Fix handling of implicit locations for variables

(cherry picked from commit bccc080)

Author: adrian-prantl

lib/SILGen/SILGenFunction.cpp

@@ -176,7 +176,7 @@ SILGenFunction::getSILDebugLocation(SILBuilder &B, SILLocation Loc,
   const SILDebugScope *Scope = B.getCurrentDebugScope();
   if (!Scope)
     Scope = F.getDebugScope();
-  if (auto *SILScope = getScopeOrNull(Loc)) {
+  if (auto *SILScope = getScopeOrNull(Loc, ForMetaInstruction)) {
     Scope = SILScope;
     // Metainstructions such as a debug_value may break the flow of scopes and
     // should not change the state of the builder.
@@ -187,14 +187,16 @@ SILGenFunction::getSILDebugLocation(SILBuilder &B, SILLocation Loc,
   return SILDebugLocation(overriddenLoc, Scope);
 }
 
-const SILDebugScope *SILGenFunction::getScopeOrNull(SILLocation Loc) {
-  if (Loc.getKind() == SILLocation::CleanupKind ||
-      Loc.getKind() == SILLocation::ImplicitReturnKind ||
-      // The source locations produced by the ResultBuilder transformation are
-      // all over the place.
-      Loc.isImplicit() ||
-      Loc.isAutoGenerated())
-    return nullptr;
+const SILDebugScope *SILGenFunction::getScopeOrNull(SILLocation Loc,
+                                                    bool ForMetaInstruction) {
+  if (!ForMetaInstruction) {
+    if (Loc.getKind() == SILLocation::CleanupKind ||
+        Loc.getKind() == SILLocation::ImplicitReturnKind ||
+        // The source locations produced by the ResultBuilder transformation are
+        // all over the place.
+        Loc.isImplicit() || Loc.isAutoGenerated())
+      return nullptr;
+  }
 
   SourceLoc SLoc = Loc.getSourceLoc();
   if (!SF || LastSourceLoc == SLoc)

lib/SILGen/SILGenFunction.h

@@ -713,7 +713,8 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
                       Optional<SILLocation> CurDebugLocOverride,
                       bool ForMetaInstruction);
 
-  const SILDebugScope *getScopeOrNull(SILLocation Loc);
+  const SILDebugScope *getScopeOrNull(SILLocation Loc,
+                                      bool ForMetaInstruction = false);
 
 private:
   const SILDebugScope *getOrCreateScope(SourceLoc SLoc);

test/DebugInfo/case-scope.swift

@@ -1,6 +1,5 @@
 // RUN: %target-swift-frontend -module-name a -parse-as-library -emit-sil -g %s | %FileCheck %s
 
-
 public enum E<T> {
 case A(T)
 case B(T)
@@ -13,15 +12,15 @@ func sink<T>(_ t: T) {}
 public func f<T>(_ e: E<T>) -> [T] {
   switch e {
   case .A(let a), .B(let a): return [a]
-  case .D(let a, _, let c): return [a, c]
-  default:
-    return []
+  case .D(let a, _, let c):  return [a, c]
+  default:                   return []
   }
 }
-// CHECK: sil_scope [[F:[0-9]+]] { loc "{{.*}}":13:13 parent @$s1a1fySayxGAA1EOyxGlF
-// CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":14:3 parent [[F]] }
-// CHECK: sil_scope [[A0:[0-9]+]] { loc "{{.*}}":15:3 parent [[S0]] }
-// CHECK: sil_scope [[A1:[0-9]+]] { loc "{{.*}}":16:3 parent [[S0]] }
-// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:15:15, scope [[A0]]
-// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:15:26, scope [[A0]]
-// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:16:15, scope [[A1]]
+
+// CHECK: sil_scope [[F:[0-9]+]] { loc "{{.*}}":12:13 parent @$s1a1fySayxGAA1EOyxGlF
+// CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":13:3 parent [[F]] }
+// CHECK: sil_scope [[A0:[0-9]+]] { loc "{{.*}}":14:3 parent [[S0]] }
+// CHECK: sil_scope [[A1:[0-9]+]] { loc "{{.*}}":15:3 parent [[S0]] }
+// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:14:15, scope [[A0]]
+// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:14:26, scope [[A0]]
+// CHECK: alloc_stack {{.*}} $T, let, name "a", {{.*}}:15:15, scope [[A1]]

test/DebugInfo/case-scope2.swift

@@ -0,0 +1,18 @@
+// RUN: %target-swift-frontend -module-name a -parse-as-library -emit-sil -g %s | %FileCheck %s
+func consume<T>(_ t: T) {}
+
+// CHECK: sil_scope [[F:[0-9]+]] { loc "{{.*}}":9:13 parent @$s1a1fyyShySiGSg_ADtF
+// CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":10:3 parent [[F]] }
+// CHECK: sil_scope [[S1:[0-9]+]] { loc "{{.*}}":11:3 parent [[S0]] }
+// CHECK: sil_scope [[S2:[0-9]+]] { loc "{{.*}}":13:5 parent [[S1]] }
+// CHECK: sil_scope [[S3:[0-9]+]] { loc "{{.*}}":14:3 parent [[S0]] }
+public func f(_ s1: Set<Int>?, _ s2: Set<Int>?) {
+  switch (s1, s2) {
+  case (nil, let a), (let a, nil):
+  // CHECK: debug_value {{.*}} $Optional<Set<Int>>, let, name "a", {{.*}}:[[@LINE-1]]:18, scope [[S1]]
+    consume(a)
+  case (let a?, _):
+  // CHECK: debug_value {{.*}} $Set<Int>, let, name "a", {{.*}}:[[@LINE-1]]:13, scope [[S3]]
+    consume((a))
+  }
+}