This takes account of the overall configuration for host PCH support
when deciding if we should build the libstdc++ PCH files.
We now require both the support is configured and that we are hosted.
A non-fatal configure warning is given if the user attempts to
--disable-host-pch-support --enable-libstdcxx-pch since the latter
conflicts with the former (but does not prevent a useable libstdc++
library build).
Signed-off-by: Iain Sandoe <i...@sandoe.co.uk>
libstdc++-v3/ChangeLog:
* acinclude.m4: Account for configured host PCH support.
* configure: Regenerate.
* configure.ac: Act on --enable-host-pch-support.
---
libstdc++-v3/acinclude.m4 | 49 ++++++++++++++++-----------
libstdc++-v3/configure | 71 ++++++++++++++++++++++++++-------------
libstdc++-v3/configure.ac | 11 ++++--
3 files changed, 86 insertions(+), 45 deletions(-)
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 90ecc4a87a2..87652306691 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -3225,7 +3225,7 @@ AC_DEFUN([GLIBCXX_ENABLE_WCHAR_T], [
])
-dnl
+≈
dnl Check to see if building and using a C++ precompiled header can be done.
dnl
dnl --enable-libstdcxx-pch=yes
@@ -3240,29 +3240,40 @@ dnl Substs:
dnl glibcxx_PCHFLAGS
dnl
AC_DEFUN([GLIBCXX_ENABLE_PCH], [
- GLIBCXX_ENABLE(libstdcxx-pch,$1,,[build pre-compiled libstdc++ headers])
+ dnl This is only allowed if host support is enabled, and we are hosted.
+ if test "$1" = "yes" && test "$2" = "yes"; then
+ can_pch=yes
+ else
+ can_pch=no
+ fi
+ GLIBCXX_ENABLE(libstdcxx-pch,$can_pch,,[build pre-compiled libstdc++
headers])
if test $enable_libstdcxx_pch = yes; then
- AC_CACHE_CHECK([for compiler with PCH support],
- [glibcxx_cv_prog_CXX_pch],
- [ac_save_CXXFLAGS="$CXXFLAGS"
- CXXFLAGS="$CXXFLAGS -Werror -Winvalid-pch -Wno-deprecated"
- AC_LANG_SAVE
- AC_LANG_CPLUSPLUS
- echo '#include <math.h>' > conftest.h
- if $CXX $CXXFLAGS $CPPFLAGS -x c++-header conftest.h \
+ if test "$2" != "yes"; then
+ glibcxx_cv_prog_CXX_pch=no
+ AC_MSG_WARN([PCH headers cannot be built since host PCH is disabled])
+ else
+ AC_CACHE_CHECK([for compiler with PCH support],
+ [glibcxx_cv_prog_CXX_pch],
+ [ac_save_CXXFLAGS="$CXXFLAGS"
+ CXXFLAGS="$CXXFLAGS -Werror -Winvalid-pch -Wno-deprecated"
+ AC_LANG_SAVE
+ AC_LANG_CPLUSPLUS
+ echo '#include <math.h>' > conftest.h
+ if $CXX $CXXFLAGS $CPPFLAGS -x c++-header conftest.h \
-o conftest.h.gch 1>&5 2>&1 &&
echo '#error "pch failed"' > conftest.h &&
echo '#include "conftest.h"' > conftest.cc &&
$CXX -c $CXXFLAGS $CPPFLAGS conftest.cc 1>&5 2>&1 ;
- then
- glibcxx_cv_prog_CXX_pch=yes
- else
- glibcxx_cv_prog_CXX_pch=no
- fi
- rm -f conftest*
- CXXFLAGS=$ac_save_CXXFLAGS
- AC_LANG_RESTORE
- ])
+ then
+ glibcxx_cv_prog_CXX_pch=yes
+ else
+ glibcxx_cv_prog_CXX_pch=no
+ fi
+ rm -f conftest*
+ CXXFLAGS=$ac_save_CXXFLAGS
+ AC_LANG_RESTORE
+ ])
+ fi
enable_libstdcxx_pch=$glibcxx_cv_prog_CXX_pch
fi
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 2d68b3672b9..ce82f16c859 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -103,7 +103,6 @@ if test "$enable_vtable_verify" = yes; then
postdep_objects_CXX="${postdep_objects_CXX}
${glibcxx_builddir}/../libgcc/vtv_end.o"
fi
-
# libtool variables for C++ shared and position-independent compiles.
#
# Use glibcxx_lt_pic_flag to designate the automake variable
@@ -147,8 +146,16 @@ GLIBCXX_ENABLE_HOSTED
# Enable descriptive messages to standard output on termination.
GLIBCXX_ENABLE_VERBOSE
+# The current default is that PCH is supported by the host unless otherwise
+# stated.
+AC_ARG_ENABLE(host_pch_support,
+AS_HELP_STRING([--disable-host-pch-support],
+ [Disable host support for precompiled headers]),
+host_pch_support=$enableval,
+host_pch_support=yes)
+
# Enable compiler support that doesn't require linking.
-GLIBCXX_ENABLE_PCH($is_hosted)
+GLIBCXX_ENABLE_PCH($is_hosted, $host_pch_support)
GLIBCXX_ENABLE_THREADS
GLIBCXX_ENABLE_ATOMIC_BUILTINS
GLIBCXX_ENABLE_LOCK_POLICY
--
2.24.3 (Apple Git-128)
