re PR c/17188 (struct Foo { } redefinition)

	PR c/17188
	* c-decl.c (diagnose_mismatched_decls): Check for duplicate
	declarations of enumerators.
	(start_struct): Check TYPE_SIZE rather than TYPE_FIELDS to check
	for redefinition.  Check for nested redefinition.
	(finish_struct): Don't check for nested redefinition.
	(start_enum): Check for nested redefinition.

testsuite:
	* gcc.dg/nested-redef-1.c, gcc.dg/pr17188-1.c: New tests.
	* gcc.dg/decl-3.c: Adjust expected message.

From-SVN: r88063

1 files changed, 31 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/pr17188-1.c b/gcc/testsuite/gcc.dg/pr17188-1.c
new file mode 100644
index 0000000..634e60c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr17188-1.c
@@ -0,0 +1,31 @@
+/* A redefinition of an empty struct should be diagnosed the same as a
+   redefinition of any other tag, but formerly only s2 and s4 were
+   diagnosed.  Bug 17188.  */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+struct s0 { };
+struct s0;
+struct s0 { }; /* { dg-error "error: redefinition of 'struct s0'" } */
+
+struct s1 { };
+struct s1 { }; /* { dg-error "error: redefinition of 'struct s1'" } */
+
+struct s2 { int a : 1; };
+struct s2 { int a : 1; }; /* { dg-error "error: redefinition of 'struct s2'" } */
+
+struct s3 { };
+struct s3 { int a : 1; }; /* { dg-error "error: redefinition of 'struct s3'" } */
+
+struct s4 { int a : 1; };
+struct s4 { }; /* { dg-error "error: redefinition of 'struct s4'" } */
+
+struct s5 { int a : 1; };
+struct s5;
+
+struct s6;
+struct s6 { int a : 1; };
+
+struct s7;
+struct s7 { };