[RFA,2/2] Add -Wduplicated-cond

Message ID 20180421214721.7232-3-tom@tromey.com
State New
Headers show
Series
  • Add -Wduplicated-cond
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Commit Message

Tom Tromey April 21, 2018, 9:47 p.m.
This adds -Wduplicated-cond to warnings.m4.  This caught one bug.

I tried adding -Wduplicated-branches as well, but it results in some
spurious failures from code like this in cgen.h:

    #define CGEN_ATTR_TYPE(n) \
    struct { unsigned int bool_; \
	     CGEN_ATTR_VALUE_TYPE nonbool[(n) ? (n) : 1]; }

This will trigger a warning if passed n==1, which seems like a
perfectly valid thing to do; and there were other issues like this as
well.

2018-04-21  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
	* warning.m4 (AM_GDB_WARNINGS): Add -Wduplicated-cond.

gdbserver/ChangeLog
2018-04-21  Tom Tromey  <tom@tromey.com>

	* configure: Rebuild.
---
 gdb/ChangeLog           |  5 +++++
 gdb/configure           | 27 ++++++++++++++-------------
 gdb/gdbserver/ChangeLog |  4 ++++
 gdb/gdbserver/configure | 32 ++++++++++++++++++++------------
 gdb/warning.m4          |  3 ++-
 5 files changed, 45 insertions(+), 26 deletions(-)

-- 
2.13.6

Comments

Pedro Alves April 22, 2018, 3:46 p.m. | #1
On 04/21/2018 10:47 PM, Tom Tromey wrote:

> diff --git a/gdb/configure b/gdb/configure

> index b313152018..29efb4b81c 100755

> --- a/gdb/configure

> +++ b/gdb/configure

> @@ -4463,9 +4463,9 @@ else

>  fi

>  

>    if test "$plugins" = "yes"; then

> -    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5

> -$as_echo_n "checking for library containing dlopen... " >&6; }

> -if test "${ac_cv_search_dlopen+set}" = set; then :

> +    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5

> +$as_echo_n "checking for library containing dlsym... " >&6; }

> +if test "${ac_cv_search_dlsym+set}" = set; then :

>    $as_echo_n "(cached) " >&6

>  else

>    ac_func_search_save_LIBS=$LIBS

> @@ -4478,11 +4478,11 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext

>  #ifdef __cplusplus

>  extern "C"

>  #endif

> -char dlopen ();

> +char dlsym ();

>  int

>  main ()

>  {

> -return dlopen ();

> +return dlsym ();

>    ;

>    return 0;

>  }

> @@ -4495,25 +4495,25 @@ for ac_lib in '' dl; do

>      LIBS="-l$ac_lib  $ac_func_search_save_LIBS"

>    fi

>    if ac_fn_c_try_link "$LINENO"; then :

> -  ac_cv_search_dlopen=$ac_res

> +  ac_cv_search_dlsym=$ac_res

>  fi

>  rm -f core conftest.err conftest.$ac_objext \

>      conftest$ac_exeext

> -  if test "${ac_cv_search_dlopen+set}" = set; then :

> +  if test "${ac_cv_search_dlsym+set}" = set; then :

>    break

>  fi

>  done

> -if test "${ac_cv_search_dlopen+set}" = set; then :

> +if test "${ac_cv_search_dlsym+set}" = set; then :

>  

>  else

> -  ac_cv_search_dlopen=no

> +  ac_cv_search_dlsym=no

>  fi

>  rm conftest.$ac_ext

>  LIBS=$ac_func_search_save_LIBS

>  fi

> -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5

> -$as_echo "$ac_cv_search_dlopen" >&6; }

> -ac_res=$ac_cv_search_dlopen

> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5

> +$as_echo "$ac_cv_search_dlsym" >&6; }

> +ac_res=$ac_cv_search_dlsym

>  if test "$ac_res" != no; then :

>    test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"

>  

> @@ -15365,7 +15365,8 @@ build_warnings="-Wall -Wpointer-arith \

>  -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \

>  -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \

>  -Wno-mismatched-tags \

> --Wno-error=deprecated-register"

> +-Wno-error=deprecated-register \

> +-Wduplicated-cond"

>  

>  case "${host}" in

>    *-*-mingw32*)

> diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure

> index ab09261946..48af8310d9 100755

> --- a/gdb/gdbserver/configure

> +++ b/gdb/gdbserver/configure

> @@ -4658,7 +4658,7 @@ program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`

>  # We require a C++11 compiler.  Check if one is available, and if

>  # necessary, set CXX_DIALECT to some -std=xxx switch.

