如何用Autotools+Libtool为静态库添加-static后缀以区分共享库

Great question! When using Automake + Libtool to build both static and shared libraries across systems, you can tweak Libtool's configuration to append a -static suffix to your static library files—just like you do with CMake on Windows. Here's how to pull this off, with cross-system compatibility in mind:

1. Ensure Libtool is Properly Initialized in configure.ac #

First, make sure your configure.ac sets up Libtool correctly. Use the LT_INIT macro (the modern replacement for AC_PROG_LIBTOOL) to enable both static and shared library support:

AC_INIT([your-project-name], [1.0.0])
AM_INIT_AUTOMAKE([-Wall foreign]) # Adjust automake flags to match your project needs
LT_INIT([enable-static enable-shared]) # Explicitly enable both library types
AC_PROG_CC # Use AC_PROG_CXX instead if this is a C++ project
AC_OUTPUT([Makefile])

If you prefer to let your Makefile.am control static/shared builds per-library, you can omit the enable-static enable-shared arguments from LT_INIT and set those flags later.

2. Configure the Static Library Suffix #

You have two flexible options here: apply the suffix globally to all libraries, or target specific libraries individually.

Option A: Global Suffix (All Libraries) #

Add this line to your Makefile.am to apply the -static suffix to every static library in your project:

AM_LIBTOOLFLAGS = --static-suffix=-static

Option B: Per-Library Suffix #

If you only want certain libraries to get the -static suffix, define the flag directly for that library in Makefile.am. For example, for a library named libfoo.la:

# Define your library target
lib_LTLIBRARIES = libfoo.la
libfoo_la_SOURCES = src/foo.c src/bar.c # Replace with your actual source files

# Enable both static and shared builds for this specific library
libfoo_la_LIBTOOLFLAGS = --enable-static --enable-shared
# Append the "-static" suffix to the static library variant
libfoo_la_LIBTOOLFLAGS += --static-suffix=-static

3. Build and Verify #

Run these commands to regenerate your build files and test the setup:

autoreconf -vfi # Generate configure script and Makefile.in
./configure # Configure the project for your system
make # Build the libraries

After building, you'll get the expected output across systems:

• On Unix-like systems: libfoo.so (shared library) and libfoo-static.a (static library)
• On Windows (MinGW/MSYS2): libfoo.dll (shared library) and libfoo-static.lib (static library)

Key Notes #

• Libtool Version Check: The --static-suffix flag is supported in Libtool 2.2 and newer. If you're using an older version, you'll need to upgrade Libtool to use this feature.
• Clean Old Builds: If you've run configure before, run make distclean first to clear cached Libtool settings and avoid conflicts with old configurations.
• Cross-Platform Auto-Handling: Libtool automatically manages system-specific file extensions (.a/.lib), so you don't need to hardcode them—just the -static suffix itself.

内容的提问来源于stack exchange，提问作者Isaac Monteiro