commit 1d348989b08a3d3c50dfa2600a5e5e2f61fb2b4a Author: Nick Mathewson nickm@torproject.org Date: Mon Dec 4 15:18:13 2017 -0500

Make tor_free only evaluate its input once (at least on gcc and clang) --- configure.ac | 1 - src/common/util.h | 10 ++++++++++ 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac index 93b18a326..bb34e5883 100644 --- a/configure.ac +++ b/configure.ac @@ -1988,7 +1988,6 @@ if test "x$enable_gcc_warnings_advisory" != "xno"; then -Winvalid-source-encoding -Winvalid-token-paste -Wknr-promoted-parameter - -Wlanguage-extension-token -Wlarge-by-value-copy -Wliteral-conversion -Wliteral-range diff --git a/src/common/util.h b/src/common/util.h index 9ed11260d..e85be57c0 100644 --- a/src/common/util.h +++ b/src/common/util.h @@ -80,12 +80,22 @@ extern int dmalloc_free(const char *file, const int line, void *pnt, * This is a macro. If you need a function pointer to release memory from * tor_malloc(), use tor_free_(). */ +#ifdef __GNUC__ +#define tor_free(p) STMT_BEGIN \ + typeof(&(p)) tor_free__tmpvar = &(p); \ + if (PREDICT_LIKELY((*tor_free__tmpvar)!=NULL)) { \ + raw_free(*tor_free__tmpvar); \ + *tor_free__tmpvar=NULL; \ + } \ + STMT_END +#else #define tor_free(p) STMT_BEGIN \ if (PREDICT_LIKELY((p)!=NULL)) { \ raw_free(p); \ (p)=NULL; \ } \ STMT_END +#endif #endif /* defined(USE_DMALLOC) */

#define tor_malloc(size) tor_malloc_(size DMALLOC_ARGS)