>  

> -      ax_cxx_compile_cxx11_required=true

> +  ax_cxx_compile_alternatives="11 0x"    ax_cxx_compile_cxx11_required=true

>    ac_ext=cpp

>  ac_cpp='$CXXCPP $CPPFLAGS'

>  ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'

> @@ -4974,7 +4974,8 @@ $as_echo "$ax_cv_cxx_compile_cxx11" >&6; }

>    fi

>  

>      if test x$ac_success = xno; then

> -    for switch in -std=gnu++11 -std=gnu++0x; do

> +    for alternative in ${ax_cxx_compile_alternatives}; do

> +      switch="-std=gnu++${alternative}"

>        cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`

>        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5

>  $as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }

> @@ -5292,16 +5293,17 @@ $as_echo "$ac_res" >&6; }

>    fi

>  

>      if test x$ac_success = xno; then

> -                for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do

> -      cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`

> -      { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5

> +                for alternative in ${ax_cxx_compile_alternatives}; do

> +      for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do

> +        cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`

> +        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5

>  $as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }

>  if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then :

>    $as_echo_n "(cached) " >&6

>  else

>    ac_save_CXX="$CXX"

> -         CXX="$CXX $switch"

> -         cat confdefs.h - <<_ACEOF >conftest.$ac_ext

> +           CXX="$CXX $switch"

> +           cat confdefs.h - <<_ACEOF >conftest.$ac_ext

>  /* end confdefs.h.  */

>  

>  

> @@ -5596,14 +5598,18 @@ else

>    eval $cachevar=no

>  fi

>  rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext

> -         CXX="$ac_save_CXX"

> +           CXX="$ac_save_CXX"

>  fi

>  eval ac_res=\$$cachevar

>  	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5

>  $as_echo "$ac_res" >&6; }

> -      if eval test x\$$cachevar = xyes; then

> -        CXX_DIALECT="$switch"

> -        ac_success=yes

> +        if eval test x\$$cachevar = xyes; then

> +          CXX_DIALECT="$switch"

> +          ac_success=yes

> +          break

> +        fi

> +      done

> +      if test x$ac_success = xyes; then

>          break

>        fi

>      done

The patch looks fine to me, but the above looks like unrelated changes.
Very much looks like gdbserver/configure was not regenerated
when gdb/warning.m4 was last touched for -Wno-error=deprecated-register,
and  gdb's configure hadn't picked up the changes to config/plugin.m4
yet either.

Could you please push the obvious preliminary patch that just
regenerates gdb/configure and gdbserver/configure,
then rebase your patch on top of that.

I've not looked at the ARM patch; Alan, do you know who can
lend a hand with that?

Thanks,
Pedro Alves
Tom Tromey April 24, 2018, 11:07 p.m. | #2
>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:


Pedro> Could you please push the obvious preliminary patch that just
Pedro> regenerates gdb/configure and gdbserver/configure,
Pedro> then rebase your patch on top of that.

I did this the other day.

Tom

Patch

diff --git a/gdb/configure b/gdb/configure
index b313152018..29efb4b81c 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -4463,9 +4463,9 @@  else
 fi
 
   if test "$plugins" = "yes"; then
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
-$as_echo_n "checking for library containing dlopen... " >&6; }
-if test "${ac_cv_search_dlopen+set}" = set; then :
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlsym" >&5
+$as_echo_n "checking for library containing dlsym... " >&6; }
+if test "${ac_cv_search_dlsym+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
   ac_func_search_save_LIBS=$LIBS
@@ -4478,11 +4478,11 @@  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 #ifdef __cplusplus
 extern "C"
 #endif
-char dlopen ();
+char dlsym ();
 int
 main ()
 {
-return dlopen ();
+return dlsym ();
   ;
   return 0;
 }
@@ -4495,25 +4495,25 @@  for ac_lib in '' dl; do
     LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
   fi
   if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_dlopen=$ac_res
+  ac_cv_search_dlsym=$ac_res
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext
-  if test "${ac_cv_search_dlopen+set}" = set; then :
+  if test "${ac_cv_search_dlsym+set}" = set; then :
   break
 fi
 done
-if test "${ac_cv_search_dlopen+set}" = set; then :
+if test "${ac_cv_search_dlsym+set}" = set; then :
 
