使用Sparse检查C代码

Question

有没有人有 Sparse 的经验？我似乎无法找到任何文档，所以警告和它产生的错误对我来说都不清楚。我尝试检查邮件列表和手册页，但实际上并没有太多。

例如，我在我的一个文件中使用INT_MAX。这会产生错误（未定义的标识符），即使我#include limits.h。

是否有任何地方可以解释错误和警告？

Answer 1

根据说，稀疏并不是一种棉绒。 Sparse旨在生成任意代码的解析树，以便进一步分析。

在您的示例中，您要么定义GNU_SOURCE（我相信它会打开__GNUC__），它会在limits.h中公开您需要的位。

我会避免单独定义__GNUC__，因为它激活的几个东西可能会以未定义的方式运行，而没有GNU_SOURCE打开的所有其他开关被定义。

我的观点不是帮助你按错误压缩错误，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README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具“功能测试套件和示例”。它是一个非常有用的工具，但如果你想使用它，你可能会考虑另一个使用角度。我喜欢它，因为它不使用* lex / bison，这使得攻击变得非常容易。

Answer 2

如果查看limits.h，您会看到INT_MAX是在#if

中定义的

/* 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

为了让它工作，你应该在包括limits.h之前取消定义__GNUC__