@matheusbsbs / matheus-bagliano / commits / 49d6cfa5c2

config: do not use C function names as struct members

According to C99, section 7.1.4: Any function declared in a header may be additionally implemented as a function-like macro defined in the header. Therefore calling our struct member function pointer "fgetc" may run afoul of unwanted macro expansion when we call: char c = cf->fgetc(cf); This turned out to be a problem on uclibc, which defines fgetc as a macro and causes compilation failure. The standard suggests fixing this in a few ways: 1. Using extra parentheses to inhibit the function-like macro expansion. E.g., "(cf->fgetc)(cf)". This is undesirable as it's ugly, and each call site needs to remember to use it (and on systems without the macro, forgetting will compile just fine). 2. Using #undef (because a conforming implementation must also be providing fgetc as a function). This is undesirable because presumably the implementation was using the macro for a performance benefit, and we are dropping that optimization. Instead, we can simply use non-colliding names. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Aug 26, 2013 at 17:57 UTC 49d6cfa5c2874d78360dc4b16558bb45b5f8e003

1 file changed +16 -16

config.c

+16 -16

@@ -27,9 +27,9 @@ struct config_source {

27 struct strbuf value;

28 struct strbuf var;

30 - int (*fgetc)(struct config_source *c);

31 - int (*ungetc)(int c, struct config_source *conf);

32 - long (*ftell)(struct config_source *c);

30 + int (*do_fgetc)(struct config_source *c);

31 + int (*do_ungetc)(int c, struct config_source *conf);

32 + long (*do_ftell)(struct config_source *c);

33 };

35 static struct config_source *cf;

@@ -217,13 +217,13 @@ int git_config_from_parameters(config_fn_t fn, void *data)

217

218 static int get_next_char(void)

219 {

220 - int c = cf->fgetc(cf);

220 + int c = cf->do_fgetc(cf);

221

222 if (c == '\r') {

223 /* DOS like systems */

224 - c = cf->fgetc(cf);

224 + c = cf->do_fgetc(cf);

225 if (c != '\n') {

226 - cf->ungetc(c, cf);

226 + cf->do_ungetc(c, cf);

227 c = '\r';

228 }

229 }

@@ -982,9 +982,9 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data)

982 top.u.file = f;

983 top.name = filename;

984 top.die_on_error = 1;

985 - top.fgetc = config_file_fgetc;

986 - top.ungetc = config_file_ungetc;

987 - top.ftell = config_file_ftell;

985 + top.do_fgetc = config_file_fgetc;

986 + top.do_ungetc = config_file_ungetc;

987 + top.do_ftell = config_file_ftell;

988

989 ret = do_config_from(&top, fn, data);

990

@@ -1003,9 +1003,9 @@ int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,

1003 top.u.buf.pos = 0;

1004 top.name = name;

1005 top.die_on_error = 0;

1006 - top.fgetc = config_buf_fgetc;

1007 - top.ungetc = config_buf_ungetc;

1008 - top.ftell = config_buf_ftell;

1006 + top.do_fgetc = config_buf_fgetc;

1007 + top.do_ungetc = config_buf_ungetc;

1008 + top.do_ftell = config_buf_ftell;

1009

1010 return do_config_from(&top, fn, data);

1011 }

@@ -1186,7 +1186,7 @@ static int store_aux(const char *key, const char *value, void *cb)

1186 return 1;

1187 }

1188

1189 - store.offset[store.seen] = cf->ftell(cf);

1189 + store.offset[store.seen] = cf->do_ftell(cf);

1190 store.seen++;

1191 }

1192 break;

@@ -1213,19 +1213,19 @@ static int store_aux(const char *key, const char *value, void *cb)

1213 * Do not increment matches: this is no match, but we

1214 * just made sure we are in the desired section.

1215 */

1216 - store.offset[store.seen] = cf->ftell(cf);

1216 + store.offset[store.seen] = cf->do_ftell(cf);

1217 /* fallthru */

1218 case SECTION_END_SEEN:

1219 case START:

1220 if (matches(key, value)) {

1221 - store.offset[store.seen] = cf->ftell(cf);

1221 + store.offset[store.seen] = cf->do_ftell(cf);

1222 store.state = KEY_SEEN;

1223 store.seen++;

1224 } else {

1225 if (strrchr(key, '.') - key == store.baselen &&

1226 !strncmp(key, store.key, store.baselen)) {

1227 store.state = SECTION_SEEN;

1228 - store.offset[store.seen] = cf->ftell(cf);

1228 + store.offset[store.seen] = cf->do_ftell(cf);

1229 }

1230 }

1231 }