[Coverage] Visit the PatternBindingDecl in a ForEachStmt

This fixes a crash which occurs because there is no mapping region
associated with non-static initializers in the loop's iterator.

Author: vedantk

lib/SILGen/SILGenProfiling.cpp

@@ -36,6 +36,30 @@ static bool isUnmappedDecl(Decl *D) {
   return D->isImplicit() || isa<EnumCaseDecl>(D);
 }
 
+/// Walk the non-static initializers in \p PBD.
+static void walkForProfiling(PatternBindingDecl *PBD, ASTWalker &Walker) {
+  if (PBD && !PBD->isStatic())
+    for (auto E : PBD->getPatternList())
+      if (E.getInit())
+        E.getInit()->walk(Walker);
+}
+
+/// Walk the AST of \c Root and related nodes that are relevant for profiling.
+static void walkForProfiling(AbstractFunctionDecl *Root, ASTWalker &Walker) {
+  Root->walk(Walker);
+
+  // We treat class initializers as part of the constructor for profiling.
+  if (auto *CD = dyn_cast<ConstructorDecl>(Root)) {
+    Type DT = CD->getDeclContext()->getDeclaredTypeInContext();
+    auto *NominalType = DT->getNominalOrBoundGenericNominal();
+    for (auto *Member : NominalType->getMembers()) {
+      // Find pattern binding declarations that have initializers.
+      if (auto *PBD = dyn_cast<PatternBindingDecl>(Member))
+        walkForProfiling(PBD, Walker);
+    }
+  }
+}
+
 ProfilerRAII::ProfilerRAII(SILGenModule &SGM, AbstractFunctionDecl *D)
     : SGM(SGM), PreviousProfiler(std::move(SGM.Profiler)) {
   const auto &Opts = SGM.M.getOptions();
@@ -82,6 +106,7 @@ struct MapRegionCounters : public ASTWalker {
       CounterMap[FS->getBody()] = NextCounter++;
     } else if (auto *FES = dyn_cast<ForEachStmt>(S)) {
       CounterMap[FES->getBody()] = NextCounter++;
+      walkForProfiling(FES->getIterator(), *this);
     } else if (auto *SS = dyn_cast<SwitchStmt>(S)) {
       CounterMap[SS] = NextCounter++;
     } else if (auto *CS = dyn_cast<CaseStmt>(S)) {
@@ -494,6 +519,7 @@ struct CoverageMapping : public ASTWalker {
     } else if (auto *FES = dyn_cast<ForEachStmt>(S)) {
       assignCounter(FES, CounterExpr::Zero());
       assignCounter(FES->getBody());
+      walkForProfiling(FES->getIterator(), *this);
 
     } else if (auto *SS = dyn_cast<SwitchStmt>(S)) {
       assignCounter(SS);
@@ -625,25 +651,6 @@ struct CoverageMapping : public ASTWalker {
 
 } // end anonymous namespace
 
-/// Walk the AST of \c Root and related nodes that are relevant for profiling.
-static void walkForProfiling(AbstractFunctionDecl *Root, ASTWalker &Walker) {
-  Root->walk(Walker);
-
-  // We treat class initializers as part of the constructor for profiling.
-  if (auto *CD = dyn_cast<ConstructorDecl>(Root)) {
-    Type DT = CD->getDeclContext()->getDeclaredTypeInContext();
-    auto *NominalType = DT->getNominalOrBoundGenericNominal();
-    for (auto *Member : NominalType->getMembers()) {
-      // Find pattern binding declarations that have initializers.
-      if (auto *PBD = dyn_cast<PatternBindingDecl>(Member))
-        if (!PBD->isStatic())
-          for (auto E : PBD->getPatternList())
-            if (E.getInit())
-              E.getInit()->walk(Walker);
-    }
-  }
-}
-
 static llvm::GlobalValue::LinkageTypes
 getEquivalentPGOLinkage(FormalLinkage Linkage) {
   switch (Linkage) {

test/SILGen/coverage_closures.swift

@@ -1,5 +1,13 @@
 // RUN: %target-swift-frontend -Xllvm -sil-full-demangle -profile-generate -profile-coverage-mapping -emit-sorted-sil -emit-sil -module-name coverage_closures %s | FileCheck %s
 
+// CHECK-LABEL: sil_coverage_map {{.*}}// coverage_closures.bar
+func bar(arr: [(Int32) -> Int32]) {
+  // CHECK: [[@LINE+1]]:13 -> [[@LINE+1]]:42
+  for a in [{ (b : Int32) -> Int32 in b }] {
+    a(0)
+  }
+}
+
 // CHECK-LABEL: sil_coverage_map {{.*}}// coverage_closures.foo
 func foo() {
   // CHECK: [[@LINE+1]]:12 -> [[@LINE+1]]:59 : 1
@@ -19,4 +27,5 @@ func foo() {
   f1 { left, right in left == 0 || right == 1 }
 }
 
+bar(arr: [{ x in x }])
 foo()