[llvm] [DebugInfo] Pass string ownership to MarkupFilter (PR #75403)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-binary-utilities

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>

Last `getline` call destroys `InputString`, and `finish` fails
accesses dead `StringRef`.

Detected with #<!-- -->72677.


---
Full diff: https://github.com/llvm/llvm-project/pull/75403.diff


3 Files Affected:

- (modified) llvm/include/llvm/DebugInfo/Symbolize/MarkupFilter.h (+2-2) 
- (modified) llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp (+6-4) 
- (modified) llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp (+1-1) 


``````````diff
diff --git a/llvm/include/llvm/DebugInfo/Symbolize/MarkupFilter.h b/llvm/include/llvm/DebugInfo/Symbolize/MarkupFilter.h
index a1514d91702b9f..10613ec57586df 100644
--- a/llvm/include/llvm/DebugInfo/Symbolize/MarkupFilter.h
+++ b/llvm/include/llvm/DebugInfo/Symbolize/MarkupFilter.h
@@ -39,7 +39,7 @@ class MarkupFilter {
   ///
   /// Invalid or unimplemented markup elements are removed. Some output may be
   /// deferred until future filter() or finish() call.
-  void filter(StringRef Line);
+  void filter(std::string &&InputLine);
 
   /// Records that the input stream has ended and writes any deferred output.
   void finish();
@@ -142,7 +142,7 @@ class MarkupFilter {
   MarkupParser Parser;
 
   // Current line being filtered.
-  StringRef Line;
+  std::string Line;
 
   // A module info line currently being built. This incorporates as much mmap
   // information as possible before being emitted.
diff --git a/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp b/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
index f7503ef49693d8..01d49709f9b29c 100644
--- a/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/MarkupFilter.cpp
@@ -41,8 +41,8 @@ MarkupFilter::MarkupFilter(raw_ostream &OS, LLVMSymbolizer &Symbolizer,
       ColorsEnabled(
           ColorsEnabled.value_or(WithColor::defaultAutoDetectFunction()(OS))) {}
 
-void MarkupFilter::filter(StringRef Line) {
-  this->Line = Line;
+void MarkupFilter::filter(std::string &&InputLine) {
+  Line = std::move(InputLine);
   resetColor();
 
   Parser.parseLine(Line);
@@ -695,7 +695,9 @@ void MarkupFilter::reportTypeError(StringRef Str, StringRef TypeName) const {
 // passed to beginLine().
 void MarkupFilter::reportLocation(StringRef::iterator Loc) const {
   errs() << Line;
-  WithColor(errs().indent(Loc - Line.begin()), HighlightColor::String) << '^';
+  WithColor(errs().indent(Loc - StringRef(Line).begin()),
+            HighlightColor::String)
+      << '^';
   errs() << '\n';
 }
 
@@ -741,7 +743,7 @@ uint64_t MarkupFilter::adjustAddr(uint64_t Addr, PCType Type) const {
 }
 
 StringRef MarkupFilter::lineEnding() const {
-  return Line.ends_with("\r\n") ? "\r\n" : "\n";
+  return StringRef(Line).ends_with("\r\n") ? "\r\n" : "\n";
 }
 
 bool MarkupFilter::MMap::contains(uint64_t Addr) const {
diff --git a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
index 447c18abadc174..3d33534d95b7e0 100644
--- a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
+++ b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
@@ -430,7 +430,7 @@ static void filterMarkup(const opt::InputArgList &Args, LLVMSymbolizer &Symboliz
   std::string InputString;
   while (std::getline(std::cin, InputString)) {
     InputString += '\n';
-    Filter.filter(InputString);
+    Filter.filter(std::move(InputString));
   }
   Filter.finish();
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/75403