[Mlir-commits] [mlir] [mlir][AsmParser] Fix comment detection in string literals (PR #174125)

[Mehdi Amini]

================
@@ -198,6 +198,43 @@ InFlightDiagnostic Parser::emitError(const Twine &message) {
   return emitError(SMLoc::getFromPointer(loc.getPointer() - 1), message);
 }
 
+/// Find the start of a line comment (`//`) in the given string, ignoring
+/// occurrences inside string literals. Returns StringRef::npos if no comment
+/// is found.
+static size_t findCommentStart(StringRef line) {
+  // Fast path: no comment in line at all.
+  size_t slashPos = line.find("//");
+  if (slashPos == StringRef::npos)
+    return StringRef::npos;
+
+  // Fast path: no quote before the '//', so it's a real comment.
+  size_t quotePos = line.find('"');
+  if (quotePos == StringRef::npos || quotePos > slashPos)
+    return slashPos;
+
+  // A quote appears before '//'. Parse carefully to handle string literals.
+  bool inString = false;
+  for (size_t i = 0, e = line.size(); i < e; ++i) {
+    char c = line[i];
+    if (inString) {
+      // Skip escaped characters inside strings.
+      if (c == '\\' && i + 1 < e) {
----------------
joker-eph wrote:

Why the `i + 1 < e` condition here?

https://github.com/llvm/llvm-project/pull/174125