Debug Info: Represent macro expansions as inlined functions.

This allows the debugger to choose whether to display the expanded macro
(inlined) or the original source code (parent frame).

rdar://102916513

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -111,7 +111,6 @@ static bool equalWithoutExistentialTypes(Type t1, Type t2) {
 }
 
 class IRGenDebugInfoImpl : public IRGenDebugInfo {
-  friend class IRGenDebugInfoImpl;
   const IRGenOptions &Opts;
   ClangImporter &CI;
   SourceManager &SM;
@@ -395,6 +394,7 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
     return false;
   }
 
+public:
   llvm::MDNode *createInlinedAt(const SILDebugScope *DS) {
     auto *CS = DS->InlinedCallSite;
     if (!CS)
@@ -414,6 +414,7 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
     InlinedAtCache.insert({CS, llvm::TrackingMDNodeRef(InlinedAt)});
     return InlinedAt;
   }
+private:
 
 #ifndef NDEBUG
   /// Perform a couple of sanity checks on scopes.
@@ -3105,16 +3106,17 @@ ArtificialLocation::ArtificialLocation(const SILDebugScope *DS,
   if (DI) {
     unsigned Line = 0;
     auto *Scope = DI->getOrCreateScope(DS);
-    if (static_cast<IRGenDebugInfoImpl *>(DI)->getDebugInfoFormat() ==
-        IRGenDebugInfoFormat::CodeView) {
+    auto DII = static_cast<IRGenDebugInfoImpl *>(DI);
+    if (DII->getDebugInfoFormat() == IRGenDebugInfoFormat::CodeView) {
       // In CodeView, line zero is not an artificial line location and so we
       // try to use the location of the scope.
       if (auto *LB = dyn_cast<llvm::DILexicalBlock>(Scope))
         Line = LB->getLine();
       else if (auto *SP = dyn_cast<llvm::DISubprogram>(Scope))
         Line = SP->getLine();
     }
-    auto DL = llvm::DILocation::get(Scope->getContext(), Line, 0, Scope);
+    auto DL = llvm::DILocation::get(Scope->getContext(), Line, 0, Scope,
+                                    DII->createInlinedAt(DS));
     Builder.SetCurrentDebugLocation(DL);
   }
 }

lib/SIL/Verifier/SILVerifier.cpp

@@ -5889,6 +5889,11 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
       // map and go on.
       auto *DS = SI.getDebugScope();
       assert(DS && "Each instruction should have a debug scope");
+
+      // We don't support this verification on inlined call sites yet.
+      if (DS->InlinedCallSite)
+        continue;
+
       if (!AlreadySeenScopes.count(DS)) {
         AlreadySeenScopes.insert(DS);
         LastSeenScope = DS;

lib/SILGen/SILGenExpr.cpp

@@ -5995,6 +5995,8 @@ RValue RValueEmitter::visitMacroExpansionExpr(MacroExpansionExpr *E,
                                               SGFContext C) {
   auto *rewritten = E->getRewritten();
   assert(rewritten && "Macro should have been rewritten by SILGen");
+  MacroScope scope(SGF, CleanupLocation(rewritten), E, E->getMacroName(),
+                   E->getMacroNameLoc());
   return visit(rewritten, C);
 }
 

lib/SILGen/SILGenFunction.cpp

@@ -16,6 +16,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "SILGenFunction.h"
+#include "Cleanup.h"
 #include "RValue.h"
 #include "SILGenFunctionBuilder.h"
 #include "Scope.h"
@@ -157,6 +158,57 @@ DeclName SILGenModule::getMagicFunctionName(SILDeclRef ref) {
   llvm_unreachable("Unhandled SILDeclRefKind in switch.");
 }
 
+void SILGenFunction::enterDebugScope(SILLocation Loc, bool isBindingScope,
+                                     Optional<SILLocation> MacroExpansion,
+                                     DeclNameRef MacroName,
+                                     DeclNameLoc MacroNameLoc) {
+  auto *Parent = DebugScopeStack.size() ? DebugScopeStack.back().getPointer()
+                                        : F.getDebugScope();
+  auto *Scope = Parent;
+  // Don't nest a scope for Loc under Parent unless it's actually different.
+  if (RegularLocation(Parent->getLoc()) != RegularLocation(Loc)) {
+    SILDebugScope *InlinedAt = nullptr;
+    // Create an inline scope for a macro expansion.
+    if (MacroExpansion && MacroName && MacroNameLoc.isValid()) {
+      InlinedAt = new (SGM.M) SILDebugScope(RegularLocation(*MacroExpansion),
+                                            &getFunction(), Parent);
+      SILGenFunctionBuilder B(SGM);
+      auto ExtInfo = SILFunctionType::ExtInfo::getThin();
+      auto FunctionType = SILFunctionType::get(
+          nullptr, ExtInfo, SILCoroutineKind::None,
+          ParameterConvention::Direct_Unowned, /*Params*/ {}, /*yields*/ {},
+          /*Results*/ {}, None, SubstitutionMap(), SubstitutionMap(),
+          SGM.M.getASTContext());
+      SILFunction *MacroFn = B.getOrCreateFunction(
+          Loc, MacroName.getBaseIdentifier().str(),
+          SILLinkage::DefaultForDeclaration, FunctionType, IsNotBare,
+          IsNotTransparent, IsNotSerialized, IsNotDynamic, IsNotDistributed,
+          IsNotRuntimeAccessible);
+      auto MacroScope = new (SGM.M) SILDebugScope(Loc, MacroFn);
+      Parent = MacroScope;
+    }
+    Scope = new (SGM.M)
+        SILDebugScope(RegularLocation(Loc), &getFunction(), Parent, InlinedAt);
+  }
+  DebugScopeStack.emplace_back(Scope, isBindingScope);
+  B.setCurrentDebugScope(Scope);
+}
+
+  /// Return to the previous debug scope.
+void SILGenFunction::leaveDebugScope() {
+  // Pop any 'guard' scopes first.
+  while (DebugScopeStack.back().getInt())
+    DebugScopeStack.pop_back();
+
+  // Pop the scope we're leaving now.
+  DebugScopeStack.pop_back();
+  if (DebugScopeStack.size())
+    B.setCurrentDebugScope(DebugScopeStack.back().getPointer());
+  // Don't reset the debug scope after leaving the outermost scope,
+  // because the debugger is not expecting the function epilogue to
+  // be in a different scope.
+}
+
 std::tuple<ManagedValue, SILType>
 SILGenFunction::emitSiblingMethodRef(SILLocation loc,
                                      SILValue selfValue,

