Improve Makefile portability and debugging

The -mno-omit-leaf-frame-pointer option is not available on all architectures (e.g., s390x) or with older compiler versions. To avoid compilation errors on such systems, this change adds a check to ensure the option is only used when the compiler supports it.

This approach is similar to the existing check for -fcf-protection.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Makefile +7 -1

index c19e0bd..d605e60 100644
@@ -60,7 +60,13 @@ FOPTS	:=	-flto=auto -ffat-lto-objects -fexceptions -fstack-protector-strong \
 		-fasynchronous-unwind-tables -fstack-clash-protection -fno-omit-frame-pointer \
 		$(strip $(FCF_PROTECTION)) -fpie
 
-MOPTS   :=  	$(strip $(MTUNE)) $(strip $(M64)) -mno-omit-leaf-frame-pointer
+# Test if compiler supports -mno-omit-leaf-frame-pointer
+OMIT_LEAF_FP := $(shell echo 'int main(void){return 0;}' | \
+		$(CC) -x c -mno-omit-leaf-frame-pointer - \
+		-o /dev/null 2>/dev/null && \
+		echo '-mno-omit-leaf-frame-pointer')
+
+MOPTS   :=  	$(strip $(MTUNE)) $(strip $(M64)) $(strip $(OMIT_LEAF_FP))
 
 WOPTS	:= 	-Wall -Werror=format-security
 

Signature · 1 line

2.51.1

The previous method of detecting support for -fcf-protection relied on a minimum GCC version check, which was not always accurate and could fail on different architectures or compiler toolchains.

This commit replaces the version check with a more robust method that directly tests if the compiler supports the -fcf-protection flag. This ensures better portability and avoids compilation errors on systems where the flag is not available.

This change mirrors the recently added detection logic for the -mno-omit-leaf-frame-pointer flag.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

Makefile +12 -11

index d605e60..23e786d 100644
@@ -20,17 +20,14 @@ IS_MINVER := $(intcmp $(GCC_VER), $(MIN_GCC_VER), false, true, true)
 $(info IS_MINVER=$(IS_MINVER))
 
 USE_BPF := 1
-FCF_PROTECTION := -fcf-protection
 MTUNE	:= -mtune=generic
 M64	:= -m64
 
 ifeq ($(ARCH),aarch64)
-FCF_PROTECTION := "-fcf-protection=none"
 M64	:=
 endif
 ifeq ($(ARCH),i686)
 USE_BPF := 0
-FCF_PROTECTION := "-fcf-protection=branch"
 endif
 ifeq ($(ARCH),s390x)
 MTUNE := -mtune=z13

@@ -43,23 +40,23 @@ ifeq ($(ARCH),powerpc)
 USE_BPF := 0
 MTUNE := -mtune=powerpc
 endif
-ifeq ($(strip $(IS_MINVER)), false)
-FCF_PROTECTION := 
-endif
-
-
-$(info USE_BPF=$(USE_BPF))
-$(info FCF_PROTECTION=$(FCF_PROTECTION))
-$(info MTUNE=$(MTUNE))
 
 DEBUG	?=	0
 
 INSTALL	=	install
 CC	:=	gcc
+
+# Test if compiler supports -fcf-protection
+FCF_PROTECTION := $(shell echo 'int main(void){return 0;}' | \
+		$(CC) -x c -fcf-protection - \
+		-o /dev/null 2>/dev/null && \
+		echo '-fcf-protection')
+
 FOPTS	:=	-flto=auto -ffat-lto-objects -fexceptions -fstack-protector-strong \
 		-fasynchronous-unwind-tables -fstack-clash-protection -fno-omit-frame-pointer \
 		$(strip $(FCF_PROTECTION)) -fpie
 
+
 # Test if compiler supports -mno-omit-leaf-frame-pointer
 OMIT_LEAF_FP := $(shell echo 'int main(void){return 0;}' | \
 		$(CC) -x c -mno-omit-leaf-frame-pointer - \

@@ -74,6 +71,10 @@ DEFS	:=	-DUSE_BPF=$(USE_BPF) -D_FORTIFY_SOURCE=3 -D_GLIBCXX_ASSERTIONS -DDEBUG_S
 
 CFLAGS	:=      -DVERSION=\"$(VERSION)\" $(FOPTS) $(MOPTS) $(WOPTS) $(DEFS)
 
+$(info USE_BPF=$(USE_BPF))
+$(info FCF_PROTECTION=$(FCF_PROTECTION))
+$(info MTUNE=$(MTUNE))
+
 ifeq ($(DEBUG),0)
 CFLAGS	+=	-g -O2
 else

Signature · 1 line

2.51.1

The 'tests' target in the main Makefile was invoking 'make' in the 'tests' subdirectory without specifying a target. This relied on the default target in the tests/Makefile, which is not explicit.

This commit adds the 'test' target to the make command, making the build process clearer and more robust.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Makefile +0 -0

index 23e786d..619413f 100644

The minimum GCC version check was introduced to handle the -fcf-protection flag, which was not available in older compiler versions. However, a more robust method that directly tests for compiler support for this flag has been implemented.

