[Stats] Add support for tracing protocol conformances.

Author: graydon

include/swift/Basic/Statistic.h

@@ -56,6 +56,7 @@ namespace clang {
 namespace swift {
 
 class Decl;
+class ProtocolConformance;
 class Expr;
 class SILFunction;
 class FrontendStatsTracer;
@@ -191,6 +192,8 @@ class FrontendStatsTracer
   /// disabled").
   FrontendStatsTracer(UnifiedStatsReporter *Reporter,  StringRef EventName,
                       const Decl *D);
+  FrontendStatsTracer(UnifiedStatsReporter *Reporter,  StringRef EventName,
+                      const ProtocolConformance *P);
   FrontendStatsTracer(UnifiedStatsReporter *Reporter,  StringRef EventName,
                       const clang::Decl *D);
   FrontendStatsTracer(UnifiedStatsReporter *Reporter,  StringRef EventName,
@@ -209,6 +212,9 @@ class FrontendStatsTracer
 template<> const UnifiedStatsReporter::TraceFormatter*
 FrontendStatsTracer::getTraceFormatter<const Decl *>();
 
+template<> const UnifiedStatsReporter::TraceFormatter*
+FrontendStatsTracer::getTraceFormatter<const ProtocolConformance *>();
+
 template<> const UnifiedStatsReporter::TraceFormatter*
 FrontendStatsTracer::getTraceFormatter<const clang::Decl *>();
 

lib/AST/ProtocolConformance.cpp

@@ -24,6 +24,7 @@
 #include "swift/AST/Substitution.h"
 #include "swift/AST/Types.h"
 #include "swift/AST/TypeWalker.h"
+#include "swift/Basic/Statistic.h"
 #include "swift/ClangImporter/ClangModule.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -1367,3 +1368,46 @@ ProtocolConformanceRef::getCanonicalConformanceRef() const {
     return *this;
   return ProtocolConformanceRef(getConcrete()->getCanonicalConformance());
 }
+
+// See swift/Basic/Statistic.h for declaration: this enables tracing
+// ProtocolConformances, is defined here to avoid too much layering violation /
+// circular linkage dependency.
+
+struct ProtocolConformanceTraceFormatter
+    : public UnifiedStatsReporter::TraceFormatter {
+  void traceName(const void *Entity, raw_ostream &OS) const {
+    if (!Entity)
+      return;
+    const ProtocolConformance *C =
+        static_cast<const ProtocolConformance *>(Entity);
+    OS << "<conformance ";
+    if (auto const *DC = C->getDeclContext()) {
+      if (auto const *N = DC->getAsNominalTypeOrNominalTypeExtensionContext()) {
+        N->getFullName().print(OS, false);
+      }
+    }
+    OS << " : ";
+    if (auto *P = C->getProtocol())
+      P->getFullName().print(OS, false);
+    OS << ">";
+  }
+  void traceLoc(const void *Entity, SourceManager *SM,
+                clang::SourceManager *CSM, raw_ostream &OS) const {
+    if (!Entity)
+      return;
+    const ProtocolConformance *C =
+        static_cast<const ProtocolConformance *>(Entity);
+    if (auto const *DC = C->getDeclContext()) {
+      if (auto const *D = DC->getAsDeclOrDeclExtensionContext())
+        D->getSourceRange().print(OS, *SM, false);
+    }
+  }
+};
+
+static ProtocolConformanceTraceFormatter TF;
+
+template<>
+const UnifiedStatsReporter::TraceFormatter*
+FrontendStatsTracer::getTraceFormatter<const ProtocolConformance *>() {
+  return &TF;
+}

lib/Basic/Statistic.cpp

@@ -276,6 +276,11 @@ FrontendStatsTracer::FrontendStatsTracer(UnifiedStatsReporter *R, StringRef S,
     : FrontendStatsTracer(R, S, D, getTraceFormatter<const Decl *>())
 {}
 
+FrontendStatsTracer::FrontendStatsTracer(UnifiedStatsReporter *R, StringRef S,
+                                         const ProtocolConformance *P)
+    : FrontendStatsTracer(R, S, P,
+                          getTraceFormatter<const ProtocolConformance *>()) {}
+
 FrontendStatsTracer::FrontendStatsTracer(UnifiedStatsReporter *R, StringRef S,
                                          const Expr *E)
     : FrontendStatsTracer(R, S, E, getTraceFormatter<const Expr *>())