[NFC][TableGen] Emit more readable builtin string table (llvm#105445)

- Add `EmitStringLiteralDef` to StringToOffsetTable class to emit more
readable string table.
- Use that in `EmitIntrinsicToBuiltinMap`.

llvm/include/llvm/TableGen/StringToOffsetTable.h

@@ -12,6 +12,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cctype>
 #include <optional>
@@ -52,6 +53,31 @@ class StringToOffsetTable {
  return II->second;
  }
 
+ // Emit the string using string literal concatenation, for better readability
+ // and searchability.
+ void EmitStringLiteralDef(raw_ostream &OS, const Twine &Decl,
+ const Twine &Indent = " ") const {
+ OS << formatv(R"(
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverlength-strings"
+#endif
+{0}{1} = )",
+ Indent, Decl);
+
+ for (StringRef Str : split(AggregateString, '\0')) {
+ OS << "\n" << Indent << " \"";
+ OS.write_escaped(Str);
+ OS << "\\0\"";
+ }
+ OS << R"(;
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+)";
+ }
+
+ // Emit the string as one single string.
  void EmitString(raw_ostream &O) {
  // Escape the string.
  SmallString<256> Str;

llvm/utils/TableGen/IntrinsicEmitter.cpp

@@ -669,9 +669,7 @@ Intrinsic::getIntrinsicFor{1}Builtin(StringRef TargetPrefix,
  }
 
  if (!Table.empty()) {
- OS << " static constexpr char BuiltinNames[] = {\n";
- Table.EmitCharArray(OS);
- OS << " };\n\n";
+ Table.EmitStringLiteralDef(OS, "static constexpr char BuiltinNames[]");
 
  OS << R"(
  struct BuiltinEntry {