diff options
| author | Pedro Alves <palves@redhat.com> | 2016-04-18 17:42:50 +0100 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2016-04-18 17:42:50 +0100 |
| commit | 9b30624b65697a5f51bb7120c48686ab5506067f (patch) | |
| tree | d5b7fcf105f1ec874d689b32e6355e83b93a0ea1 /gdb/ptrace.m4 | |
| parent | a22df60ad216517bbca4b391bec09f9ded06ab7b (diff) | |
Fix PR gdb/19250: ptrace prototype is not detected properly in C++ mode
The ptrace args/return types detection doesn't work properly in C++
mode, on non-GNU/Linux hosts. For example, on gcc70 (NetBSD 5.1),
where the prototype is:
int ptrace(int, __pid_t, void*, int);
configure misdetects it as:
$ grep PTRACE_TYPE config.h
#define PTRACE_TYPE_ARG1 int
#define PTRACE_TYPE_ARG3 int *
#define PTRACE_TYPE_ARG4 int
/* #undef PTRACE_TYPE_ARG5 */
#define PTRACE_TYPE_RET int
resulting in:
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_fetch_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:56: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_store_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:104: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c:110: warning: dereferencing type-punned pointer will break strict-aliasing rules
We could address this [1], however despite ptrace.m4's claim:
# Needs to be tested in C++ mode, to detect whether we need to cast
# the first argument to enum __ptrace_request.
it appears that there's actually no need to test in C++ mode. Always
running the ptrace tests in C mode works just the same on GNU/Linux.
I remember experimenting with several different ways to handle the
original issue back then, and maybe that was needed in some other
attempt and then I didn't realize it ended up not really necessary.
Confirmed that this fixes the NetBSD 5.1 C++ build, and confirmed that
C and C++ builds on Fedora 23 are unaffected.
[1] - https://sourceware.org/ml/gdb-patches/2016-04/msg00374.html
gdb/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* ptrace.m4 (GDB_AC_PTRACE): Don't run tests in C++ mode.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
Diffstat (limited to 'gdb/ptrace.m4')
| -rw-r--r-- | gdb/ptrace.m4 | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/gdb/ptrace.m4 b/gdb/ptrace.m4 index ca2b7c63d9..89591d4b67 100644 --- a/gdb/ptrace.m4 +++ b/gdb/ptrace.m4 @@ -22,12 +22,6 @@ AC_DEFUN([GDB_AC_PTRACE], AC_CHECK_HEADERS([sys/ptrace.h ptrace.h]) -# Needs to be tested in C++ mode, to detect whether we need to cast -# the first argument to enum __ptrace_request. -if test "$enable_build_with_cxx" = "yes"; then - AC_LANG_PUSH([C++]) -fi - gdb_ptrace_headers=' #include <sys/types.h> #if HAVE_SYS_PTRACE_H @@ -97,8 +91,4 @@ if test -n "$[5]"; then AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG5, $[5], [Define to the type of arg 5 for ptrace.]) fi - -if test "$enable_build_with_cxx" = "yes"; then - AC_LANG_POP([C++]) -fi ]) |