[PATCH] D98622: [-Wcalled-once-parameter] Let escapes overwrite MaybeCalled states

[Valeriy Savchenko via Phabricator via cfe-commits]

vsavchenko updated this revision to Diff 330760.
vsavchenko added a comment.

Unify the way we deal with escapes


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D98622/new/

https://reviews.llvm.org/D98622

Files:
  clang/lib/Analysis/CalledOnceCheck.cpp
  clang/test/SemaObjC/warn-called-once.m


Index: clang/test/SemaObjC/warn-called-once.m
===================================================================
--- clang/test/SemaObjC/warn-called-once.m
+++ clang/test/SemaObjC/warn-called-once.m
@@ -1130,4 +1130,32 @@
   }
 }
 
+- (void)test_escape_before_branch:(int)cond
+                   withCompletion:(void (^)(void))handler {
+  if (cond) {
+    filler();
+  }
+
+  void (^copiedHandler)(void) = ^{
+    handler();
+  };
+
+  if (cond) {
+    // no-warning
+    handler();
+  } else {
+    copiedHandler();
+  }
+}
+
+- (void)test_escape_after_branch:(int)cond
+                  withCompletion:(void (^)(void))handler {
+  if (cond) {
+    // no-warning
+    handler();
+  }
+
+  escape(handler);
+}
+
 @end
Index: clang/lib/Analysis/CalledOnceCheck.cpp
===================================================================
--- clang/lib/Analysis/CalledOnceCheck.cpp
+++ clang/lib/Analysis/CalledOnceCheck.cpp
@@ -867,16 +867,14 @@
     // Let's check if any of the call arguments is a point of interest.
     for (const auto &Argument : llvm::enumerate(Arguments)) {
       if (auto Index = getIndexOfExpression(Argument.value())) {
-        ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(*Index);
-
         if (shouldBeCalledOnce(CallOrMessage, Argument.index())) {
           // If the corresponding parameter is marked as 'called_once' we should
           // consider it as a call.
           processCallFor(*Index, CallOrMessage);
-        } else if (CurrentParamStatus.getKind() == ParameterStatus::NotCalled) {
+        } else {
           // Otherwise, we mark this parameter as escaped, which can be
           // interpreted both as called or not called depending on the context.
-          CurrentParamStatus = ParameterStatus::Escaped;
+          processEscapeFor(*Index);
         }
         // Otherwise, let's keep the state as it is.
       }
@@ -910,6 +908,16 @@
     }
   }
 
+  /// Process escape of the parameter with the given index
+  void processEscapeFor(unsigned Index) {
+    ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(Index);
+
+    // Escape overrides whatever error we think happened.
+    if (CurrentParamStatus.isErrorStatus()) {
+      CurrentParamStatus = ParameterStatus::Escaped;
+    }
+  }
+
   void findAndReportNotCalledBranches(const CFGBlock *Parent, unsigned Index,
                                       bool IsEscape = false) {
     for (const CFGBlock *Succ : Parent->succs()) {
@@ -1365,11 +1373,7 @@
   /// Check given parameter that was discovered to escape.
   void checkEscapee(const ParmVarDecl &Parameter) {
     if (auto Index = getIndex(Parameter)) {
-      ParameterStatus &CurrentParamStatus = CurrentState.getStatusFor(*Index);
-
-      if (CurrentParamStatus.getKind() == ParameterStatus::NotCalled) {
-        CurrentParamStatus = ParameterStatus::Escaped;
-      }
+      processEscapeFor(*Index);
     }
   }
 


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