Subject: [Boost-commit] svn:boost r80304 - trunk/tools/build/v2/engine
From: jurko.gospodnetic_at_[hidden]
Date: 2012-08-29 11:52:29
Author: jurko
Date: 2012-08-29 11:52:29 EDT (Wed, 29 Aug 2012)
New Revision: 80304
URL: http://svn.boost.org/trac/boost/changeset/80304
Log:
Boost Jam cleanup on Linux/Free-BSD - replaced strndup() usage with malloc()/strncpy() as strndup() does not get declared in older glibc version header files unless some version specific symbols are defined first. This corrects a compiler warning on such systems about strndup() function being implicitly (and incorrectly) declared.
Text files modified:
trunk/tools/build/v2/engine/jam.c | 38 +++++++++++++++++++++++++++++++++++---
1 files changed, 35 insertions(+), 3 deletions(-)
Modified: trunk/tools/build/v2/engine/jam.c
==============================================================================
--- trunk/tools/build/v2/engine/jam.c (original)
+++ trunk/tools/build/v2/engine/jam.c 2012-08-29 11:52:29 EDT (Wed, 29 Aug 2012)
@@ -628,6 +628,8 @@
return strdup( getexecname() );
}
#elif defined(__FreeBSD__)
+# include <stdlib.h>
+# include <string.h>
# include <sys/sysctl.h>
char * executable_path( char const * argv0 )
{
@@ -635,15 +637,45 @@
char buf[ 1024 ];
size_t size = sizeof( buf );
sysctl( mib, 4, buf, &size, NULL, 0 );
- return ( !size || size == sizeof( buf ) ) ? NULL : strndup( buf, size );
+ if ( size && size != sizeof( buf ) )
+ {
+ /* Using strndup() here might not work with older glibc installations as
+ * their headers do not declare that function unless certain symbols are
+ * defined. We could work around this issue by defining appropriate
+ * symbols but they depend on the exact glibc version used so simply
+ * using malloc()/strncpy() seems like a cleaner solution.
+ *
+ * Note: such old glibc installations have so far only been found on
+ * Linux and not Free-BSD installations but using the same logic on
+ * Free-BSD seems like something that could not hurt.
+ */
+ char * const result = (char *)malloc( size );
+ if ( result )
+ return strncpy( result, buf, size );
+ }
+ return NULL;
}
#elif defined(__linux__)
+# include <stdlib.h>
+# include <string.h>
# include <unistd.h>
char * executable_path( char const * argv0 )
{
char buf[ 1024 ];
- ssize_t const ret = readlink( "/proc/self/exe", buf, sizeof( buf ) );
- return ( !ret || ret == sizeof( buf ) ) ? NULL : strndup( buf, ret );
+ ssize_t const size = readlink( "/proc/self/exe", buf, sizeof( buf ) );
+ if ( size && size != sizeof( buf ) )
+ {
+ /* Using strndup() here might not work with older glibc installations as
+ * their headers do not declare that function unless certain symbols are
+ * defined. We could work around this issue by defining appropriate
+ * symbols but they depend on the exact glibc version used so simply
+ * using malloc()/strncpy() seems like a cleaner solution.
+ */
+ char * const result = (char *)malloc( size );
+ if ( result )
+ return strncpy( result, buf, size );
+ }
+ return NULL;
}
#else
char * executable_path( char const * argv0 )