From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12542 invoked by alias); 29 Jun 2005 13:54:01 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 12519 invoked by uid 48); 29 Jun 2005 13:53:58 -0000 Date: Wed, 29 Jun 2005 13:54:00 -0000 From: "js at linuxtv dot org" To: gcc-bugs@gcc.gnu.org Message-ID: <20050629135356.22231.js@linuxtv.org> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug driver/22231] New: -MG ignores missing headers even with -c X-Bugzilla-Reason: CC X-SW-Source: 2005-06/txt/msg03441.txt.bz2 List-Id: I just spent half an hour to debug mysterious build failures (make complaining about missing dependencies) in some third party code. (The reason was a missing -Ipath.) Given what the documentation of -MG in the preprocessor says I'm not sure this is a real bug, but as an enhancement request I think gcc shouldn't pass -MG to the preprocessor if it is used in combination with -c (or -S etc.), or produce an error (it doesn't really make sense to use -MG with -c). This behaviour is the same in gcc --version: gcc-3.3 (GCC) 3.3.6 (Debian 1:3.3.6-7) gcc-3.4 (GCC) 3.4.5 20050613 (prerelease) (Debian 3.4.4-1) gcc-4.0 (GCC) 4.0.1 20050617 (prerelease) (Debian 4.0.0-10) $ cat >t.c #include "foo.h" $ gcc -MD -c t.c t.c:1:17: foo.h: No such file or directory $ ls -l t.* -rw-r--r-- 1 js js 17 Jun 29 15:35 t.c -rw-r--r-- 1 js js 0 Jun 29 15:36 t.d $ gcc -MD -MG -c t.c $ ls -l t.* -rw-r--r-- 1 js js 17 Jun 29 15:35 t.c -rw-r--r-- 1 js js 15 Jun 29 15:35 t.d -rw-r--r-- 1 js js 637 Jun 29 15:35 t.o $ cat t.d t.o: t.c foo.h $ -- Summary: -MG ignores missing headers even with -c Product: gcc Version: 4.0.1 Status: UNCONFIRMED Severity: normal Priority: P2 Component: driver AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: js at linuxtv dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22231