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| author | Victor Stinner <victor.stinner@gmail.com> | 2017-04-28 15:07:10 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-04-28 15:07:10 +0200 |
| commit | 826f83f1d562a7b878499bc3af2267cfdfe5f2f9 (patch) | |
| tree | d35096a04bd036d1e807309764002f40d4274f9e /Makefile.pre.in | |
| parent | 5a4e3d8f9c37e700402b23fafbfc413e5ca3113d (diff) | |
| download | cpython-git-826f83f1d562a7b878499bc3af2267cfdfe5f2f9.tar.gz | |
bpo-30104: Only use -fno-strict-aliasing on dtoa.c (#1340)
On clang, only compile dtoa.c with -fno-strict-aliasing, use strict
aliasing to compile all other C files.
Diffstat (limited to 'Makefile.pre.in')
| -rw-r--r-- | Makefile.pre.in | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Makefile.pre.in b/Makefile.pre.in index 4145634c03..e5141f11da 100644 --- a/Makefile.pre.in +++ b/Makefile.pre.in @@ -107,6 +107,8 @@ ARFLAGS= @ARFLAGS@ CFLAGSFORSHARED=@CFLAGSFORSHARED@ # C flags used for building the interpreter object files PY_CORE_CFLAGS= $(PY_CFLAGS) $(PY_CFLAGS_NODIST) $(PY_CPPFLAGS) $(CFLAGSFORSHARED) -DPy_BUILD_CORE +# Strict or non-strict aliasing flags used to compile dtoa.c, see above +CFLAGS_ALIASING=@CFLAGS_ALIASING@ # Machine-dependent subdirectories @@ -1536,6 +1538,13 @@ config.status: $(srcdir)/configure .c.o: $(CC) -c $(PY_CORE_CFLAGS) -o $@ $< +# bpo-30104: dtoa.c uses union to cast double to unsigned long[2]. clang 4.0 +# with -O2 or higher and strict aliasing miscompiles the ratio() function +# causing rounding issues. Compile dtoa.c using -fno-strict-aliasing on clang. +# https://bugs.llvm.org//show_bug.cgi?id=31928 +Python/dtoa.o: Python/dtoa.c + $(CC) -c $(PY_CORE_CFLAGS) $(CFLAGS_ALIASING) -o $@ $< + # Run reindent on the library reindent: ./$(BUILDPYTHON) $(srcdir)/Tools/scripts/reindent.py -r $(srcdir)/Lib |