forked from OSchip/llvm-project
7c4575e15f
There are several `::IsStructurallyEquivalent` overloads for Decl subclasses that are used for comparing declarations. There is also one overload that takes just two Decl pointers which ends up queuing the passed Decls to be later compared in `CheckKindSpecificEquivalence`. `CheckKindSpecificEquivalence` implements the dispatch logic for the different Decl subclasses. It is supposed to hand over the queued Decls to the subclass-specific `::IsStructurallyEquivalent` overload that will actually compare the Decl instance. It also seems to implement a few pieces of actual node comparison logic inbetween the dispatch code. This implementation causes that the different overloads of `::IsStructurallyEquivalent` do different (and sometimes no) comparisons depending on which overload of `::IsStructurallyEquivalent` ends up being called. For example, if I want to compare two FieldDecl instances, then I could either call the `::IsStructurallyEquivalent` with `Decl *` or with `FieldDecl *` parameters. The overload that takes FieldDecls is doing a correct comparison. However, the `Decl *` overload just queues the Decl pair. `CheckKindSpecificEquivalence` has no dispatch logic for `FieldDecl`, so it always returns true and never does any actual comparison. On the other hand, if I try to compare two FunctionDecl instances the two possible overloads of `::IsStructurallyEquivalent` have the opposite behaviour: The overload that takes `FunctionDecl` pointers isn't comparing the names of the FunctionDecls while the overload taking a plain `Decl` ends up comparing the function names (as the comparison logic for that is implemented in `CheckKindSpecificEquivalence`). This patch tries to make this set of functions more consistent by making `CheckKindSpecificEquivalence` a pure dispatch function without any subclass-specific comparison logic. Also the dispatch logic is now autogenerated so it can no longer miss certain subclasses. The comparison code from `CheckKindSpecificEquivalence` is moved to the respective `::IsStructurallyEquivalent` overload so that the comparison result no longer depends if one calls the `Decl *` overload or the overload for the specific subclass. The only difference is now that the `Decl *` overload is queuing the parameter while the subclass-specific overload is directly doing the comparison. `::IsStructurallyEquivalent` is an implementation detail and I don't think the behaviour causes any bugs in the current implementation (as carefully calling the right overload for the different classes works around the issue), so the test for this change is that I added some new code for comparing `MemberExpr`. The new comparison code always calls the dispatching overload and it previously failed as the dispatch didn't support FieldDecls. Reviewed By: martong, a_sidorin Differential Revision: https://reviews.llvm.org/D87619 |
||
|---|---|---|
| .. | ||
| AST | ||
| ASTMatchers | ||
| Analysis | ||
| Basic | ||
| CodeGen | ||
| CrossTU | ||
| DirectoryWatcher | ||
| Driver | ||
| Format | ||
| Frontend | ||
| Index | ||
| Lex | ||
| Rename | ||
| Rewrite | ||
| Sema | ||
| Serialization | ||
| StaticAnalyzer | ||
| Tooling | ||
| libclang | ||
| CMakeLists.txt | ||