re PR preprocessor/20078 (Gcc doesn't complain about non-benign macro definitions)

libcpp:
	PR preprocessor/20078
	* include/cpp-id-data.h (struct cpp_macro): Add extra_tokens
	field.
	* include/cpplib.h (SP_DIGRAPH, SP_PREV_WHITE): Define.
	(struct cpp_token): Change flags to unsigned short.
	* lex.c (_cpp_lex_direct): Initialize arg_no for CPP_PASTE tokens.
	(_cpp_equiv_tokens): Check arg_no for CPP_PASTE tokens.
	(cpp_token_val_index): Return CPP_TOKEN_FLD_ARG_NO for CPP_PASTE
	tokens.
	* macro.c (macro_real_token_count): New.
	(enter_macro_context, replace_args): Use macro_real_token_count.
	(create_iso_definition): Record whitespace surrounding and digraph
	spelling of # and ## tokens using SP_PREV_WHITE and SP_DIGRAPH.
	Set extra_tokens and save CPP_PASTE tokens with arg_no set for
	multiple consecutive ## tokens.
	(_cpp_create_definition): Initialize extra_tokens.
	(cpp_macro_definition): Use macro_real_token_count.

gcc/testsuite:
	* gcc.dg/cpp/paste16.c, gcc.dg/cpp/redef4.c: New tests.

From-SVN: r146352

3 files changed, 510 insertions, 0 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5454921..bb2fab6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-19  Joseph Myers  <joseph@codesourcery.com>
+
+	PR preprocessor/20078
+	* gcc.dg/cpp/paste16.c, gcc.dg/cpp/redef4.c: New tests.
+
 2009-04-19  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* lib/gnat.exp (local_find_gnatmake): Pass --LINK to gnatlink.
diff --git a/gcc/testsuite/gcc.dg/cpp/paste16.c b/gcc/testsuite/gcc.dg/cpp/paste16.c
new file mode 100644
index 0000000..11aca2b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/paste16.c
@@ -0,0 +1,6 @@
+/* Test multiple consecutive ## tokens.  */
+/* { dg-do compile } */
+/* { dg-options "" } */
+#define cat(x,y) x##########y
+int abcd;
+int *p = &cat(ab,cd);
diff --git a/gcc/testsuite/gcc.dg/cpp/redef4.c b/gcc/testsuite/gcc.dg/cpp/redef4.c
new file mode 100644
index 0000000..b34635b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/redef4.c
@@ -0,0 +1,499 @@
+/* Test redefinitions differing only in the spelling of paste and
+   stringify tokens, whitespace around them, or the number of
+   consecutive paste tokens.  */
+/* { dg-do preprocess } */
+/* { dg-options "" } */
+
+#define str(x) #x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) #x /* { dg-message "previous definition" } */
+#define str(x) # x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) #x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %:x /* { dg-message "previous definition" } */
+#define str(x) #x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %:x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %:x /* { dg-message "previous definition" } */
+#define str(x) # x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %:x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) # x /* { dg-message "previous definition" } */
+#define str(x) #x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) # x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) # x /* { dg-message "previous definition" } */
+#define str(x) %: x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %: x /* { dg-message "previous definition" } */
+#define str(x) #x /* { dg-warning "redefined" } */
+#undef str
+#define str(x) %: x /* { dg-message "previous definition" } */
+#define str(x) # x /* { dg-warning "redefined" } */
+#undef str
+
+#define str(x) #x
+#define str(x) #x
+#undef str
+#define str(x) # x
+#define str(x) # x
+#undef str
+#define str(x) %: x
+#define str(x) %: x
+#undef str
+#define str(x) %: x
+#define str(x) %: x
+#undef str
+
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a#x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%:x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a# x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a%: x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a #x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %:x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a # x /* { dg-message "previous definition" } */
+#define astr(x) a %: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a#x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a# x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a%: x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a #x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a %:x /* { dg-warning "redefined" } */
+#undef astr
+#define astr(x) a %: x /* { dg-message "previous definition" } */
+#define astr(x) a # x /* { dg-warning "redefined" } */
+#undef astr
+
+#define astr(x) a#x
+#define astr(x) a#x
+#undef astr
+#define astr(x) a# x
+#define astr(x) a# x
+#undef astr
+#define astr(x) a%: x
+#define astr(x) a%: x
+#undef astr
+#define astr(x) a%: x
+#define astr(x) a%: x
+#undef astr
+#define astr(x) a #x
+#define astr(x) a #x
+#undef astr
+#define astr(x) a %:x
+#define astr(x) a %:x
+#undef astr
+#define astr(x) a # x
+#define astr(x) a # x
+#undef astr
+#define astr(x) a %: x
+#define astr(x) a %: x
+#undef astr
+
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x##y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x## y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x%:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ##y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%:y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x ## y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x## y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x%:%: y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x ##y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x %:%:y /* { dg-warning "redefined" } */
+#undef cat
+#define cat(x,y) x %:%: y /* { dg-message "previous definition" } */
+#define cat(x,y) x ## y /* { dg-warning "redefined" } */
+#undef cat
+
+#define cat(x,y) x##y
+#define cat(x,y) x##y
+#undef cat
+#define cat(x,y) x## y
+#define cat(x,y) x## y
+#undef cat
+#define cat(x,y) x%:%: y
+#define cat(x,y) x%:%: y
+#undef cat
+#define cat(x,y) x%:%: y
+#define cat(x,y) x%:%: y
+#undef cat
+#define cat(x,y) x ##y
+#define cat(x,y) x ##y
+#undef cat
+#define cat(x,y) x %:%:y
+#define cat(x,y) x %:%:y
+#undef cat
+#define cat(x,y) x ## y
+#define cat(x,y) x ## y
+#undef cat
+#define cat(x,y) x %:%: y
+#define cat(x,y) x %:%: y
+#undef cat
+
+#define cat3(x,y,z) x##y##z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x##y####z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y####z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x####y##z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y####z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x##y## ##z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y####z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x##y##%:%:z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y######## ####z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x##y############z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y############z /* { dg-message "previous definition" } */
+#define cat3(x,y,z) x##y########%:%:##z /* { dg-warning "redefined" } */
+#undef cat3
+
+#define cat3(x,y,z) x##y##z
+#define cat3(x,y,z) x##y##z
+#undef cat3
+
+#define cat3(x,y,z) x##y####z
+#define cat3(x,y,z) x##y####z
+#undef cat3
+
+#define cat3(x,y,z) x####y##z
+#define cat3(x,y,z) x####y##z
+#undef cat3
+
+#define cat3(x,y,z) x##y## ##z
+#define cat3(x,y,z) x##y## ##z
+#undef cat3
+
+#define cat3(x,y,z) x##y##%:%:z
+#define cat3(x,y,z) x##y##%:%:z
+#undef cat3
+
+#define cat3(x,y,z) x##y######## ####z
+#define cat3(x,y,z) x##y######## ####z
+#undef cat3
+
+#define cat3(x,y,z) x##y############z
+#define cat3(x,y,z) x##y############z
+#undef cat3
+
+#define cat3(x,y,z) x##y########%:%:##z
+#define cat3(x,y,z) x##y########%:%:##z
+#undef cat3