[llvm] d089e1f - [llvm] Change the implementation of isValidFeatureListFormat (#219266)

[via llvm-commits]

Author: Jun Wang
Date: 2026-08-28T12:07:25-07:00
New Revision: d089e1f04ded2b691bc431e43799d7e93ff56015

URL: https://github.com/llvm/llvm-project/commit/d089e1f04ded2b691bc431e43799d7e93ff56015
DIFF: https://github.com/llvm/llvm-project/commit/d089e1f04ded2b691bc431e43799d7e93ff56015.diff

LOG: [llvm] Change the implementation of isValidFeatureListFormat (#219266)

This is mostly to change the function-local static variable because some
programs are having static initialization order problems. Also the
coding standard states statics with ctor/dtor should be avoided. The new
implementation also does not use Regex anymore.

Added: 
    

Modified: 
    llvm/lib/MC/TargetRegistry.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/MC/TargetRegistry.cpp b/llvm/lib/MC/TargetRegistry.cpp
index 2727e587496f3..185f63637a460 100644
--- a/llvm/lib/MC/TargetRegistry.cpp
+++ b/llvm/lib/MC/TargetRegistry.cpp
@@ -16,7 +16,6 @@
 #include "llvm/MC/MCLFI.h"
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/MCObjectWriter.h"
-#include "llvm/Support/Regex.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <vector>
@@ -29,8 +28,17 @@ bool Target::isValidFeatureListFormat(StringRef Features) {
   if (Features.empty())
     return true;
 
-  static const llvm::Regex pattern("^([+-][^,]+)(,[+-][^,]+)*,?$");
-  return pattern.match(Features);
+  // Each feature starts with '+'/'-' followed by at least one non-comma
+  // character. Features are comma-separated with an optional trailing comma.
+  for (size_t I = 0, E = Features.size(); I != E; ++I) {
+    if (I == 0 || Features[I - 1] == ',') {
+      // At the start of a feature: must have a sign and a non-empty name.
+      if ((Features[I] != '+' && Features[I] != '-') ||
+          I + 1 == Features.size() || Features[I + 1] == ',')
+        return false;
+    }
+  }
+  return true;
 }
 
 MCStreamer *Target::createMCObjectStreamer(