This commit removes the now-redundant GCC version check, simplifying the Makefile and relying on the more accurate feature detection.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 5 -----
 1 file changed, 5 deletions(-)

Makefile +0 -5

index 619413f..ba67698 100644
@@ -14,11 +14,6 @@ GCC_VER=$(shell gcc --version | grep ^gcc | cut -f 3 -d ' ' | cut -f 1 -d '.')
 endif
 $(info GCC_VER=$(GCC_VER))
 
-# Does the current GCC compiler have fcf-protection and c99+ as default?
-MIN_GCC_VER := 8
-IS_MINVER := $(intcmp $(GCC_VER), $(MIN_GCC_VER), false, true, true)
-$(info IS_MINVER=$(IS_MINVER))
-
 USE_BPF := 1
 MTUNE	:= -mtune=generic
 M64	:= -m64

Signature · 1 line

2.51.1

The minimum GCC version check was introduced to handle the -fcf-protection flag, which was not available in older compiler versions. However, a more robust method that directly tests for compiler support for this flag has been implemented.

This commit removes the now-redundant GCC version check, simplifying the Makefile and relying on the more accurate feature detection.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 5 -----
 1 file changed, 5 deletions(-)

Makefile +0 -5

index 619413f..ba67698 100644
@@ -14,11 +14,6 @@ GCC_VER=$(shell gcc --version | grep ^gcc | cut -f 3 -d ' ' | cut -f 1 -d '.')
 endif
 $(info GCC_VER=$(GCC_VER))
 
-# Does the current GCC compiler have fcf-protection and c99+ as default?
-MIN_GCC_VER := 8
-IS_MINVER := $(intcmp $(GCC_VER), $(MIN_GCC_VER), false, true, true)
-$(info IS_MINVER=$(IS_MINVER))
-
 USE_BPF := 1
 MTUNE	:= -mtune=generic
 M64	:= -m64

Signature · 1 line

2.51.1

This commit adds informational messages to the Makefile to print the kernel version, clang version, and bpftool version. This will help in debugging BPF-related compilation issues by providing clear information about the build environment.

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>

---
 Makefile | 4 ++++
 1 file changed, 4 insertions(+)

Makefile +4 -0

index ba67698..43eb9b8 100644
@@ -121,6 +121,10 @@ VMLINUX_BTF_PATHS	:= /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL)
 VMLINUX_BTF_PATH	:= $(or $(VMLINUX_BTF),$(firstword                            \
                                           $(wildcard $(VMLINUX_BTF_PATHS))))
 
+$(info KERNEL=$(KERNEL_REL))
+$(info $(shell $(CLANG) --version | head -1))
+$(info $(shell $(BPFTOOL) --version))
+
 ifeq ($(ARCH),x86_64)
 CLANGARCH="-D__x86_64__"
 endif

Signature · 1 line

2.51.1

This commit adds .serena and CLAUDE.md to the .gitignore file to prevent Serena IDE metadata and Claude Code documentation from being tracked in version control. These files are development environment specific and should not be part of the repository.

The .serena directory contains IDE-specific configuration and cache files, while CLAUDE.md is used for AI-assisted development guidance. Both are local-only files that vary between development environments and should remain untracked.

Signed-off-by Wander Lairson Costa <[email protected]>

---
 .gitignore | 2 ++
 1 file changed, 2 insertions(+)

.gitignore +2 -0

index dc802f6..62fddc0 100644
@@ -18,3 +18,5 @@ node_modules/
 patches/
 tests/legacy/test01
 *.patch
+.serena
+CLAUDE.md

Signature · 1 line

2.51.1

This patch series improves the stalld build system to be more portable across different architectures and compiler toolchains while adding better debugging capabilities. The main motivation is to eliminate hard-coded compiler version checks that were brittle and could fail on non-standard toolchains or different architectures.

The changes replace minimum version checks with direct compiler feature detection tests, ensuring that compiler flags are only used when actually supported. This approach tests each flag by attempting to compile a minimal test program, making the build system resilient to variations in compiler implementations across architectures like x86_64, aarch64, s390x, i686, and powerpc. Additionally, the series adds build environment information output and cleans up redundant checks to improve maintainability.

The series also includes minor improvements to explicitly specify the test target invocation and exclude development environment metadata from version control.

Wander Lairson Costa (6):
Makefile: Conditionally add -mno-omit-leaf-frame-pointer
Makefile: Improve compiler flag detection for -fcf-protection
Makefile: Explicitly run the 'test' target in the tests directory
Makefile: Remove redundant GCC version check
Makefile: Print BPF tool versions for debugging
gitignore: Exclude Serena and Claude Code metadata

 .gitignore |  2 ++
 Makefile   | 42 ++++++++++++++++++++++++------------------
 2 files changed, 26 insertions(+), 18 deletions(-)

Signed-off-by Wander Lairson Costa <[email protected]>

Cc Derek Barbosa <[email protected]>

Cc John Kacur <[email protected]>

Cc Juri Lelli <[email protected]>

Cc Chunsheng Luo <[email protected]>