forked from OSchip/llvm-project
814e7974c6
Summary: The goal is to allow analyses such as clang-tidy checks to run on a subset of the AST, e.g. "only on main-file decls" for interactive tools. Today, these become "problematically global" by running RecursiveASTVisitors rooted at the TUDecl, or by navigating up via ASTContext::getParent(). The scope is restricted using a set of top-level-decls that RecursiveASTVisitors should be rooted at. This also applies to the visitor that populates the parent map, and so the top-level-decls are considered to have no parents. This patch makes the traversal scope a mutable property of ASTContext. The more obvious way to do this is to pass the top-level decls to relevant functions directly, but this has some problems: - it's error-prone: accidentally mixing restricted and unrestricted scopes is a performance trap. Interleaving multiple analyses is common (many clang-tidy checks run matchers or RAVs from matcher callbacks) - it doesn't map well to the actual use cases, where we really do want *all* traversals to be restricted. - it involves a lot of plumbing in parts of the code that don't care about traversals. This approach was tried out in D54259 and D54261, I wanted to like it but it feels pretty awful in practice. Caveats: to get scope-limiting behavior of RecursiveASTVisitors, callers have to call the new TraverseAST(Ctx) function instead of TraverseDecl(TU). I think this is an improvement to the API regardless. Reviewers: klimek, ioeric Subscribers: mgorny, cfe-commits Differential Revision: https://reviews.llvm.org/D54309 llvm-svn: 346847 |
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| INPUTS | ||
| bindings | ||
| cmake | ||
| docs | ||
| examples | ||
| include | ||
| lib | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| www | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| INSTALL.txt | ||
| LICENSE.TXT | ||
| ModuleInfo.txt | ||
| NOTES.txt | ||
| README.txt | ||
README.txt
//===----------------------------------------------------------------------===// // C Language Family Front-end //===----------------------------------------------------------------------===// Welcome to Clang. This is a compiler front-end for the C family of languages (C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM compiler infrastructure project. Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer. If you're interested in more (including how to build Clang) it is best to read the relevant web sites. Here are some pointers: Information on Clang: http://clang.llvm.org/ Building and using Clang: http://clang.llvm.org/get_started.html Clang Static Analyzer: http://clang-analyzer.llvm.org/ Information on the LLVM project: http://llvm.org/ If you have questions or comments about Clang, a great place to discuss them is on the Clang development mailing list: http://lists.llvm.org/mailman/listinfo/cfe-dev If you find a bug in Clang, please file it in the LLVM bug tracker: http://llvm.org/bugs/