[IRGen] Add some PrettyStackTraces for metadata emission

lib/IRGen/GenClass.cpp

@@ -2101,6 +2101,7 @@ namespace {
 llvm::Constant *irgen::emitClassPrivateData(IRGenModule &IGM,
                                             ClassDecl *cls) {
   assert(IGM.ObjCInterop && "emitting RO-data outside of interop mode");
+  PrettyStackTraceDecl stackTraceRAII("emitting ObjC metadata for", cls);
   SILType selfType = getSelfType(cls);
   auto &classTI = IGM.getTypeInfo(selfType).as<ClassTypeInfo>();
 
@@ -2121,6 +2122,7 @@ irgen::emitClassPrivateDataFields(IRGenModule &IGM,
                                   ConstantStructBuilder &init,
                                   ClassDecl *cls) {
   assert(IGM.ObjCInterop && "emitting RO-data outside of interop mode");
+  PrettyStackTraceDecl stackTraceRAII("emitting ObjC metadata for", cls);
 
   SILType selfType = getSelfType(cls);
   auto &classTI = IGM.getTypeInfo(selfType).as<ClassTypeInfo>();
@@ -2157,15 +2159,16 @@ llvm::Constant *irgen::emitCategoryData(IRGenModule &IGM,
   ClassDecl *cls = ext->getAsClassOrClassExtensionContext();
   assert(cls && "generating category metadata for a non-class extension");
 
+  PrettyStackTraceDecl stackTraceRAII("emitting ObjC metadata for", ext);
   ClassDataBuilder builder(IGM, cls, ext);
-
   return builder.emitCategory();
 }
 
 /// Emit the metadata for an ObjC protocol.
 llvm::Constant *irgen::emitObjCProtocolData(IRGenModule &IGM,
                                             ProtocolDecl *proto) {
   assert(proto->isObjC() && "not an objc protocol");
+  PrettyStackTraceDecl stackTraceRAII("emitting ObjC metadata for", proto);
   ClassDataBuilder builder(IGM, proto);
   return builder.emitProtocol();
 }

lib/IRGen/GenMeta.cpp

@@ -22,6 +22,7 @@
 #include "swift/AST/Decl.h"
 #include "swift/AST/Attr.h"
 #include "swift/AST/IRGenOptions.h"
+#include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/SubstitutionMap.h"
 #include "swift/AST/Types.h"
 #include "swift/ClangImporter/ClangModule.h"
@@ -2730,6 +2731,7 @@ static void emitObjCClassSymbol(IRGenModule &IGM,
 void irgen::emitClassMetadata(IRGenModule &IGM, ClassDecl *classDecl,
                               const ClassLayout &fieldLayout) {
   assert(!classDecl->isForeign());
+  PrettyStackTraceDecl stackTraceRAII("emitting metadata for", classDecl);
 
   emitFieldOffsetGlobals(IGM, classDecl, fieldLayout);
 
@@ -3185,6 +3187,7 @@ namespace {
 
 /// Emit the type metadata or metadata template for a struct.
 void irgen::emitStructMetadata(IRGenModule &IGM, StructDecl *structDecl) {
+  PrettyStackTraceDecl stackTraceRAII("emitting metadata for", structDecl);
   ConstantInitBuilder initBuilder(IGM);
   auto init = initBuilder.beginStruct();
   init.setPacked(true);
@@ -3401,6 +3404,7 @@ namespace {
 } // end anonymous namespace
 
 void irgen::emitEnumMetadata(IRGenModule &IGM, EnumDecl *theEnum) {
+  PrettyStackTraceDecl stackTraceRAII("emitting metadata for", theEnum);
   ConstantInitBuilder initBuilder(IGM);
   auto init = initBuilder.beginStruct();
   init.setPacked(true);
@@ -3837,6 +3841,8 @@ SpecialProtocol irgen::getSpecialProtocolID(ProtocolDecl *P) {
 /// the protocol descriptor, and for ObjC interop, references to the descriptor
 /// that the ObjC runtime uses for uniquing.
 void IRGenModule::emitProtocolDecl(ProtocolDecl *protocol) {
+  PrettyStackTraceDecl stackTraceRAII("emitting metadata for", protocol);
+
   // Emit remote reflection metadata for the protocol.
   emitFieldMetadataRecord(protocol);
 

lib/IRGen/GenProto.cpp

@@ -33,6 +33,7 @@
 #include "swift/AST/Decl.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/IRGenOptions.h"
+#include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/SubstitutionMap.h"
 #include "swift/ClangImporter/ClangModule.h"
 #include "swift/IRGen/Linking.h"
@@ -2213,6 +2214,9 @@ void IRGenModule::emitSILWitnessTable(SILWitnessTable *wt) {
     return;
 
   auto *conf = wt->getConformance();
+  PrettyStackTraceType stackTraceRAII(Context, "emitting witness table for",
+                                      conf->getType());
+  PrettyStackTraceDecl stackTraceRAII2("...conforming to", conf->getProtocol());
 
   // Build the witnesses.
   ConstantInitBuilder builder(*this);