[clang] 4d218ca - [Clang] [Sema] Effects: Correctly detect `(x ? a : b)` as nonblocking when a and b are (#111224)

[via cfe-commits]

Author: Doug Wyatt
Date: 2024-10-08T10:20:05+02:00
New Revision: 4d218caa7716743061e8d34d61b2181c94b16440

URL: https://github.com/llvm/llvm-project/commit/4d218caa7716743061e8d34d61b2181c94b16440
DIFF: https://github.com/llvm/llvm-project/commit/4d218caa7716743061e8d34d61b2181c94b16440.diff

LOG: [Clang] [Sema] Effects: Correctly detect `(x ? a : b)` as nonblocking when a and b are (#111224)

Correctly detect `(x ? a : b)` as nonblocking when `a` and `b` are. Use 
`FunctionEffectsRef::get` to get to the actual effect set instead of trying 
to retrieve it manually via the `FunctionProtoType` as we may have to 
look through function pointers etc. in some cases.

---------

Co-authored-by: Doug Wyatt <dwyatt at apple.com>

Added: 
    

Modified: 
    clang/lib/Sema/SemaFunctionEffects.cpp
    clang/test/Sema/attr-nonblocking-constraints.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaFunctionEffects.cpp b/clang/lib/Sema/SemaFunctionEffects.cpp
index 0fb18d207a50ba..0ac5de29f66aa7 100644
--- a/clang/lib/Sema/SemaFunctionEffects.cpp
+++ b/clang/lib/Sema/SemaFunctionEffects.cpp
@@ -1048,15 +1048,14 @@ class Analyzer {
     }
 
     void checkIndirectCall(CallExpr *Call, QualType CalleeType) {
-      auto *FPT =
-          CalleeType->getAs<FunctionProtoType>(); // Null if FunctionType.
       FunctionEffectKindSet CalleeEffects;
-      if (FPT)
-        CalleeEffects.insert(FPT->getFunctionEffects());
+      if (FunctionEffectsRef Effects = FunctionEffectsRef::get(CalleeType);
+          !Effects.empty())
+        CalleeEffects.insert(Effects);
 
       auto Check1Effect = [&](FunctionEffect Effect, bool Inferring) {
-        if (FPT == nullptr || Effect.shouldDiagnoseFunctionCall(
-                                  /*direct=*/false, CalleeEffects))
+        if (Effect.shouldDiagnoseFunctionCall(
+                /*direct=*/false, CalleeEffects))
           addViolation(Inferring, Effect, ViolationID::CallsExprWithoutEffect,
                        Call->getBeginLoc());
       };

diff  --git a/clang/test/Sema/attr-nonblocking-constraints.cpp b/clang/test/Sema/attr-nonblocking-constraints.cpp
index c694860069c960..f23093d4dc8a96 100644
--- a/clang/test/Sema/attr-nonblocking-constraints.cpp
+++ b/clang/test/Sema/attr-nonblocking-constraints.cpp
@@ -156,6 +156,17 @@ void nb10(
 	static_cast<void (*)()>(fp1)(); // expected-warning {{function with 'nonblocking' attribute must not call non-'nonblocking' expression}}
 }
 
+// Expression involving indirection
+int nb10a() [[clang::nonblocking]];
+int nb10b() [[clang::nonblocking]];
+int blocking();
+
+int nb10c(bool x) [[clang::nonblocking]]
+{
+	int y = (x ? nb10a : blocking)(); // expected-warning {{attribute 'nonblocking' should not be added via type conversion}}
+	return (x ? nb10a : nb10b)(); // No diagnostic.
+}
+
 // Interactions with nonblocking(false)
 void nb11_no_inference_1() [[clang::nonblocking(false)]] // expected-note {{function does not permit inference of 'nonblocking'}}
 {