From: Mattias Nissler <mnissler@chromium.org>
Date: Mon, 4 Nov 2019 10:11:20 +0000 (+0000)
Subject: toolchain-funcs.eclass: fix tc-cpp-is-true() to work with clang
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=3ef6b33339da7bb04afd77e1bc5db011b02d658a;p=gentoo.git

toolchain-funcs.eclass: fix tc-cpp-is-true() to work with clang

Clang's preprocessor likes to output a leading newline, which makes
the comparison always fail. GCC generates additional output with certain
flags (e.g. -ggdb3) as well. Hence, switch the test to trigger a
preprocessor error when the condition is not true and examine the exit
code.

Bug: https://bugs.gentoo.org/698912

Signed-off-by: Mattias Nissler <mnissler@chromium.org>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---

diff --git a/eclass/toolchain-funcs.eclass b/eclass/toolchain-funcs.eclass
index e358d484417a..1bc6cbbc1088 100644
--- a/eclass/toolchain-funcs.eclass
+++ b/eclass/toolchain-funcs.eclass
@@ -207,14 +207,13 @@ tc-cpp-is-true() {
 	local CONDITION=${1}
 	shift
 
-	local RESULT=$($(tc-getTARGET_CPP) "${@}" -P - <<-EOF 2>/dev/null
-			#if ${CONDITION}
-			true
-			#endif
-		EOF
-	)
-
-	[[ ${RESULT} == true ]]
+	$(tc-getTARGET_CPP) "${@}" -P - <<-EOF >/dev/null 2>&1
+		#if ${CONDITION}
+		true
+		#else
+		#error false
+		#endif
+	EOF
 }
 
 # @FUNCTION: tc-detect-is-softfloat