lib/SILGen/SILGenFunction.h

@@ -598,31 +598,13 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
   /// \param isBindingScope If true, this is a scope for the bindings introduced
   /// by a let expression. This scope ends when the next innermost BraceStmt
   /// ends.
-  void enterDebugScope(SILLocation Loc, bool isBindingScope = false) {
-    auto *Parent = DebugScopeStack.size() ? DebugScopeStack.back().getPointer()
-                                          : F.getDebugScope();
-    auto *DS = Parent;
-    // Don't nest a scope for Loc under Parent unless it's actually different.
-    if (RegularLocation(DS->getLoc()) != RegularLocation(Loc))
-      DS = new (SGM.M) SILDebugScope(RegularLocation(Loc), &getFunction(), DS);
-    DebugScopeStack.emplace_back(DS, isBindingScope);
-    B.setCurrentDebugScope(DS);
-  }
+  void enterDebugScope(SILLocation Loc, bool isBindingScope = false,
+                       Optional<SILLocation> MacroExpansion = {},
+                       DeclNameRef MacroName = {},
+                       DeclNameLoc MacroNameLoc = {});
 
   /// Return to the previous debug scope.
-  void leaveDebugScope() {
-    // Pop any 'guard' scopes first.
-    while (DebugScopeStack.back().getInt())
-      DebugScopeStack.pop_back();
-
-    // Pop the scope we're leaving now.
-    DebugScopeStack.pop_back();
-    if (DebugScopeStack.size())
-      B.setCurrentDebugScope(DebugScopeStack.back().getPointer());
-    // Don't reset the debug scope after leaving the outermost scope,
-    // because the debugger is not expecting the function epilogue to
-    // be in a different scope.
-  }
+  void leaveDebugScope();
 
   std::unique_ptr<Initialization>
   prepareIndirectResultInit(AbstractionPattern origResultType,

lib/SILGen/Scope.h

@@ -161,6 +161,22 @@ class LLVM_LIBRARY_VISIBILITY DebugScope {
   ~DebugScope() { SGF.leaveDebugScope(); }
 };
 
+/// A scope that represents a Macro expansion.
+class LLVM_LIBRARY_VISIBILITY MacroScope {
+  SILGenFunction &SGF;
+
+public:
+  explicit MacroScope(SILGenFunction &SGF, CleanupLocation loc,
+                      SILLocation MacroExpansion, DeclNameRef MacroName,
+                      DeclNameLoc MacroNameLoc)
+      : SGF(SGF) {
+    SGF.enterDebugScope(loc, false, MacroExpansion, MacroName, MacroNameLoc);
+  }
+
+  ~MacroScope() { SGF.leaveDebugScope(); }
+};
+
+
 } // end namespace Lowering
 } // end namespace swift
 

test/Macros/macro_expand.swift

@@ -8,9 +8,11 @@
 // RUN: not %target-swift-frontend -typecheck -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand.dia %s
 // RUN: c-index-test -read-diagnostics %t/macro_expand.dia 2>&1 | %FileCheck -check-prefix CHECK-DIAGS %s
 
-// Debug IR testing
-// RUN: %target-swift-frontend -emit-ir -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-IR %s
+// Debug info SIL testing
+// RUN: %target-swift-frontend -emit-sil -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
 
+// Debug info IR testing
+// RUN: %target-swift-frontend -emit-ir -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-IR %s
 
 // Execution testing
 // RUN: %target-build-swift -g -enable-experimental-feature Macros -enable-experimental-feature Macros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -L %swift-host-lib-dir %s -o %t/main -module-name MacroUser
@@ -28,7 +30,11 @@
 func testFileID(a: Int, b: Int) {
   // CHECK: MacroUser/macro_expand.swift
   print("Result is \(#customFileID)")
+  // CHECK-SIL: sil_scope [[MACRO_SCOPE:[0-9]+]] { loc "{{.*}}":1:1 parent @customFileID {{.*}} }
+  // CHECK-SIL: sil_scope [[SRC_SCOPE:[0-9]+]] { loc "{{.*}}macro_expand.swift":[[@LINE-2]]
+  // CHECK-SIL: sil_scope {{[0-9]+}} { loc "{{.*}}":1:1 parent [[MACRO_SCOPE]] inlined_at [[SRC_SCOPE]] }
 
+  
   // CHECK: Builtin result is MacroUser/macro_expand.swift
   // CHECK-AST: macro_expansion_expr type='String'{{.*}}name=line
   print("Builtin result is \(#fileID)")