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kbuild: Fix gcc -x syntax

PATCH Superseded Jean Delvare 2 participants 2 messages Sep 29, 2012 – Oct 1, 2012

Subsystems (6)
x86 Kbuild MIPS perf events +2 more subsystems

v2 of 3 Superseded Latest is v3 →

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PATCH v2 1/1 kbuild: Fix gcc -x syntax

The correct syntax for gcc -x is "gcc -x assembler", not "gcc -xassembler". Even though the latter happens to work, the former is what is documented in the manual page and thus what gcc wrappers such as icecream do expect.

This isn't a cosmetic change. The missing space prevents icecream from recognizing compilation tasks it can't handle, leading to silent kernel miscompilations.

Besides me, credits go to Richard Guenther and Dirk Mueller for investigating the miscompilation issue and tracking it down to this incorrect -x parameter syntax.

Cc Bernhard Walle <[email protected]>
Cc Michal Marek <[email protected]>
Cc Ralf Baechle <[email protected]>

---
Changes since v1:
* Found more occurrences of the same. These are probably less problematic in practice but let's fix them all still.

 arch/mips/Makefile                         |    2 +-
 arch/mips/kernel/Makefile                  |    2 +-
 arch/x86/Makefile                          |    2 +-
 scripts/Kbuild.include                     |   12 ++++++------
 scripts/gcc-version.sh                     |    6 +++---
 scripts/gcc-x86_32-has-stack-protector.sh  |    2 +-
 scripts/gcc-x86_64-has-stack-protector.sh  |    2 +-
 scripts/kconfig/check.sh                   |    2 +-
 scripts/kconfig/lxdialog/check-lxdialog.sh |    2 +-
 tools/perf/Makefile                        |    2 +-
 tools/power/cpupower/Makefile              |    2 +-
 11 files changed, 18 insertions(+), 18 deletions(-)
arch/mips/Makefile +1 -1
@@ -225,7 +225,7 @@ KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(d
 LDFLAGS			+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
-CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -xc /dev/null | \
+CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
 	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
 	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/")
 ifdef CONFIG_64BIT
arch/mips/kernel/Makefile +1 -1
@@ -104,7 +104,7 @@ obj-$(CONFIG_MIPS_MACHINE)	+= mips_machi
 
 obj-$(CONFIG_OF)		+= prom.o
 
-CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
+CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -x c /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)	+= 8250-platform.o
 
arch/x86/Makefile +1 -1
@@ -92,7 +92,7 @@ endif
 ifdef CONFIG_X86_X32
 	x32_ld_ok := $(call try-run,\
 			/bin/echo -e '1: .quad 1b' | \
-			$(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" - && \
+			$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
 			$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
 			$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
         ifeq ($(x32_ld_ok),y)
scripts/Kbuild.include +6 -6
@@ -98,24 +98,24 @@ try-run = $(shell set -e;		\
 # Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
 
 as-option = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2))
 
 # as-instr
 # Usage: cflags-y += $(call as-instr,instr,option1,option2)
 
 as-instr = $(call try-run,\
-	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -xassembler -o "$$TMP" -,$(2),$(3))
+	printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
 
 # cc-option
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
+	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign
@@ -125,7 +125,7 @@ cc-option-align = $(subst -functions=0,,
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -xc /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 
 # cc-version
 # Usage gcc-ver := $(call cc-version)
@@ -143,7 +143,7 @@ cc-ifversion = $(shell [ $(call cc-versi
 # cc-ldoption
 # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
 cc-ldoption = $(call try-run,\
-	$(CC) $(1) -nostdlib -xc /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # ld-option
 # Usage: LDFLAGS += $(call ld-option, -X)
scripts/gcc-version.sh +3 -3
@@ -22,10 +22,10 @@ if [ ${#compiler} -eq 0 ]; then
 	exit 1
 fi
 
