Merge pull request #69300 from eeckstein/fix-perf-diagnostics

PerformanceDiagnostics: exclude error handling from performance-checked code

Author: swift-ci

lib/SILOptimizer/Mandatory/PerformanceDiagnostics.cpp

@@ -157,11 +157,22 @@ bool PerformanceDiagnostics::visitFunction(SILFunction *function,
   if (!function->isDefinition())
     return false;
 
+  NonErrorHandlingBlocks neBlocks(function);
+
   for (SILBasicBlock &block : *function) {
     // Exclude fatal-error blocks.
     if (isa<UnreachableInst>(block.getTerminator()))
       continue;
 
+    // TODO: it's not yet clear how to deal with error existentials.
+    // Ignore them for now. If we have typed throws we could ban error existentials
+    // because typed throws would provide and alternative.
+    if (isa<ThrowInst>(block.getTerminator()))
+      continue;
+
+    if (!neBlocks.isNonErrorHandling(&block))
+      continue;
+
     for (SILInstruction &inst : block) {
       if (visitInst(&inst, perfConstr, parentLoc)) {
         LLVM_DEBUG(llvm::dbgs() << inst << *inst.getFunction());

test/SILOptimizer/performance-annotations.swift

@@ -98,14 +98,14 @@ func errorExistential(_ b: Bool) throws -> Int {
   if b {
     return 28
   }
-  throw MyError()  // expected-error {{Using type 'MyError' can cause metadata allocation or locks}}
+  throw MyError()
 }
 
 @_noLocks
 func testCatch(_ b: Bool) throws -> Int? {
   do {
     return try errorExistential(true)
-  } catch let e as MyError { // expected-error {{this code performs reference counting operations which can cause locking}}
+  } catch let e as MyError {
     print(e)
     return nil
   }