Added workarounds and options for gcc 4.6.2

* add -Wno-unused-but-set-variable for gcc 4.6.x with a TODO
* fix warnings about wrong size of pointer cast in ioapic.cpp and AudioBuffer.cpp

build/jam/BuildSetup

@@ -1185,24 +1185,24 @@ AUTO_SET_UP_CONFIG_VARIABLES +=
 
 
 # enable -Werror for certain parts of the source tree
-
-if $(HAIKU_GCC_VERSION[1]) = 2 {
-	rule EnableWerror dirTokens : scope {
-		AppendToConfigVar CCFLAGS : HAIKU_TOP $(dirTokens) : -Werror
-			: $(scope) ;
-		AppendToConfigVar C++FLAGS : HAIKU_TOP $(dirTokens) : -Werror
-			: $(scope) ;
-	}
-} else {
+HAIKU_WERRORFLAGS = ;
+if $(HAIKU_GCC_VERSION[1]) >= 4 {
 	# -Wuninitialized gives too many false positives.
-	rule EnableWerror dirTokens : scope {
-		AppendToConfigVar CCFLAGS : HAIKU_TOP $(dirTokens)
-			: -Werror -Wno-error=uninitialized : $(scope) ;
-		AppendToConfigVar C++FLAGS : HAIKU_TOP $(dirTokens)
-			: -Werror -Wno-error=uninitialized : $(scope) ;
+	HAIKU_WERRORFLAGS = -Wno-error=uninitialized ;
+
+	if $(HAIKU_GCC_VERSION[2]) >= 6 {
+		# TODO: remove the -Wno-unused-but-set-variable option
+		HAIKU_WERRORFLAGS += -Wno-unused-but-set-variable ;
 	}
 }
 
+rule EnableWerror dirTokens : scope {
+	AppendToConfigVar CCFLAGS : HAIKU_TOP $(dirTokens)
+		: -Werror $(HAIKU_WERRORFLAGS) : $(scope) ;
+	AppendToConfigVar C++FLAGS : HAIKU_TOP $(dirTokens)
+		: -Werror $(HAIKU_WERRORFLAGS) : $(scope) ;
+}
+
 # Work-around for GCC 2 problem -- despite -Wno-multichar it reports
 # multichar warnings in headers/private/kernel/debugger_keymaps.h included by
 # src/system/kernel/arch/x86/arch_debug_console.cpp.

build/scripts/build_cross_tools_gcc4

@@ -144,7 +144,7 @@ copy_headers $haikuSourceDir/headers/posix $tmpIncludeDir/posix
 cd $gccObjDir
 CFLAGS="-O2" CXXFLAGS="-O2" $gccSourceDir/configure --prefix=$installDir \
 	--target=$haikuMachine --disable-nls --disable-shared \
-	--enable-languages=c,c++ \
+	--enable-languages=c,c++ --enable-lto --enable-frame-pointer \
 	--with-headers=$tmpIncludeDir --with-libs=$tmpLibDir \
 	$gccConfigureArgs || exit 1
 

src/apps/cortex/addons/common/AudioBuffer.cpp

@@ -223,8 +223,8 @@ uint32 AudioBuffer::copyTo(
 	// convert and copy a sample at a time
 	for(; remaining; remaining -= sampleSize) {
 		convert_sample(
-			(void*) *((int8*)m_pData + fromOffset),
-			(void*) *((int8*)target.m_pData + targetOffset),
+			(void*) ((int8*)m_pData + fromOffset),
+			(void*) ((int8*)target.m_pData + targetOffset),
 			m_format.format,
 			target.m_format.format);
 		

src/system/kernel/arch/x86/ioapic.cpp

@@ -529,8 +529,8 @@ acpi_configure_source_overrides(acpi_table_madt* madt)
 				if (info->SourceIrq != info->GlobalIrq) {
 					// we need a vector mapping
 					install_io_interrupt_handler(info->GlobalIrq,
-						&ioapic_source_override_handler, (void*)info->SourceIrq,
-						B_NO_ENABLE_COUNTER);
+						&ioapic_source_override_handler,
+						(void*)(addr_t)info->SourceIrq, B_NO_ENABLE_COUNTER);
 
 					sSourceOverrides[info->SourceIrq] = info->GlobalIrq;
 				}