From a81d5bb62c236d1fc8acc3130f271a97460a9830 Mon Sep 17 00:00:00 2001
From: Michael Wetherell <mike.wetherell@ntlworld.com>
Date: Mon, 23 Oct 2006 21:20:26 +0000
Subject: [PATCH] On unicode builds detect gcc 3.4 precompiled header bug
 (bugzilla 13361).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42302 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 configure    | 55 +++++++++++++++++++++++++++++++++++++++++++++----
 configure.in | 58 +++++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 102 insertions(+), 11 deletions(-)

diff --git a/configure b/configure
index 87b9dbee5b..3cdc5dc7d8 100755
--- a/configure
+++ b/configure
@@ -47084,6 +47084,43 @@ if test "$wxUSE_MAC" = 1 ; then
     #       The makefile currently uses AR and RANLIB, which libtool apparently supercedes.
 fi
 
+if test "$wxUSE_UNICODE" = yes -a "$GCC" = yes -a "$bk_use_pch" != no
+then
+    echo "$as_me:$LINENO: checking for gcc precompiled header bug" >&5
+echo $ECHO_N "checking for gcc precompiled header bug... $ECHO_C" >&6
+if test "${wx_cv_gcc_pch_bug+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+            wx_cv_gcc_pch_bug=no
+            echo 'const wchar_t test_var[] = L"wide string";' > conftest.h
+
+            if $CXX conftest.h >& /dev/null
+            then
+                {
+                    echo '#include "conftest.h"'
+                    echo 'const wchar_t *test() { return test_var; }'
+                } > conftest.cpp
+
+                if $CXX -c -o conftest.o conftest.cpp >& /dev/null
+                then
+                    tr -dc 'a-z' < conftest.o |
+                        grep 'widestring' >& /dev/null ||
+                        wx_cv_gcc_pch_bug=yes
+                fi
+            fi
+
+            rm -f conftest.h conftest.gch conftest.cpp conftest.o
+
+fi
+echo "$as_me:$LINENO: result: $wx_cv_gcc_pch_bug" >&5
+echo "${ECHO_T}$wx_cv_gcc_pch_bug" >&6
+
+    if test "$wx_cv_gcc_pch_bug" = yes; then
+                        bk_use_pch=no
+    fi
+fi
+
 
 
 
@@ -50018,6 +50055,20 @@ echo "$as_me: error: Versions of Bakefile used to generate makefiles ($BAKEFILE_
     fi
 
 
+if test $GCC_PCH = 1
+then
+    if test "$wx_cv_gcc_pch_bug" = yes; then
+        { echo "$as_me:$LINENO: WARNING: *** Precompiled header support is broken on this compiler" >&5
+echo "$as_me: WARNING: *** Precompiled header support is broken on this compiler" >&2;}
+        { echo "$as_me:$LINENO: WARNING: *** --enable-precomp-headers is not recommended" >&5
+echo "$as_me: WARNING: *** --enable-precomp-headers is not recommended" >&2;}
+        { echo "$as_me:$LINENO: WARNING: *** see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13361" >&5
+echo "$as_me: WARNING: *** see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13361" >&2;}
+    fi
+
+    CPPFLAGS="-DWX_PRECOMP $CPPFLAGS"
+fi
+
 
 if test "$wxUSE_MAC" = 1 ; then
     if test "x$wxUSE_UNIVERSAL_BINARY" != "xno" ; then
@@ -50055,10 +50106,6 @@ if test "$wxUSE_OMF" = "yes"; then
     esac
 fi
 
-if test $GCC_PCH = 1 ; then
-    CPPFLAGS="-DWX_PRECOMP $CPPFLAGS"
-fi
-
 WXCONFIG_CPPFLAGS="$WXCONFIG_CPPFLAGS $TOOLCHAIN_DEFS"
 
 SAMPLES_SUBDIRS="`echo $SAMPLES_SUBDIRS | tr -s ' ' | tr ' ' '\n' | sort | uniq | tr '\n' ' '| tr -d '\r'`"
diff --git a/configure.in b/configure.in
index f3df19aa1f..1dfe34170f 100644
--- a/configure.in
+++ b/configure.in
@@ -7583,8 +7583,59 @@ if test "$wxUSE_MAC" = 1 ; then
     #       The makefile currently uses AR and RANLIB, which libtool apparently supercedes.
 fi
 
+dnl gcc 3.4 has a pch bug which truncates wide character constants in headers.
+dnl Hopefully for a non-unicode build there aren't any wide constants in
+dnl headers, but for a unicode build it's best to disable pch.
+if test "$wxUSE_UNICODE" = yes -a "$GCC" = yes -a "$bk_use_pch" != no
+then
+    AC_CACHE_CHECK(
+        [for gcc precompiled header bug],
+        [wx_cv_gcc_pch_bug],
+        [[
+            wx_cv_gcc_pch_bug=no
+            echo 'const wchar_t test_var[] = L"wide string";' > conftest.h
+
+            if $CXX conftest.h >& /dev/null
+            then
+                {
+                    echo '#include "conftest.h"'
+                    echo 'const wchar_t *test() { return test_var; }'
+                } > conftest.cpp
+
+                if $CXX -c -o conftest.o conftest.cpp >& /dev/null
+                then
+                    tr -dc 'a-z' < conftest.o |
+                        grep 'widestring' >& /dev/null ||
+                        wx_cv_gcc_pch_bug=yes
+                fi
+            fi
+
+            rm -f conftest.h conftest.gch conftest.cpp conftest.o
+        ]])
+
+    if test "$wx_cv_gcc_pch_bug" = yes; then
+        dnl make the default for pch 'no'
+        dnl further below check whether the user overrode and warn them
+        bk_use_pch=no
+    fi
+fi
+
 AC_BAKEFILE([m4_include(autoconf_inc.m4)])
 
+dnl find out if the compiler supports PCH
+dnl
+dnl TODO: this should be in bakefile
+if test $GCC_PCH = 1
+then
+    if test "$wx_cv_gcc_pch_bug" = yes; then
+        AC_MSG_WARN([*** Precompiled header support is broken on this compiler])
+        AC_MSG_WARN([*** --enable-precomp-headers is not recommended])
+        AC_MSG_WARN([*** see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13361])
+    fi
+
+    CPPFLAGS="-DWX_PRECOMP $CPPFLAGS"
+fi
+
 dnl HACK ALERT!! 
 dnl For now, we need to alter bk-deps not to generate deps
 dnl when we've configured a Universal binary build.
@@ -7637,13 +7688,6 @@ if test "$wxUSE_OMF" = "yes"; then
     esac
 fi
 
-dnl find out if the compiler supports PCH
-dnl
-dnl TODO: this should be in bakefile
-if test $GCC_PCH = 1 ; then
-    CPPFLAGS="-DWX_PRECOMP $CPPFLAGS"
-fi
-
 dnl TOOLCHAIN_DEFS should be used for both wx and client code
 WXCONFIG_CPPFLAGS="$WXCONFIG_CPPFLAGS $TOOLCHAIN_DEFS"
 
-- 
2.47.2