Why does a fastdebug build compile with -O3 and -O0? (original) (raw)
Mikael Gerdin mikael.gerdin at oracle.com
Tue Apr 28 08:55:56 UTC 2015
- Previous message: Why does a fastdebug build compile with -O3 *and* -O0?
- Next message: Why does a fastdebug build compile with -O3 *and* -O0?
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Severin,
On 2015-04-27 16:33, Severin Gehwolf wrote:
Hi,
I've noticed that a fastdebug build of recent hs-rt compiles objects with -O3 and -O0. Is this a bug or a feature? If it's a feature, what's the rationale?
This does not appear to be the case when I build on my machine. I also don't get "-fstack-protector-all --param ssp-buffer-size=1" Those appear to be set in DEBUG_CFLAGS in gcc.make. The first line of fastdebug.make uses an interesting hack to set FASTDEBUG_CFLAGS to DEBUG_CFLAGS unless FASTDEBUG_CFLAGS is already set. FASTDEBUG_CFLAGS is only set in gcc.make if ENABLE_FULL_DEBUG_SYMBOLS is 0. So I tried with: hs-rt-open/hotspot$ make -C make/ ALT_BOOTDIR=/usr/lib/jvm/jdk-8-oracle-x64 HOTSPOT_BUILD_JOBS=24 ARCH_DATA_MODEL=64 ENABLE_FULL_DEBUG_SYMBOLS=0 fastdebug
And that reproduces your problem. This is most certainly a bug in the build system.
The hotspot makefiles are horrible.
/Mikael
I'm not sure what GCC does with that, but it appears it just uses -O0 (last seen option?). Example: /usr/bin/g++ -DLINUX -DGNUSOURCE -DAMD64 -DASSERT -DCHECKUNHANDLEDOOPS -I. -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/share/vm/prims -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/share/vm -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/share/vm/precompiled -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/cpu/x86/vm -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/oscpu/linuxx86/vm -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/os/linux/vm -I/home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/os/posix/vm -I../generated -DHOTSPOTBUILDUSER=""sgehwolf"" -DHOTSPOTLIBARCH="amd64" -DHOTSPOTVMDISTRO=""OpenJDK"" -DTARGETOSFAMILYlinux -DTARGETARCHx86 -DTARGETARCHMODELx8664 -DTARGETOSARCHlinuxx86 -DTARGETOSARCHMODELlinuxx8664 -DTARGE! T_COMPILER _gcc -DCOMPILER2 -DCOMPILER1 -fPIC -fno-rtti -fno-exceptions -D_REENTRANT -fcheck-new -fvisibility=hidden -m64 -pipe -fno-strict-aliasing -g -fno-omit-frame-pointer -O3 -O0 -fstack-protector-all --param ssp-buffer-size=1 -DVM_LITTLE_ENDIAN -D_LP64=1 -Werror -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2 -Wreturn-type -Woverloaded-virtual -Wtype-limits -DDTRACE_ENABLED -c -MMD -MP -MF ../generated/dependencies/virtualMemoryTracker.o.d -fpch-deps -o virtualMemoryTracker.o /home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/share/vm/services/virtualMemoryTracker.cpp Compiling /home/sgehwolf/Documents/openjdk/upstream-sources/openjdk9-hs-rt/hotspot/src/share/vm/runtime/virtualspace.cpp Cheers, Severin
- Previous message: Why does a fastdebug build compile with -O3 *and* -O0?
- Next message: Why does a fastdebug build compile with -O3 *and* -O0?
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]