Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751609AbcLFH3J (ORCPT ); Tue, 6 Dec 2016 02:29:09 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:26746 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751064AbcLFH3H (ORCPT ); Tue, 6 Dec 2016 02:29:07 -0500 From: Wang Nan To: CC: , , Wang Nan , Arnaldo Carvalho de Melo , "Alexei Starovoitov" , He Kuang , Jiri Olsa , Zefan Li , Subject: [PATCH v4 02/18] perf build: Support dynamic linking clang libraries Date: Tue, 6 Dec 2016 07:13:40 +0000 Message-ID: <20161206071356.5312-3-wangnan0@huawei.com> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161206071356.5312-1-wangnan0@huawei.com> References: <20161206071356.5312-1-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2497 Lines: 70 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 Cc: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: He Kuang Cc: Jiri Olsa Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/Makefile.perf | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 10495c9..192f2d6 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -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) -- 2.10.1