diff options
Diffstat (limited to 'usr/src/Makefile.master')
| -rw-r--r-- | usr/src/Makefile.master | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/usr/src/Makefile.master b/usr/src/Makefile.master index 501853a6ed..5321004bff 100644 --- a/usr/src/Makefile.master +++ b/usr/src/Makefile.master @@ -372,6 +372,17 @@ CCNOREORDER= \ -_gcc7=-fno-reorder-functions \ -_gcc8=-fno-reorder-functions +# +# gcc has a rather aggressive optimization on by default that infers loop +# bounds based on undefined behavior (!!). This can lead to some VERY +# surprising optimizations -- ones that may be technically correct in the +# strictest sense but also result in incorrect program behavior. We turn +# this optimization off, with extreme prejudice. +# +CCNOAGGRESSIVELOOPS= \ + -_gcc7=-fno-aggressive-loop-optimizations \ + -_gcc8=-fno-aggressive-loop-optimizations + # One optimization the compiler might perform is to turn this: # #pragma weak foo # extern int foo; @@ -601,10 +612,12 @@ $(SRCDBGBLD)CCSOURCEDEBUGFLAGS = $(CCGDEBUG) -xs CFLAGS= $(COPTFLAG) $($(MACH)_CFLAGS) $(SPACEFLAG) $(CCMODE) \ $(ILDOFF) $(CERRWARN) $(CSTD) $(CCUNBOUND) $(IROPTFLAG) \ $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CCNOREORDER) \ + $(CCNOAGGRESSIVELOOPS) \ $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS) CFLAGS64= $(COPTFLAG64) $($(MACH64)_CFLAGS) $(SPACEFLAG64) $(CCMODE64) \ $(ILDOFF) $(CERRWARN) $(CSTD) $(CCUNBOUND) $(IROPTFLAG64) \ $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CCNOREORDER) \ + $(CCNOAGGRESSIVELOOPS) \ $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS64) # # Flags that are used to build parts of the code that are subsequently |