[Qemu-devel] [PATCH] win32: provide separate macros for weak decls and definitions

[Qemu-devel] [PATCH] win32: provide separate macros for weak decls and definitions

[Anthony Liguori]

mingw32 seems to want the declaration to also carry the weak attribute.
Strangely, gcc on Linux absolutely does not want the declaration to be marked
as weak.  This may not be the right fix, but it seems to do the trick.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 arch_init.h                 |    4 ++++
 compiler.h                  |    6 ++++++
 qmp.c                       |    8 +++++++-
 target-i386/cpu.c           |    4 ++--
 target-ppc/translate_init.c |    4 ++--
 5 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch_init.h b/arch_init.h
index 547f93c..d9c572a 100644
--- a/arch_init.h
+++ b/arch_init.h
@@ -1,6 +1,8 @@
 #ifndef QEMU_ARCH_INIT_H
 #define QEMU_ARCH_INIT_H
 
+#include "qmp-commands.h"
+
 enum {
     QEMU_ARCH_ALL = -1,
     QEMU_ARCH_ALPHA = 1,
@@ -32,4 +34,6 @@ int tcg_available(void);
 int kvm_available(void);
 int xen_available(void);
 
+CpuDefinitionInfoList GCC_WEAK_DECL *arch_query_cpu_definitions(Error **errp);
+
 #endif
diff --git a/compiler.h b/compiler.h
index f76921e..07ba1f8 100644
--- a/compiler.h
+++ b/compiler.h
@@ -45,7 +45,13 @@
 #  define GCC_ATTR __attribute__((__unused__, format(gnu_printf, 1, 2)))
 #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
 # endif
+#if defined(_WIN32)
+#define GCC_WEAK __attribute__((weak))
+#define GCC_WEAK_DECL GCC_WEAK
+#else
 #define GCC_WEAK __attribute__((weak))
+#define GCC_WEAK_DECL
+#endif
 #else
 #define GCC_ATTR /**/
 #define GCC_FMT_ATTR(n, m)
diff --git a/qmp.c b/qmp.c
index 6c1e4e8..8463922 100644
--- a/qmp.c
+++ b/qmp.c
@@ -468,8 +468,14 @@ DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
     return prop_list;
 }
 
-CpuDefinitionInfoList GCC_WEAK *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList GCC_WEAK *arch_query_cpu_definitions(Error **errp)
 {
     error_set(errp, QERR_NOT_SUPPORTED);
     return NULL;
 }
+
+CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+{
+    return arch_query_cpu_definitions(errp);
+}
+
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 6d5d0d6..120a2e3 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -28,7 +28,7 @@
 #include "qemu-config.h"
 
 #include "qapi/qapi-visit-core.h"
-#include "qmp-commands.h"
+#include "arch_init.h"
 
 #include "hyperv.h"
 
@@ -1126,7 +1126,7 @@ void x86_cpu_list(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
     }
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp)
 {
     CpuDefinitionInfoList *cpu_list = NULL;
     x86_def_t *def;
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 6fe4168..fba2b42 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -27,7 +27,7 @@
 #include "gdbstub.h"
 #include <kvm.h>
 #include "kvm_ppc.h"
-#include "qmp-commands.h"
+#include "arch_init.h"
 
 //#define PPC_DUMP_CPU
 //#define PPC_DEBUG_SPR
@@ -10346,7 +10346,7 @@ void ppc_cpu_list (FILE *f, fprintf_function cpu_fprintf)
     }
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp)
 {
     CpuDefinitionInfoList *cpu_list = NULL;
     int i;
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH] win32: provide separate macros for weak decls and definitions

[Richard Henderson]

On 08/14/2012 08:17 PM, Anthony Liguori wrote:
> Strangely, gcc on Linux absolutely does not want the declaration to be marked
> as weak.

Err... that's incorrect.

> +CpuDefinitionInfoList GCC_WEAK_DECL *arch_query_cpu_definitions(Error **errp);

... and probably seen because you put the attribute in the wrong place.
You've put the attribute in the middle of the return type, where it is
attempting to be applied to the return type pointer.

Try one of

  GCC_WEAK_DECL CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp);

  CpuDefinitionInfoList * GCC_WEAK_DECL arch_query_cpu_definitions(Error **errp);

  CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp) GCC_WEAK_DECL;

I suspect all three alternatives will work.


r~