Autotools交叉编译和生成源

Question

我正在尝试使用autotools(autoconf,automake,libtool)创建一个库作为构建系统.该库必须是可交叉编译的,但构建它的步骤之一是通过在整个过程中从源构建的可执行文件生成源.

问题是我不能使用automake的系统来构建中间二进制文件,因为当它交叉编译时,它不会在'--build'上运行来生成源代码.

解决这个问题的一种方法是创建单独的autools项目来构建中间二进制文件,但我想避免它,因为有许多标题和其他"数据"文件对于中间可执行文件和最终库是常见的,所以我想将它保存在一个地方,除了那些中间二进制文件应该是"noinst".

有没有其他方法可以使其正常工作并保持可移植性？我试图使用ax_prog_cxx_for_build,但在交叉编译时我找不到--build的EXEEXT.

这是一个问题的例子,只是为了说明我的问题:

configure.ac

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ([2.68])
AC_INIT([libfoobar], [0.1.0], [<NOBUGS>])
AM_INIT_AUTOMAKE([foreign])
LT_INIT

AC_CONFIG_SRCDIR([src/bar.cpp])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_FILES([Makefile
                 src/Makefile])

# Checks for programs.
AC_PROG_CXX

# Checks for libraries.

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.

# Checks for library functions.

AC_OUTPUT

Makefile.am

ACLOCAL_AMFLAGS = -I m4

SUBDIRS = src

SRC/Makefile.am

bin_PROGRAMS = bar
lib_LTLIBRARIES = libfoo.la

noinst_bar_SOURCES = bar.cpp

libfoo_la_SOURCES = foo.cpp
nodist_libfoo_la_SOURCES = foobar.h

BUILT_SOURCES: foobar.h

foobar.h: bar$(EXEEXT) Makefile
    ./$< >$@
CLEANFILES = foobar.h

SRC/Foo.cpp中

#include "foobar.h"

extern "C" int foo() {
    return foobar_value;
}

SRC/bar.cpp

#include <iostream>

int main() {
    std::cout << "#ifndef FOOBAR_H" << std::endl;
    std::cout << "#define FOOBAR_H" << std::endl;
    std::cout << std::endl;
    std::cout << "static const int foobar_value = 0xdeadbeef;" << std::endl;
    std::cout << std::endl;
    std::cout << "#endif" << std::endl;
}

Answer 1

如果您正在使用AX_PROG_CXX_FOR_BUILD,那么EXEEXT您应该使用的是BUILD_EXEEXT宏中定义的AX_PROG_CC_FOR_BUILD(AX_PROG_CXX_FOR_BUILD需要).使用EXEEXT构建的东西CXX_FOR_BUILD将是一个错误,因为这是主机工具链的扩展.所以在这种情况下你需要更像的东西:

configure.ac

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ([2.68])
AC_INIT([libfoobar], [0.1.0], [<NOBUGS>])
AM_INIT_AUTOMAKE([foreign])
LT_INIT
AC_CANONICAL_BUILD
AC_CANONICAL_HOST

AC_CONFIG_SRCDIR([src/bar.cpp])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_FILES([Makefile
                 src/Makefile])

# Checks for programs.
AC_PROG_CXX
AX_PROG_CXX_FOR_BUILD

# Checks for libraries.

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.

# Checks for library functions.

AC_OUTPUT

SRC/Makefile.am

noinst_PROGRAMS = bar
lib_LTLIBRARIES = libfoo.la

bar_SOURCES = bar.cpp

LINK_FOR_BUILD.cpp = $(CXX_FOR_BUILD) $(CXXFLAGS_FOR_BUILD) $(CPPFLAGS_FOR_BUILD) $(LDFLAGS_FOR_BUILD) $(TARGET_ARCH_FOR_BUILD)

bar$(BUILD_EXEEXT) : $(bar_OBJECTS)
            $(LINK_FOR_BUILD.cpp) $^ $(LOADLIBES_FOR_BUILD) $(LDLIBS_FOR_BUILD) -o $@

$(bar_OBJECTS) : CC=$(CC_FOR_BUILD)
$(bar_OBJECTS) : CXXFLAGS=$(CXXFLAGS_FOR_BUILD)
$(bar_OBJECTS) : CPPFLAGS=$(CPPFLAGS_FOR_BUILD)

libfoo_la_SOURCES = foo.cpp
nodist_libfoo_la_SOURCES = foobar.h

BUILT_SOURCES: foobar.h

foobar.h: bar$(BUILD_EXEEXT) Makefile
    ./$< >$@
CLEANFILES = foobar.h