Fix regression causing ICE for structs with VLAs [PR 112488]

A previous patch that fixed several ICEs related to size expressions
of VM types (PR c/70418, ...) caused a regression for structs where
a DECL_EXPR is not generated anymore although reqired.  We now call
add_decl_expr introduced by the previous patch from finish_struct.
The function is revised with a new argument to not set the TYPE_NAME
for the type to the DECL_EXPR in this specific case.

	PR c/112488

gcc/c
	* c-decl.cc (add_decl_expr): Revise.
	(finish_struct): Create DECL_EXPR.
	* c-parser.cc (c_parser_struct_or_union_specifier): Call
	finish_struct with expression for VLA sizes.
	* c-tree.h (finish_struct): Add argument.

gcc/testsuite
	* gcc.dg/pr112488-1.c: New test.
	* gcc.dg/pr112488-2.c: New test.
	* gcc.dg/pr112898.c: New test.
	* gcc.misc-tests/gcov-pr85350.c: Adapt.

diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 92c83e1bf10de1ee627d0e562835079a212af725..039a66fef09c28629817f06b904813f96d349d30 100644 (file)
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -6618,12 +6618,10 @@ smallest_type_quals_location (const location_t *locations,
    the size evaluation prior to the side effects.  We therefore
    use BIND_EXPRs in TYPENAME contexts too.  */
 static void
-add_decl_expr (location_t loc, enum decl_context decl_context, tree type,
-              tree *expr)
+add_decl_expr (location_t loc, tree type, tree *expr, bool set_name_p)
 {
   tree bind = NULL_TREE;
-  if (decl_context == TYPENAME || decl_context == PARM
-      || decl_context == FIELD)
+  if (expr)
     {
       bind = build3 (BIND_EXPR, void_type_node, NULL_TREE, NULL_TREE,
                     NULL_TREE);
@@ -6636,7 +6634,8 @@ add_decl_expr (location_t loc, enum decl_context decl_context, tree type,
   pushdecl (decl);
   DECL_ARTIFICIAL (decl) = 1;
   add_stmt (build_stmt (DECL_SOURCE_LOCATION (decl), DECL_EXPR, decl));
-  TYPE_NAME (type) = decl;
+  if (set_name_p)
+    TYPE_NAME (type) = decl;
 
   if (bind)
     {
@@ -7635,7 +7634,12 @@ grokdeclarator (const struct c_declarator *declarator,
               type has a name/declaration of it's own, but special attention
               is required if the type is anonymous. */
            if (!TYPE_NAME (type) && c_type_variably_modified_p (type))
-             add_decl_expr (loc, decl_context, type, expr);
+             {
+               bool bind_p = decl_context == TYPENAME
+                             || decl_context == FIELD
+                             || decl_context == PARM;
+               add_decl_expr (loc, type, bind_p ? expr : NULL, true);
+             }
 
            type = c_build_pointer_type (type);
 
@@ -7900,7 +7904,12 @@ grokdeclarator (const struct c_declarator *declarator,
 
            /* The pointed-to type may need a decl expr (see above).  */
            if (!TYPE_NAME (type) && c_type_variably_modified_p (type))
-             add_decl_expr (loc, decl_context, type, expr);
+             {
+               bool bind_p = decl_context == TYPENAME
+                             || decl_context == FIELD
+                             || decl_context == PARM;
+               add_decl_expr (loc, type, bind_p ? expr : NULL, true);
+             }
 
            type = c_build_pointer_type (type);
            type_quals = array_ptr_quals;
@@ -9257,7 +9266,8 @@ is_flexible_array_member_p (bool is_last_field,
 
 tree
 finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
-              class c_struct_parse_info *enclosing_struct_parse_info)
+              class c_struct_parse_info *enclosing_struct_parse_info,
+              tree *expr)
 {
   tree x;
   bool toplevel = file_scope == current_scope;
@@ -9595,6 +9605,13 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
 
   finish_incomplete_vars (incomplete_vars, toplevel);
 
