[PATCH] D88275: [ASTMatchers] Add matcher `hasParentIgnoringImplicit`.

[Yitzhak Mandelbaum via Phabricator via cfe-commits]

ymandel added a comment.

> I'm not concerned about the basic idea behind the proposed matcher, I'm only worried we're making AST matching more confusing by having two different ways of inconsistently accomplishing the same-ish thing.

Aaron, I appreciate this concern, but I would argue that this matcher isn't making things any worse. We already have the various `ignoringImplicit` matchers, and this new one simply parallels those, but for parents. So, it is in some sense "completing" an existing API, which together is an alternative to  `traverse`.

We should decide our general policy on these implict matchers vs the traverse matchers. Personally, I view `traverse` as an experimental feature that we're still figuring out and so would prefer that it not block progress on new matchers. But, I'm open to discussion. I can implement this one in my own codebase in the meantime if this requires longer discussion (that is, it's not blocking me, fwiw).

Also, I don't believe that traverse work in this case. When I change the test to use `traverse`, it fails:

  TEST(HasParentIgnoringImplicit, TraverseMatchesExplicitParents) {
    std::string Input = R"cc(
      float f() {
          int x = 3;
          int y = 3.0;
          return y;
      }
    )cc";
     // ---> Passes because there are not implicit parents.
    EXPECT_TRUE(matches(
        Input, integerLiteral(traverse(TK_IgnoreImplicitCastsAndParentheses,
                                       hasParent(varDecl())))));
  
    EXPECT_TRUE(
        matches(Input, declRefExpr(traverse(TK_IgnoreImplicitCastsAndParentheses,
                                            hasParent(returnStmt())))));
    EXPECT_TRUE(
        matches(Input, floatLiteral(traverse(TK_IgnoreImplicitCastsAndParentheses,
                                             hasParent(varDecl())))));
  }


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D88275/new/

https://reviews.llvm.org/D88275