store std::string, print before BB identifier

Author: ktoso

include/swift/SIL/SILModule.h

@@ -164,7 +164,7 @@ class SILModule {
   using CoverageMapCollectionType =
       llvm::MapVector<StringRef, SILCoverageMap *>;
   using BasicBlockNameMapType =
-      llvm::DenseMap<const SILBasicBlock *, llvm::StringRef>;
+      llvm::DenseMap<const SILBasicBlock *, std::string>;
 
   enum class LinkingMode : uint8_t {
     /// Link functions with non-public linkage. Used by the mandatory pipeline.
@@ -455,7 +455,7 @@ class SILModule {
 
   void setBasicBlockName(const SILBasicBlock *block, StringRef name) {
     #if NDEBUG
-    basicBlockNames[block] = name;
+    basicBlockNames[block] = name.str();
     #endif
   }
   Optional<StringRef> getBasicBlockName(const SILBasicBlock *block) {
@@ -464,7 +464,7 @@ class SILModule {
     if (Known == basicBlockNames.end())
       return None;
 
-    return Known->second;
+    return StringRef(Known->second);
     #else
     return None;
     #endif

lib/SIL/IR/SILPrinter.cpp

@@ -791,6 +791,12 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
     // the block header.
     printBlockArgumentUses(BB);
 
+    // If the basic block has a name available, print it as well
+    auto debugName = BB->getDebugName();
+    if (debugName.hasValue()) {
+      *this << "// " << debugName.getValue() << '\n';
+    }
+
     // Then print the name of our block, the arguments, and the block colon.
     *this << Ctx.getID(BB);
     printBlockArguments(BB);
@@ -816,12 +822,6 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
       for (auto Id : PredIDs)
         *this << ' ' << Id;
     }
-
-    // If the basic block has a name available, print it as well
-    auto debugName = BB->getDebugName();
-    if (debugName.hasValue()) {
-      *this << " /// " << debugName.getValue();
-    }
     *this << '\n';
 
     const auto &SM = BB->getModule().getASTContext().SourceMgr;