icc adjustments:

Enable more icc warnings.

  Optimization disabling options used only for icc 9.1

m4/cares-compilers.m4

@@ -16,7 +16,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 41
+# serial 42
 
 
 dnl CARES_CHECK_COMPILER
@@ -923,9 +923,31 @@ AC_DEFUN([CARES_SET_COMPILER_WARNING_OPTS], [
             tmp_CPPFLAGS="$tmp_CPPFLAGS -Wall -w2"
             dnl Perform extra compile-time code checking
             tmp_CPPFLAGS="$tmp_CPPFLAGS -Wcheck"
+            dnl Warn on nested comments
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wcomment"
+            dnl Show warnings relative to deprecated features
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wdeprecated"
+            dnl Enable warnings for missing prototypes
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wmissing-prototypes"
+            dnl Enable warnings for 64-bit portability issues
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wp64"
+            dnl Enable warnings for questionable pointer arithmetic
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wpointer-arith"
+            dnl Check for function return typw issues
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wreturn-type"
+            dnl Warn on variable declarations hiding a previous one
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wshadow"
+            dnl Warn when a variable is used before initialized
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wuninitialized"
+            dnl Warn if a declared function is not used
+            tmp_CPPFLAGS="$tmp_CPPFLAGS -Wunused-function"
           fi
           dnl Disable using EBP register in optimizations
           tmp_CFLAGS="$tmp_CFLAGS -fno-omit-frame-pointer"
+          dnl Disable use of ANSI C aliasing rules in optimizations
+          tmp_CFLAGS="$tmp_CFLAGS -no-ansi-alias"
+          dnl Disable some optimizations to debug icc 9.1 SIGSEGV
+          if test "$INTEL_UNIX_C_OPT_SIGSEGV" = "yes"; then
             dnl Disable inlining of user-defined functions
             tmp_CFLAGS="$tmp_CFLAGS -Ob0"
             dnl Disable inline expansion of intrinsic functions
@@ -942,8 +964,6 @@ AC_DEFUN([CARES_SET_COMPILER_WARNING_OPTS], [
             tmp_CFLAGS="$tmp_CFLAGS -fpstkchk"
             dnl Enable run-time detection of buffer overruns.
             tmp_CFLAGS="$tmp_CFLAGS -fstack-security-check"
-          dnl Disable use of ANSI C aliasing rules in optimizations
-          tmp_CFLAGS="$tmp_CFLAGS -no-ansi-alias"
             dnl Disable floating point optimizations
             tmp_CFLAGS="$tmp_CFLAGS -fp-model precise"
             dnl Assume aliasing in the program.
@@ -957,6 +977,7 @@ AC_DEFUN([CARES_SET_COMPILER_WARNING_OPTS], [
             dnl Disable loop unrolling optimization
             tmp_CFLAGS="$tmp_CFLAGS -unroll0"
           fi
+        fi
         ;;
         #
       INTEL_WINDOWS_C)
@@ -970,7 +991,7 @@ AC_DEFUN([CARES_SET_COMPILER_WARNING_OPTS], [
         if test "$want_warnings" = "yes"; then
           dnl Highest warning level is double -A, next is single -A.
           dnl Due to the big number of warnings these trigger on third
-          dnl party header files it is impratical for us to use any of
+          dnl party header files it is impractical for us to use any of
           dnl them here. If you want them simply define it in CPPFLAGS.
           tmp_CFLAGS="$tmp_CFLAGS"
         fi