[Qemu-devel] [PATCH v4 0/3]: Fix build issue with error.h saga

[Qemu-devel] [PATCH v4 0/3]: Fix build issue with error.h saga

[Luiz Capitulino]

A .c file including error.h and not including qemu-common.h will break the
build, because error.h uses a macro defined in qemu-common.h.

The simple and obvious fix would be to change error.h to include
qemu-common.h. But this is overkill, so this series does some splitting in
qemu-common.h and changes error.h to include only what it really needs.

Please, refer to the patches for more details.

v4
 o Fix use of reserved double underscores
 o Add license text as asked by Malc

v3
 o Drop license text from compiler.h

v2
 o Move compiler related macros from qemu-common.h to compiler.h

 compiler.h    |   34 ++++++++++++++++++++++++++++++++++
 error.h       |    1 +
 qemu-common.h |   25 +------------------------
 3 files changed, 36 insertions(+), 24 deletions(-)

[Qemu-devel] [PATCH 1/2] Introduce compiler.h header file

[Luiz Capitulino]

From: Luiz Capitulino <lcapitulino@gmail.com>

This moves compiler related macros from qemu-common.h to compiler.h.

The reason for this change is that there are simple header files that
depend only on the compiler macros, so including qemu-common.h is overkill.

Besides, qemu-common.h is bloated and will benefit from some splitting.

Please, also note that the QEMU_BUILD_BUG_ON() macro is being fixed to
not use double underscores as a prefix and the license text was added
by Vassili Karpov (malc), who is one of the authors of the new file.

Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
---
 compiler.h    |   34 ++++++++++++++++++++++++++++++++++
 qemu-common.h |   25 +------------------------
 2 files changed, 35 insertions(+), 24 deletions(-)
 create mode 100644 compiler.h

diff --git a/compiler.h b/compiler.h
new file mode 100644
index 0000000..9af5dc6
--- /dev/null
+++ b/compiler.h
@@ -0,0 +1,34 @@
+/* public domain */
+
+#ifndef COMPILER_H
+#define COMPILER_H
+
+#include "config-host.h"
+
+#define QEMU_NORETURN __attribute__ ((__noreturn__))
+#ifdef CONFIG_GCC_ATTRIBUTE_WARN_UNUSED_RESULT
+#define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define QEMU_WARN_UNUSED_RESULT
+#endif
+
+#define QEMU_BUILD_BUG_ON(x) \
+    typedef char qemu_build_bug_on__##__LINE__[(x)?-1:1];
+
+#if defined __GNUC__
+# if (__GNUC__ < 4) || \
+     defined(__GNUC_MINOR__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 4)
+   /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
+#  define GCC_ATTR __attribute__((__unused__, format(printf, 1, 2)))
+#  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
+# else
+   /* Use gnu_printf when supported (qemu uses standard format strings). */
+#  define GCC_ATTR __attribute__((__unused__, format(gnu_printf, 1, 2)))
+#  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
+# endif
+#else
+#define GCC_ATTR /**/
+#define GCC_FMT_ATTR(n, m)
+#endif
+
+#endif /* COMPILER_H */
diff --git a/qemu-common.h b/qemu-common.h
index c2b79bd..ba55719 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -2,16 +2,9 @@
 #ifndef QEMU_COMMON_H
 #define QEMU_COMMON_H
 
+#include "compiler.h"
 #include "config-host.h"
 
-#define QEMU_NORETURN __attribute__ ((__noreturn__))
-#ifdef CONFIG_GCC_ATTRIBUTE_WARN_UNUSED_RESULT
-#define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
-#else
-#define QEMU_WARN_UNUSED_RESULT
-#endif
-
-#define QEMU_BUILD_BUG_ON(x) typedef char __build_bug_on__##__LINE__[(x)?-1:1];
 #define TFR(expr) do { if ((expr) != -1) break; } while (errno == EINTR)
 
 typedef struct QEMUTimer QEMUTimer;
@@ -82,22 +75,6 @@ struct iovec {
 #include <sys/uio.h>
 #endif
 
-#if defined __GNUC__
-# if (__GNUC__ < 4) || \
-     defined(__GNUC_MINOR__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 4)
-   /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
-#  define GCC_ATTR __attribute__((__unused__, format(printf, 1, 2)))
-#  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
-# else
-   /* Use gnu_printf when supported (qemu uses standard format strings). */
-#  define GCC_ATTR __attribute__((__unused__, format(gnu_printf, 1, 2)))
-#  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
-# endif
-#else
-#define GCC_ATTR /**/
-#define GCC_FMT_ATTR(n, m)
-#endif
-
 typedef int (*fprintf_function)(FILE *f, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 
-- 
1.7.6.178.g55272

[Qemu-devel] [PATCH 2/2] Error: Fix build when qemu-common.h is not included

[Luiz Capitulino]

From: Luiz Capitulino <lcapitulino@gmail.com>

Commit e4ea5e2d0e0e4c5188ab45b66f3195062ae059dc added the use of
the macro GCC_FMT_ATTR to error.h, however compiler.h is not
included by error.h

This will cause a build error when files including error.h
don't include qemu-common.h (or compiler.h). Not an issue today
because the only file including it is json-parser.h and it does
include qemu-common.h, but let's get it fixed.

Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
---
 error.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/error.h b/error.h
index 0f92a6f..6361f40 100644
--- a/error.h
+++ b/error.h
@@ -12,6 +12,7 @@
 #ifndef ERROR_H
 #define ERROR_H
 
+#include "compiler.h"
 #include <stdbool.h>
 
 /**
-- 
1.7.6.178.g55272

[Qemu-devel] [PATCH 2/2] Error: Fix build when qemu-common.h is not included

[Luiz Capitulino]

From: Luiz Capitulino <lcapitulino@gmail.com>

Commit e4ea5e2d0e0e4c5188ab45b66f3195062ae059dc added the use of
the macro GCC_FMT_ATTR to error.h, however compiler.h is not
included by error.h

This will cause a build error when files including error.h
don't include qemu-common.h (or compiler.h). Not an issue today
because the only file including it is json-parser.h and it does
include qemu-common.h, but let's get it fixed.

Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
---
 error.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/error.h b/error.h
index 0f92a6f..6361f40 100644
--- a/error.h
+++ b/error.h
@@ -12,6 +12,7 @@
 #ifndef ERROR_H
 #define ERROR_H
 
+#include "compiler.h"
 #include <stdbool.h>
 
 /**
-- 
1.7.6.134.gcf13f

[Qemu-devel] [PATCH 2/2] Error: Fix build when qemu-common.h is not included

[Luiz Capitulino]

From: Luiz Capitulino <lcapitulino@gmail.com>

Commit e4ea5e2d0e0e4c5188ab45b66f3195062ae059dc added the use of
the macro GCC_FMT_ATTR to error.h, however compiler.h is not
included by error.h

This will cause a build error when files including error.h
don't include qemu-common.h (or compiler.h). Not an issue today
because the only file including it is json-parser.h and it does
include qemu-common.h, but let's get it fixed.

Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
---
 error.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/error.h b/error.h
index 0f92a6f..6361f40 100644
--- a/error.h
+++ b/error.h
@@ -12,6 +12,7 @@
 #ifndef ERROR_H
 #define ERROR_H
 
+#include "compiler.h"
 #include <stdbool.h>
 
 /**
-- 
1.7.6.134.gcf13f