[lld] [lld-macho] Avoid infinite recursion when parsing corrupted export tries (PR #152569)

[via llvm-commits]

github-actions[bot] wrote:

<!--LLVM CODE FORMAT COMMENT: {clang-format}-->


:warning: C/C++ code formatter, clang-format found issues in your code. :warning:

<details>
<summary>
You can test this locally with the following command:
</summary>

``````````bash
git-clang-format --diff HEAD~1 HEAD --extensions cpp,h -- lld/MachO/ExportTrie.cpp lld/MachO/ExportTrie.h lld/MachO/InputFiles.cpp
``````````

</details>

<details>
<summary>
View the diff from clang-format here.
</summary>

``````````diff
diff --git a/lld/MachO/ExportTrie.cpp b/lld/MachO/ExportTrie.cpp
index 8ba48ebc1..405a0f84b 100644
--- a/lld/MachO/ExportTrie.cpp
+++ b/lld/MachO/ExportTrie.cpp
@@ -296,7 +296,8 @@ namespace {
 // Parse a serialized trie and invoke a callback for each entry.
 class TrieParser {
 public:
-  TrieParser(const std::string &fileName, const uint8_t *buf, size_t size, const TrieEntryCallback &callback)
+  TrieParser(const std::string &fileName, const uint8_t *buf, size_t size,
+             const TrieEntryCallback &callback)
       : fileName(fileName), start(buf), end(start + size), callback(callback) {}
 
   void parse(const uint8_t *buf, const Twine &cumulativeString);
@@ -333,14 +334,14 @@ void TrieParser::parse(const uint8_t *buf, const Twine &cumulativeString) {
     offset = decodeULEB128(buf, &ulebSize);
     buf += ulebSize;
     if (start + offset < buf)
-      fatal(fileName + ": export trie child node offset points before parent node");
+      fatal(fileName +
+            ": export trie child node offset points before parent node");
     parse(start + offset, cumulativeString + substring);
   }
 }
 
-void macho::parseTrie(const std::string &fileName,
-                      const uint8_t *buf, size_t size,
-                      const TrieEntryCallback &callback) {
+void macho::parseTrie(const std::string &fileName, const uint8_t *buf,
+                      size_t size, const TrieEntryCallback &callback) {
   if (size == 0)
     return;
 
diff --git a/lld/MachO/ExportTrie.h b/lld/MachO/ExportTrie.h
index 5a5565d52..fa73fc4ef 100644
--- a/lld/MachO/ExportTrie.h
+++ b/lld/MachO/ExportTrie.h
@@ -41,7 +41,8 @@ private:
 using TrieEntryCallback =
     llvm::function_ref<void(const llvm::Twine & /*name*/, uint64_t /*flags*/)>;
 
-void parseTrie(const std::string &fileName, const uint8_t *buf, size_t size, const TrieEntryCallback &);
+void parseTrie(const std::string &fileName, const uint8_t *buf, size_t size,
+               const TrieEntryCallback &);
 
 } // namespace lld::macho
 
diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp
index 607867325..442fc6088 100644
--- a/lld/MachO/InputFiles.cpp
+++ b/lld/MachO/InputFiles.cpp
@@ -1789,12 +1789,13 @@ void DylibFile::parseExportedSymbols(uint32_t offset, uint32_t size) {
   auto *buf = reinterpret_cast<const uint8_t *>(mb.getBufferStart());
   std::vector<TrieEntry> entries;
   // Find all the $ld$* symbols to process first.
-  parseTrie(toString(this), buf + offset, size, [&](const Twine &name, uint64_t flags) {
-    StringRef savedName = saver().save(name);
-    if (handleLDSymbol(savedName))
-      return;
-    entries.push_back({savedName, flags});
-  });
+  parseTrie(toString(this), buf + offset, size,
+            [&](const Twine &name, uint64_t flags) {
+              StringRef savedName = saver().save(name);
+              if (handleLDSymbol(savedName))
+                return;
+              entries.push_back({savedName, flags});
+            });
 
   // Process the "normal" symbols.
   for (TrieEntry &entry : entries) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/152569