pythondistutils在不同的机器上构建不同的扩展

我查看了Mercurial回购,发现了以下变化:

Issue #5372 :删除Distutils的ccompiler中.o文件的重用(因为Extension extra选项可能会更改输出而不更改.c文件)。

我追踪到了Python2.6.4和Python2.6.5之间的差异。中的两种方法 distutils.ccompiler.CCompiler _setup_compile _prep_compile ,删除了相同的代码块:

if self.force:
    skip_source = {}            # rebuild everything
    for source in sources:
        skip_source[source] = 0
elif depends is None:
    # If depends is None, figure out which source files we
    # have to recompile according to a simplistic check. We
    # just compare the source and object file, no deep
    # dependency checking involving header files.
    skip_source = {}            # rebuild everything
    for source in sources:      # no wait, rebuild nothing
        skip_source[source] = 1

    n_sources, n_objects = newer_pairwise(sources, objects)
    for source in n_sources:    # no really, only rebuild what's
        skip_source[source] = 0 # out-of-date
else:
    # If depends is a list of files, then do a different
    # simplistic check.  Assume that each object depends on
    # its source and all files in the depends list.
    skip_source = {}
    # L contains all the depends plus a spot at the end for a
    # particular source file
    L = depends[:] + [None]
    for i in range(len(objects)):
        source = sources[i]
        L[-1] = source
        if newer_group(L, objects[i]):
            skip_source[source] = 0
        else:
            skip_source[source] = 1

这段代码将每个源文件与其目标对象进行检查,如果源文件早于目标对象,则将其标记为跳过。我不知道为什么它被删除,但它解释了差异。当我把它作为一个测试放回去时,编译器会恢复到每源依赖性分析。