From a94e8d439acbaa1634e59420749ffdb7ee15e353 Mon Sep 17 00:00:00 2001
From: grischka <grischka>
Date: Fri, 6 May 2016 08:32:54 +0200
Subject: [PATCH] tccgen: scopes levels for local symbols (update 2)

allow
    typedef int xxx;
    typedef int xxx;
in the same scope as long as it is the same type
---
 tccgen.c          | 25 ++++++++++++++-----------
 tests/Makefile    |  1 +
 tests/pp/Makefile | 12 ++++++------
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/tccgen.c b/tccgen.c
index 6954d3a..7842309 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2927,13 +2927,10 @@ static void struct_decl(CType *type, AttributeDef *ad, int u)
         if (v < TOK_IDENT)
             expect("struct/union/enum name");
         s = struct_find(v);
-        if (s && s->type.t == a) {
-            if (0 == local_scope)
-                goto do_decl; /* compatibility with past behavior */
-            if (tok != '{' && tok != ';')
-                goto do_decl; /* variable declaration: 'struct s x;' */
-            if (s->scope == local_scope && (s->c == -1 || tok != '{'))
-                goto do_decl; /* at least one must be incomplete type */
+        if (s && (s->scope == local_scope || (tok != '{' && tok != ';'))) {
+            if (s->type.t != a)
+                tcc_error("redefinition of '%s'", get_tok_str(v, NULL));
+            goto do_decl;
         }
     } else {
         v = anon_sym++;
@@ -3435,8 +3432,6 @@ static void post_type(CType *type, AttributeDef *ad)
         plast = &first;
         arg_size = 0;
         if (tok != ')') {
-            int ls = local_scope;
-            local_scope = 1; /* for struct decl inside function params */
             for(;;) {
                 /* read param name and compute offset */
                 if (l != FUNC_OLD) {
@@ -3476,7 +3471,6 @@ static void post_type(CType *type, AttributeDef *ad)
                     break;
                 }
             }
-            local_scope = ls;
         }
         /* if no parameters, then old type prototype */
         if (l == 0)
@@ -6434,7 +6428,16 @@ static int decl0(int l, int is_for_loop_init)
                 if (btype.t & VT_TYPEDEF) {
                     /* save typedefed type  */
                     /* XXX: test storage specifiers ? */
-                    sym = sym_push(v, &type, 0, 0);
+                    sym = sym_find(v);
+                    if (sym && sym->scope == local_scope) {
+                        if (!is_compatible_types(&sym->type, &type)
+                            || !(sym->type.t & VT_TYPEDEF))
+                            tcc_error("incompatible redefinition of '%s'",
+                                get_tok_str(v, NULL));
+                        sym->type = type;
+                    } else {
+                        sym = sym_push(v, &type, 0, 0);
+                    }
                     sym->a = ad.a;
                     sym->type.t |= VT_TYPEDEF;
                 } else {
diff --git a/tests/Makefile b/tests/Makefile
index e9f173b..cf817ad 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -250,6 +250,7 @@ cache: tcc_g
 # clean
 clean:
 	$(MAKE) -C tests2 $@
+	$(MAKE) -C pp $@
 	rm -vf *~ *.o *.a *.bin *.i *.ref *.out *.out? *.out?b *.cc \
 		*-cc *-tcc *.exe \
 		hello libtcc_test vla_test tcctest[1234] ex? tcc_g
diff --git a/tests/pp/Makefile b/tests/pp/Makefile
index 7f42a3e..ad97f9b 100644
--- a/tests/pp/Makefile
+++ b/tests/pp/Makefile
@@ -8,16 +8,18 @@ TESTS += $(patsubst %.S,%.test,$(wildcard *.S))
 
 all test : $(sort $(TESTS))
 
+DIFF_OPTS = -Nu -b -B -I "^\#"
+
 %.test: %.c %.expect
 	@echo PPTest $* ...
 	-@$(TCC) -E -P $< >$*.output 2>&1 ; \
-	    diff -Nu -b -B -I "^#" $(EXTRA_DIFF_OPTS) $*.expect $*.output \
+	    diff $(DIFF_OPTS) $*.expect $*.output \
 	    && rm -f $*.output
 
 %.test: %.S %.expect
 	@echo PPTest $* ...
 	-@$(TCC) -E -P $< >$*.output 2>&1 ; \
-	    diff -Nu -b -B -I "^#" $(EXTRA_DIFF_OPTS) $*.expect $*.output \
+	    diff $(DIFF_OPTS) $*.expect $*.output \
 	    && rm -f $*.output
 
 # automatically generate .expect files with gcc:
@@ -33,10 +35,8 @@ all test : $(sort $(TESTS))
 clean:
 	rm -vf *.output
 
-# 02.test : EXTRA_DIFF_OPTS = -w
-# 03.test : EXTRA_DIFF_OPTS = -w
-# 04.test : EXTRA_DIFF_OPTS = -w
-# 10.test : EXTRA_DIFF_OPTS = -w
+02.test : DIFF_OPTS += -w
+15.test : DIFF_OPTS += -w
 
 # diff options:
 # -b ighore space changes