[clang] Use a StringRef instead of a raw char pointer to store builtin and call information

This avoids recomputing string length that is already known at compile time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.

The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.

Differential Revision: https://reviews.llvm.org/D139881

1 files changed, 20 insertions, 10 deletions

diff --git a/llvm/tools/llvm-rc/llvm-rc.cpp b/llvm/tools/llvm-rc/llvm-rc.cpp
index 00fb9c1..f7f9ce2 100644
--- a/llvm/tools/llvm-rc/llvm-rc.cpp
+++ b/llvm/tools/llvm-rc/llvm-rc.cpp
@@ -55,7 +55,11 @@ enum ID {
 #undef OPTION
 };
 
-#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
+namespace rc_opt {
+#define PREFIX(NAME, VALUE)                                                    \
+  static constexpr StringLiteral NAME##_init[] = VALUE;                        \
+  static constexpr ArrayRef<StringLiteral> NAME(NAME##_init,                   \
+                                                std::size(NAME##_init) - 1);
 #include "Opts.inc"
 #undef PREFIX
 
@@ -70,10 +74,11 @@ static constexpr opt::OptTable::Info InfoTable[] = {
 #include "Opts.inc"
 #undef OPTION
 };
+} // namespace rc_opt
 
 class RcOptTable : public opt::OptTable {
 public:
-  RcOptTable() : OptTable(InfoTable, /* IgnoreCase = */ true) {}
+  RcOptTable() : OptTable(rc_opt::InfoTable, /* IgnoreCase = */ true) {}
 };
 
 enum Windres_ID {
@@ -85,25 +90,30 @@ enum Windres_ID {
 #undef OPTION
 };
 
-#define PREFIX(NAME, VALUE) const char *const WINDRES_##NAME[] = VALUE;
+namespace windres_opt {
+#define PREFIX(NAME, VALUE)                                                    \
+  static constexpr StringLiteral NAME##_init[] = VALUE;                        \
+  static constexpr ArrayRef<StringLiteral> NAME(NAME##_init,                   \
+                                                std::size(NAME##_init) - 1);
 #include "WindresOpts.inc"
 #undef PREFIX
 
-static constexpr opt::OptTable::Info WindresInfoTable[] = {
+static constexpr opt::OptTable::Info InfoTable[] = {
 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
                HELPTEXT, METAVAR, VALUES)                                      \
-  {                                                                            \
-      WINDRES_##PREFIX, NAME,         HELPTEXT,                                \
-      METAVAR,          WINDRES_##ID, opt::Option::KIND##Class,                \
-      PARAM,            FLAGS,        WINDRES_##GROUP,                         \
-      WINDRES_##ALIAS,  ALIASARGS,    VALUES},
+  {PREFIX,          NAME,         HELPTEXT,                                    \
+   METAVAR,         WINDRES_##ID, opt::Option::KIND##Class,                    \
+   PARAM,           FLAGS,        WINDRES_##GROUP,                             \
+   WINDRES_##ALIAS, ALIASARGS,    VALUES},
 #include "WindresOpts.inc"
 #undef OPTION
 };
+} // namespace windres_opt
 
 class WindresOptTable : public opt::OptTable {
 public:
-  WindresOptTable() : OptTable(WindresInfoTable, /* IgnoreCase = */ false) {}
+  WindresOptTable()
+      : OptTable(windres_opt::InfoTable, /* IgnoreCase = */ false) {}
 };
 
 static ExitOnError ExitOnErr;