Bug 20767
| Summary: | gcc const produces invalid warning | ||
|---|---|---|---|
| Product: | Base System | Reporter: | marka <marka> |
| Component: | gnu | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 4.1-STABLE | ||
| Hardware: | Any | ||
| OS: | Any | ||
<<On Tue, 22 Aug 2000 13:03:35 +1000 (EST), marka@nominum.com said: > gcc incorrectly reports 'incompatible pointer type' when function > is declared with 'const pointer to const pointer' arguement and is > just passed pointer to pointer. The code is in error, and the warning is in fact correct. The type `const foo * const *' is not compatible with `foo **'. Only the outermost qualifier participates in this form of promotion. -GAWollman Acutally shouldn't it.... Don't you want *argv ? as just argv implies the array of command line arguments instead of any single character string ! I could be wrong, if you do use the * it works fine with no warning and -Wall option as well. ***************************************************************************** Philip M. Gollucci (p6m7g8) Web-site : http://www.p6m7g8.com E-mail : gollucci@wam.umd.edu Philip@p6m7g8.com Phone : 301.249.6261 (Home) 301. . (College) Major : Computer Science Electrical Engineering Minor : Classical & Jazz Performance Current Job : Co Science, Discovery, & the Universe Webmaster URL: http://www.sdu.umd.edu Resume : http://www.wam.umd.edu/~gollucci/resume.html ***************************************************************************** On Tue, 22 Aug 2000 marka@nominum.com wrote: > > >Number: 20767 > >Category: gnu > >Synopsis: gcc const produces invalid warning > >Confidential: no > >Severity: non-critical > >Priority: medium > >Responsible: freebsd-bugs > >State: open > >Quarter: > >Keywords: > >Date-Required: > >Class: sw-bug > >Submitter-Id: current-users > >Arrival-Date: Mon Aug 21 20:10:00 PDT 2000 > >Closed-Date: > >Last-Modified: > >Originator: Mark Andrews > >Release: FreeBSD 4.1-STABLE i386 > >Organization: > Nominum > >Environment: > > FreeBSD drugs.dv.isc.org 4.1-STABLE FreeBSD 4.1-STABLE #0: Fri Aug 18 13:53:08 EST 2000 marka@drugs.dv.isc.org:/usr/obj/usr/src/sys/DRUGS i386 > > Using builtin specs. > gcc version 2.95.2 19991024 (release) > > >Description: > > gcc incorrectly reports 'incompatible pointer type' when function > is declared with 'const pointer to const pointer' arguement and is > just passed pointer to pointer. > > Also generates error with 'const pointer to pointer' and 'pointer to > const pointer', i.e. removing either of the consts still generates > the warning. > > >How-To-Repeat: > > % cc xx.c > xx.c: In function `main': > xx.c:22: warning: passing arg 1 of `f' from incompatible pointer type > > #include <stdio.h> > > static const char *foo[] = { "test", NULL }; > > static int > f(const char * const *args) { > int i, j, k; > > k = 0; > for (i = 0; args[i] != NULL; i++) > for (j = 0; args[i][j] != '\0'; j++) > k += args[i][j]; > return (k); > } > > int > main(int argc, char **argv) { > int i; > > i = f(foo); > printf("%d\n", i); > i = f(argv); /* This should not generate a warning! */ > printf("%d\n", i); > return (0); > } > > >Fix: > > > > >Release-Note: > >Audit-Trail: > >Unformatted: > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-bugs" in the body of the message > > Acutally shouldn't it.... > Don't you want *argv ? No. Remove all the consts and it is clearer. e.g. f(char **args); > as just argv implies the array of command line > arguments instead of any single character string ! > > I could be wrong, if you do use the * it works fine with no warning and > -Wall option as well. > -- Mark Andrews, Nominum Inc. 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: Mark.Andrews@nominum.com > <<On Tue, 22 Aug 2000 13:03:35 +1000 (EST), marka@nominum.com said: > > > gcc incorrectly reports 'incompatible pointer type' when function > > is declared with 'const pointer to const pointer' arguement and is > > just passed pointer to pointer. > > The code is in error, and the warning is in fact correct. The type > `const foo * const *' is not compatible with `foo **'. Only the > outermost qualifier participates in this form of promotion. > > -GAWollman > If that is what ANSI C says I'll have to live with it but it is illogical, not that logic applies to standards. Mark -- Mark Andrews, Nominum Inc. 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: Mark.Andrews@nominum.com State Changed From-To: open->closed Garrett reckons that gcc is conformant in this regard. |
gcc incorrectly reports 'incompatible pointer type' when function is declared with 'const pointer to const pointer' arguement and is just passed pointer to pointer. Also generates error with 'const pointer to pointer' and 'pointer to const pointer', i.e. removing either of the consts still generates the warning. How-To-Repeat: % cc xx.c xx.c: In function `main': xx.c:22: warning: passing arg 1 of `f' from incompatible pointer type #include <stdio.h> static const char *foo[] = { "test", NULL }; static int f(const char * const *args) { int i, j, k; k = 0; for (i = 0; args[i] != NULL; i++) for (j = 0; args[i][j] != '\0'; j++) k += args[i][j]; return (k); } int main(int argc, char **argv) { int i; i = f(foo); printf("%d\n", i); i = f(argv); /* This should not generate a warning! */ printf("%d\n", i); return (0); }