https://sourceware.org/git/?p=glibc.git;a=commit;h=fc3e1337be1c6935ab58bd13520f97a535cf70cc commit dc23a45db566095e83ff0b7a57afc87fb5ca89a1 Author: Florian Weimer Date: Wed Sep 21 10:45:32 2016 +0200 Avoid running $(CXX) during build to obtain header file paths This reduces the build time somewhat and is particularly noticeable during rebuilds with few code changes. diff --git a/Makerules b/Makerules index 7e4077ee50..c338850de5 100644 --- a/Makerules +++ b/Makerules @@ -121,14 +121,10 @@ ifneq (,$(CXX)) # 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 " | $(CXX) -M -MP -x c++ - \ - | sed -n "/cstdlib:/{s/:$$//;p}") -$(common-objpfx)cstdlib: $(cstdlib) +$(common-objpfx)cstdlib: $(c++-cstdlib-header) $(INSTALL_DATA) $< $@T $(move-if-change) $@T $@ -cmath=$(shell echo "\#include " | $(CXX) -M -MP -x c++ - \ - | sed -n "/cmath:/{s/:$$//;p}") -$(common-objpfx)cmath: $(cmath) +$(common-objpfx)cmath: $(c++-cmath-header) $(INSTALL_DATA) $< $@T $(move-if-change) $@T $@ endif diff --git a/config.make.in b/config.make.in index 95c6f36876..04a8b3ed7f 100644 --- a/config.make.in +++ b/config.make.in @@ -45,6 +45,8 @@ defines = @DEFINES@ sysheaders = @sysheaders@ sysincludes = @SYSINCLUDES@ c++-sysincludes = @CXX_SYSINCLUDES@ +c++-cstdlib-header = @CXX_CSTDLIB_HEADER@ +c++-cmath-header = @CXX_CMATH_HEADER@ all-warnings = @all_warnings@ enable-werror = @enable_werror@ diff --git a/configure b/configure index 17625e1041..6ff252744b 100755 --- a/configure +++ b/configure @@ -635,6 +635,8 @@ BISON INSTALL_INFO PERL BASH_SHELL +CXX_CMATH_HEADER +CXX_CSTDLIB_HEADER CXX_SYSINCLUDES SYSINCLUDES AUTOCONF @@ -5054,6 +5056,18 @@ fi +# Obtain some C++ header file paths. This is used to make a local +# copy of those headers in Makerules. +if test -n "$CXX"; then + find_cxx_header () { + echo "#include <$1>" | $CXX -M -MP -x c++ - | sed -n "/$1:/{s/:\$//;p}" + } + CXX_CSTDLIB_HEADER="$(find_cxx_header cstdlib)" + CXX_CMATH_HEADER="$(find_cxx_header cmath)" +fi + + + # Test if LD_LIBRARY_PATH contains the notation for the current directory # since this would lead to problems installing/building glibc. # LD_LIBRARY_PATH contains the current directory if one of the following diff --git a/configure.ac b/configure.ac index 33bcd62180..9938ab0dc2 100644 --- a/configure.ac +++ b/configure.ac @@ -1039,6 +1039,18 @@ fi AC_SUBST(SYSINCLUDES) AC_SUBST(CXX_SYSINCLUDES) +# Obtain some C++ header file paths. This is used to make a local +# copy of those headers in Makerules. +if test -n "$CXX"; then + find_cxx_header () { + echo "#include <$1>" | $CXX -M -MP -x c++ - | sed -n "/$1:/{s/:\$//;p}" + } + CXX_CSTDLIB_HEADER="$(find_cxx_header cstdlib)" + CXX_CMATH_HEADER="$(find_cxx_header cmath)" +fi +AC_SUBST(CXX_CSTDLIB_HEADER) +AC_SUBST(CXX_CMATH_HEADER) + # Test if LD_LIBRARY_PATH contains the notation for the current directory # since this would lead to problems installing/building glibc. # LD_LIBRARY_PATH contains the current directory if one of the following