I am interested in looking at the GCC loop optimization. There are some tree
dump flags that are registered (via register_dump_files() in tree-optimize.c).
In particular, -fdump-tree-loopinit-raw and -fdump-tree-loopdone-raw that
generate warnings when they should not. Specifically:
gcc -O3 -S -fdump-tree-loopinit-raw short.c
The problem is that there is also -fdump-tree-loop-raw as well, and "loop" is
a prefix of "loopinit" and "loopdone". The function dump_switch_p_1() in tree-
dump.c calls skip_leading_substring() which works correctly for "loopinit" but
then skips only the first four bytes when processing "loop". This
leaves "init" dangling, and generates:
cc1: warning: ignoring unknown option 'init' in '-fdump-tree-loop'
Same for "done" of course.
No need to do -save-temps or look at any of the compiler output - this happens
before any processing of the input file (a 4-line C program will suffice).
Also, no urgency because the --first-- encounter where it does match the
entire option works, so you do get the requested dumps, just the incorrect
warning.
--
Summary: Certain flags generate warnings when they should not.
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: wmahoney at unomaha dot edu
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20061
