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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@88063 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 76 insertions, 1 deletions

diff --git a/gcc/testsuite/gcc.dg/decl-3.c b/gcc/testsuite/gcc.dg/decl-3.c
index 2bfac89c136..5bbe19cd224 100644
--- a/gcc/testsuite/gcc.dg/decl-3.c
+++ b/gcc/testsuite/gcc.dg/decl-3.c
@@ -2,4 +2,4 @@
 /* { dg-do compile } */
 
 enum { CODES }; /* { dg-error "previous definition" } */
-enum { CODES }; /* { dg-error "conflicting types" } */
+enum { CODES }; /* { dg-error "conflicting types|redeclaration of enumerator" } */
diff --git a/gcc/testsuite/gcc.dg/nested-redef-1.c b/gcc/testsuite/gcc.dg/nested-redef-1.c
new file mode 100644
index 00000000000..34b92d8f571
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/nested-redef-1.c
@@ -0,0 +1,44 @@
+/* Test diagnosis of nested tag redefinitions.  */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+struct s0 {
+  struct s0 { int a; } x; /* { dg-error "error: nested redefinition of 'struct s0'" } */
+};
+
+struct s1 {
+  const struct s1 { int b; } x; /* { dg-error "error: nested redefinition of 'struct s1'" } */
+};
+
+struct s2 {
+  struct s2 { int c; } *x; /* { dg-error "error: nested redefinition of 'struct s2'" } */
+};
+
+struct s3 {
+  struct s4 {
+    struct s5 {
+      struct s3 { int a; } **x; /* { dg-error "error: nested redefinition of 'struct s3'" } */
+    } y;
+  } z;
+};
+
+struct s6;
+struct s6 { struct s6 *p; };
+
+union u0 {
+  union u0 { int c; } *x; /* { dg-error "error: nested redefinition of 'union u0'" } */
+};
+
+enum e0 {
+  E0 = sizeof(enum e0 { E1 }) /* { dg-error "error: nested redefinition of 'enum e0'" } */
+};
+
+enum e1 {
+  E2 = sizeof(enum e2 { E2 }), /* { dg-error "error: redeclaration of enumerator 'E2'" } */
+  /* { dg-error "previous definition" "previous E2" { target *-*-* } 38 } */
+  E3
+};
+
+enum e3;
+enum e3 { E4 = 0 };
diff --git a/gcc/testsuite/gcc.dg/pr17188-1.c b/gcc/testsuite/gcc.dg/pr17188-1.c
new file mode 100644
index 00000000000..634e60c0363
--- /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 { };