[NFC] Add names of deserialized decls to pretty stack traces

Several declarations must be at least partially deserialized before their names can be determined. Add those names to pretty stack traces to make deserialization crashes easier to debug.

We don’t test pretty stack traces, so this doesn’t contain any test changes.

Author: beccadax

lib/Serialization/Deserialization.cpp

@@ -113,6 +113,17 @@ namespace {
     }
   };
 
+  class PrettySupplementalDeclNameTrace : public llvm::PrettyStackTraceEntry {
+    DeclName name;
+  public:
+    PrettySupplementalDeclNameTrace(DeclName name)
+      : name(name) { }
+
+    void print(raw_ostream &os) const override {
+      os << "    ...decl is named '" << name << "'\n";
+    }
+  };
+
   class PrettyXRefTrace :
       public llvm::PrettyStackTraceEntry,
       public XRefTracePath {
@@ -2375,6 +2386,7 @@ class DeclDeserializer {
                                              rawAccessLevel, dependencyIDs);
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     for (TypeID dependencyID : dependencyIDs) {
       auto dependency = MF.getTypeChecked(dependencyID);
@@ -2505,6 +2517,7 @@ class DeclDeserializer {
                                           rawInheritedAndDependencyIDs);
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     for (TypeID dependencyID :
            rawInheritedAndDependencyIDs.slice(numInheritedTypes)) {
@@ -2582,6 +2595,7 @@ class DeclDeserializer {
     for (auto argNameID : argNameAndDependencyIDs.slice(0, numArgNames))
       argNames.push_back(MF.getIdentifier(argNameID));
     DeclName name(ctx, DeclBaseName::createConstructor(), argNames);
+    PrettySupplementalDeclNameTrace trace(name);
 
     Optional<swift::CtorInitializerKind> initKind =
         getActualCtorInitializerKind(storedInitKind);
@@ -2712,6 +2726,7 @@ class DeclDeserializer {
                                        arrayFieldIDs);
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     auto getErrorFlags = [&]() {
       // Stored properties in classes still impact class object layout because
@@ -2879,6 +2894,10 @@ class DeclDeserializer {
                                          interfaceTypeID, isIUO, isVariadic,
                                          isAutoClosure, rawDefaultArg);
 
+    auto argName = MF.getIdentifier(argNameID);
+    auto paramName = MF.getIdentifier(paramNameID);
+    PrettySupplementalDeclNameTrace trace(paramName);
+
     auto DC = MF.getDeclContext(contextID);
     if (declOrOffset.isComplete())
       return declOrOffset;
@@ -2888,10 +2907,8 @@ class DeclDeserializer {
     if (!specifier)
       MF.fatal();
 
-    auto param = MF.createDecl<ParamDecl>(SourceLoc(), SourceLoc(),
-                                          MF.getIdentifier(argNameID),
-                                          SourceLoc(),
-                                          MF.getIdentifier(paramNameID), DC);
+    auto param = MF.createDecl<ParamDecl>(SourceLoc(), SourceLoc(), argName,
+                                          SourceLoc(), paramName, DC);
     param->setSpecifier(*specifier);
 
     declOrOffset = param;
@@ -3023,6 +3040,7 @@ class DeclDeserializer {
         dependencyIDs = nameAndDependencyIDs.drop_front();
       }
     }
+    PrettySupplementalDeclNameTrace trace(name);
 
     Expected<Decl *> overriddenOrError = MF.getDeclChecked(overriddenID);
     Decl *overridden;
@@ -3281,6 +3299,7 @@ class DeclDeserializer {
                                             rawInheritedAndDependencyIDs);
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     for (TypeID dependencyID :
            rawInheritedAndDependencyIDs.slice(numInheritedTypes)) {
@@ -3340,6 +3359,10 @@ class DeclDeserializer {
 
     OperatorLayout::readRecord(scratch, nameID, contextID,
                                designatedNominalTypeDeclIDs);
+
+    Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
+
     auto DC = MF.getDeclContext(contextID);
 
     SmallVector<NominalTypeDecl *, 1> designatedNominalTypes;
@@ -3351,7 +3374,7 @@ class DeclDeserializer {
     }
 
     auto result = MF.createDecl<OperatorDecl>(
-        DC, SourceLoc(), MF.getIdentifier(nameID), SourceLoc(),
+        DC, SourceLoc(), name, SourceLoc(),
         ctx.AllocateCopy(designatedNominalTypes));
 
     declOrOffset = result;
@@ -3380,6 +3403,8 @@ class DeclDeserializer {
     decls_block::InfixOperatorLayout::readRecord(scratch, nameID, contextID,
                                                  precedenceGroupID,
                                                  designatedNominalTypeDeclIDs);
+    Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     Expected<Decl *> precedenceGroup = MF.getDeclChecked(precedenceGroupID);
     if (!precedenceGroup)
@@ -3396,7 +3421,7 @@ class DeclDeserializer {
     }
 
     auto result = MF.createDecl<InfixOperatorDecl>(
-        DC, SourceLoc(), MF.getIdentifier(nameID), SourceLoc(), SourceLoc(),
+        DC, SourceLoc(), name, SourceLoc(), SourceLoc(),
         ArrayRef<Identifier>{}, ArrayRef<SourceLoc>{});
     result->setDesignatedNominalTypes(ctx.AllocateCopy(designatedNominalTypes));
     ctx.evaluator.cacheOutput(
@@ -3487,6 +3512,7 @@ class DeclDeserializer {
                                          rawInheritedAndDependencyIDs);
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
 
     for (TypeID dependencyID :
            rawInheritedAndDependencyIDs.slice(numInheritedTypes)) {
@@ -3560,6 +3586,8 @@ class DeclDeserializer {
       return declOrOffset;
 
     Identifier name = MF.getIdentifier(nameID);
+    PrettySupplementalDeclNameTrace trace(name);
+
     for (TypeID dependencyID :
            rawInheritedAndDependencyIDs.slice(numInherited)) {
       auto dependency = MF.getTypeChecked(dependencyID);
@@ -3638,6 +3666,7 @@ class DeclDeserializer {
       argNames.push_back(MF.getIdentifier(argNameID));
     DeclName compoundName(ctx, baseName, argNames);
     DeclName name = argNames.empty() ? baseName : compoundName;
+    PrettySupplementalDeclNameTrace trace(name);
 
     for (TypeID dependencyID : argNameAndDependencyIDs.slice(numArgNames)) {
       auto dependency = MF.getTypeChecked(dependencyID);
@@ -3730,6 +3759,8 @@ class DeclDeserializer {
     for (auto argNameID : argNameAndDependencyIDs.slice(0, numArgNames))
       argNames.push_back(MF.getIdentifier(argNameID));
     DeclName name(ctx, DeclBaseName::createSubscript(), argNames);
+    PrettySupplementalDeclNameTrace trace(name);
+
     argNameAndDependencyIDs = argNameAndDependencyIDs.slice(numArgNames);
 
     // Exctract the accessor IDs.