+    printf("fn %s, line %d, num %d\n", fn, line, num);
+}
+
+void recursive_macro_test(void)
+{
+#if 0 /* doesnt work yet */
+#define ELF32_ST_TYPE(val)              ((val) & 0xf)
+#define ELF32_ST_INFO(bind, type)       (((bind) << 4) + ((type) & 0xf))
+#define STB_WEAK        2               /* Weak symbol */
+#define ELFW(type) ELF##32##_##type
+    printf("%d\n", ELFW(ST_INFO)(STB_WEAK, ELFW(ST_TYPE)(123)));
+#endif
+
+#define WRAP(x) x
+    
+#define print_num(x) print_num(__FILE__,__LINE__,x)
+    print_num(123);
+    WRAP(print_num(123));
+    WRAP(WRAP(print_num(123)));
+
+static struct recursive_macro { int rm_field; } G;
+#define rm_field (G.rm_field)
+    printf("rm_field = %d\n", rm_field);
+    printf("rm_field = %d\n", WRAP(rm_field));
+    WRAP((printf("rm_field = %d %d\n", rm_field, WRAP(rm_field))));
+}
+
 int op(a,b)
 {
     return a / b;
@@ -501,6 +531,7 @@ int main(int argc, char **argv)
     string_test();
     expr_test();
     macro_test();
+    recursive_macro_test();
     scope_test();
     forward_test();
     funcptr_test();