[pushed] c++: designator and anon struct [PR101767]

Message ID 20220321204540.2408524-1-jason@redhat.com
State Committed
Commit e3e191b4104c7d6a177f66dbb77cabf05ab63781
Headers
Series [pushed] c++: designator and anon struct [PR101767] |

Commit Message

Jason Merrill March 21, 2022, 8:45 p.m. UTC
  We found .x in the anonymous struct, but then didn't find .y there; we
should decide that means we're done with the struct rather than that the
code is wrong.

Tested x86_64-pc-linux-gnu, applying to trunk.

	PR c++/101767

gcc/cp/ChangeLog:

	* decl.cc (reshape_init_class): Back out of anon struct
	if a designator doesn't match.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/anon-struct10.C: New test.
---
 gcc/cp/decl.cc                           |  5 +++++
 gcc/testsuite/g++.dg/ext/anon-struct10.C | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/ext/anon-struct10.C


base-commit: 70b8f43695b0e6fabc760d247ac83f354092b21d
  

Patch

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 8afda8264c4..375385e0013 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -6626,6 +6626,11 @@  reshape_init_class (tree type, reshape_iter *d, bool first_initializer_p,
 	      return error_mark_node;
 	    }
 
+	  if (!field && ANON_AGGR_TYPE_P (type))
+	    /* Apparently the designator isn't for a member of this anonymous
+	       struct, so head back to the enclosing class.  */
+	    break;
+
 	  if (!field || TREE_CODE (field) != FIELD_DECL)
 	    {
 	      if (complain & tf_error)
diff --git a/gcc/testsuite/g++.dg/ext/anon-struct10.C b/gcc/testsuite/g++.dg/ext/anon-struct10.C
new file mode 100644
index 00000000000..9b01bf3fada
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/anon-struct10.C
@@ -0,0 +1,21 @@ 
+// PR c++/101767
+// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-pedantic" }
+
+typedef struct {
+  struct {
+    int x;
+  };
+  union {
+    int y;
+    float z;
+  };
+} S;
+
+void foo(void)
+{
+  [[maybe_unused]] S a = {
+    .x = 1,
+    .y = 0
+  };
+}