 else
-  ac_cv_search_dlopen=no
+  ac_cv_search_dlsym=no
 fi
 rm conftest.$ac_ext
 LIBS=$ac_func_search_save_LIBS
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
-$as_echo "$ac_cv_search_dlopen" >&6; }
-ac_res=$ac_cv_search_dlopen
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlsym" >&5
+$as_echo "$ac_cv_search_dlsym" >&6; }
+ac_res=$ac_cv_search_dlsym
 if test "$ac_res" != no; then :
   test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
 
@@ -15365,7 +15365,8 @@  build_warnings="-Wall -Wpointer-arith \
 -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
 -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \
 -Wno-mismatched-tags \
--Wno-error=deprecated-register"
+-Wno-error=deprecated-register \
+-Wduplicated-cond"
 
 case "${host}" in
   *-*-mingw32*)
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index ab09261946..48af8310d9 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -4658,7 +4658,7 @@  program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`
 # We require a C++11 compiler.  Check if one is available, and if
 # necessary, set CXX_DIALECT to some -std=xxx switch.
 
-      ax_cxx_compile_cxx11_required=true
+  ax_cxx_compile_alternatives="11 0x"    ax_cxx_compile_cxx11_required=true
   ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -4974,7 +4974,8 @@  $as_echo "$ax_cv_cxx_compile_cxx11" >&6; }
   fi
 
     if test x$ac_success = xno; then
-    for switch in -std=gnu++11 -std=gnu++0x; do
+    for alternative in ${ax_cxx_compile_alternatives}; do
+      switch="-std=gnu++${alternative}"
       cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
 $as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
@@ -5292,16 +5293,17 @@  $as_echo "$ac_res" >&6; }
   fi
 
     if test x$ac_success = xno; then
-                for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do
-      cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+                for alternative in ${ax_cxx_compile_alternatives}; do
+      for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+        cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
 $as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
 if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then :
   $as_echo_n "(cached) " >&6
 else
   ac_save_CXX="$CXX"
-         CXX="$CXX $switch"
-         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+           CXX="$CXX $switch"
+           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 
@@ -5596,14 +5598,18 @@  else
   eval $cachevar=no
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-         CXX="$ac_save_CXX"
+           CXX="$ac_save_CXX"
 fi
 eval ac_res=\$$cachevar
 	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
 $as_echo "$ac_res" >&6; }
-      if eval test x\$$cachevar = xyes; then
-        CXX_DIALECT="$switch"
-        ac_success=yes
+        if eval test x\$$cachevar = xyes; then
+          CXX_DIALECT="$switch"
+          ac_success=yes
+          break
+        fi
+      done
+      if test x$ac_success = xyes; then
         break
       fi
     done
@@ -7165,7 +7171,9 @@  build_warnings="-Wall -Wpointer-arith \
 -Wno-switch -Wno-char-subscripts \
 -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
 -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \
--Wno-mismatched-tags"
+-Wno-mismatched-tags \
+-Wno-error=deprecated-register \
+-Wduplicated-cond"
 
 case "${host}" in
   *-*-mingw32*)
diff --git a/gdb/warning.m4 b/gdb/warning.m4
index 3cfae65e78..2c85933c8d 100644
--- a/gdb/warning.m4
+++ b/gdb/warning.m4
@@ -42,7 +42,8 @@  build_warnings="-Wall -Wpointer-arith \
 -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
 -Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized \
 -Wno-mismatched-tags \
--Wno-error=deprecated-register"
+-Wno-error=deprecated-register \
+-Wduplicated-cond"
 
 case "${host}" in
   *-*-mingw32*)