sparse: suppress some "using sizeof on a function" warnings

Ramsay Jones · jrn · commit 9371322a6093 · 2013-10-14T16:22:28.000-07:00
Sparse issues an "using sizeof on a function" warning for each
call to curl_easy_setopt() which sets an option that takes a
function pointer parameter. (currently 12 such warnings over 4
files.)

The warnings relate to the use of the "typecheck-gcc.h" header
file which adds a layer of type-checking macros to the curl
function invocations (for gcc &gt;= 4.3 and !__cplusplus). As part
of the type-checking layer, 'sizeof' is applied to the function
parameter of curl_easy_setopt(). Note that, in the context of
sizeof, the function to function pointer conversion is not
performed and that sizeof(f) != sizeof(&amp;f).

A simple solution, therefore, would be to replace the function
name in each such call to curl_easy_setopt() with an explicit
function pointer expression (i.e. replace f with &amp;f).

However, the "typecheck-gcc.h" header file is only conditionally
included, in addition to the gcc and C++ checks mentioned above,
depending on the CURL_DISABLE_TYPECHECK preprocessor variable.

In order to suppress the warnings, we use target-specific variable
assignments to add -DCURL_DISABLE_TYPECHECK to SPARSE_FLAGS for
each file affected (http-push.c, http.c, http-walker.c and
remote-curl.c).

Signed-off-by: Ramsay Jones &lt;ramsay@ramsay1.demon.co.uk&gt;
Signed-off-by: Jonathan Nieder &lt;jrnieder@gmail.com&gt;
diff --git a/Makefile b/Makefile
@@ -2018,6 +2018,9 @@ gettext.sp gettext.s gettext.o: GIT-PREFIX
 gettext.sp gettext.s gettext.o: EXTRA_CPPFLAGS = \
 	-DGIT_LOCALE_PATH='"$(localedir_SQ)"'
 
+http-push.sp http.sp http-walker.sp remote-curl.sp: SPARSE_FLAGS += \
+	-DCURL_DISABLE_TYPECHECK
+
 ifdef NO_EXPAT
 http-walker.sp http-walker.s http-walker.o: EXTRA_CPPFLAGS = -DNO_EXPAT
 endif
