[ovs-dev] [PATCH 1/5] CodingStyle: Allow C99 mixing of declarations and code.

[Jarno Rajahalme]

As even the MSVC 2013 now supports the C99 mixing of declarations and
code, we can now allow them in OVS code.

GCC (at least some versions of it) require the -std=c99 option to not
issue warnings, and since we rely in GCC extensions when compiling
with GCC, the option -std=gnu99 is now added to the CFLAGS by
configure, if the compiler accepts it.

Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>
---
 CodingStyle  |   10 +++++-----
 acinclude.m4 |    2 +-
 configure.ac |    1 +
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/CodingStyle b/CodingStyle
index bae8cd6..ef72c3e 100644
--- a/CodingStyle
+++ b/CodingStyle
@@ -533,14 +533,14 @@ C DIALECT
     * Designated initializers (e.g. "struct foo foo = {.a = 1};" and
       "int a[] = {[2] = 5};").
 
-  Don't use other C99 features that are not widely implemented in
-older compilers:
-
-    * Don't mix declarations and code within a block.
+    * Mixing of declarations and code within a block.
 
-    * Don't use declarations in iteration statements (e.g. don't write
+    * Use of declarations in iteration statements (e.g.
       "for (int i = 0; i < 10; i++)").
 
+  Don't use other C99 features that are not widely implemented in
+older compilers:
+
     * Don't put a trailing comma in an enum declaration (e.g. don't
       write "enum { x = 1, };").
 
diff --git a/acinclude.m4 b/acinclude.m4
index 5ed02d2..bd71a82 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -403,7 +403,7 @@ dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
 AC_DEFUN([_OVS_CHECK_CC_OPTION], [dnl
-  m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-], [_])])dnl
+  m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-=], [__])])dnl
   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name], 
     [ovs_save_CFLAGS="$CFLAGS"
      dnl Include -Werror in the compiler options, because without -Werror
diff --git a/configure.ac b/configure.ac
index 3379ff6..3387230 100644
--- a/configure.ac
+++ b/configure.ac
@@ -115,6 +115,7 @@ OVS_ENABLE_OPTION([-Wmissing-field-initializers])
 OVS_ENABLE_OPTION([-Wthread-safety])
 OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
 OVS_CONDITIONAL_CC_OPTION([-Wno-unused-parameter], [HAVE_WNO_UNUSED_PARAMETER])
+OVS_CHECK_CC_OPTION([-std=gnu99], [CFLAGS="$CFLAGS -std=gnu99"])
 OVS_ENABLE_WERROR
 OVS_ENABLE_SPARSE
 
-- 
1.7.10.4