[clang] [clang][Diagnostics] Highlight code snippets (PR #66514)

[Timm Baeder via cfe-commits]

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In-Reply-To: <llvm/llvm-project/pull/66514/clang at github.com>


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@@ -878,15 +879,46 @@ bool Preprocessor::HandleIdentifier(Token &Identifier) {
   return true;
 }
 
+void Preprocessor::saveCheckPoint(const char *P) {
+  static constexpr ptrdiff_t Limit = 1000;
+  if (CheckPoints.empty()) {
+    CheckPoints.push_back(P);
+    return;
+  }
+
+  const char *Cur = CheckPoints.back();
+  if (Cur == P)
+    return;
+  if ((P - Cur) > Limit)
+    CheckPoints.push_back(P);
+}
+
+const char *Preprocessor::getSaveFor(const char *S) const {
+  const char *C = S;
+  // FIXME: Use std::lower_bound or something smart. Aaron knows what I'm
+  // talking about.
+  for (ssize_t I = CheckPoints.size() - 1; I >= 0; --I) {
+    C = CheckPoints[I];
+    if (CheckPoints[I] <= S)
+      break;
+  }
+  return C;
+}
+
 void Preprocessor::Lex(Token &Result) {
   ++LexLevel;
 
   // We loop here until a lex function returns a token; this avoids recursion.
   bool ReturnedToken;
+  // const char *Save = nullptr;
   do {
     switch (CurLexerKind) {
     case CLK_Lexer:
       ReturnedToken = CurLexer->Lex(Result);
+      if (ReturnedToken && CurLexer &&
+          CurLexer->getFileID() == SourceMgr.getMainFileID()) {
----------------
tbaederr wrote:

I guess we should be doing that for all files and not just the main file.

https://github.com/llvm/llvm-project/pull/66514