gcc:

2016-11-23  Paolo Bonzini  <bonzini@gnu.org>

	* system.h (HAVE_DESIGNATED_INITIALIZERS,
	HAVE_DESIGNATED_UNION_INITIALIZERS): Do not use
	"defined" in macros.
	* doc/cpp.texi (Defined): Mention -Wexpansion-to-defined.
	* doc/cppopts.texi (Invocation): Document -Wexpansion-to-defined.
	* doc/invoke.texi (Warning Options): Document -Wexpansion-to-defined.

gcc/c-family:
2016-11-23  Paolo Bonzini  <bonzini@gnu.org>

	* c.opt (Wexpansion-to-defined): New.

gcc/testsuite:
2016-11-23  Paolo Bonzini  <bonzini@gnu.org>

	* gcc.dg/cpp/defined.c: Mark newly introduced warnings and
	adjust for warning->pedwarn change.
	* gcc.dg/cpp/defined-syshdr.c,
	gcc.dg/cpp/defined-Wexpansion-to-defined.c,
	gcc.dg/cpp/defined-Wextra-Wno-expansion-to-defined.c,
	gcc.dg/cpp/defined-Wextra.c,
	gcc.dg/cpp/defined-Wno-expansion-to-defined.c: New testcases.

libcpp:
2016-11-23  Paolo Bonzini  <bonzini@gnu.org>

	* include/cpplib.h (struct cpp_options): Add new member
	warn_expansion_to_defined.
	(CPP_W_EXPANSION_TO_DEFINED): New enum member.
	* expr.c (parse_defined): Warn for all uses of "defined"
	in macros, and tie warning to CPP_W_EXPANSION_TO_DEFINED.
	Make it a pedwarning instead of a warning.
	* system.h (HAVE_DESIGNATED_INITIALIZERS): Do not use
	"defined" in macros.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@242743 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 27 insertions, 6 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 6b928078636..1a7e737cd95 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,14 @@
+2016-11-23  Paolo Bonzini  <bonzini@gnu.org>
+
+	* include/cpplib.h (struct cpp_options): Add new member
+	warn_expansion_to_defined.
+	(CPP_W_EXPANSION_TO_DEFINED): New enum member.
+	* expr.c (parse_defined): Warn for all uses of "defined"
+	in macros, and tie warning to CPP_W_EXPANSION_TO_DEFINED.
+	Make it a pedwarning instead of a warning.
+	* system.h (HAVE_DESIGNATED_INITIALIZERS): Do not use
+	"defined" in macros.
+
 2016-11-17  David Malcolm  <dmalcolm@redhat.com>
 
 	* charset.c (cpp_interpret_string_1): Skip locations from
diff --git a/libcpp/expr.c b/libcpp/expr.c
index 61bc1b21af1..a4cf7505958 100644
--- a/libcpp/expr.c
+++ b/libcpp/expr.c
@@ -1031,9 +1031,11 @@ parse_defined (cpp_reader *pfile)
 
   if (node)
     {
-      if (pfile->context != initial_context && CPP_PEDANTIC (pfile))
-	cpp_error (pfile, CPP_DL_WARNING,
-		   "this use of \"defined\" may not be portable");
+      if ((pfile->context != initial_context
+	   || initial_context != &pfile->base_context)
+	  && CPP_OPTION (pfile, warn_expansion_to_defined))
+        cpp_pedwarning (pfile, CPP_W_EXPANSION_TO_DEFINED,
+		        "this use of \"defined\" may not be portable");
 
       _cpp_mark_macro_used (node);
       if (!(node->flags & NODE_USED))
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 0781c095156..56c2491d2ee 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -415,6 +415,10 @@ struct cpp_options
   /* Nonzero means warn if undefined identifiers are evaluated in an #if.  */
   unsigned char warn_undef;
 
+  /* Nonzero means warn if "defined" is encountered in a place other than
+     an #if.  */
+  unsigned char warn_expansion_to_defined;
+
   /* Nonzero means warn of unused macros from the main file.  */
   unsigned char warn_unused_macros;
 
@@ -1040,7 +1044,8 @@ enum {
   CPP_W_DATE_TIME,
   CPP_W_PEDANTIC,
   CPP_W_C90_C99_COMPAT,
-  CPP_W_CXX11_COMPAT
+  CPP_W_CXX11_COMPAT,
+  CPP_W_EXPANSION_TO_DEFINED
 };
 
 /* Output a diagnostic of some kind.  */
diff --git a/libcpp/system.h b/libcpp/system.h
index e89131e900e..67b02bb4578 100644
--- a/libcpp/system.h
+++ b/libcpp/system.h
@@ -375,9 +375,12 @@ extern void abort (void);
    ??? C99 designated initializers are not supported by most C++
    compilers, including G++.  -- gdr, 2005-05-18  */
 #if !defined(HAVE_DESIGNATED_INITIALIZERS)
+#ifdef __cplusplus
+#define HAVE_DESIGNATED_INITIALIZERS 0
+#else
 #define HAVE_DESIGNATED_INITIALIZERS \
-  (!defined(__cplusplus) \
-   && ((GCC_VERSION >= 2007) || (__STDC_VERSION__ >= 199901L)))
+   ((GCC_VERSION >= 2007) || (__STDC_VERSION__ >= 199901L))
+#endif
 #endif
 
 #ifndef offsetof