Tested powerpc64-linux, pushed to trunk.
-- >8 --
As reported in PR libbacktrace/105240, libbacktrace leaks memory when
using malloc for allocations. I originally thought it would be simpler
to just use malloc unconditionally (because it's supported on all
targets) but the leaks make that problematic.
This adds libbacktrace's detection for mmap to the libstdc++
configury, so that we use mmap.c and mmapio.c when possible. This avoids
the leaks seen previously, at least on linux.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_ENABLE_BACKTRACE): Check for mmap.
* config.h.in: Regenerate.
* configure: Regenerate.
---
libstdc++-v3/acinclude.m4 | 35 +++++++++++++++++++----
libstdc++-v3/config.h.in | 3 ++
libstdc++-v3/configure | 59 +++++++++++++++++++++++++++++++++------
3 files changed, 83 insertions(+), 14 deletions(-)
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index f53461c85a5..eac8aeda48b 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -5003,18 +5003,41 @@ elf64) elfsize=64 ;;
esac
BACKTRACE_CPPFLAGS="$BACKTRACE_CPPFLAGS -DBACKTRACE_ELF_SIZE=$elfsize"
- ALLOC_FILE=alloc.lo
- AC_SUBST(ALLOC_FILE)
- VIEW_FILE=read.lo
- AC_SUBST(VIEW_FILE)
-
AC_MSG_CHECKING([whether to build libbacktrace support])
if test "$enable_libstdcxx_backtrace" == "auto"; then
enable_libstdcxx_backtrace=no
fi
if test "$enable_libstdcxx_backtrace" == "yes"; then
BACKTRACE_SUPPORTED=1
- BACKTRACE_USES_MALLOC=1
+
+ AC_CHECK_HEADERS(sys/mman.h)
+ case "${host}" in
+ *-*-msdosdjgpp) # DJGPP has sys/man.h, but no mmap
+ have_mmap=no ;;
+ *-*-*)
+ have_mmap="$ac_cv_header_sys_mman_h" ;;
+ esac
+
+ if test "$have_mmap" = "no"; then
+ VIEW_FILE=read.lo
+ ALLOC_FILE=alloc.lo
+ else
+ VIEW_FILE=mmapio.lo
+ AC_PREPROC_IFELSE([AC_LANG_SOURCE([
+ #include <sys/mman.h>
+ #if !defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
+ #error no MAP_ANONYMOUS
+ #endif
+ ])], [ALLOC_FILE=mmap.lo], [ALLOC_FILE=alloc.lo])
+ fi
+ AC_SUBST(VIEW_FILE)
+ AC_SUBST(ALLOC_FILE)
+
+ BACKTRACE_USES_MALLOC=0
+ if test "$ALLOC_FILE" = "alloc.lo"; then
+ BACKTRACE_USES_MALLOC=1
+ fi
+
if test "$ac_has_gthreads" = "yes"; then
BACKTRACE_SUPPORTS_THREADS=1
else
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index f6212de9268..f30a8c51c45 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -420,6 +420,9 @@
/* Define to 1 if you have the <sys/machine.h> header file. */
#undef HAVE_SYS_MACHINE_H
+/* Define to 1 if you have the <sys/mman.h> header file. */
+#undef HAVE_SYS_MMAN_H
+
/* Define to 1 if you have the <sys/param.h> header file. */
#undef HAVE_SYS_PARAM_H
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index ef80912d0b9..35dc3f49383 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -681,8 +681,8 @@ BACKTRACE_SUPPORTS_THREADS
BACKTRACE_USES_MALLOC
BACKTRACE_SUPPORTED
BACKTRACE_CPPFLAGS
-VIEW_FILE
ALLOC_FILE
+VIEW_FILE
FORMAT_FILE
ENABLE_FILESYSTEM_TS_FALSE
ENABLE_FILESYSTEM_TS_TRUE
@@ -16190,7 +16190,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
ac_save_CXXFLAGS="$CXXFLAGS"
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#if ! defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2
@@ -77463,11 +77463,6 @@ elf64) elfsize=64 ;;
esac
BACKTRACE_CPPFLAGS="$BACKTRACE_CPPFLAGS -DBACKTRACE_ELF_SIZE=$elfsize"
- ALLOC_FILE=alloc.lo
-
- VIEW_FILE=read.lo
-
-
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build
libbacktrace support" >&5
$as_echo_n "checking whether to build libbacktrace support... " >&6; }
if test "$enable_libstdcxx_backtrace" == "auto"; then
@@ -77475,7 +77470,55 @@ $as_echo_n "checking whether to build libbacktrace
support... " >&6; }
fi
if test "$enable_libstdcxx_backtrace" == "yes"; then
BACKTRACE_SUPPORTED=1
- BACKTRACE_USES_MALLOC=1
+
+ for ac_header in sys/mman.h
+do :
+ ac_fn_c_check_header_mongrel "$LINENO" "sys/mman.h"
"ac_cv_header_sys_mman_h" "$ac_includes_default"
+if test "x$ac_cv_header_sys_mman_h" = xyes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_SYS_MMAN_H 1
+_ACEOF
+
+fi
+
+done
+
+ case "${host}" in
+ *-*-msdosdjgpp) # DJGPP has sys/man.h, but no mmap
+ have_mmap=no ;;
+ *-*-*)
+ have_mmap="$ac_cv_header_sys_mman_h" ;;
+ esac
+
+ if test "$have_mmap" = "no"; then
+ VIEW_FILE=read.lo
+ ALLOC_FILE=alloc.lo
+ else
+ VIEW_FILE=mmapio.lo
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+ #include <sys/mman.h>
+ #if !defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
+ #error no MAP_ANONYMOUS
+ #endif
+
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+ ALLOC_FILE=mmap.lo
+else
+ ALLOC_FILE=alloc.lo
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+ fi
+
+
+
+ BACKTRACE_USES_MALLOC=0
+ if test "$ALLOC_FILE" = "alloc.lo"; then
+ BACKTRACE_USES_MALLOC=1
+ fi
+
if test "$ac_has_gthreads" = "yes"; then
BACKTRACE_SUPPORTS_THREADS=1
else
--
2.34.1