+  /* Make sure a DECL_EXPR is created for structs with VLA members.
+     Because we do not know the context, we always pass expr
+     to force creation of a BIND_EXPR which is required in some
+     contexts.  */
+  if (c_type_variably_modified_p (t))
+    add_decl_expr (loc, t, expr, false);
+
   if (warn_cxx_compat)
     warn_cxx_compat_finish_struct (fieldlist, TREE_CODE (t), loc);
 

diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 5700ccccc4930e8a95c2228a01c395b2f6fd7f6b..0c301015d8803ae750dfb10a6095615a24a7ed87 100644 (file)
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -4087,7 +4087,7 @@ c_parser_struct_or_union_specifier (c_parser *parser)
       ret.spec = finish_struct (struct_loc, type, nreverse (contents),
                                chainon (std_attrs,
                                         chainon (attrs, postfix_attrs)),
-                               struct_info);
+                               struct_info, &expr);
       ret.kind = ctsk_tagdef;
       ret.expr = expr;
       ret.expr_const_operands = true;

diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
index d0bdc3df2c2c2205052cc9478887eb4c0aeab348..b325723a7345d502d8d8a539331747c7ee93709c 100644 (file)
--- a/gcc/c/c-tree.h
+++ b/gcc/c/c-tree.h
@@ -656,7 +656,8 @@ extern void finish_decl (tree, location_t, tree, tree, tree);
 extern tree finish_enum (tree, tree, tree);
 extern void finish_function (location_t = input_location);
 extern tree finish_struct (location_t, tree, tree, tree,
-                          class c_struct_parse_info *);
+                          class c_struct_parse_info *,
+                          tree *expr = NULL);
 extern tree c_simulate_enum_decl (location_t, const char *,
                                  vec<string_int_pair> *);
 extern tree c_simulate_record_decl (location_t, const char *,

diff --git a/gcc/testsuite/gcc.dg/pr112488-1.c b/gcc/testsuite/gcc.dg/pr112488-1.c
new file mode 100644 (file)
index 0000000..b53295c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112488-1.c
@@ -0,0 +1,14 @@
+/* { dg-do compile }
+ * { dg-options "-O1" } */
+
+extern void abort(void);
+
+int test(int *n) {
+  struct T { char a[*n], b[*n]; };
+  return sizeof(struct T) - sizeof(struct T);
+}
+
+void f1(int *p) {
+  if (!test(p)) abort();
+}
+

diff --git a/gcc/testsuite/gcc.dg/pr112488-2.c b/gcc/testsuite/gcc.dg/pr112488-2.c
new file mode 100644 (file)
index 0000000..3f0fc43
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112488-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile }
+ * { dg-options "-std=gnu23 -O1" } */
+
+extern void abort(void);
+
+int test(int *n, struct T { char a[*n], b[*n]; }*) {   /* { dg-warning "declared inside parameter list" } */
+  return sizeof(struct T) - sizeof(struct T);
+}
+
+void f1(int *p) {
+  if (test(p, 0)) abort();
+}
+

diff --git a/gcc/testsuite/gcc.dg/pr112898.c b/gcc/testsuite/gcc.dg/pr112898.c
new file mode 100644 (file)
index 0000000..395f3af
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112898.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } 
+   { dg-options "-O2 -finstrument-functions-once" } */
+
+void func(int n)
+{
+        struct T { int x[n]; };
+       struct T *t = __builtin_malloc(sizeof *t);
+}
+

diff --git a/gcc/testsuite/gcc.misc-tests/gcov-pr85350.c b/gcc/testsuite/gcc.misc-tests/gcov-pr85350.c
index a42bf1282b2f8ac3eb03c8f87216041cc2eb3ddd..0383b81fdfb6c3d101e940d3ff9fea80ad9f21c2 100644 (file)
--- a/gcc/testsuite/gcc.misc-tests/gcov-pr85350.c
+++ b/gcc/testsuite/gcc.misc-tests/gcov-pr85350.c
@@ -4,7 +4,7 @@
 int main (void)
 {
   const int t = 2; /* count(1) */
-  struct s1 {  /* count(-) */
+  struct s1 {  /* count(1) */
     int x;
     int g[t];
   };