4 files changed, 96 insertions, 15 deletions

diff --git a/llvm/lib/DebugInfo/GSYM/CallSiteInfo.cpp b/llvm/lib/DebugInfo/GSYM/CallSiteInfo.cpp
index 85b41e2..c112c0b 100644
--- a/llvm/lib/DebugInfo/GSYM/CallSiteInfo.cpp
+++ b/llvm/lib/DebugInfo/GSYM/CallSiteInfo.cpp
@@ -151,7 +151,7 @@ LLVM_YAML_IS_SEQUENCE_VECTOR(FunctionYAML)
 
 Error CallSiteInfoLoader::loadYAML(StringRef YAMLFile) {
   // Step 1: Read YAML file
-  auto BufferOrError = MemoryBuffer::getFile(YAMLFile);
+  auto BufferOrError = MemoryBuffer::getFile(YAMLFile, /*IsText=*/true);
   if (!BufferOrError)
     return errorCodeToError(BufferOrError.getError());
 
diff --git a/llvm/lib/DebugInfo/GSYM/FunctionInfo.cpp b/llvm/lib/DebugInfo/GSYM/FunctionInfo.cpp
index dd754c70..785a8da 100644
--- a/llvm/lib/DebugInfo/GSYM/FunctionInfo.cpp
+++ b/llvm/lib/DebugInfo/GSYM/FunctionInfo.cpp
@@ -235,10 +235,10 @@ llvm::Expected<uint64_t> FunctionInfo::encode(FileWriter &Out,
   return FuncInfoOffset;
 }
 
-llvm::Expected<LookupResult> FunctionInfo::lookup(DataExtractor &Data,
-                                                  const GsymReader &GR,
-                                                  uint64_t FuncAddr,
-                                                  uint64_t Addr) {
+llvm::Expected<LookupResult>
+FunctionInfo::lookup(DataExtractor &Data, const GsymReader &GR,
+                     uint64_t FuncAddr, uint64_t Addr,
+                     std::optional<DataExtractor> *MergedFuncsData) {
   LookupResult LR;
   LR.LookupAddr = Addr;
   uint64_t Offset = 0;
@@ -289,6 +289,12 @@ llvm::Expected<LookupResult> FunctionInfo::lookup(DataExtractor &Data,
           return ExpectedLE.takeError();
         break;
 
+      case InfoType::MergedFunctionsInfo:
+        // Store the merged functions data for later parsing, if needed.
+        if (MergedFuncsData)
+          *MergedFuncsData = InfoData;
+        break;
+
       case InfoType::InlineInfo:
         // We will parse the inline info after our line table, but only if
         // we have a line entry.
diff --git a/llvm/lib/DebugInfo/GSYM/GsymReader.cpp b/llvm/lib/DebugInfo/GSYM/GsymReader.cpp
index fa5476d..0a5bb7c 100644
--- a/llvm/lib/DebugInfo/GSYM/GsymReader.cpp
+++ b/llvm/lib/DebugInfo/GSYM/GsymReader.cpp
@@ -334,14 +334,52 @@ GsymReader::getFunctionInfoAtIndex(uint64_t Idx) const {
     return ExpectedData.takeError();
 }
 
-llvm::Expected<LookupResult> GsymReader::lookup(uint64_t Addr) const {
+llvm::Expected<LookupResult>
+GsymReader::lookup(uint64_t Addr,
+                   std::optional<DataExtractor> *MergedFunctionsData) const {
   uint64_t FuncStartAddr = 0;
   if (auto ExpectedData = getFunctionInfoDataForAddress(Addr, FuncStartAddr))
-    return FunctionInfo::lookup(*ExpectedData, *this, FuncStartAddr, Addr);
+    return FunctionInfo::lookup(*ExpectedData, *this, FuncStartAddr, Addr,
+                                MergedFunctionsData);
   else
     return ExpectedData.takeError();
 }
 
