[gcc r12-3131] aix: SYSTEM_IMPLICIT_EXTERN_C

[gcc r12-3131] aix: SYSTEM_IMPLICIT_EXTERN_C

[David Edelsohn]

https://gcc.gnu.org/g:9cf3f026e281f5eb978a78055d8949a3295b7f10

commit r12-3131-g9cf3f026e281f5eb978a78055d8949a3295b7f10
Author: David Edelsohn <dje.gcc@gmail.com>
Date:   Tue Aug 24 16:48:57 2021 -0400

    aix: SYSTEM_IMPLICIT_EXTERN_C
    
    AIX 7.3 system headers are C++ safe and GCC no longer needs to define
    SYSTEM_IMPLICIT_EXTERN_C for AIX 7.3.  This patch moves the definition
    from aix.h to the individual OS-level configuration files and does not
    define the macro for AIX 7.3.
    
    The patch also corrects the definition of TARGET_AIX_VERSION to 73.
    
    gcc/ChangeLog:
            * config/rs6000/aix.h (SYSTEM_IMPLICIT_EXTERN_C): Delete.
            * config/rs6000/aix71.h (SYSTEM_IMPLICIT_EXTERN_C): Define.
            * config/rs6000/aix72.h (SYSTEM_IMPLICIT_EXTERN_C): Define.
            * config/rs6000/aix73.h (TARGET_AIX_VERSION): Increase to 73.

Diff:
---
 gcc/config/rs6000/aix.h   | 4 +---
 gcc/config/rs6000/aix71.h | 4 ++++
 gcc/config/rs6000/aix72.h | 3 +++
 gcc/config/rs6000/aix73.h | 2 +-
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/gcc/config/rs6000/aix.h b/gcc/config/rs6000/aix.h
index 662785cc7db..0f4d8cb2dc8 100644
--- a/gcc/config/rs6000/aix.h
+++ b/gcc/config/rs6000/aix.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
 /* Definitions of target machine for GNU compiler,
    for IBM RS/6000 POWER running AIX.
    Copyright (C) 2000-2021 Free Software Foundation, Inc.
@@ -23,9 +24,6 @@
 #undef  TARGET_AIX
 #define TARGET_AIX 1
 
-/* System headers are not C++-aware.  */
-#define SYSTEM_IMPLICIT_EXTERN_C 1
-
 /* Linux64.h wants to redefine TARGET_AIX based on -m64, but it can't be used
    in the #if conditional in options-default.h, so provide another macro.  */
 #undef  TARGET_AIX_OS
diff --git a/gcc/config/rs6000/aix71.h b/gcc/config/rs6000/aix71.h
index 38cfa9e158a..1bc1560c496 100644
--- a/gcc/config/rs6000/aix71.h
+++ b/gcc/config/rs6000/aix71.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
 /* Definitions of target machine for GNU compiler,
    for IBM RS/6000 POWER running AIX V7.1.
    Copyright (C) 2002-2021 Free Software Foundation, Inc.
@@ -268,6 +269,9 @@ extern long long int    atoll(const char *);
 #define SET_CMODEL(opt) do {} while (0)
 #endif
 
+/* System headers are not C++-aware.  */
+#define SYSTEM_IMPLICIT_EXTERN_C 1
+
 /* This target defines SUPPORTS_WEAK and TARGET_ASM_NAMED_SECTION,
    but does not have crtbegin/end.  */
 
diff --git a/gcc/config/rs6000/aix72.h b/gcc/config/rs6000/aix72.h
index a497a7d8541..cca64f14f3a 100644
--- a/gcc/config/rs6000/aix72.h
+++ b/gcc/config/rs6000/aix72.h
@@ -270,6 +270,9 @@ extern long long int    atoll(const char *);
 #define SET_CMODEL(opt) do {} while (0)
 #endif
 
+/* System headers are not C++-aware.  */
+#define SYSTEM_IMPLICIT_EXTERN_C 1
+
 /* This target defines SUPPORTS_WEAK and TARGET_ASM_NAMED_SECTION,
    but does not have crtbegin/end.  */
 
diff --git a/gcc/config/rs6000/aix73.h b/gcc/config/rs6000/aix73.h
index c707c7e76b6..f0ca1a55e5d 100644
--- a/gcc/config/rs6000/aix73.h
+++ b/gcc/config/rs6000/aix73.h
@@ -274,7 +274,7 @@ extern long long int    atoll(const char *);
 /* This target defines SUPPORTS_WEAK and TARGET_ASM_NAMED_SECTION,
    but does not have crtbegin/end.  */
 
-#define TARGET_AIX_VERSION 72
+#define TARGET_AIX_VERSION 73
 
 /* AIX 7.2 supports DWARF3+ debugging.  */
 #define DWARF2_DEBUGGING_INFO 1