[tip:perf/urgent] perf build: Don't unconditionally link the libbfd feature test to -liberty and -lz

From: tip-bot for Stanislav Fomichev
Date: Thu Jan 03 2019 - 08:11:40 EST

Commit-ID: 14541b1e7e723859ff2c75c6fc10cdbbec6b8c34
Gitweb: https://git.kernel.org/tip/14541b1e7e723859ff2c75c6fc10cdbbec6b8c34
Author: Stanislav Fomichev <sdf@xxxxxxxxxx>
AuthorDate: Thu, 15 Nov 2018 16:32:01 -0800
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 21 Dec 2018 09:42:46 -0300

perf build: Don't unconditionally link the libbfd feature test to -liberty and -lz

Current libbfd feature test unconditionally links against -liberty and -lz.
While it's required on some systems (e.g. opensuse), it's completely
unnecessary on the others, where only -lbdf is sufficient (debian).
This patch streamlines (and renames) the following feature checks:

feature-libbfd - only link against -lbfd (debian),
see commit 2cf9040714f3 ("perf tools: Fix bfd
dependency libraries detection")
feature-libbfd-liberty - link against -lbfd and -liberty
feature-libbfd-liberty-z - link against -lbfd, -liberty and -lz (opensuse),
see commit 280e7c48c3b8 ("perf tools: fix BFD
detection on opensuse")

(feature-liberty{,-z} were renamed to feature-libbfd-liberty{,z}
for clarity)

The main motivation is to fix this feature test for bpftool which is
currently broken on debian (libbfd feature shows OFF, but we still
unconditionally link against -lbfd and it works).

Tested on debian with only -lbfd installed (without -liberty); I'd
appreciate if somebody on the other systems can test this new detection
method.

Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/4dfc634cfcfb236883971b5107cf3c28ec8a31be.1542328222.git.sdf@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/build/Makefile.feature | 4 ++--
tools/build/feature/Makefile | 10 +++++-----
tools/perf/Makefile.config | 44 +++++++++++++++++++++++---------------------
3 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index d47b8f73e2e7..5467c6bf9ceb 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -82,8 +82,8 @@ FEATURE_TESTS_EXTRA := \
cplus-demangle \
hello \
libbabeltrace \
- liberty \
- liberty-z \
+ libbfd-liberty \
+ libbfd-liberty-z \
libunwind-debug-frame \
libunwind-debug-frame-arm \
libunwind-debug-frame-aarch64 \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 2dbcc0d00f52..7ceb4441b627 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -17,8 +17,8 @@ FILES= \
test-libbfd.bin \
test-disassembler-four-args.bin \
test-reallocarray.bin \
- test-liberty.bin \
- test-liberty-z.bin \
+ test-libbfd-liberty.bin \
+ test-libbfd-liberty-z.bin \
test-cplus-demangle.bin \
test-libelf.bin \
test-libelf-getphdrnum.bin \
@@ -210,7 +210,7 @@ $(OUTPUT)test-libpython-version.bin:
$(BUILD)

$(OUTPUT)test-libbfd.bin:
- $(BUILD) -DPACKAGE='"perf"' -lbfd -lz -liberty -ldl
+ $(BUILD) -DPACKAGE='"perf"' -lbfd -ldl

$(OUTPUT)test-disassembler-four-args.bin:
$(BUILD) -DPACKAGE='"perf"' -lbfd -lopcodes
@@ -218,10 +218,10 @@ $(OUTPUT)test-disassembler-four-args.bin:
$(OUTPUT)test-reallocarray.bin:
$(BUILD)

-$(OUTPUT)test-liberty.bin:
+$(OUTPUT)test-libbfd-liberty.bin:
$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty

-$(OUTPUT)test-liberty-z.bin:
+$(OUTPUT)test-libbfd-liberty-z.bin:
$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty -lz

$(OUTPUT)test-cplus-demangle.bin:
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 07c1857c3d7a..b441c88cafa1 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -702,18 +702,20 @@ endif

ifeq ($(feature-libbfd), 1)
EXTLIBS += -lbfd
+else
+ # we are on a system that requires -liberty and (maybe) -lz
+ # to link against -lbfd; test each case individually here

# call all detections now so we get correct
# status in VF output
- $(call feature_check,liberty)
- $(call feature_check,liberty-z)
- $(call feature_check,cplus-demangle)
+ $(call feature_check,libbfd-liberty)
+ $(call feature_check,libbfd-liberty-z)

- ifeq ($(feature-liberty), 1)
- EXTLIBS += -liberty
+ ifeq ($(feature-libbfd-liberty), 1)
+ EXTLIBS += -lbfd -liberty
else
- ifeq ($(feature-liberty-z), 1)
- EXTLIBS += -liberty -lz
+ ifeq ($(feature-libbfd-liberty-z), 1)
+ EXTLIBS += -lbfd -liberty -lz
endif
endif
endif
@@ -723,24 +725,24 @@ ifdef NO_DEMANGLE
else
ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
EXTLIBS += -liberty
- CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
else
- ifneq ($(feature-libbfd), 1)
- ifneq ($(feature-liberty), 1)
- ifneq ($(feature-liberty-z), 1)
- # we dont have neither HAVE_CPLUS_DEMANGLE_SUPPORT
- # or any of 'bfd iberty z' trinity
- ifeq ($(feature-cplus-demangle), 1)
- EXTLIBS += -liberty
- CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
- else
- msg := $(warning No bfd.h/libbfd found, please install binutils-dev[el]/zlib-static/libiberty-dev to gain symbol demangling)
- CFLAGS += -DNO_DEMANGLE
- endif
- endif
+ ifeq ($(filter -liberty,$(EXTLIBS)),)
+ $(call feature_check,cplus-demangle)
+
+ # we dont have neither HAVE_CPLUS_DEMANGLE_SUPPORT
+ # or any of 'bfd iberty z' trinity
+ ifeq ($(feature-cplus-demangle), 1)
+ EXTLIBS += -liberty
+ else
+ msg := $(warning No bfd.h/libbfd found, please install binutils-dev[el]/zlib-static/libiberty-dev to gain symbol demangling)
+ CFLAGS += -DNO_DEMANGLE
endif
endif
endif
+
+ ifneq ($(filter -liberty,$(EXTLIBS)),)
+ CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
+ endif
endif

ifneq ($(filter -lbfd,$(EXTLIBS)),)