--- firefox-19.0.2.ebuild	2013-03-24 16:32:21.994600938 +0100
+++ firefox-19.0.2.ebuild.new	2013-03-24 16:26:02.000000000 +0100
@@ -210,9 +210,34 @@
 	mozconfig_use_enable gstreamer
 	mozconfig_use_enable system-sqlite
 	mozconfig_use_with system-jpeg
-	# Feature is know to cause problems on hardened
-	mozconfig_use_enable jit methodjit
-	mozconfig_use_enable jit tracejit
+
+	# compiler-dependent settings
+	if [[ $(tc-getCC) =~ clang ]]; then
+		mozconfig_annotate 'from ebuild, CC=clang detected' --enable-address-sanitizer
+		mozconfig_annotate 'from ebuild, CC=clang detected' --enable-llvm-hacks
+
+		# --enable-methodjit causes clang build to segfault (see bug #462608)
+		# --enable-llvm-hacks does not fix it, so make sure it is disabled
+		mozconfig_annotate 'from ebuild, CC=clang detected' --disable-methodjit
+		mozconfig_use_enable jit tracejit
+	else
+		# Feature is know to cause problems on hardened
+		mozconfig_use_enable jit methodjit
+		mozconfig_use_enable jit tracejit
+
+		if [[ $(gcc-major-version) -lt 4 ]]; then
+			append-cxxflags -fno-stack-protector
+		elif [[ $(gcc-major-version) -gt 4 || $(gcc-minor-version) -gt 3 ]]; then
+			if use amd64 || use x86; then
+				append-flags -mno-avx
+			fi
+		fi
+	fi
+
+	# support EXTRA_ECONF, maybe this should be in mozcoreconf-2.eclass ..
+	for eeopt in $EXTRA_ECONF; do
+		mozconfig_annotate 'from ebuild, passed using EXTRA_ECONF' $eeopt
+	done

 	# Allow for a proper pgo build
 	if use pgo; then
@@ -221,14 +246,6 @@

 	# Finalize and report settings
 	mozconfig_final
-
-	if [[ $(gcc-major-version) -lt 4 ]]; then
-		append-cxxflags -fno-stack-protector
-	elif [[ $(gcc-major-version) -gt 4 || $(gcc-minor-version) -gt 3 ]]; then
-		if use amd64 || use x86; then
-			append-flags -mno-avx
-		fi
-	fi
 }

 src_compile() {