[Xen-changelog] [xen-3.2-testing] Revert all usages of gcc's __extension__ keyword, and instead assert

["Xen patchbot-3.2-testing" <patchbot-3.2-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1206982124 -3600
# Node ID 382e8107dfefce855ba092bb53007e1d3a5ce736
# Parent  ca7bfc8f5ea5d39188309fed05afb4b55974df4a
Revert all usages of gcc's __extension__ keyword, and instead assert
that our headers are not built with __GNUC__ and __STRICT_ANSI__.

__extension__ had some weird (and buggy) behaviours when nested which
make it a risky proposition for general usage in our header
files. Better to disallow -ansi, -std=c99, and similar gcc options
when building against Xen headers.

Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
xen-unstable changeset:   17326:615ee2933137e057e625ffdb9c84ace56d07881b
xen-unstable date:        Mon Mar 31 17:43:18 2008 +0100
---
 xen/include/public/arch-ia64.h           |   14 +++++++-------
 xen/include/public/arch-powerpc.h        |    2 ++
 xen/include/public/arch-x86/xen-x86_64.h |    4 ++--
 xen/include/public/arch-x86/xen.h        |    2 ++
 xen/include/public/foreign/mkheader.py   |    2 +-
 xen/include/public/xen-compat.h          |    4 ++++
 6 files changed, 18 insertions(+), 10 deletions(-)

diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/arch-ia64.h
--- a/xen/include/public/arch-ia64.h    Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/arch-ia64.h    Mon Mar 31 17:48:44 2008 +0100
@@ -23,6 +23,8 @@
  *
  */
 
+#include "xen.h"
+
 #ifndef __HYPERVISOR_IF_IA64_H__
 #define __HYPERVISOR_IF_IA64_H__
 
@@ -72,8 +74,6 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
 #define MAX_VIRT_CPUS 64
 
 #ifndef __ASSEMBLY__
-
-#define __anonymous_union __extension__ union
 
 typedef unsigned long xen_ulong_t;
 
@@ -176,11 +176,11 @@ struct mapped_regs {
     unsigned long  reserved1[29];
     unsigned long  vhpi;
     unsigned long  reserved2[95];
-    __anonymous_union {
+    union {
         unsigned long  vgr[16];
         unsigned long bank1_regs[16]; // bank1 regs (r16-r31) when bank0 active
     };
-    __anonymous_union {
+    union {
         unsigned long  vbgr[16];
         unsigned long bank0_regs[16]; // bank0 regs (r16-r31) when bank1 active
     };
@@ -191,7 +191,7 @@ struct mapped_regs {
     unsigned long  vpsr;
     unsigned long  vpr;
     unsigned long  reserved4[76];
-    __anonymous_union {
+    union {
         unsigned long  vcr[128];
         struct {
             unsigned long dcr;  // CR0
@@ -225,7 +225,7 @@ struct mapped_regs {
             unsigned long rsv6[46];
         };
     };
-    __anonymous_union {
+    union {
         unsigned long  reserved5[128];
         struct {
             unsigned long precover_ifs;
@@ -619,7 +619,7 @@ struct xen_ia64_opt_feature {
 struct xen_ia64_opt_feature {
        unsigned long cmd;              /* Which feature */
        unsigned char on;               /* Switch feature on/off */
-       __anonymous_union {
+       union {
                struct {
                                /* The page protection bit mask of the pte.
                                 * This will be or'ed with the pte. */
diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/arch-powerpc.h
--- a/xen/include/public/arch-powerpc.h Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/arch-powerpc.h Mon Mar 31 17:48:44 2008 +0100
@@ -21,6 +21,8 @@
  *
  * Authors: Hollis Blanchard <hollisb@xxxxxxxxxx>
  */
+
+#include "xen.h"
 
 #ifndef __XEN_PUBLIC_ARCH_PPC_64_H__
 #define __XEN_PUBLIC_ARCH_PPC_64_H__
diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/arch-x86/xen-x86_64.h
--- a/xen/include/public/arch-x86/xen-x86_64.h  Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/arch-x86/xen-x86_64.h  Mon Mar 31 17:48:44 2008 +0100
@@ -139,9 +139,9 @@ struct iret_context {
     /* Bottom of iret stack frame. */
 };
 
-#ifdef __GNUC__
+#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 /* Anonymous union includes both 32- and 64-bit names (e.g., eax/rax). */
-#define __DECL_REG(name) __extension__ union { \
+#define __DECL_REG(name) union { \
     uint64_t r ## name, e ## name; \
     uint32_t _e ## name; \
 }
diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/arch-x86/xen.h
--- a/xen/include/public/arch-x86/xen.h Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/arch-x86/xen.h Mon Mar 31 17:48:44 2008 +0100
@@ -23,6 +23,8 @@
  *
  * Copyright (c) 2004-2006, K A Fraser
  */
+
+#include "../xen.h"
 
 #ifndef __XEN_PUBLIC_ARCH_X86_XEN_H__
 #define __XEN_PUBLIC_ARCH_X86_XEN_H__
diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/foreign/mkheader.py
--- a/xen/include/public/foreign/mkheader.py    Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/foreign/mkheader.py    Mon Mar 31 17:48:44 2008 +0100
@@ -37,7 +37,7 @@ inttypes["x86_64"] = {
     "xen_pfn_t"     : "__align8__ uint64_t",
 };
 header["x86_64"] = """
-#ifdef __GNUC__
+#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 # define __DECL_REG(name) __extension__ union { uint64_t r ## name, e ## name; 
}
 # define __align8__ __attribute__((aligned (8)))
 #else
diff -r ca7bfc8f5ea5 -r 382e8107dfef xen/include/public/xen-compat.h
--- a/xen/include/public/xen-compat.h   Mon Mar 31 16:40:34 2008 +0100
+++ b/xen/include/public/xen-compat.h   Mon Mar 31 17:48:44 2008 +0100
@@ -48,4 +48,8 @@
 #define XEN_GUEST_HANDLE_00030205(type) type *
 #endif
 
+#if defined(__GNUC__) && defined(__STRICT_ANSI__)
+#error "These headers files use GNU extensions when built with GCC."
+#endif
+
 #endif /* __XEN_PUBLIC_XEN_COMPAT_H__ */

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