We're actually -Wmissing-field-initializers clean thanks to the cmake

build so check and turn on -Wmissing-field-initializers. While there,
reorganize the conditional warning code based on compiler to be a bit
more obvious and inside a switch statement.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244330 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 54 insertions, 40 deletions

diff --git a/Makefile.config.in b/Makefile.config.in
index 9df9834f4db..5ca264320c5 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -396,8 +396,8 @@ endif
 BINUTILS_INCDIR := @BINUTILS_INCDIR@
 
 # Optional flags supported by the compiler
-# -Wno-missing-field-initializers
-NO_MISSING_FIELD_INITIALIZERS = @NO_MISSING_FIELD_INITIALIZERS@
+# -Wmissing-field-initializers
+MISSING_FIELD_INITIALIZERS = @MISSING_FIELD_INITIALIZERS@
 # -Wno-variadic-macros
 NO_VARIADIC_MACROS = @NO_VARIADIC_MACROS@
 # -Wcovered-switch-default
diff --git a/Makefile.rules b/Makefile.rules
index 24cac3b3765..42d6a96cf52 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -686,7 +686,7 @@ endif
 CompileCommonOpts += -Wall -W -Wno-unused-parameter -Wwrite-strings \
                      $(EXTRA_OPTIONS) $(COVERED_SWITCH_DEFAULT) \
                      $(NO_UNINITIALIZED) $(NO_MAYBE_UNINITIALIZED) \
-                     $(NO_MISSING_FIELD_INITIALIZERS) $(NO_COMMENT)
+                     $(MISSING_FIELD_INITIALIZERS) $(NO_COMMENT)
 # Enable cast-qual for C++; the workaround is to use const_cast.
 CXX.Flags += -Wcast-qual
 
diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 0451f7e3cfa..26f6ee46889 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -1548,25 +1548,31 @@ AC_MSG_RESULT([ok])
 
 dnl Check optional compiler flags.
 AC_MSG_CHECKING([optional compiler flags])
-CXX_FLAG_CHECK(NO_VARIADIC_MACROS, [-Wno-variadic-macros])
-CXX_FLAG_CHECK(NO_MISSING_FIELD_INITIALIZERS, [-Wno-missing-field-initializers])
-CXX_FLAG_CHECK(COVERED_SWITCH_DEFAULT, [-Wcovered-switch-default])
-
-dnl GCC's potential uninitialized use analysis is weak and presents lots of
-dnl false positives, so disable it.
-NO_UNINITIALIZED=
-NO_MAYBE_UNINITIALIZED=
-if test "$GXX" = "yes"
-then
-  CXX_FLAG_CHECK(NO_MAYBE_UNINITIALIZED, [-Wno-maybe-uninitialized])
-  dnl gcc 4.7 introduced -Wmaybe-uninitialized to distinguish cases which are
-  dnl known to be uninitialized from cases which might be uninitialized.  We
-  dnl still want to catch the first kind of errors.
-  if test -z "$NO_MAYBE_UNINITIALIZED"
-  then
-    CXX_FLAG_CHECK(NO_UNINITIALIZED, [-Wno-uninitialized])
-  fi
-fi
+case "$llvm_cv_cxx_compiler" in
+  clang)
+    CXX_FLAG_CHECK(NO_VARIADIC_MACROS, [-Wno-variadic-macros])
+    CXX_FLAG_CHECK(MISSING_FIELD_INITIALIZERS, [-Wmissing-field-initializers])
+    CXX_FLAG_CHECK(COVERED_SWITCH_DEFAULT, [-Wcovered-switch-default])
+    ;;
+  gcc)
+    dnl If we're using gcc check for -Wno-missing-field-initializers as gcc will warn
+    dnl on plain open brace initializations. clang won't so use -Wmissing-field-initializers
+    dnl there.
+    CXX_FLAG_CHECK(MISSING_FIELD_INITIALIZERS, [-Wno-missing-field-initializers])
+    CXX_FLAG_CHECK(NO_VARIADIC_MACROS, [-Wno-variadic-macros])
+    CXX_FLAG_CHECK(COVERED_SWITCH_DEFAULT, [-Wcovered-switch-default])
+    CXX_FLAG_CHECK(NO_MAYBE_UNINITIALIZED, [-Wno-maybe-uninitialized])
+    dnl gcc 4.7 introduced -Wmaybe-uninitialized to distinguish cases which are
+    dnl known to be uninitialized from cases which might be uninitialized.  We
+    dnl still want to catch the first kind of errors.
+    if test -z "$NO_MAYBE_UNINITIALIZED"
+    then
+      CXX_FLAG_CHECK(NO_UNINITIALIZED, [-Wno-uninitialized])
+    fi
+    ;;
+  unknown)
+    ;;
+esac
 
 dnl Check for misbehaving -Wcomment (gcc-4.7 has this) and maybe add
 dnl -Wno-comment to the flags.
@@ -1587,7 +1593,7 @@ int main() { return 0; }
 AC_SUBST(NO_COMMENT, [$no_comment])
 CXXFLAGS="$llvm_cv_old_cxxflags"
 
-AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT])
+AC_MSG_RESULT([$NO_VARIADIC_MACROS $MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT])
 
 AC_ARG_WITH([python],
             [AS_HELP_STRING([--with-python], [path to python])],
diff --git a/configure b/configure
index 5b5cbf25be0..b5ccaff17ce 100755
--- a/configure
+++ b/configure
@@ -777,7 +777,7 @@ GAS
 HAVE_LINK_VERSION_SCRIPT
 EGREP
 NO_VARIADIC_MACROS
-NO_MISSING_FIELD_INITIALIZERS
+MISSING_FIELD_INITIALIZERS
 COVERED_SWITCH_DEFAULT
 NO_MAYBE_UNINITIALIZED
 NO_UNINITIALIZED
@@ -8379,25 +8379,33 @@ echo "${ECHO_T}ok" >&6; }
 
 { echo "$as_me:$LINENO: checking optional compiler flags" >&5
 echo $ECHO_N "checking optional compiler flags... $ECHO_C" >&6; }
-NO_VARIADIC_MACROS=`$CXX -Werror -Wvariadic-macros -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-variadic-macros`
+case "$llvm_cv_cxx_compiler" in
+  clang)
+    NO_VARIADIC_MACROS=`$CXX -Werror -Wvariadic-macros -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-variadic-macros`
 
-NO_MISSING_FIELD_INITIALIZERS=`$CXX -Werror -Wmissing-field-initializers -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-missing-field-initializers`
+    MISSING_FIELD_INITIALIZERS=`$CXX -Werror -Wmissing-field-initializers -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wmissing-field-initializers`
 
-COVERED_SWITCH_DEFAULT=`$CXX -Werror -Wcovered-switch-default -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wcovered-switch-default`
+    COVERED_SWITCH_DEFAULT=`$CXX -Werror -Wcovered-switch-default -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wcovered-switch-default`
 
+    ;;
+  gcc)
+                MISSING_FIELD_INITIALIZERS=`$CXX -Werror -Wmissing-field-initializers -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-missing-field-initializers`
 
-NO_UNINITIALIZED=
-NO_MAYBE_UNINITIALIZED=
-if test "$GXX" = "yes"
-then
-  NO_MAYBE_UNINITIALIZED=`$CXX -Werror -Wmaybe-uninitialized -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-maybe-uninitialized`
+    NO_VARIADIC_MACROS=`$CXX -Werror -Wvariadic-macros -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-variadic-macros`
 
-        if test -z "$NO_MAYBE_UNINITIALIZED"
-  then
-    NO_UNINITIALIZED=`$CXX -Werror -Wuninitialized -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-uninitialized`
+    COVERED_SWITCH_DEFAULT=`$CXX -Werror -Wcovered-switch-default -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wcovered-switch-default`
 
-  fi
-fi
+    NO_MAYBE_UNINITIALIZED=`$CXX -Werror -Wmaybe-uninitialized -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-maybe-uninitialized`
+
+                if test -z "$NO_MAYBE_UNINITIALIZED"
+    then
+      NO_UNINITIALIZED=`$CXX -Werror -Wuninitialized -fsyntax-only -xc /dev/null 2>/dev/null && echo -Wno-uninitialized`
+
+    fi
+    ;;
+  unknown)
+    ;;
+esac
 
 no_comment=
 llvm_cv_old_cxxflags="$CXXFLAGS"
@@ -8464,8 +8472,8 @@ NO_COMMENT=$no_comment
 
 CXXFLAGS="$llvm_cv_old_cxxflags"
 
-{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT" >&5
-echo "${ECHO_T}$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT" >&6; }
+{ echo "$as_me:$LINENO: result: $NO_VARIADIC_MACROS $MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT" >&5
+echo "${ECHO_T}$NO_VARIADIC_MACROS $MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED $NO_COMMENT" >&6; }
 
 
 # Check whether --with-python was given.
@@ -18653,7 +18661,7 @@ GAS!$GAS$ac_delim
 HAVE_LINK_VERSION_SCRIPT!$HAVE_LINK_VERSION_SCRIPT$ac_delim
 EGREP!$EGREP$ac_delim
 NO_VARIADIC_MACROS!$NO_VARIADIC_MACROS$ac_delim
-NO_MISSING_FIELD_INITIALIZERS!$NO_MISSING_FIELD_INITIALIZERS$ac_delim
+MISSING_FIELD_INITIALIZERS!$MISSING_FIELD_INITIALIZERS$ac_delim
 COVERED_SWITCH_DEFAULT!$COVERED_SWITCH_DEFAULT$ac_delim
 NO_MAYBE_UNINITIALIZED!$NO_MAYBE_UNINITIALIZED$ac_delim
 NO_UNINITIALIZED!$NO_UNINITIALIZED$ac_delim