diff mbox series

tools/build: Add clang cross-compilation flags to feature detection

Message ID 20231102081441.240280-1-bjorn@kernel.org (mailing list archive)
State Superseded
Headers show
Series tools/build: Add clang cross-compilation flags to feature detection | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Björn Töpel Nov. 2, 2023, 8:14 a.m. UTC 
From: Björn Töpel <bjorn@rivosinc.com>

When a tool cross-build has LLVM=1 set, the clang cross-compilation
flags are not passed to the feature detection build system. This
results in the host's features are detected instead of the targets.

E.g, triggering a cross-build of bpftool:

  cd tools/bpf/bpftool
  make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- LLVM=1

would report the host's, and not the target's features.

Correct the issue by passing the CLANG_CROSS_FLAGS variable to the
feature detection makefile.

Fixes: cebdb7374577 ("tools: Help cross-building with clang")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
 tools/build/Makefile.feature | 2 +-
 tools/build/feature/Makefile | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)


base-commit: 21e80f3841c01aeaf32d7aee7bbc87b3db1aa0c6

Comments

Jiri Olsa Nov. 2, 2023, 9:29 a.m. UTC | #1 
On Thu, Nov 02, 2023 at 09:14:41AM +0100, Björn Töpel wrote:
> From: Björn Töpel <bjorn@rivosinc.com>
> 
> When a tool cross-build has LLVM=1 set, the clang cross-compilation
> flags are not passed to the feature detection build system. This
> results in the host's features are detected instead of the targets.
> 
> E.g, triggering a cross-build of bpftool:
> 
>   cd tools/bpf/bpftool
>   make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- LLVM=1
> 
> would report the host's, and not the target's features.
> 
> Correct the issue by passing the CLANG_CROSS_FLAGS variable to the
> feature detection makefile.
> 
> Fixes: cebdb7374577 ("tools: Help cross-building with clang")
> Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
> ---
>  tools/build/Makefile.feature | 2 +-
>  tools/build/feature/Makefile | 8 ++++----
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 934e2777a2db..25b009a6c05f 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -8,7 +8,7 @@ endif
>  
>  feature_check = $(eval $(feature_check_code))
>  define feature_check_code
> -  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
> +  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" CLANG_CROSS_FLAGS="$(CLANG_CROSS_FLAGS)" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
>  endef
>  
>  feature_set = $(eval $(feature_set_code))
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index dad79ede4e0a..0231a53024c7 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -84,12 +84,12 @@ PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
>  
>  all: $(FILES)
>  
> -__BUILD = $(CC) $(CFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
> +__BUILD = $(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
>    BUILD = $(__BUILD) > $(@:.bin=.make.output) 2>&1
>    BUILD_BFD = $(BUILD) -DPACKAGE='"perf"' -lbfd -ldl
>    BUILD_ALL = $(BUILD) -fstack-protector-all -O2 -D_FORTIFY_SOURCE=2 -ldw -lelf -lnuma -lelf -lslang $(FLAGS_PERL_EMBED) $(FLAGS_PYTHON_EMBED) -DPACKAGE='"perf"' -lbfd -ldl -lz -llzma -lzstd -lcap
>  
> -__BUILDXX = $(CXX) $(CXXFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
> +__BUILDXX = $(CXX) $(CXXFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
>    BUILDXX = $(__BUILDXX) > $(@:.bin=.make.output) 2>&1
>  
>  ###############################
> @@ -259,10 +259,10 @@ $(OUTPUT)test-reallocarray.bin:
>  	$(BUILD)
>  
>  $(OUTPUT)test-libbfd-liberty.bin:
> -	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
> +	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
>  
>  $(OUTPUT)test-libbfd-liberty-z.bin:
> -	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz
> +	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz

should we add this also to test-compile-32.bin/test-compile-x32.bin
targets?

jirka

>  
>  $(OUTPUT)test-cplus-demangle.bin:
>  	$(BUILD) -liberty
> 
> base-commit: 21e80f3841c01aeaf32d7aee7bbc87b3db1aa0c6
> -- 
> 2.40.1
> 
>
Björn Töpel Nov. 2, 2023, 9:53 a.m. UTC | #2 
Jiri Olsa <olsajiri@gmail.com> writes:

