[PATCH v3 05/11] perf build: Combine libdw-dwarf-unwind into libdw feature tests

Ian Rogers
2024-10-17T00:34:07Z

Support in libdw has been present for 10 years so let's simplify the
build logic with a single feature test.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/build/Makefile.feature | 2 --
tools/build/feature/Makefile | 4 ----
tools/build/feature/test-all.c | 5 -----
tools/build/feature/test-libdw-dwarf-unwind.c | 14 --------------
tools/build/feature/test-libdw.c | 19 ++++++++++++++++++-
tools/perf/Makefile.config | 8 --------
6 files changed, 18 insertions(+), 34 deletions(-)
delete mode 100644 tools/build/feature/test-libdw-dwarf-unwind.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 6025810cc346..db3695ec5f83 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -60,7 +60,6 @@ FEATURE_TESTS_BASIC := \
reallocarray \
stackprotector-all \
timerfd \
- libdw-dwarf-unwind \
zlib \
lzma \
get_cpuid \
@@ -133,7 +132,6 @@ FEATURE_DISPLAY ?= \
libpython \
libcrypto \
libunwind \
- libdw-dwarf-unwind \
libcapstone \
llvm-perf \
zlib \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 7a1c028ce40b..18f8fef5e843 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -52,7 +52,6 @@ FILES= \
test-pthread-barrier.bin \
test-stackprotector-all.bin \
test-timerfd.bin \
- test-libdw-dwarf-unwind.bin \
test-libbabeltrace.bin \
test-libcapstone.bin \
test-compile-32.bin \
@@ -317,9 +316,6 @@ $(OUTPUT)test-backtrace.bin:
$(OUTPUT)test-timerfd.bin:
$(BUILD)

-$(OUTPUT)test-libdw-dwarf-unwind.bin:
- $(BUILD) # -ldw provided by $(FEATURE_CHECK_LDFLAGS-libdw-dwarf-unwind)
-
$(OUTPUT)test-libbabeltrace.bin:
$(BUILD) # -lbabeltrace provided by $(FEATURE_CHECK_LDFLAGS-libbabeltrace)

diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
index d60e072b6eca..863c82516433 100644
--- a/tools/build/feature/test-all.c
+++ b/tools/build/feature/test-all.c
@@ -98,10 +98,6 @@
# include "test-stackprotector-all.c"
#undef main

-#define main main_test_libdw_dwarf_unwind
-# include "test-libdw-dwarf-unwind.c"
-#undef main
-
#define main main_test_zlib
# include "test-zlib.c"
#undef main
@@ -202,7 +198,6 @@ int main(int argc, char *argv[])
main_test_numa_num_possible_cpus();
main_test_timerfd();
main_test_stackprotector_all();
- main_test_libdw_dwarf_unwind();
main_test_zlib();
main_test_pthread_attr_setaffinity_np();
main_test_pthread_barrier();
diff --git a/tools/build/feature/test-libdw-dwarf-unwind.c b/tools/build/feature/test-libdw-dwarf-unwind.c
deleted file mode 100644
index ed03d9505609..000000000000
--- a/tools/build/feature/test-libdw-dwarf-unwind.c
+++ /dev/null
@@ -1,14 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-#include <elfutils/libdwfl.h>
-
-int main(void)
-{
- /*
- * This function is guarded via: __nonnull_attribute__ (1, 2).
- * Passing '1' as arguments value. This code is never executed,
- * only compiled.
- */
- dwfl_thread_getframes((void *) 1, (void *) 1, NULL);
- return 0;
-}
diff --git a/tools/build/feature/test-libdw.c b/tools/build/feature/test-libdw.c
index 8d474bd7371b..793f4ac49514 100644
--- a/tools/build/feature/test-libdw.c
+++ b/tools/build/feature/test-libdw.c
@@ -1,11 +1,28 @@
// SPDX-License-Identifier: GPL-2.0
#include <dwarf.h>
#include <elfutils/libdw.h>
+#include <elfutils/libdwfl.h>
#include <elfutils/version.h>

-int main(void)
+int test_libdw(void)
{
Dwarf *dbg = dwarf_begin(0, DWARF_C_READ);

return (long)dbg;
}
+
+int test_libdw_unwind(void)
+{
+ /*
+ * This function is guarded via: __nonnull_attribute__ (1, 2).
+ * Passing '1' as arguments value. This code is never executed,
+ * only compiled.
+ */
+ dwfl_thread_getframes((void *) 1, (void *) 1, NULL);
+ return 0;
+}
+
+int main(void)
+{
+ return test_libdw() + test_libdw_unwind();
+}
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index f1e24c4ae123..fa59ecce4470 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -164,8 +164,6 @@ ifeq ($(findstring -static,${LDFLAGS}),-static)
endif
FEATURE_CHECK_CFLAGS-libdw := $(LIBDW_CFLAGS)
FEATURE_CHECK_LDFLAGS-libdw := $(LIBDW_LDFLAGS) $(DWARFLIBS)
-FEATURE_CHECK_CFLAGS-libdw-dwarf-unwind := $(LIBDW_CFLAGS)
-FEATURE_CHECK_LDFLAGS-libdw-dwarf-unwind := $(LIBDW_LDFLAGS) $(DWARFLIBS)
FEATURE_CHECK_CFLAGS-dwarf_getlocations := $(LIBDW_CFLAGS)
FEATURE_CHECK_LDFLAGS-dwarf_getlocations := $(LIBDW_LDFLAGS) $(DWARFLIBS)
FEATURE_CHECK_CFLAGS-dwarf_getcfi := $(LIBDW_CFLAGS)
@@ -467,12 +465,6 @@ else
endif
endif
else
- ifndef NO_LIBDW_DWARF_UNWIND
- ifneq ($(feature-libdw-dwarf-unwind),1)
- NO_LIBDW_DWARF_UNWIND := 1
- $(warning No libdw DWARF unwind found, Please install elfutils-devel/libdw-dev >= 0.158 and/or set LIBDW_DIR)
- endif
- endif
ifneq ($(feature-libdw), 1)
ifndef NO_LIBDW
$(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev)