[clang-tools-extra] 26ff268 - [include-cleaner] Report references to operator calls as implicit

[Kadir Cetinkaya via cfe-commits]

Author: Kadir Cetinkaya
Date: 2023-04-03T15:49:28+02:00
New Revision: 26ff268b80c589fd9f71c1c214af77cd972642ca

URL: https://github.com/llvm/llvm-project/commit/26ff268b80c589fd9f71c1c214af77cd972642ca
DIFF: https://github.com/llvm/llvm-project/commit/26ff268b80c589fd9f71c1c214af77cd972642ca.diff

LOG: [include-cleaner] Report references to operator calls as implicit

Missing these references can result in false negatives in the used-ness
analysis and break builds.

Differential Revision: https://reviews.llvm.org/D147144

Added: 
    

Modified: 
    clang-tools-extra/include-cleaner/lib/WalkAST.cpp
    clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp

Removed: 
    


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diff  --git a/clang-tools-extra/include-cleaner/lib/WalkAST.cpp b/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
index b10c722b6653a..8a1dd77176cdf 100644
--- a/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
+++ b/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
@@ -91,14 +91,23 @@ class ASTWalker : public RecursiveASTVisitor<ASTWalker> {
 public:
   ASTWalker(DeclCallback Callback) : Callback(Callback) {}
 
+  // Operators are almost always ADL extension points and by design references
+  // to them doesn't count as uses (generally the type should provide them, so
+  // ignore them).
+  // Unless we're using an operator defined as a member, in such cases treat
+  // this as a regular reference.
   bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *S) {
     if (!WalkUpFromCXXOperatorCallExpr(S))
       return false;
-
-    // Operators are always ADL extension points, by design references to them
-    // doesn't count as uses (generally the type should provide them).
-    // Don't traverse the callee.
-
+    if (auto *CD = S->getCalleeDecl()) {
+      if (llvm::isa<CXXMethodDecl>(CD)) {
+        // Treat this as a regular member reference.
+        report(S->getOperatorLoc(), getMemberProvider(S->getArg(0)->getType()));
+      } else {
+        report(S->getOperatorLoc(), llvm::dyn_cast<NamedDecl>(CD),
+               RefType::Implicit);
+      }
+    }
     for (auto *Arg : S->arguments())
       if (!TraverseStmt(Arg))
         return false;

diff  --git a/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp b/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
index fd6c6da9d5509..fceec670076c9 100644
--- a/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
+++ b/clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp
@@ -291,13 +291,18 @@ TEST(WalkAST, ConstructExprs) {
 }
 
 TEST(WalkAST, Operator) {
-  // References to operators are not counted as uses.
-  testWalk("struct string {}; int operator+(string, string);",
-           "int k = string() ^+ string();");
-  testWalk("struct string {int operator+(string); }; ",
-           "int k = string() ^+ string();");
-  testWalk("struct string { friend int operator+(string, string); }; ",
+  // Operator calls are marked as implicit references as they're ADL-used and
+  // type should be providing them.
+  testWalk(
+      "struct string { friend int $implicit^operator+(string, string); }; ",
+      "int k = string() ^+ string();");
+  // Unless they're members, we treat them as regular member expr calls.
+  testWalk("struct $explicit^string {int operator+(string); }; ",
            "int k = string() ^+ string();");
+  // Make sure usage is attributed to the alias.
+  testWalk(
+      "struct string {int operator+(string); }; using $explicit^foo = string;",
+      "int k = foo() ^+ string();");
 }
 
 TEST(WalkAST, VarDecls) {