From 54019719152ab269fb4cec2c6a8a245ba6af6e49 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 24 Jul 2015 14:57:20 +0100 Subject: [PATCH] C++: handle glibc's ptrace(enum __ptrace_request, ...) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Building in C++ mode issues ~40 warnings like this: ../../src/gdb/linux-nat.c: In function ‘int linux_handle_extended_wait(lwp_info*, int, int)’: ../../src/gdb/linux-nat.c:2016:51: warning: invalid conversion from ‘int’ to ‘__ptrace_request’ [-fpermissive] ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); The issue is that in glibc, ptrace's first parameter is an enum. That's not a problem if we pick the PTRACE_XXX requests from sys/ptrace.h, as those will be values of the corresponding enum. However, we have fallback definitions for PTRACE_XXX symbols when the system headers miss them (such as PTRACE_GETEVENTMSG above), and those are plain integer constants. E.g., nat/linux-ptrace.h: #define PTRACE_GETEVENTMSG 0x4201 One idea would be to fix this by defining those fallbacks like: -#define PTRACE_GETEVENTMSG 0x4201 +#define PTRACE_GETEVENTMSG ((enum __ptrace_request) 0x4201) However, while glibc's ptrace uses enum __ptrace_request for first parameter: extern long int ptrace (enum __ptrace_request __request, ...) __THROW; other libc's, like e.g., Android's bionic do not -- in that case, the first parameter is int: long ptrace(int request, pid_t pid, void * addr, void * data); So the fix I came up is to make configure/ptrace.m4 also detect the type of the ptrace's first parameter and defin PTRACE_TYPE_ARG1, as already does the for parameters 3-4, and then simply wrap ptrace with a macro that casts the first argument to the detected type. (I'm leaving adding a nicer wrapper for when we drop building in C). While this adds the wrapper, GNU/Linux files won't use it until the next patch, which makes all native GNU/Linux files include gdb_ptrace.h. gdb/ChangeLog: 2015-07-24 Pedro Alves * ptrace.m4 (ptrace tests): Test in C++ mode. Try with 'enum __ptrace_request as first parameter type instead of int. (PTRACE_TYPE_ARG1): Define. * nat/gdb_ptrace.h [!PTRACE_TYPE_ARG5] (ptrace): Define as wrapper that casts first argument to PTRACE_TYPE_ARG1. * config.in: Regenerate. * configure: Regenerate. gdb/gdbserver/ChangeLog: 2015-07-24 Pedro Alves * config.in: Regenerate. * configure: Regenerate. --- gdb/ChangeLog | 10 ++++ gdb/config.in | 3 ++ gdb/configure | 109 ++++++++++++++++++++++++++++++++++++---- gdb/gdbserver/ChangeLog | 5 ++ gdb/gdbserver/config.in | 3 ++ gdb/gdbserver/configure | 88 ++++++++++++++++++++++++++++---- gdb/nat/gdb_ptrace.h | 4 ++ gdb/ptrace.m4 | 14 +++++- 8 files changed, 215 insertions(+), 21 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0272d67eea7..57be70778c5 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2015-07-24 Pedro Alves + + * ptrace.m4 (ptrace tests): Test in C++ mode. Try with 'enum + __ptrace_request as first parameter type instead of int. + (PTRACE_TYPE_ARG1): Define. + * nat/gdb_ptrace.h [!PTRACE_TYPE_ARG5] (ptrace): Define as wrapper + that casts first argument to PTRACE_TYPE_ARG1. + * config.in: Regenerate. + * configure: Regenerate. + 2015-07-24 Pedro Alves * gdb_ptrace.h: Move ... diff --git a/gdb/config.in b/gdb/config.in index 9ef53b3fb7f..d1880884bee 100644 --- a/gdb/config.in +++ b/gdb/config.in @@ -653,6 +653,9 @@ assorted other type changes. */ #undef PROC_SERVICE_IS_OLD +/* Define to the type of arg 1 for ptrace. */ +#undef PTRACE_TYPE_ARG1 + /* Define to the type of arg 3 for ptrace. */ #undef PTRACE_TYPE_ARG3 diff --git a/gdb/configure b/gdb/configure index e8979f03218..e1b778b2103 100755 --- a/gdb/configure +++ b/gdb/configure @@ -2398,6 +2398,51 @@ $as_echo "$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. @@ -11926,8 +11971,36 @@ $as_echo "#define HAVE_SIGSETJMP 1" >>confdefs.h fi -# Check the return and argument types of ptrace. No canned test for -# this, so roll our own. +# Check the return and argument types of ptrace. + + + +for ac_header in sys/ptrace.h ptrace.h +do : + as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh` +ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default" +eval as_val=\$$as_ac_Header + if test "x$as_val" = x""yes; then : + cat >>confdefs.h <<_ACEOF +#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1 +_ACEOF + +fi + +done + + +# Needs to be tested in C++ mode, to detect whether we need to cast +# the first argument to enum __ptrace_request. +if test "$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 @@ -11938,7 +12011,7 @@ gdb_ptrace_headers=' #endif ' # There is no point in checking if we don't have a prototype. -ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers +ac_fn_cxx_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers " if test "x$ac_cv_have_decl_ptrace" = x""yes; then : ac_have_decl=1 @@ -11976,7 +12049,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='long' else cat confdefs.h - <<_ACEOF >conftest.$ac_ext @@ -11990,7 +12063,7 @@ extern int ptrace (); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='int' else gdb_cv_func_ptrace_ret='long' @@ -12024,8 +12097,8 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : - gdb_cv_func_ptrace_args='int,int,long,long' +if ac_fn_cxx_try_compile "$LINENO"; then : + gdb_cv_func_ptrace_args='enum __ptrace_request,int,long,long' else for gdb_arg1 in 'int' 'long'; do @@ -12046,7 +12119,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4"; break 4; fi @@ -12066,7 +12139,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4,$gdb_arg5"; break 5; @@ -12090,6 +12163,11 @@ set dummy `echo "$gdb_cv_func_ptrace_args" | sed 's/\*/\*/g'` IFS=$ac_save_IFS shift +cat >>confdefs.h <<_ACEOF +#define PTRACE_TYPE_ARG1 $1 +_ACEOF + + cat >>confdefs.h <<_ACEOF #define PTRACE_TYPE_ARG3 $3 _ACEOF @@ -12107,6 +12185,16 @@ _ACEOF fi +if test "$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 $as_echo_n "checking whether setpgrp takes no argument... " >&6; } @@ -13925,8 +14013,7 @@ $as_echo_n "checking compiler warning flags... " >&6; } CFLAGS="$CFLAGS $w" saved_CXXFLAGS="$CXXFLAGS" CXXFLAGS="$CXXFLAGS $w" - -cat confdefs.h - <<_ACEOF >conftest.$ac_ext + cat confdefs.h - <<_ACEOF >conftest.$ac_ext /* end confdefs.h. */ int diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index d1f10cd206c..664f674aa27 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,8 @@ +2015-07-24 Pedro Alves + + * config.in: Regenerate. + * configure: Regenerate. + 2015-07-24 Pedro Alves * acinclude.m4: Include ../ptrace.m4. diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in index 6f2d0a1ea79..e2566a9c9ea 100644 --- a/gdb/gdbserver/config.in +++ b/gdb/gdbserver/config.in @@ -310,6 +310,9 @@ /* Additional package description */ #undef PKGVERSION +/* Define to the type of arg 1 for ptrace. */ +#undef PTRACE_TYPE_ARG1 + /* Define to the type of arg 3 for ptrace. */ #undef PTRACE_TYPE_ARG3 diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure index fc6b9664702..409f42bf388 100755 --- a/gdb/gdbserver/configure +++ b/gdb/gdbserver/configure @@ -1878,6 +1878,51 @@ $as_echo "$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_check_type LINENO TYPE VAR INCLUDES # ------------------------------------------- # Tests whether TYPE exists after having included INCLUDES, setting cache @@ -5751,6 +5796,7 @@ 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" | $as_tr_sh` @@ -5766,6 +5812,17 @@ fi done +# Needs to be tested in C++ mode, to detect whether we need to cast +# the first argument to enum __ptrace_request. +if test "$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 @@ -5776,7 +5833,7 @@ gdb_ptrace_headers=' #endif ' # There is no point in checking if we don't have a prototype. -ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers +ac_fn_cxx_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers " if test "x$ac_cv_have_decl_ptrace" = x""yes; then : ac_have_decl=1 @@ -5814,7 +5871,7 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='long' else cat confdefs.h - <<_ACEOF >conftest.