[NFC][TableGen] Refactor JSON and detailed record emitter

- Fix JSON and detailed record emitters to use const reference and
  pointers.
- Fix code to use C++ structured bindings and range based loops,
  include reverse() range for locations.
- Eliminate `NL` define for "\n".
- Change JSON emitter to populate `instance_list` in an earlier
  loop over superclasses instead of a separate loop.

Author: jurahul

llvm/include/llvm/TableGen/Record.h

@@ -2328,8 +2328,8 @@ class HasReferenceResolver final : public Resolver {
   Init *resolve(Init *VarName) override;
 };
 
-void EmitDetailedRecords(RecordKeeper &RK, raw_ostream &OS);
-void EmitJSON(RecordKeeper &RK, raw_ostream &OS);
+void EmitDetailedRecords(const RecordKeeper &RK, raw_ostream &OS);
+void EmitJSON(const RecordKeeper &RK, raw_ostream &OS);
 
 } // end namespace llvm
 

llvm/lib/TableGen/DetailedRecordsBackend.cpp

@@ -21,36 +21,30 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include <map>
-#include <memory>
 #include <string>
 #include <utility>
 
-#define DEBUG_TYPE "detailed-records-backend"
-
-#define NL "\n"
-
 using namespace llvm;
 
 namespace {
 
 class DetailedRecordsEmitter {
 private:
-  RecordKeeper &Records;
+  const RecordKeeper &Records;
 
 public:
-  DetailedRecordsEmitter(RecordKeeper &RK) : Records(RK) {}
+  explicit DetailedRecordsEmitter(const RecordKeeper &RK) : Records(RK) {}
 
   void run(raw_ostream &OS);
   void printReportHeading(raw_ostream &OS);
+  void printSectionHeading(StringRef Title, int Count, raw_ostream &OS);
   void printVariables(raw_ostream &OS);
   void printClasses(raw_ostream &OS);
   void printRecords(raw_ostream &OS);
-  void printSectionHeading(StringRef Title, int Count, raw_ostream &OS);
-  void printDefms(Record *Rec, raw_ostream &OS);
-  void printTemplateArgs(Record *Rec, raw_ostream &OS);
-  void printSuperclasses(Record *Rec, raw_ostream &OS);
-  void printFields(Record *Rec, raw_ostream &OS);
+  void printDefms(const Record &Rec, raw_ostream &OS);
+  void printTemplateArgs(const Record &Rec, raw_ostream &OS);
+  void printSuperclasses(const Record &Rec, raw_ostream &OS);
+  void printFields(const Record &Rec, raw_ostream &OS);
 }; // emitter class
 
 } // anonymous namespace
@@ -68,15 +62,21 @@ void DetailedRecordsEmitter::printReportHeading(raw_ostream &OS) {
   OS << formatv("DETAILED RECORDS for file {0}\n", Records.getInputFilename());
 }
 
+// Print a section heading with the name of the section and
+// the item count.
+void DetailedRecordsEmitter::printSectionHeading(StringRef Title, int Count,
+                                                 raw_ostream &OS) {
+  OS << formatv("\n{0} {1} ({2}) {0}\n", "--------------------", Title, Count);
+}
+
 // Print the global variables.
 void DetailedRecordsEmitter::printVariables(raw_ostream &OS) {
   const auto GlobalList = Records.getGlobals();
   printSectionHeading("Global Variables", GlobalList.size(), OS);
 
-  OS << NL;
-  for (const auto &Var : GlobalList) {
-    OS << Var.first << " = " << Var.second->getAsString() << NL;
-  }
+  OS << '\n';
+  for (const auto &Var : GlobalList)
+    OS << Var.first << " = " << Var.second->getAsString() << '\n';
 }
 
 // Print the classes, including the template arguments, superclasses,
@@ -85,13 +85,12 @@ void DetailedRecordsEmitter::printClasses(raw_ostream &OS) {
   const auto &ClassList = Records.getClasses();
   printSectionHeading("Classes", ClassList.size(), OS);
 
-  for (const auto &ClassPair : ClassList) {
-    auto *const Class = ClassPair.second.get();
+  for (const auto &[Name, Class] : ClassList) {
     OS << formatv("\n{0}  |{1}|\n", Class->getNameInitAsString(),
                   SrcMgr.getFormattedLocationNoOffset(Class->getLoc().front()));
-    printTemplateArgs(Class, OS);
-    printSuperclasses(Class, OS);
-    printFields(Class, OS);
+    printTemplateArgs(*Class, OS);
+    printSuperclasses(*Class, OS);
+    printFields(*Class, OS);
   }
 }
 
@@ -101,103 +100,89 @@ void DetailedRecordsEmitter::printRecords(raw_ostream &OS) {
   const auto &RecordList = Records.getDefs();
   printSectionHeading("Records", RecordList.size(), OS);
 
