[clang] [llvm] [NFC] Use const members of `StringToOffsetTable` (PR #105824)

[Rahul Joshi via llvm-commits]

https://github.com/jurahul created https://github.com/llvm/llvm-project/pull/105824

- After the table is populated and emitted as a string, we do not expect any modifications to the table. So use const reference and const members to access the table from that point on.

>From 154c0728820a8a6e1e50e3b079d5df09abb198cd Mon Sep 17 00:00:00 2001
From: Rahul Joshi <rjoshi at nvidia.com>
Date: Fri, 23 Aug 2024 05:45:25 -0700
Subject: [PATCH] [NFC] Use const members of `StringToOffsetTable`

- After the table is populated and emitted as a string, we do not expect
  any modifications to the table. So use const reference and const members
  to access the table from that point on.
---
 clang/utils/TableGen/ClangDiagnosticsEmitter.cpp |  9 +++++----
 llvm/utils/TableGen/AsmMatcherEmitter.cpp        | 10 +++++-----
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/clang/utils/TableGen/ClangDiagnosticsEmitter.cpp b/clang/utils/TableGen/ClangDiagnosticsEmitter.cpp
index b290530444d2ab..6ca24a8c74b2ff 100644
--- a/clang/utils/TableGen/ClangDiagnosticsEmitter.cpp
+++ b/clang/utils/TableGen/ClangDiagnosticsEmitter.cpp
@@ -1634,7 +1634,7 @@ static void emitDiagArrays(std::map<std::string, GroupInfo> &DiagsInGroup,
 ///     \000\020#pragma-messages\t#warnings\020CFString-literal"
 ///   };
 /// \endcode
-static void emitDiagGroupNames(StringToOffsetTable &GroupNames,
+static void emitDiagGroupNames(const StringToOffsetTable &GroupNames,
                                raw_ostream &OS) {
   OS << "static const char DiagGroupNames[] = {\n";
   GroupNames.EmitString(OS);
@@ -1656,7 +1656,7 @@ static void emitDiagGroupNames(StringToOffsetTable &GroupNames,
 static void emitAllDiagArrays(std::map<std::string, GroupInfo> &DiagsInGroup,
                               RecordVec &DiagsInPedantic,
                               RecordVec &GroupsInPedantic,
-                              StringToOffsetTable &GroupNames,
+                              const StringToOffsetTable &GroupNames,
                               raw_ostream &OS) {
   OS << "\n#ifdef GET_DIAG_ARRAYS\n";
   emitDiagArrays(DiagsInGroup, DiagsInPedantic, OS);
@@ -1683,7 +1683,8 @@ static void emitAllDiagArrays(std::map<std::string, GroupInfo> &DiagsInGroup,
 static void emitDiagTable(std::map<std::string, GroupInfo> &DiagsInGroup,
                           RecordVec &DiagsInPedantic,
                           RecordVec &GroupsInPedantic,
-                          StringToOffsetTable &GroupNames, raw_ostream &OS) {
+                          const StringToOffsetTable &GroupNames,
+                          raw_ostream &OS) {
   unsigned MaxLen = 0;
 
   for (auto const &I: DiagsInGroup)
@@ -1705,7 +1706,7 @@ static void emitDiagTable(std::map<std::string, GroupInfo> &DiagsInGroup,
     OS << I.first << " */, ";
     // Store a pascal-style length byte at the beginning of the string.
     std::string Name = char(I.first.size()) + I.first;
-    OS << GroupNames.GetOrAddStringOffset(Name, false) << ", ";
+    OS << *GroupNames.GetStringOffset(Name) << ", ";
 
     // Special handling for 'pedantic'.
     const bool IsPedantic = I.first == "pedantic";
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index 5035ef52707f4e..98d0231d3055c2 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -2871,7 +2871,7 @@ static bool emitMnemonicAliases(raw_ostream &OS, const AsmMatcherInfo &Info,
 static void
 emitCustomOperandParsing(raw_ostream &OS, CodeGenTarget &Target,
                          const AsmMatcherInfo &Info, StringRef ClassName,
-                         StringToOffsetTable &StringTable,
+                         const StringToOffsetTable &StringTable,
                          unsigned MaxMnemonicIndex, unsigned MaxFeaturesIndex,
                          bool HasMnemonicFirst, const Record &AsmParser) {
   unsigned MaxMask = 0;
@@ -2924,8 +2924,8 @@ emitCustomOperandParsing(raw_ostream &OS, CodeGenTarget &Target,
 
     // Store a pascal-style length byte in the mnemonic.
     std::string LenMnemonic = char(II.Mnemonic.size()) + II.Mnemonic.lower();
-    OS << StringTable.GetOrAddStringOffset(LenMnemonic, false) << " /* "
-       << II.Mnemonic << " */, ";
+    OS << *StringTable.GetStringOffset(LenMnemonic) << " /* " << II.Mnemonic
+       << " */, ";
 
     OS << OMI.OperandMask;
     OS << " /* ";
@@ -3554,8 +3554,8 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
       // Store a pascal-style length byte in the mnemonic.
       std::string LenMnemonic =
           char(MI->Mnemonic.size()) + MI->Mnemonic.lower();
-      OS << "  { " << StringTable.GetOrAddStringOffset(LenMnemonic, false)
-         << " /* " << MI->Mnemonic << " */, " << Target.getInstNamespace()
+      OS << "  { " << *StringTable.GetStringOffset(LenMnemonic) << " /* "
+         << MI->Mnemonic << " */, " << Target.getInstNamespace()
          << "::" << MI->getResultInst()->TheDef->getName() << ", "
          << MI->ConversionFnKind << ", ";