From: Pedro Alves Date: Mon, 18 Apr 2016 16:42:50 +0000 (+0100) Subject: Fix PR gdb/19250: ptrace prototype is not detected properly in C++ mode X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=9b30624b65697a5f51bb7120c48686ab5506067f;p=deliverable%2Fbinutils-gdb.git 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 * ptrace.m4 (GDB_AC_PTRACE): Don't run tests in C++ mode. * configure: Regenerate. gdb/gdbserver/ChangeLog: 2016-04-18 Pedro Alves * configure: Regenerate. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3af2212a62..3bbd5d5f41 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2016-04-18 Pedro Alves + + * ptrace.m4 (GDB_AC_PTRACE): Don't run tests in C++ mode. + * configure: Regenerate. + 2016-04-18 Martin Galvan * valops.c (value_addr): For C++ references, set the copied value's diff --git a/gdb/configure b/gdb/configure index b523debe48..8c2ec0f78d 100755 --- a/gdb/configure +++ b/gdb/configure @@ -2401,51 +2401,6 @@ $as_echo "$ac_res" >&6; } eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;} } # ac_fn_c_check_member - -# ac_fn_cxx_check_decl LINENO SYMBOL VAR -# -------------------------------------- -# Tests whether SYMBOL is declared, setting cache variable VAR accordingly. -ac_fn_cxx_check_decl () -{ - as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack - as_decl_name=`echo $2|sed 's/ *(.*//'` - as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'` - { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5 -$as_echo_n "checking whether $as_decl_name is declared... " >&6; } -if { as_var=$3; eval "test \"\${$as_var+set}\" = set"; }; then : - $as_echo_n "(cached) " >&6 -else - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -$4 -int -main () -{ -#ifndef $as_decl_name -#ifdef __cplusplus - (void) $as_decl_use; -#else - (void) $as_decl_name; -#endif -#endif - - ; - return 0; -} -_ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : - eval "$3=yes" -else - eval "$3=no" -fi -rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext -fi -eval ac_res=\$$3 - { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 -$as_echo "$ac_res" >&6; } - eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;} - -} # ac_fn_cxx_check_decl cat >config.log <<_ACEOF This file contains any messages produced by compilers while running configure, to aid debugging if configure makes a mistake. @@ -12351,7 +12306,6 @@ fi # Check the return and argument types of ptrace. - for ac_header in sys/ptrace.h ptrace.h do : as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh` @@ -12367,17 +12321,6 @@ fi done -# Needs to be tested in C++ mode, to detect whether we need to cast -# the first argument to enum __ptrace_request. -if test "$enable_build_with_cxx" = "yes"; then - ac_ext=cpp -ac_cpp='$CXXCPP $CPPFLAGS' -ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' -ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' -ac_compiler_gnu=$ac_cv_cxx_compiler_gnu - -fi - gdb_ptrace_headers=' #include #if HAVE_SYS_PTRACE_H @@ -12388,7 +12331,7 @@ gdb_ptrace_headers=' #endif ' # There is no point in checking if we don't have a prototype. -ac_fn_cxx_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers +ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers " if test "x$ac_cv_have_decl_ptrace" = x""yes; then : ac_have_decl=1 @@ -12426,7 +12369,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='long' else cat confdefs.h - <<_ACEOF >conftest.$ac_ext @@ -12440,7 +12383,7 @@ extern int ptrace (); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='int' else gdb_cv_func_ptrace_ret='long' @@ -12474,7 +12417,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args='enum __ptrace_request,int,long,long' else @@ -12496,7 +12439,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4"; break 4; fi @@ -12516,7 +12459,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4,$gdb_arg5"; break 5; @@ -12562,15 +12505,6 @@ _ACEOF fi -if test "$enable_build_with_cxx" = "yes"; then - ac_ext=c -ac_cpp='$CPP $CPPFLAGS' -ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' -ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' -ac_compiler_gnu=$ac_cv_c_compiler_gnu - -fi - if test "$cross_compiling" = no; then { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether setpgrp takes no argument" >&5 @@ -14265,6 +14199,7 @@ _ACEOF + # Check whether --enable-werror was given. if test "${enable_werror+set}" = set; then : enableval=$enable_werror; case "${enableval}" in diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 44c4f12932..495ce41df0 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,7 @@ +2016-04-18 Pedro Alves + + * configure: Regenerate. + 2016-04-13 Antoine Tremblay * linux-aarch64-low.c (aarch64_emit_add): Switch x1 and x0. diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure index bb01922c2c..208233571f 100755 --- a/gdb/gdbserver/configure +++ b/gdb/gdbserver/configure @@ -1939,51 +1939,6 @@ $as_echo "$ac_res" >&6; } } # ac_fn_c_check_decl -# ac_fn_cxx_check_decl LINENO SYMBOL VAR -# -------------------------------------- -# Tests whether SYMBOL is declared, setting cache variable VAR accordingly. -ac_fn_cxx_check_decl () -{ - as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack - as_decl_name=`echo $2|sed 's/ *(.*//'` - as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'` - { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5 -$as_echo_n "checking whether $as_decl_name is declared... " >&6; } -if { as_var=$3; eval "test \"\${$as_var+set}\" = set"; }; then : - $as_echo_n "(cached) " >&6 -else - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -$4 -int -main () -{ -#ifndef $as_decl_name -#ifdef __cplusplus - (void) $as_decl_use; -#else - (void) $as_decl_name; -#endif -#endif - - ; - return 0; -} -_ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : - eval "$3=yes" -else - eval "$3=no" -fi -rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext -fi -eval ac_res=\$$3 - { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 -$as_echo "$ac_res" >&6; } - eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;} - -} # ac_fn_cxx_check_decl - # ac_fn_c_compute_int LINENO EXPR VAR INCLUDES # -------------------------------------------- # Tries to find the compile-time value of EXPR in a program that includes @@ -6030,7 +5985,6 @@ fi # Check the return and argument types of ptrace. - for ac_header in sys/ptrace.h ptrace.h do : as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh` @@ -6046,17 +6000,6 @@ fi done -# Needs to be tested in C++ mode, to detect whether we need to cast -# the first argument to enum __ptrace_request. -if test "$enable_build_with_cxx" = "yes"; then - ac_ext=cpp -ac_cpp='$CXXCPP $CPPFLAGS' -ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' -ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' -ac_compiler_gnu=$ac_cv_cxx_compiler_gnu - -fi - gdb_ptrace_headers=' #include #if HAVE_SYS_PTRACE_H @@ -6067,7 +6010,7 @@ gdb_ptrace_headers=' #endif ' # There is no point in checking if we don't have a prototype. -ac_fn_cxx_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers +ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers " if test "x$ac_cv_have_decl_ptrace" = x""yes; then : ac_have_decl=1 @@ -6105,7 +6048,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='long' else cat confdefs.h - <<_ACEOF >conftest.$ac_ext @@ -6119,7 +6062,7 @@ extern int ptrace (); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='int' else gdb_cv_func_ptrace_ret='long' @@ -6153,7 +6096,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args='enum __ptrace_request,int,long,long' else @@ -6175,7 +6118,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4"; break 4; fi @@ -6195,7 +6138,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_cxx_try_compile "$LINENO"; then : +if ac_fn_c_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4,$gdb_arg5"; break 5; @@ -6241,15 +6184,6 @@ _ACEOF fi -if test "$enable_build_with_cxx" = "yes"; then - ac_ext=c -ac_cpp='$CPP $CPPFLAGS' -ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' -ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' -ac_compiler_gnu=$ac_cv_c_compiler_gnu - -fi - # Check for UST ustlibs="" @@ -6332,6 +6266,7 @@ fi + # Check whether --enable-werror was given. if test "${enable_werror+set}" = set; then : enableval=$enable_werror; case "${enableval}" in diff --git a/gdb/ptrace.m4 b/gdb/ptrace.m4 index ca2b7c63d9..89591d4b67 100644 --- a/gdb/ptrace.m4 +++ b/gdb/ptrace.m4 @@ -22,12 +22,6 @@ AC_DEFUN([GDB_AC_PTRACE], AC_CHECK_HEADERS([sys/ptrace.h ptrace.h]) -# Needs to be tested in C++ mode, to detect whether we need to cast -# the first argument to enum __ptrace_request. -if test "$enable_build_with_cxx" = "yes"; then - AC_LANG_PUSH([C++]) -fi - gdb_ptrace_headers=' #include #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 ])