[PATCH] init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash

From: alexandre . belloni
Date: Thu Aug 04 2022 - 15:03:48 EST


From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

When using dash as /bin/sh, the CC_HAS_ASM_GOTO_TIED_OUTPUT test fails
with a syntax error which is not the one we are looking for:

<stdin>: In function ‘foo’:
<stdin>:1:29: warning: missing terminating " character
<stdin>:1:29: error: missing terminating " character
<stdin>:2:5: error: expected ‘:’ before ‘+’ token
<stdin>:2:7: warning: missing terminating " character
<stdin>:2:7: error: missing terminating " character
<stdin>:2:5: error: expected declaration or statement at end of input

Move all the CC_HAS_ASM_GOTO tests to scripts/gcc-goto.sh to solve the
escaping issues.

Fixes: 1aa0e8b144b6 ("Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug")
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
init/Kconfig | 6 +++---
scripts/gcc-goto.sh | 31 +++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index c984afc489de..9903a11cfe7d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -71,16 +71,16 @@ config CC_CAN_LINK_STATIC
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)

config CC_HAS_ASM_GOTO
- def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
+ def_bool $(success,$(srctree)/scripts/gcc-goto.sh goto $(CC))

config CC_HAS_ASM_GOTO_OUTPUT
depends on CC_HAS_ASM_GOTO
- def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
+ def_bool $(success,$(srctree)/scripts/gcc-goto.sh goto_output $(CC))

config CC_HAS_ASM_GOTO_TIED_OUTPUT
depends on CC_HAS_ASM_GOTO_OUTPUT
# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
- def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .\n": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
+ def_bool $(success,$(srctree)/scripts/gcc-goto.sh goto_tied_output $(CC))

config TOOLS_SUPPORT_RELR
def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh
index 8b980fb2270a..aa9498b74df8 100755
--- a/scripts/gcc-goto.sh
+++ b/scripts/gcc-goto.sh
@@ -3,6 +3,11 @@
# Test for gcc 'asm goto' support
# Copyright (C) 2010, Jason Baron <jbaron@xxxxxxxxxx>

+TEST=$1
+shift
+
+case $TEST in
+ "goto")
cat << "END" | $@ -x c - -fno-PIE -c -o /dev/null
int main(void)
{
@@ -20,3 +25,29 @@ entry:
return 0;
}
END
+ ;;
+
+ "goto_output")
+cat << "END" | $@ -x c - -c -o /dev/null
+int foo(int x) {
+ asm goto ("": "=r"(x) ::: bar);
+ return x;
+ bar: return 0;
+}
+END
+ ;;
+
+ "goto_tied_output")
+cat << "END" | $@ -x c - -c -o /dev/null
+int foo(int *x) {
+ asm goto (".long (%l[bar]) - .\n": "+m"(*x) ::: bar);
+ return *x;
+ bar: return 0;
+}
+END
+ ;;
+
+ *)
+ exit -1
+ ;;
+esac
--
2.37.1