[codeview] Add TypeVisitorCallbackPipeline.

We were kind of hacking this together before by embedding the
ability to forward requests into the TypeDeserializer.  When
we want to start adding more different kinds of visitor callback
interfaces though, this doesn't scale well and is very inflexible.

So introduce the notion of a pipeline, which itself implements
the TypeVisitorCallbacks interface, but which contains an internal
list of other callbacks to invoke in sequence.

Also update the existing uses of CVTypeVisitor to use this new
pipeline class for deserializing records before visiting them
with another visitor.

llvm-svn: 280293

2 files changed, 22 insertions, 7 deletions

diff --git a/llvm/tools/llvm-pdbdump/CodeViewYaml.cpp b/llvm/tools/llvm-pdbdump/CodeViewYaml.cpp
index 690e46fb041..96bf1c19aa6 100644
--- a/llvm/tools/llvm-pdbdump/CodeViewYaml.cpp
+++ b/llvm/tools/llvm-pdbdump/CodeViewYaml.cpp
@@ -13,6 +13,7 @@
 #include "llvm/DebugInfo/CodeView/EnumTables.h"
 #include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/CodeView/TypeVisitorCallbackPipeline.h"
 
 using namespace llvm;
 using namespace llvm::codeview;
@@ -240,10 +241,14 @@ template <> struct ScalarTraits<APSInt> {
 
 void MappingTraits<CVType>::mapping(IO &IO, CVType &Record) {
   if (IO.outputting()) {
+    codeview::TypeDeserializer Deserializer;
     codeview::yaml::YamlTypeDumperCallbacks Callbacks(IO);
-    codeview::TypeDeserializer Deserializer(Callbacks);
 
-    codeview::CVTypeVisitor Visitor(Deserializer);
+    codeview::TypeVisitorCallbackPipeline Pipeline;
+    Pipeline.addCallbackToPipeline(Deserializer);
+    Pipeline.addCallbackToPipeline(Callbacks);
+
+    codeview::CVTypeVisitor Visitor(Pipeline);
     consumeError(Visitor.visitTypeRecord(Record));
   }
 }
@@ -252,8 +257,13 @@ void MappingTraits<FieldListRecord>::mapping(IO &IO,
                                              FieldListRecord &FieldList) {
   if (IO.outputting()) {
     codeview::yaml::YamlTypeDumperCallbacks Callbacks(IO);
-    codeview::TypeDeserializer Deserializer(Callbacks);
-    codeview::CVTypeVisitor Visitor(Deserializer);
+    codeview::TypeDeserializer Deserializer;
+
+    codeview::TypeVisitorCallbackPipeline Pipeline;
+    Pipeline.addCallbackToPipeline(Deserializer);
+    Pipeline.addCallbackToPipeline(Callbacks);
+
+    codeview::CVTypeVisitor Visitor(Pipeline);
     consumeError(Visitor.visitFieldListMemberStream(FieldList.Data));
   }
 }
diff --git a/llvm/tools/llvm-pdbdump/PdbYaml.cpp b/llvm/tools/llvm-pdbdump/PdbYaml.cpp
index 187264acdbe..566d6b89986 100644
--- a/llvm/tools/llvm-pdbdump/PdbYaml.cpp
+++ b/llvm/tools/llvm-pdbdump/PdbYaml.cpp
@@ -8,10 +8,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "PdbYaml.h"
+
 #include "CodeViewYaml.h"
 
 #include "llvm/DebugInfo/CodeView/CVTypeVisitor.h"
 #include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
+#include "llvm/DebugInfo/CodeView/TypeVisitorCallbackPipeline.h"
 #include "llvm/DebugInfo/PDB/PDBExtras.h"
 #include "llvm/DebugInfo/PDB/PDBTypes.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
@@ -200,11 +202,14 @@ void MappingTraits<PdbDbiModuleInfo>::mapping(IO &IO, PdbDbiModuleInfo &Obj) {
 void MappingTraits<PdbTpiRecord>::mapping(IO &IO,
                                           pdb::yaml::PdbTpiRecord &Obj) {
   if (IO.outputting()) {
-    // If we're going from Pdb To Yaml, deserialize the Pdb record
+    codeview::TypeDeserializer Deserializer;
     codeview::yaml::YamlTypeDumperCallbacks Callbacks(IO);
-    codeview::TypeDeserializer Deserializer(Callbacks);
 
-    codeview::CVTypeVisitor Visitor(Deserializer);
+    codeview::TypeVisitorCallbackPipeline Pipeline;
+    Pipeline.addCallbackToPipeline(Deserializer);
+    Pipeline.addCallbackToPipeline(Callbacks);
+
+    codeview::CVTypeVisitor Visitor(Pipeline);
     consumeError(Visitor.visitTypeRecord(Obj.Record));
   } else {
     codeview::yaml::YamlTypeDumperCallbacks Callbacks(IO);