Make copies of cstdlib/cmath and use them [BZ #20314]

If C++ headers <cstdlib> or <cmath> are used, GCC 6 will include
/usr/include/stdlib.h or /usr/include/math.h from "#include_next"
(instead of stdlib/stdlib.h or math/math.h in the glibc source
directory), and this turns up as a make dependency.  An implicit
rule will kick in and make will try to install stdlib/stdlib.h or
math/math.h as /usr/include/stdlib.h or /usr/include/math.h because
the target is out of date.  We make a copy of <cstdlib> and <cmath>
in the glibc build directory so that stdlib/stdlib.h and math/math.h
will be used instead of /usr/include/stdlib.h and /usr/include/math.h.

	[BZ #20314]
	* Makeconfig (CXXFLAGS): Prepend -I$(common-objpfx).
	* Makerules (before-compile): Add $(common-objpfx)cstdlib and
	$(common-objpfx)cmath.
	($(common-objpfx)cstdlib): New target.
	($(common-objpfx)cmath): Likewise.
This commit is contained in:
H.J. Lu 2016-07-05 15:01:33 -07:00
parent 00068ce40c
commit 8321286846
3 changed files with 35 additions and 1 deletions

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@ -1,3 +1,12 @@
2016-07-05 H.J. Lu <hongjiu.lu@intel.com>
[BZ #20314]
* Makeconfig (CXXFLAGS): Prepend -I$(common-objpfx).
* Makerules (before-compile): Add $(common-objpfx)cstdlib and
$(common-objpfx)cmath.
($(common-objpfx)cstdlib): New target.
($(common-objpfx)cmath): Likewise.
2016-07-05 Chris Metcalf <cmetcalf@mellanox.com>
* malloc/tst-malloc-thread-fail.c (TIMEOUT): Bump up to 30s.

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@ -889,7 +889,8 @@ override CFLAGS = -std=gnu11 -fgnu89-inline $(config-extra-cflags) \
$(CFLAGS-$(@F)) $(tls-model) \
$(foreach lib,$(libof-$(basename $(@F))) \
$(libof-$(<F)) $(libof-$(@F)),$(CFLAGS-$(lib)))
override CXXFLAGS = $(c++-sysincludes) \
# Use our copies of cstdlib and cmath.
override CXXFLAGS = -I$(common-objpfx) $(c++-sysincludes) \
$(filter-out %frame-pointer,$(+cflags)) $(sysdep-CFLAGS) \
$(CFLAGS-$(suffix $@)) $(CFLAGS-$(<F)) $(CFLAGS-$(@F))

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@ -109,6 +109,30 @@ endif # avoid-generated
endif # $(build-shared) = yes
ifndef avoid-generated
ifneq (,$(CXX))
# If C++ headers <cstdlib> or <cmath> are used, GCC 6 will include
# /usr/include/stdlib.h or /usr/include/math.h from "#include_next"
# (instead of stdlib/stdlib.h or math/math.h in the glibc source
# directory), and this turns up as a make dependency. An implicit
# rule will kick in and make will try to install stdlib/stdlib.h or
# math/math.h as /usr/include/stdlib.h or /usr/include/math.h because
# the target is out of date. We make a copy of <cstdlib> and <cmath>
# in the glibc build directory so that stdlib/stdlib.h and math/math.h
# will be used instead of /usr/include/stdlib.h and /usr/include/math.h.
before-compile := $(common-objpfx)cstdlib $(common-objpfx)cmath \
$(before-compile)
cstdlib=$(shell echo "\#include <cstdlib>" | $(CXX) -M -MP -x c++ - \
| sed -n "/cstdlib:/{s/:$$//;p}")
$(common-objpfx)cstdlib: $(cstdlib)
$(INSTALL_DATA) $< $@T
$(move-if-change) $@T $@
cmath=$(shell echo "\#include <cmath>" | $(CXX) -M -MP -x c++ - \
| sed -n "/cmath:/{s/:$$//;p}")
$(common-objpfx)cmath: $(cmath)
$(INSTALL_DATA) $< $@T
$(move-if-change) $@T $@
endif
before-compile := $(common-objpfx)libc-abis.h $(before-compile)
$(common-objpfx)libc-abis.h: $(common-objpfx)libc-abis.stamp; @:
$(common-objpfx)libc-abis.stamp: $(..)scripts/gen-libc-abis \