$ac_ext @@ -5828,7 +5885,7 @@ extern int ptrace (); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_ret='int' else gdb_cv_func_ptrace_ret='long' @@ -5862,8 +5919,8 @@ extern long ptrace (enum __ptrace_request, ...); return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : - gdb_cv_func_ptrace_args='int,int,long,long' +if ac_fn_cxx_try_compile "$LINENO"; then : + gdb_cv_func_ptrace_args='enum __ptrace_request,int,long,long' else for gdb_arg1 in 'int' 'long'; do @@ -5884,7 +5941,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4"; break 4; fi @@ -5904,7 +5961,7 @@ extern $gdb_cv_func_ptrace_ret return 0; } _ACEOF -if ac_fn_c_try_compile "$LINENO"; then : +if ac_fn_cxx_try_compile "$LINENO"; then : gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4,$gdb_arg5"; break 5; @@ -5928,6 +5985,11 @@ set dummy `echo "$gdb_cv_func_ptrace_args" | sed 's/\*/\*/g'` IFS=$ac_save_IFS shift +cat >>confdefs.h <<_ACEOF +#define PTRACE_TYPE_ARG1 $1 +_ACEOF + + cat >>confdefs.h <<_ACEOF #define PTRACE_TYPE_ARG3 $3 _ACEOF @@ -5945,6 +6007,15 @@ _ACEOF fi +if test "$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="" @@ -6087,8 +6158,7 @@ $as_echo_n "checking compiler warning flags... " >&6; } CFLAGS="$CFLAGS $w" saved_CXXFLAGS="$CXXFLAGS" CXXFLAGS="$CXXFLAGS $w" - -cat confdefs.h - <<_ACEOF >conftest.$ac_ext + cat confdefs.h - <<_ACEOF >conftest.$ac_ext /* end confdefs.h. */ int diff --git a/gdb/nat/gdb_ptrace.h b/gdb/nat/gdb_ptrace.h index a9696815598..0a98239183d 100644 --- a/gdb/nat/gdb_ptrace.h +++ b/gdb/nat/gdb_ptrace.h @@ -144,6 +144,10 @@ extern PTRACE_TYPE_RET ptrace(); # define ptrace(request, pid, addr, data) \ ptrace (request, pid, addr, data, 0) # endif +#else +/* Wrapper that avoids adding a pointless cast to all callers. */ +# define ptrace(request, pid, addr, data) \ + ptrace ((PTRACE_TYPE_ARG1) request, pid, addr, data) #endif #endif /* gdb_ptrace.h */ diff --git a/gdb/ptrace.m4 b/gdb/ptrace.m4 index e5fe7fa9660..f01c692c205 100644 --- a/gdb/ptrace.m4 +++ b/gdb/ptrace.m4 @@ -22,6 +22,12 @@ AC_DEFUN([GDB_AC_PTRACE], AC_CHECK_HEADERS([sys/ptrace.h ptrace.h]) +# Needs to be tested in C++ mode, to detect whether we need to cast +# the first argument to enum __ptrace_request. +if test "$enable_build_with_cxx" = "yes"; then + AC_LANG_PUSH([C++]) +fi + gdb_ptrace_headers=' #include #if HAVE_SYS_PTRACE_H @@ -52,7 +58,7 @@ AC_DEFINE_UNQUOTED(PTRACE_TYPE_RET, $gdb_cv_func_ptrace_ret, AC_CACHE_CHECK([types of arguments for ptrace], gdb_cv_func_ptrace_args, [ AC_TRY_COMPILE($gdb_ptrace_headers, [extern long ptrace (enum __ptrace_request, ...);], - [gdb_cv_func_ptrace_args='int,int,long,long'],[ + [gdb_cv_func_ptrace_args='enum __ptrace_request,int,long,long'],[ for gdb_arg1 in 'int' 'long'; do for gdb_arg2 in 'pid_t' 'int' 'long'; do for gdb_arg3 in 'int *' 'caddr_t' 'int' 'long' 'void *'; do @@ -81,6 +87,8 @@ ac_save_IFS=$IFS; IFS=',' set dummy `echo "$gdb_cv_func_ptrace_args" | sed 's/\*/\*/g'` IFS=$ac_save_IFS shift +AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG1, $[1], + [Define to the type of arg 1 for ptrace.]) AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG3, $[3], [Define to the type of arg 3 for ptrace.]) AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG4, $[4], @@ -89,4 +97,8 @@ if test -n "$[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 ]) -- 2.30.2