http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47035
--- Comment #2 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-12-22 15:24:27 UTC --- This issue actually exists on linux as well. The behavior is rather complex. For example, the first instance of a compilation of trunctfxf2.c shows the missing prototype warnings ... /home/howarth/work/./gcc/xgcc -B/home/howarth/work/./gcc/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/bin/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/lib/ -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/include -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -fno-stack-protector -I. -I. -I../.././gcc -I../../../gcc/libgcc -I../../../gcc/libgcc/. -I../../../gcc/libgcc/../gcc -I../../../gcc/libgcc/../include -I../../../gcc/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o trunctfxf2.o -MT trunctfxf2.o -MD -MP -MF trunctfxf2.dep -fexceptions -c ../../../gcc/libgcc/../gcc/config/soft-fp/trunctfxf2.c -fvisibility=hidden -DHIDE_EXPORTS ../../../gcc/libgcc/../gcc/config/soft-fp/trunctfdf2.c:36:8: warning: no previous prototype for ‘__trunctfdf2’ [-Wmissing-prototypes] ../../../gcc/libgcc/../gcc/config/soft-fp/trunctfsf2.c:36:8: warning: no previous prototype for ‘__trunctfsf2’ [-Wmissing-prototypes] ../../../gcc/libgcc/../gcc/config/soft-fp/trunctfxf2.c:35:8: warning: no previous prototype for ‘__trunctfxf2’ [-Wmissing-prototypes] whereas the next instance properly uses '-Wno-missing-prototypes -Wno-type-limits' from libgcc/config/t-softfp... /home/howarth/work/./gcc/xgcc -B/home/howarth/work/./gcc/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/bin/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/lib/ -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/include -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/sys-include -g -O2 -m32 -O2 -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -fno-stack-protector -I. -I. -I../../.././gcc -I../../../../gcc/libgcc -I../../../../gcc/libgcc/. -I../../../../gcc/libgcc/../gcc -I../../../../gcc/libgcc/../include -I../../../../gcc/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -Wno-missing-prototypes -Wno-type-limits -o trunctfxf2.o -MT trunctfxf2.o -MD -MP -MF trunctfxf2.dep -fexceptions -c ../../../../gcc/libgcc/../gcc/config/soft-fp/trunctfxf2.c -fvisibility=hidden -DHIDE_EXPORTS and doesn't generate the 'missing prototype' warnings. I am having a difficult time seeing the logic of when '-Wno-missing-prototypes -Wno-type-limits' since immediately after the second compilation of trunctfxf2.c, which gets '-Wno-missing-prototypes -Wno-type-limits', occurs... /home/howarth/work/./gcc/xgcc -B/home/howarth/work/./gcc/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/bin/ -B/home/howarth/dist/x86_64-unknown-linux-gnu/lib/ -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/include -isystem /home/howarth/dist/x86_64-unknown-linux-gnu/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -fno-stack-protector -I. -I. -I../.././gcc -I../../../gcc/libgcc -I../../../gcc/libgcc/. -I../../../gcc/libgcc/../gcc -I../../../gcc/libgcc/../include -I../../../gcc/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o unordtf2_s.o -MT unordtf2_s.o -MD -MP -MF unordtf2_s.dep -DSHARED -fexceptions -c ../../../gcc/libgcc/../gcc/config/soft-fp/unordtf2.c ../../../gcc/libgcc/../gcc/config/soft-fp/unordtf2.c:34:9: warning: no previous prototype for ‘__unordtf2’ [-Wmissing-prototypes] ../../../gcc/libgcc/../gcc/config/soft-fp/unordtf2.c: In function ‘__unordtf2’: ../../../gcc/libgcc/../gcc/config/soft-fp/unordtf2.c:37:1: warning: variable ‘B_s’ set but not used [-Wunused-but-set-variable] ../../../gcc/libgcc/../gcc/config/soft-fp/unordtf2.c:36:1: warning: variable ‘A_s’ set but not used [-Wunused-but-set-variable] where '-Wno-missing-prototypes -Wno-type-limits' is omitted. Odd.
