RFR: 8210703: vmStructs.cpp compiled with -O0 (was: Why is vmStructs.cpp compiled with -O0?
sgehwolf at redhat.com
Thu Sep 13 08:43:40 UTC 2018
On Wed, 2018-09-12 at 10:25 -0700, Erik Joelsson wrote:
> I very much doubt it was included with the new build system. We were
> extremely careful to use the exact same flags then, and did binary
> comparisons of all object files to verify equal builds.
> Tracing back, it was caused (probably unintentionally) by this change:
Thanks for the detective work! This looks very much unintentional to me
as JDK-8114853 is about silencing a note.
> In the old build, setting OPT_CFLAGS/<file> overrides the common
> OPT_CFLAGS. In the new build, we have a more general way of adding flags
> for specific files that does not directly override any other flags. To
> get the same behavior for vmStructs.cpp in the new build as in the old
> at the time of the switch, we had to add -O0 explicitly in the new build.
I've filed JDK-8210703 and posting this patch as review for the bug.
Note I've changed the subject. Does this look OK?
diff --git a/make/hotspot/lib/JvmOverrideFiles.gmk b/make/hotspot/lib/JvmOverrideFiles.gmk
@@ -30,7 +30,7 @@
# status for individual files on specific platforms.
ifeq ($(TOOLCHAIN_TYPE), gcc)
- BUILD_LIBJVM_vmStructs.cpp_CXXFLAGS := -fno-var-tracking-assignments -O0
+ BUILD_LIBJVM_vmStructs.cpp_CXXFLAGS := -fno-var-tracking-assignments
BUILD_LIBJVM_jvmciCompilerToVM.cpp_CXXFLAGS := -fno-var-tracking-assignments
BUILD_LIBJVM_jvmciCompilerToVMInit.cpp_CXXFLAGS := -fno-var-tracking-assignments
BUILD_LIBJVM_assembler_x86.cpp_CXXFLAGS := -Wno-maybe-uninitialized
On 2018-09-12 09:13, Severin Gehwolf wrote:
> > Hi,
> > Does anybody know why vmStructs.cpp gets an override in
> > JvmOverrideFiles.gmk:
> > $ grep -C3 -n vmStructs.cpp make/hotspot/lib/JvmOverrideFiles.gmk
> > 30-# status for individual files on specific platforms.
> > 31-
> > 32-ifeq ($(TOOLCHAIN_TYPE), gcc)
> > 33: BUILD_LIBJVM_vmStructs.cpp_CXXFLAGS := -fno-var-tracking-assignments -O0
> > 34- BUILD_LIBJVM_jvmciCompilerToVM.cpp_CXXFLAGS := -fno-var-tracking-assignments
> > 35- BUILD_LIBJVM_jvmciCompilerToVMInit.cpp_CXXFLAGS := -fno-var-tracking-assignments
> > 36- BUILD_LIBJVM_assembler_x86.cpp_CXXFLAGS := -Wno-maybe-uninitialized
> > It seems to have been introduced with the new build system. JDK 8
> > doesn't seem to have it. Thoughts?
> > Thanks,
> > Severin
More information about the hotspot-dev