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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-04-12 17:56:45 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-04-12 22:38:31 +0100 |
| commit | 3c742621ed28540cf42d4cfbc2bf03433cd26738 (patch) | |
| tree | fb0b6e89fda4b8eeffd65d81304b4e118691e188 /libstdc++-v3/acinclude.m4 | |
| parent | b2c007b87dcd5db5d59447de2081777aea66f35f (diff) | |
| download | gcc-3c742621ed28540cf42d4cfbc2bf03433cd26738.zip gcc-3c742621ed28540cf42d4cfbc2bf03433cd26738.tar.gz gcc-3c742621ed28540cf42d4cfbc2bf03433cd26738.tar.bz2 | |
libstdc++: Prefer to use mmap instead of malloc in libbacktrace
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.
Diffstat (limited to 'libstdc++-v3/acinclude.m4')
| -rw-r--r-- | libstdc++-v3/acinclude.m4 | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4 index f53461c..eac8aed 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 |