-  for (const auto &RecPair : RecordList) {
-    auto *const Rec = RecPair.second.get();
+  for (const auto &[DefName, Rec] : RecordList) {
     std::string Name = Rec->getNameInitAsString();
     OS << formatv("\n{0}  |{1}|\n", Name.empty() ? "\"\"" : Name,
                   SrcMgr.getFormattedLocationNoOffset(Rec->getLoc().front()));
-    printDefms(Rec, OS);
-    printSuperclasses(Rec, OS);
-    printFields(Rec, OS);
+    printDefms(*Rec, OS);
+    printSuperclasses(*Rec, OS);
+    printFields(*Rec, OS);
   }
 }
 
-// Print a section heading with the name of the section and
-// the item count.
-void DetailedRecordsEmitter::printSectionHeading(StringRef Title, int Count,
-                                                 raw_ostream &OS) {
-  OS << formatv("\n{0} {1} ({2}) {0}\n", "--------------------", Title, Count);
-}
-
 // Print the record's defm source locations, if any. Note that they
 // are stored in the reverse order of their invocation.
-void DetailedRecordsEmitter::printDefms(Record *Rec, raw_ostream &OS) {
-  const auto &LocList = Rec->getLoc();
+void DetailedRecordsEmitter::printDefms(const Record &Rec, raw_ostream &OS) {
+  const auto &LocList = Rec.getLoc();
   if (LocList.size() < 2)
     return;
 
   OS << "  Defm sequence:";
-  for (unsigned I = LocList.size() - 1; I >= 1; --I) {
-    OS << formatv(" |{0}|", SrcMgr.getFormattedLocationNoOffset(LocList[I]));
-  }
-  OS << NL;
+  for (const SMLoc Loc : reverse(LocList))
+    OS << formatv(" |{0}|", SrcMgr.getFormattedLocationNoOffset(Loc));
+  OS << '\n';
 }
 
 // Print the template arguments of a class.
-void DetailedRecordsEmitter::printTemplateArgs(Record *Rec,
+void DetailedRecordsEmitter::printTemplateArgs(const Record &Rec,
                                                raw_ostream &OS) {
-  ArrayRef<Init *> Args = Rec->getTemplateArgs();
+  ArrayRef<Init *> Args = Rec.getTemplateArgs();
   if (Args.empty()) {
     OS << "  Template args: (none)\n";
     return;
   }
 
   OS << "  Template args:\n";
   for (const Init *ArgName : Args) {
-    const RecordVal *Value = Rec->getValue(ArgName);
+    const RecordVal *Value = Rec.getValue(ArgName);
     assert(Value && "Template argument value not found.");
     OS << "    ";
     Value->print(OS, false);
-    OS << formatv("  |{0}|", SrcMgr.getFormattedLocationNoOffset(Value->getLoc()));
-    OS << NL;
+    OS << formatv("  |{0}|\n",
+                  SrcMgr.getFormattedLocationNoOffset(Value->getLoc()));
   }
 }
 
 // Print the superclasses of a class or record. Indirect superclasses
 // are enclosed in parentheses.
-void DetailedRecordsEmitter::printSuperclasses(Record *Rec, raw_ostream &OS) {
-  ArrayRef<std::pair<Record *, SMRange>> Superclasses = Rec->getSuperClasses();
+void DetailedRecordsEmitter::printSuperclasses(const Record &Rec,
+                                               raw_ostream &OS) {
+  ArrayRef<std::pair<Record *, SMRange>> Superclasses = Rec.getSuperClasses();
   if (Superclasses.empty()) {
     OS << "  Superclasses: (none)\n";
     return;
   }
 
   OS << "  Superclasses:";
-  for (const auto &SuperclassPair : Superclasses) {
-    auto *ClassRec = SuperclassPair.first;
-    if (Rec->hasDirectSuperClass(ClassRec))
+  for (const auto &[ClassRec, Loc] : Superclasses) {
+    if (Rec.hasDirectSuperClass(ClassRec))
       OS << formatv(" {0}", ClassRec->getNameInitAsString());
     else
       OS << formatv(" ({0})", ClassRec->getNameInitAsString());
   }
-  OS << NL;
+  OS << '\n';
 }
 
 // Print the fields of a class or record, including their source locations.
-void DetailedRecordsEmitter::printFields(Record *Rec, raw_ostream &OS) {
-  const auto &ValueList = Rec->getValues();
+void DetailedRecordsEmitter::printFields(const Record &Rec, raw_ostream &OS) {
+  const auto &ValueList = Rec.getValues();
   if (ValueList.empty()) {
     OS << "  Fields: (none)\n";
     return;
   }
 
   OS << "  Fields:\n";
   for (const RecordVal &Value : ValueList)
-    if (!Rec->isTemplateArg(Value.getNameInit())) {
+    if (!Rec.isTemplateArg(Value.getNameInit())) {
       OS << "    ";
       Value.print(OS, false);
       OS << formatv("  |{0}|\n",
                     SrcMgr.getFormattedLocationNoOffset(Value.getLoc()));
     }
 }
 
-namespace llvm {
-
 // This function is called by TableGen after parsing the files.
-
-void EmitDetailedRecords(RecordKeeper &RK, raw_ostream &OS) {
+void llvm::EmitDetailedRecords(const RecordKeeper &RK, raw_ostream &OS) {
   // Instantiate the emitter class and invoke run().
   DetailedRecordsEmitter(RK).run(OS);
 }
-
-} // namespace llvm