怪异
我已经为“膨胀”编译不使用额外参数编译了 Google 协议缓冲区,并使用以下命令进行编译./configure CXXFLAGS="-ffunction-sections -fdata-sections"
。一个 du-h 揭示:
120K ./bloat/bin
124K ./bloat/include/google/protobuf/io
8.0K ./bloat/include/google/protobuf/compiler/java
12K ./bloat/include/google/protobuf/compiler/python
8.0K ./bloat/include/google/protobuf/compiler/cpp
128K ./bloat/include/google/protobuf/compiler
52K ./bloat/include/google/protobuf/stubs
848K ./bloat/include/google/protobuf
852K ./bloat/include/google
856K ./bloat/include
12K ./bloat/lib/pkgconfig
37M ./bloat/lib
38M ./bloat
20K ./unbloat/bin
124K ./unbloat/include/google/protobuf/io
8.0K ./unbloat/include/google/protobuf/compiler/java
12K ./unbloat/include/google/protobuf/compiler/python
8.0K ./unbloat/include/google/protobuf/compiler/cpp
128K ./unbloat/include/google/protobuf/compiler
52K ./unbloat/include/google/protobuf/stubs
848K ./unbloat/include/google/protobuf
852K ./unbloat/include/google
856K ./unbloat/include
12K ./unbloat/lib/pkgconfig
15M ./unbloat/lib
16M ./unbloat
53M .
向下钻取:
ls -gGh bloat/lib/
total 37M
-rw-r--r-- 1 13M 2010-09-07 13:57 libprotobuf.a
-rwxr-xr-x 1 986 2010-09-07 13:57 libprotobuf.la
-rw-r--r-- 1 1.6M 2010-09-07 13:57 libprotobuf-lite.a
-rwxr-xr-x 1 1021 2010-09-07 13:57 libprotobuf-lite.la
lrwxrwxrwx 1 25 2010-09-07 13:57 libprotobuf-lite.so -> libprotobuf-lite.so.6.0.0
lrwxrwxrwx 1 25 2010-09-07 13:57 libprotobuf-lite.so.6 -> libprotobuf-lite.so.6.0.0
-rwxr-xr-x 1 771K 2010-09-07 13:57 libprotobuf-lite.so.6.0.0
lrwxrwxrwx 1 20 2010-09-07 13:57 libprotobuf.so -> libprotobuf.so.6.0.0
lrwxrwxrwx 1 20 2010-09-07 13:57 libprotobuf.so.6 -> libprotobuf.so.6.0.0
-rwxr-xr-x 1 5.5M 2010-09-07 13:57 libprotobuf.so.6.0.0
-rw-r--r-- 1 12M 2010-09-07 13:57 libprotoc.a
-rwxr-xr-x 1 1.1K 2010-09-07 13:57 libprotoc.la
lrwxrwxrwx 1 18 2010-09-07 13:57 libprotoc.so -> libprotoc.so.6.0.0
lrwxrwxrwx 1 18 2010-09-07 13:57 libprotoc.so.6 -> libprotoc.so.6.0.0
-rwxr-xr-x 1 4.6M 2010-09-07 13:57 libprotoc.so.6.0.0
drwxr-xr-x 2 4.0K 2010-09-07 13:57 pkgconfig
ls -gGh unbloat/lib/
total 15M
-rw-r--r-- 1 5.8M 2010-09-07 14:03 libprotobuf.a
-rwxr-xr-x 1 988 2010-09-07 14:03 libprotobuf.la
-rw-r--r-- 1 764K 2010-09-07 14:03 libprotobuf-lite.a
-rwxr-xr-x 1 1023 2010-09-07 14:03 libprotobuf-lite.la
lrwxrwxrwx 1 25 2010-09-07 14:03 libprotobuf-lite.so -> libprotobuf-lite.so.6.0.0
lrwxrwxrwx 1 25 2010-09-07 14:03 libprotobuf-lite.so.6 -> libprotobuf-lite.so.6.0.0
-rwxr-xr-x 1 393K 2010-09-07 14:03 libprotobuf-lite.so.6.0.0
lrwxrwxrwx 1 20 2010-09-07 14:03 libprotobuf.so -> libprotobuf.so.6.0.0
lrwxrwxrwx 1 20 2010-09-07 14:03 libprotobuf.so.6 -> libprotobuf.so.6.0.0
-rwxr-xr-x 1 2.7M 2010-09-07 14:03 libprotobuf.so.6.0.0
-rw-r--r-- 1 3.7M 2010-09-07 14:04 libprotoc.a
-rwxr-xr-x 1 1.1K 2010-09-07 14:04 libprotoc.la
lrwxrwxrwx 1 18 2010-09-07 14:04 libprotoc.so -> libprotoc.so.6.0.0
lrwxrwxrwx 1 18 2010-09-07 14:04 libprotoc.so.6 -> libprotoc.so.6.0.0
-rwxr-xr-x 1 1.3M 2010-09-07 14:04 libprotoc.so.6.0.0
drwxr-xr-x 2 4.0K 2010-09-07 14:03 pkgconfig
问题
我没有更改构建脚本以--gc-sections
在链接期间执行“”,因此如果不是更大的话,unbloat 构建是否应该相同?是什么导致尺寸减小?
背景
我现在正在用 gcc 编译一个低级库,该库是一个巨大的 2.5MB 非条带化和 970KB 剥离。这是不可接受的,我需要删除死代码——我依赖于 Boost 的 OpenSSL、Protocol Buffers 和 3 个库,我会将最后 2 个静态链接到我的库中。这两个静态链接的库必须使用“-ffunction-sections -fdata-sections”编译它们,以便我删除死代码。
相关问题
我的下一个问题是关于如何指定用于消除死代码的根。