@@ -329,9 +329,25 @@ endif
LIBS = -Wl,--whole-archive $(PERFLIBS) -Wl,--no-whole-archive -Wl,--start-group $(EXTLIBS) -Wl,--end-group
ifeq ($(USE_CLANG), 1)
+ # Only partial of the required clang libraries are listed.
+ #
+ # In case of dynamical linking, if clang is built and installed
+ # correctly, ld can infer the full list automatically. However,
+ # I observed a potential bug in 3.9.0 that four libraries
+ # (ASTMatchers, Format Rewrite and ToolingCore) are lost.
+ #
+ # In case of statical linking, providing the full list causes
+ # linking time dramatically increases because of --{start,end}-group.
+ #
+ # If linking error, replace CLANGLIBS_LIST with the full list
+ # and try again.
+ #
+ # The full list should be:
+ #
+ # Basic CodeGen Frontend Tooling AST Lex Driver Edit Parse Sema
+ # Serialization ASTMatchers Format Rewrite ToolingCore Analysis
CLANGLIBS_LIST = AST Basic CodeGen Driver Frontend Lex Tooling Edit Sema Analysis Parse Serialization
- LIBCLANG = $(foreach l,$(CLANGLIBS_LIST),$(wildcard $(shell $(LLVM_CONFIG) --libdir)/libclang$(l).a))
- LIBS += -Wl,--start-group $(LIBCLANG) -Wl,--end-group
+ LIBS += -L$(shell $(LLVM_CONFIG) --libdir) -Wl,--start-group $(foreach l,$(CLANGLIBS_LIST),-lclang$(l)) -Wl,--end-group
endif
ifeq ($(USE_LLVM), 1)
Statical linking result a very large perf executable. This patch makes perf link clang libraries dynamically by using '-lclangBasic' style linking option. If dynamic clang libraries are detected, gcc will use them by default. Test result: (Build clang/llvm dynamically by setting -DBUILD_SHARED_LIBS=ON in its cmake configuration.) $ size ~/perf text data bss dec hex filename 4223234 754544 23956048 28933826 1b97ec2 /home/wn/perf $ strip ~/perf $ ls -sh ~/perf 4.8M /home/wn/perf Compare with statical linking: $ ls -sh ~/perf 969M /home/wn/perf $ strip ~/perf $ ls -sh ~/perf 52M /home/wn/perf Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/Makefile.perf | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) -- 2.10.1