-MAJOR=$(echo __GNUC__ | $compiler -E -xc - | tail -n 1)
-MINOR=$(echo __GNUC_MINOR__ | $compiler -E -xc - | tail -n 1)
+MAJOR=$(echo __GNUC__ | $compiler -E -x c - | tail -n 1)
+MINOR=$(echo __GNUC_MINOR__ | $compiler -E -x c - | tail -n 1)
 if [ "x$with_patchlevel" != "x" ] ; then
-	PATCHLEVEL=$(echo __GNUC_PATCHLEVEL__ | $compiler -E -xc - | tail -n 1)
+	PATCHLEVEL=$(echo __GNUC_PATCHLEVEL__ | $compiler -E -x c - | tail -n 1)
 	printf "%02d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL
 else
 	printf "%02d%02d\\n" $MAJOR $MINOR
scripts/gcc-x86_32-has-stack-protector.sh +1 -1
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -xc -c -O0 -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
+echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -O0 -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
 if [ "$?" -eq "0" ] ; then
 	echo y
 else
scripts/gcc-x86_64-has-stack-protector.sh +1 -1
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -xc -c -O0 -mcmodel=kernel -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
+echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -O0 -mcmodel=kernel -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
 if [ "$?" -eq "0" ] ; then
 	echo y
 else
scripts/kconfig/check.sh +1 -1
@@ -1,6 +1,6 @@
 #!/bin/sh
 # Needed for systems without gettext
-$* -xc -o /dev/null - > /dev/null 2>&1 << EOF
+$* -x c -o /dev/null - > /dev/null 2>&1 << EOF
 #include <libintl.h>
 int main()
 {
scripts/kconfig/lxdialog/check-lxdialog.sh +1 -1
@@ -38,7 +38,7 @@ trap "rm -f $tmp" 0 1 2 3 15
 
 # Check if we can link to ncurses
 check() {
-        $cc -xc - -o $tmp 2>/dev/null <<'EOF'
+        $cc -x c - -o $tmp 2>/dev/null <<'EOF'
 #include CURSES_LOC
 main() {}
 EOF
tools/perf/Makefile +1 -1
@@ -62,7 +62,7 @@ ifeq ($(ARCH),x86_64)
 	ARCH := x86
 	IS_X86_64 := 0
 	ifeq (, $(findstring m32,$(EXTRA_CFLAGS)))
-		IS_X86_64 := $(shell echo __x86_64__ | ${CC} -E -xc - | tail -n 1)
+		IS_X86_64 := $(shell echo __x86_64__ | ${CC} -E -x c - | tail -n 1)
 	endif
 	ifeq (${IS_X86_64}, 1)
 		RAW_ARCH := x86_64
tools/power/cpupower/Makefile +1 -1
@@ -111,7 +111,7 @@ GMO_FILES = ${shell for HLANG in ${LANGU
 export CROSS CC AR STRIP RANLIB CFLAGS LDFLAGS LIB_OBJS
 
 # check if compiler option is supported
-cc-supports = ${shell if $(CC) ${1} -S -o /dev/null -xc /dev/null > /dev/null 2>&1; then echo "$(1)"; fi;}
+cc-supports = ${shell if $(CC) ${1} -S -o /dev/null -x c /dev/null > /dev/null 2>&1; then echo "$(1)"; fi;}
 
 # use '-Os' optimization if available, else use -O2
 OPTIMIZATION := $(call cc-supports,-Os,-O2)
Signature · 2 lines
Jean Delvare
Suse L3
Acked-by on v2 1/1
#1 lore raw
Quoted 23 lines · Jean Delvare

The correct syntax for gcc -x is "gcc -x assembler", not "gcc -xassembler". Even though the latter happens to work, the former is what is documented in the manual page and thus what gcc wrappers such as icecream do expect.

This isn't a cosmetic change. The missing space prevents icecream from recognizing compilation tasks it can't handle, leading to silent kernel miscompilations.

Besides me, credits go to Richard Guenther and Dirk Mueller for investigating the miscompilation issue and tracking it down to this incorrect -x parameter syntax.

Cc Bernhard Walle <[email protected]>
Cc Michal Marek <[email protected]>
Cc Ralf Baechle <[email protected]>

---
Changes since v1:
* Found more occurrences of the same. These are probably less problematic in practice but let's fix them all still.

Quoted 12 lines
 arch/mips/Makefile                         |    2 +-
 arch/mips/kernel/Makefile                  |    2 +-
 arch/x86/Makefile                          |    2 +-
 scripts/Kbuild.include                     |   12 ++++++------
 scripts/gcc-version.sh                     |    6 +++---
 scripts/gcc-x86_32-has-stack-protector.sh  |    2 +-
 scripts/gcc-x86_64-has-stack-protector.sh  |    2 +-
 scripts/kconfig/check.sh                   |    2 +-
 scripts/kconfig/lxdialog/check-lxdialog.sh |    2 +-
 tools/perf/Makefile                        |    2 +-
 tools/power/cpupower/Makefile              |    2 +-
 11 files changed, 18 insertions(+), 18 deletions(-)

Michal, want to pick this one up into the kbuild tree?

Thanks,

Ingo