[include-cleaner] Turn new/delete usages to ambiguous references

[kadircet]

In practice most of these expressions just resolve to implicitly
provided operator new and standard says it's not necessary to include
<new> for that.
Hence this is resulting in a lot of churn in cases where inclusion of
<new> doesn't matter, and might even be undesired by the developer.

By switching to an ambiguous reference we try to find a middle ground
here, ensuring that we don't drop providers of operator new when the
developer explicitly listed them in the includes, and chose to believe
it's the implicitly provided operator new and don't insert an include
in other cases.

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

Author: kadir çetinkaya (kadircet)

Changes

In practice most of these expressions just resolve to implicitly
provided operator new and standard says it's not necessary to include
<new> for that.
Hence this is resulting in a lot of churn in cases where inclusion of
<new> doesn't matter, and might even be undesired by the developer.

By switching to an ambiguous reference we try to find a middle ground
here, ensuring that we don't drop providers of operator new when the
developer explicitly listed them in the includes, and chose to believe
it's the implicitly provided operator new and don't insert an include
in other cases.

---

Full diff: https://github.com/llvm/llvm-project/pull/105844.diff

2 Files Affected:

• (modified) clang-tools-extra/include-cleaner/lib/WalkAST.cpp (+2-2)
• (modified) clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp (+2-2)

diff --git a/clang-tools-extra/include-cleaner/lib/WalkAST.cpp b/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
index a5ac3760a3be2a..598484d09712e5 100644
--- a/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
+++ b/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
@@ -351,11 +351,11 @@ class ASTWalker : public RecursiveASTVisitor<ASTWalker> {
   }
 
   bool VisitCXXNewExpr(CXXNewExpr *E) {
-    report(E->getExprLoc(), E->getOperatorNew());
+    report(E->getExprLoc(), E->getOperatorNew(), RefType::Ambiguous);
     return true;
   }
   bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
-    report(E->getExprLoc(), E->getOperatorDelete());
+    report(E->getExprLoc(), E->getOperatorDelete(), RefType::Ambiguous);
     return true;
   }
 };
diff --git a/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp b/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
index b0a4473d4ad2b7..6c8eacbff1cea3 100644
--- a/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
+++ b/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
@@ -557,9 +557,9 @@ TEST(WalkAST, FriendDecl) {
 }
 
 TEST(WalkAST, OperatorNewDelete) {
-  testWalk("void* $explicit^operator new(decltype(sizeof(int)), void*);",
+  testWalk("void* $ambiguous^operator new(decltype(sizeof(int)), void*);",
            "struct Bar { void foo() { Bar b; ^new (&b) Bar; } };");
-  testWalk("struct A { static void $explicit^operator delete(void*); };",
+  testWalk("struct A { static void $ambiguous^operator delete(void*); };",
            "void foo() { A a; ^delete &a; }");
 }
 } // namespace

[ilya-biryukov]

LGTM.