Initial attempt to support configure's --(dis|en)able-optimize

option to specify dis(activation) of compiler optimizations.

If option is specified, it will be honored independant of the
--(dis|en)able-debug option.

1 files changed, 66 insertions, 10 deletions

diff --git a/m4/curl-confopts.m4 b/m4/curl-confopts.m4
index 0c125d9c3..b0c1f3cd4 100644
--- a/m4/curl-confopts.m4
+++ b/m4/curl-confopts.m4
@@ -22,7 +22,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 2
+# serial 3
 
 
 dnl CURL_CHECK_OPTION_DEBUG
@@ -33,13 +33,13 @@ dnl variable want_debug value as appropriate.
 
 AC_DEFUN([CURL_CHECK_OPTION_DEBUG], [
   AC_BEFORE([$0],[CURL_CHECK_OPTION_WARNINGS])dnl
-  AC_BEFORE([$0],[AC_PROG_CC])dnl
+  AC_BEFORE([$0],[CURL_CHECK_PROG_CC])dnl
   AC_MSG_CHECKING([whether to enable debug build options])
   OPT_DEBUG_BUILD="default"
   AC_ARG_ENABLE(debug,
-    AC_HELP_STRING([--enable-debug],[Enable debug build options])
-    AC_HELP_STRING([--disable-debug],[Disable debug build options]),
-    OPT_DEBUG_BUILD=$enableval)
+AC_HELP_STRING([--enable-debug],[Enable debug build options])
+AC_HELP_STRING([--disable-debug],[Disable debug build options]),
+  OPT_DEBUG_BUILD=$enableval)
   case "$OPT_DEBUG_BUILD" in
     no)
       dnl --disable-debug option used
@@ -58,21 +58,77 @@ AC_DEFUN([CURL_CHECK_OPTION_DEBUG], [
 ])
 
 
+dnl CURL_CHECK_OPTION_OPTIMIZE
+dnl -------------------------------------------------
+dnl Verify if configure has been invoked with option
+dnl --enable-optimize or --disable-optimize, and set
+dnl shell variable want_optimize value as appropriate.
+
+AC_DEFUN([CURL_CHECK_OPTION_OPTIMIZE], [
+  AC_REQUIRE([CURL_CHECK_OPTION_DEBUG])dnl
+  AC_BEFORE([$0],[CURL_CHECK_PROG_CC])dnl
+  AC_MSG_CHECKING([whether to enable compiler optimizer])
+  OPT_COMPILER_OPTIMIZE="default"
+  AC_ARG_ENABLE(optimize,
+AC_HELP_STRING([--enable-optimize],[Enable compiler optimizations])
+AC_HELP_STRING([--disable-optimize],[Disable compiler optimizations]),
+  OPT_COMPILER_OPTIMIZE=$enableval)
+  case "$OPT_COMPILER_OPTIMIZE" in
+    no)
+      dnl --disable-optimize option used. We will handle this as
+      dnl a request to disable compiler optimizations if possible.
+      dnl If the compiler is known CFLAGS and CPPFLAGS will be
+      dnl overridden, otherwise this can not be honored.
+      want_optimize="no"
+      AC_MSG_RESULT([no])
+      ;;
+    default)
+      dnl configure's optimize option not specified. Initially we will
+      dnl handle this as a a request contrary to configure's setting
+      dnl for --enable-debug. IOW, initially, for debug-enabled builds
+      dnl this will be handled as a request to disable optimizations if
+      dnl possible, and for debug-disabled builds this will be handled
+      dnl initially as a request to enable optimizations if possible.
+      dnl Finally, if the compiler is known and CFLAGS and CPPFLAGS do
+      dnl not have any optimizer flag the request will be honored, in
+      dnl any other case the request can not be honored.
+      dnl IOW, existing optimizer flags defined in CFLAGS or CPPFLAGS
+      dnl will always take precedence over any initial assumption.
+      if test "$want_debug" = "yes"; then
+        want_optimize="assume_no"
+        AC_MSG_RESULT([not specified (assuming no)])
+      else
+        want_optimize="assume_yes"
+        AC_MSG_RESULT([not specified (assuming yes)])
+      fi
+      ;;
+    *)
+      dnl --enable-optimize option used. We will handle this as
+      dnl a request to enable compiler optimizations if possible.
+      dnl If the compiler is known CFLAGS and CPPFLAGS will be
+      dnl overridden, otherwise this can not be honored.
+      want_optimize="yes"
+      AC_MSG_RESULT([yes])
+      ;;
+  esac
+])
+
+
 dnl CURL_CHECK_OPTION_WARNINGS
 dnl -------------------------------------------------
 dnl Verify if configure has been invoked with option
 dnl --enable-warnings or --disable-warnings, and set
-DNL shell variable want_warnings as appropriate.
+dnl shell variable want_warnings as appropriate.
 
 AC_DEFUN([CURL_CHECK_OPTION_WARNINGS], [
   AC_REQUIRE([CURL_CHECK_OPTION_DEBUG])dnl
-  AC_BEFORE([$0],[AC_PROG_CC])dnl
+  AC_BEFORE([$0],[CURL_CHECK_PROG_CC])dnl
   AC_MSG_CHECKING([whether to enable strict compiler warnings])
   OPT_COMPILER_WARNINGS="default"
   AC_ARG_ENABLE(warnings,
-    AC_HELP_STRING([--enable-warnings],[Enable strict compiler warnings])
-    AC_HELP_STRING([--disable-warnings],[Disable strict compiler warnings]),
-    OPT_COMPILER_WARNINGS=$enableval)
+AC_HELP_STRING([--enable-warnings],[Enable strict compiler warnings])
+AC_HELP_STRING([--disable-warnings],[Disable strict compiler warnings]),
+  OPT_COMPILER_WARNINGS=$enableval)
   case "$OPT_COMPILER_WARNINGS" in
     no)
       dnl --disable-warnings option used