使用 Sparse 检查 C 代码

Question

有人有 Sparse 的经验吗？我似乎找不到任何文档，因此我不清楚它产生的警告和错误。我尝试检查邮件列表和手册页，但实际上两者都没有太多内容。

例如，我在我的一个文件中使用 INT_MAX。即使我#include limits.h，这也会生成错误（未定义的标识符）。

是否有任何地方对错误和警告进行了解释？

Answer 1

可以说，稀疏并不是为了成为 lint。 Sparse 旨在生成任意代码的解析树，以便可以对其进行进一步分析。

在您的示例中，您要么想要定义 GNU_SOURCE （我相信它会打开 __GNUC__ ），它会公开您在 limit.h 中需要的位，

我会避免单独定义 __GNUC__ ，因为它激活的一些东西可能会以未定义的方式运行，而不需要GNU_SOURCE 打开的所有其他开关都已定义。

我的观点不是帮助您逐个消除错误，而是重申稀疏主要用作库，而不是作为独立的静态分析工具。

从我的自述文件副本（不确定我是否有当前版本）：

This means that a user of the library will literally just need to do

  struct string_list *filelist = NULL;
  char *file;

  action(sparse_initialize(argc, argv, filelist));

  FOR_EACH_PTR_NOTAG(filelist, file) {
    action(sparse(file));
  } END_FOR_EACH_PTR_NOTAG(file);

and he is now done - having a full C parse of the file he opened.  The
library doesn't need any more setup, and once done does not impose any
more requirements.  The user is free to do whatever he wants with the
parse tree that got built up, and needs not worry about the library ever
again.  There is no extra state, there are no parser callbacks, there is
only the parse tree that is described by the header files. The action
function takes a pointer to a symbol_list and does whatever it likes with it.

The library also contains (as an example user) a few clients that do the
preprocessing, parsing and type evaluation and just print out the
results.  These clients were done to verify and debug the library, and
also as trivial examples of what you can do with the parse tree once it
is formed, so that users can see how the tree is organized.

包含的客户端比任何东西都更多是“功能测试套件和示例”。它是一个非常有用的工具，但如果您想使用它，您可能会考虑另一个使用角度。我喜欢它，因为它不使用 *lex / bison ，这使得它更容易被破解。

Answer 2

如果您查看 limit.h，您会发现 INT_MAX 是在 #if 内定义的，

/* If we are not using GNU CC we have to define all the symbols ourself.
 Otherwise use gcc's definitions (see below).  */
#if !defined __GNUC__ || __GNUC__ < 2

因此要使其正常工作，您应该在包含 limit.h 之前取消定义 __GNUC__