Fix crashes when the macro expansion is empty

amane-ame · amane-ame · commit 3a4c1a924fae · 2024-12-11T02:13:43.000+08:00
diff --git a/clang/lib/Format/MacroExpander.cpp b/clang/lib/Format/MacroExpander.cpp
@@ -233,6 +233,10 @@ MacroExpander::expand(FormatToken *ID,
   if (Result.size() > 1) {
     ++Result[0]->MacroCtx->StartOfExpansion;
     ++Result[Result.size() - 2]->MacroCtx->EndOfExpansion;
+  } else {
+    // If the macro expansion is empty, mark the start and end
+    Result[0]->MacroCtx->StartOfExpansion = 1;
+    Result[0]->MacroCtx->EndOfExpansion = 1;
   }
   return Result;
 }

Original file line number	Diff line number	Diff line change
`@@ -233,6 +233,10 @@ MacroExpander::expand(FormatToken *ID,`
`233`	`233`	`if (Result.size() > 1) {`
`234`	`234`	`++Result[0]->MacroCtx->StartOfExpansion;`
`235`	`235`	`++Result[Result.size() - 2]->MacroCtx->EndOfExpansion;`
	`236`	`+ } else {`
	`237`	`+ // If the macro expansion is empty, mark the start and end`
	`238`	`+ Result[0]->MacroCtx->StartOfExpansion = 1;`
	`239`	`+ Result[0]->MacroCtx->EndOfExpansion = 1;`
`236`	`240`	`}`
`237`	`241`	`return Result;`
`238`	`242`	`}`