+llvm::Expected<std::vector<LookupResult>>
+GsymReader::lookupAll(uint64_t Addr) const {
+  std::vector<LookupResult> Results;
+  std::optional<DataExtractor> MergedFunctionsData;
+
+  // First perform a lookup to get the primary function info result.
+  auto MainResult = lookup(Addr, &MergedFunctionsData);
+  if (!MainResult)
+    return MainResult.takeError();
+
+  // Add the main result as the first entry.
+  Results.push_back(std::move(*MainResult));
+
+  // Now process any merged functions data that was found during the lookup.
+  if (MergedFunctionsData) {
+    // Get data extractors for each merged function.
+    auto ExpectedMergedFuncExtractors =
+        MergedFunctionsInfo::getFuncsDataExtractors(*MergedFunctionsData);
+    if (!ExpectedMergedFuncExtractors)
+      return ExpectedMergedFuncExtractors.takeError();
+
+    // Process each merged function data.
+    for (DataExtractor &MergedData : *ExpectedMergedFuncExtractors) {
+      if (auto FI = FunctionInfo::lookup(MergedData, *this,
+                                         MainResult->FuncRange.start(), Addr)) {
+        Results.push_back(std::move(*FI));
+      } else {
+        return FI.takeError();
+      }
+    }
+  }
+
+  return Results;
+}
+
 void GsymReader::dump(raw_ostream &OS) {
   const auto &Header = getHeader();
   // Dump the GSYM header.
diff --git a/llvm/lib/DebugInfo/GSYM/MergedFunctionsInfo.cpp b/llvm/lib/DebugInfo/GSYM/MergedFunctionsInfo.cpp
index 4efae22..d2c28f3 100644
--- a/llvm/lib/DebugInfo/GSYM/MergedFunctionsInfo.cpp
+++ b/llvm/lib/DebugInfo/GSYM/MergedFunctionsInfo.cpp
@@ -35,22 +35,59 @@ llvm::Error MergedFunctionsInfo::encode(FileWriter &Out) const {
 llvm::Expected<MergedFunctionsInfo>
 MergedFunctionsInfo::decode(DataExtractor &Data, uint64_t BaseAddr) {
   MergedFunctionsInfo MFI;
+  auto FuncExtractorsOrError = MFI.getFuncsDataExtractors(Data);
+
+  if (!FuncExtractorsOrError)
+    return FuncExtractorsOrError.takeError();
+
+  for (DataExtractor &FuncData : *FuncExtractorsOrError) {
+    llvm::Expected<FunctionInfo> FI = FunctionInfo::decode(FuncData, BaseAddr);
+    if (!FI)
+      return FI.takeError();
+    MFI.MergedFunctions.push_back(std::move(*FI));
+  }
+
+  return MFI;
+}
+
+llvm::Expected<std::vector<DataExtractor>>
+MergedFunctionsInfo::getFuncsDataExtractors(DataExtractor &Data) {
+  std::vector<DataExtractor> Results;
   uint64_t Offset = 0;
+
+  // Ensure there is enough data to read the function count.
+  if (!Data.isValidOffsetForDataOfSize(Offset, 4))
+    return createStringError(
+        std::errc::io_error,
+        "unable to read the function count at offset 0x%8.8" PRIx64, Offset);
+
   uint32_t Count = Data.getU32(&Offset);
 
   for (uint32_t i = 0; i < Count; ++i) {
+    // Ensure there is enough data to read the function size.
+    if (!Data.isValidOffsetForDataOfSize(Offset, 4))
+      return createStringError(
+          std::errc::io_error,
+          "unable to read size of function %u at offset 0x%8.8" PRIx64, i,
+          Offset);
+
     uint32_t FnSize = Data.getU32(&Offset);
-    DataExtractor FnData(Data.getData().substr(Offset, FnSize),
+
+    // Ensure there is enough data for the function content.
+    if (!Data.isValidOffsetForDataOfSize(Offset, FnSize))
+      return createStringError(
+          std::errc::io_error,
+          "function data is truncated for function %u at offset 0x%8.8" PRIx64
+          ", expected size %u",
+          i, Offset, FnSize);
+
+    // Extract the function data.
+    Results.emplace_back(Data.getData().substr(Offset, FnSize),
                          Data.isLittleEndian(), Data.getAddressSize());
-    llvm::Expected<FunctionInfo> FI =
-        FunctionInfo::decode(FnData, BaseAddr + Offset);
-    if (!FI)
-      return FI.takeError();
-    MFI.MergedFunctions.push_back(std::move(*FI));
+
     Offset += FnSize;
   }
-
-  return MFI;
+  return Results;
 }
 
 bool operator==(const MergedFunctionsInfo &LHS,