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From: rcampbell@tropicnetworks.com To: gcc-gnats@gcc.gnu.org Subject: c/8828: gcc reports some code is unreachable when it is not Date: Thu, 05 Dec 2002 13:06:00 -0000 [thread overview] Message-ID: <20021205210447.31385.qmail@sources.redhat.com> (raw) >Number: 8828 >Category: c >Synopsis: gcc reports some code is unreachable when it is not >Confidential: no >Severity: non-critical >Priority: low >Responsible: unassigned >State: open >Class: rejects-legal >Submitter-Id: net >Arrival-Date: Thu Dec 05 13:06:00 PST 2002 >Closed-Date: >Last-Modified: >Originator: Rolf Campbell >Release: GNU C version 3.2 20020927 (prerelease) (i686-pc-cygwin) >Organization: >Environment: Cygwin 1.3.17 running under Win2000 (SP3) >Description: When gcc is run with "-Wunreachable-code", certain reachable code sections involving switch's generate warnings about unreachable code. Here's "a.i" # 1 "a.c" # 1 "<built-in>" # 1 "<command line>" # 1 "a.c" int b; int func(int a) { int j = 2; switch(a) { case 0: for(j=0; j<b; j++) j++; break; case 1: for(j=0; j<3; j++) j++; break; } return j; } When I compile it with gcc -v -save-temps -Wunreachable-code -c a.c I get: Reading specs from /usr/lib/gcc-lib/i686-pc-cygwin/3.2/specs Configured with: /netrel/src/gcc-3.2-3/configure --enable-languages=c,c++,f77,java --enable-libgcj --enable-threads=posix --with-system-zlib --enable-nls --without-included-gettext --enable-interpreter --disable-sjlj-exceptions --disable-version-specific-runtime-libs --enable-shared --build=i686-pc-linux --host=i686-pc-cygwin --target=i686-pc-cygwin --enable-haifa --prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib --includedir=/nonexistent/include --libexecdir=/usr/sbin Thread model: posix gcc version 3.2 20020927 (prerelease) /usr/lib/gcc-lib/i686-pc-cygwin/3.2/cpp0.exe -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=0 -D__GXX_ABI_VERSION=102 -D_X86_=1 -D_X86_=1 -Asystem=winnt -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ -D__tune_pentium2__ -D__tune_pentium3__ -D__stdcall=__attribute__((__stdcall__)) -D__fastcall=__attribute__((__fastcall__)) -D__cdecl=__attribute__((__cdecl__)) -D_stdcall=__attribute__((__stdcall__)) -D_fastcall=__attribute__((__fastcall__)) -D_cdecl=__attribute__((__cdecl__)) -D__declspec(x)=__attribute__((x)) -D__i386__ -D__i386 -D__CYGWIN32__ -D__CYGWIN__ -Dunix -D__unix__ -D__unix -isystem /usr/lib/gcc-lib/i686-pc-cygwin/3.2/../../../../include/w32api -isystem /usr/lib/gcc-lib/i686-pc-cygwin/3.2/../../../../i686-pc-cygwin/lib/../../include/w32api a.c -Wunreachable-code a.i GNU CPP version 3.2 20020927 (prerelease) (cpplib) (80386, BSD syntax) ignoring nonexistent directory "/usr/i686-pc-cygwin/include" ignoring duplicate directory "/usr/i686-pc-cygwin/lib/../../include/w32api" #include "..." search starts here: #include <...> search starts here: /usr/include/w32api /usr/local/include /usr/lib/gcc-lib/i686-pc-cygwin/3.2/include /usr/include End of search list. /usr/lib/gcc-lib/i686-pc-cygwin/3.2/cc1.exe -fpreprocessed a.i -quiet -dumpbase a.c -Wunreachable-code -version -o a.s GNU CPP version 3.2 20020927 (prerelease) (cpplib) (80386, BSD syntax) GNU C version 3.2 20020927 (prerelease) (i686-pc-cygwin) compiled by GNU C version 3.2 20020927 (prerelease). a.c: In function `func': a.c:10: warning: will never be executed a.c:14: warning: will never be executed >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: >Unformatted:
next reply other threads:[~2002-12-05 21:06 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2002-12-05 13:06 rcampbell [this message] 2002-12-06 1:29 reichelt 2002-12-06 8:16 Christian Ehrhardt 2002-12-06 8:26 Rolf Campbell 2002-12-06 15:56 Wolfgang Bangerth 2002-12-06 17:06 Christian Ehrhardt
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