https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82354
Bug ID: 82354
Summary: semi-colon instead of comma in parameter list produces
confusing diagnostics
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
CC: dmalcolm at gcc dot gnu.org
Target Milestone: ---
int main(int argc; char **argv) { (void) argc; (void) argv; return 0; }
With -Wpedantic this prints:
sscce.c:1:1: warning: ISO C forbids forward parameter declarations [-Wpedantic]
int main(int argc; char **argv) { (void) argc; (void) argv; return 0; }
^~~
sscce.c:1:14: error: parameter ‘argc’ has just a forward declaration
int main(int argc; char **argv) { (void) argc; (void) argv; return 0; }
^~~~
sscce.c:1:5: warning: first argument of ‘main’ should be ‘int’ [-Wmain]
int main(int argc; char **argv) { (void) argc; (void) argv; return 0; }
^~~~
sscce.c:1:5: warning: ‘main’ takes only zero or two arguments [-Wmain]
sscce.c: In function ‘main’:
sscce.c:1:42: error: ‘argc’ undeclared (first use in this function); did you
mean ‘argv’?
int main(int argc; char **argv) { (void) argc; (void) argv; return 0; }
^~~~
argv
sscce.c:1:42: note: each undeclared identifier is reported only once for each
function it appears in
Without -Wpedantic it's even less clear what's going on.
Most users have probably got no idea what "forward parameter declarations" are
(is this extension even documented?) so maybe it would be better to assume the
user didn't mean to type a semi-colon there.
Instead of a cryptic message about an obscure extension, maybe suggest a fix-it
to replace the ';' with ','