> On Thu, Nov 02, 2023 at 09:14:41AM +0100, Björn Töpel wrote:
>> From: Björn Töpel <bjorn@rivosinc.com>
>> 
>> When a tool cross-build has LLVM=1 set, the clang cross-compilation
>> flags are not passed to the feature detection build system. This
>> results in the host's features are detected instead of the targets.
>> 
>> E.g, triggering a cross-build of bpftool:
>> 
>>   cd tools/bpf/bpftool
>>   make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- LLVM=1
>> 
>> would report the host's, and not the target's features.
>> 
>> Correct the issue by passing the CLANG_CROSS_FLAGS variable to the
>> feature detection makefile.
>> 
>> Fixes: cebdb7374577 ("tools: Help cross-building with clang")
>> Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
>> ---
>>  tools/build/Makefile.feature | 2 +-
>>  tools/build/feature/Makefile | 8 ++++----
>>  2 files changed, 5 insertions(+), 5 deletions(-)
>> 
>> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
>> index 934e2777a2db..25b009a6c05f 100644
>> --- a/tools/build/Makefile.feature
>> +++ b/tools/build/Makefile.feature
>> @@ -8,7 +8,7 @@ endif
>>  
>>  feature_check = $(eval $(feature_check_code))
>>  define feature_check_code
>> -  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
>> +  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" CLANG_CROSS_FLAGS="$(CLANG_CROSS_FLAGS)" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
>>  endef
>>  
>>  feature_set = $(eval $(feature_set_code))
>> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
>> index dad79ede4e0a..0231a53024c7 100644
>> --- a/tools/build/feature/Makefile
>> +++ b/tools/build/feature/Makefile
>> @@ -84,12 +84,12 @@ PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
>>  
>>  all: $(FILES)
>>  
>> -__BUILD = $(CC) $(CFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
>> +__BUILD = $(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
>>    BUILD = $(__BUILD) > $(@:.bin=.make.output) 2>&1
>>    BUILD_BFD = $(BUILD) -DPACKAGE='"perf"' -lbfd -ldl
>>    BUILD_ALL = $(BUILD) -fstack-protector-all -O2 -D_FORTIFY_SOURCE=2 -ldw -lelf -lnuma -lelf -lslang $(FLAGS_PERL_EMBED) $(FLAGS_PYTHON_EMBED) -DPACKAGE='"perf"' -lbfd -ldl -lz -llzma -lzstd -lcap
>>  
>> -__BUILDXX = $(CXX) $(CXXFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
>> +__BUILDXX = $(CXX) $(CXXFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
>>    BUILDXX = $(__BUILDXX) > $(@:.bin=.make.output) 2>&1
>>  
>>  ###############################
>> @@ -259,10 +259,10 @@ $(OUTPUT)test-reallocarray.bin:
>>  	$(BUILD)
>>  
>>  $(OUTPUT)test-libbfd-liberty.bin:
>> -	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
>> +	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
>>  
>>  $(OUTPUT)test-libbfd-liberty-z.bin:
>> -	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz
>> +	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz
>
> should we add this also to test-compile-32.bin/test-compile-x32.bin
> targets?

Ah, yes!

I'll spin a v2 with:
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 0231a53024c7..c4458345e564 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -283,10 +283,10 @@ $(OUTPUT)test-libbabeltrace.bin:
        $(BUILD) # -lbabeltrace provided by $(FEATURE_CHECK_LDFLAGS-libbabeltrace)
 
 $(OUTPUT)test-compile-32.bin:
-       $(CC) -m32 -o $@ test-compile.c
+       $(CC) $(CLANG_CROSS_FLAGS) -m32 -o $@ test-compile.c
 
 $(OUTPUT)test-compile-x32.bin:
-       $(CC) -mx32 -o $@ test-compile.c
+       $(CC) $(CLANG_CROSS_FLAGS) -mx32 -o $@ test-compile.c
 
 $(OUTPUT)test-zlib.bin:
        $(BUILD) -lz


Thanks for having a look, jirka!


Björn
diff mbox series

Patch

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 934e2777a2db..25b009a6c05f 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -8,7 +8,7 @@  endif
 
 feature_check = $(eval $(feature_check_code))
 define feature_check_code
-  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
+  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC="$(CC)" CXX="$(CXX)" CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" CLANG_CROSS_FLAGS="$(CLANG_CROSS_FLAGS)" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
 endef
 
 feature_set = $(eval $(feature_set_code))
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index dad79ede4e0a..0231a53024c7 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -84,12 +84,12 @@  PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
 
 all: $(FILES)
 
-__BUILD = $(CC) $(CFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
+__BUILD = $(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
   BUILD = $(__BUILD) > $(@:.bin=.make.output) 2>&1
   BUILD_BFD = $(BUILD) -DPACKAGE='"perf"' -lbfd -ldl
   BUILD_ALL = $(BUILD) -fstack-protector-all -O2 -D_FORTIFY_SOURCE=2 -ldw -lelf -lnuma -lelf -lslang $(FLAGS_PERL_EMBED) $(FLAGS_PYTHON_EMBED) -DPACKAGE='"perf"' -lbfd -ldl -lz -llzma -lzstd -lcap
 
-__BUILDXX = $(CXX) $(CXXFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
+__BUILDXX = $(CXX) $(CXXFLAGS) $(CLANG_CROSS_FLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
   BUILDXX = $(__BUILDXX) > $(@:.bin=.make.output) 2>&1
 
 ###############################
@@ -259,10 +259,10 @@  $(OUTPUT)test-reallocarray.bin:
 	$(BUILD)
 
 $(OUTPUT)test-libbfd-liberty.bin:
-	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
+	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
 
 $(OUTPUT)test-libbfd-liberty-z.bin:
-	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz
+	$(CC) $(CFLAGS) $(CLANG_CROSS_FLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz
 
 $(OUTPUT)test-cplus-demangle.bin:
 	$(BUILD) -liberty