2 files changed, 25 insertions, 0 deletions
diff --git a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
index 0471baa1f9c..b8884486c33 100644
--- a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
@@ -78,6 +78,13 @@ struct LLVMRustCoverageCodeRegion {
 };
 
 // Must match the layout of
+// `rustc_codegen_llvm::coverageinfo::ffi::ExpansionRegion`.
+struct LLVMRustCoverageExpansionRegion {
+  LLVMRustCoverageSpan Span;
+  uint32_t ExpandedFileID;
+};
+
+// Must match the layout of
 // `rustc_codegen_llvm::coverageinfo::ffi::BranchRegion`.
 struct LLVMRustCoverageBranchRegion {
   LLVMRustCoverageSpan Span;
@@ -151,6 +158,8 @@ extern "C" void LLVMRustCoverageWriteFunctionMappingsToBuffer(
     const unsigned *VirtualFileMappingIDs, size_t NumVirtualFileMappingIDs,
     const LLVMRustCounterExpression *RustExpressions, size_t NumExpressions,
     const LLVMRustCoverageCodeRegion *CodeRegions, size_t NumCodeRegions,
+    const LLVMRustCoverageExpansionRegion *ExpansionRegions,
+    size_t NumExpansionRegions,
     const LLVMRustCoverageBranchRegion *BranchRegions, size_t NumBranchRegions,
     const LLVMRustCoverageMCDCBranchRegion *MCDCBranchRegions,
     size_t NumMCDCBranchRegions,
@@ -179,6 +188,13 @@ extern "C" void LLVMRustCoverageWriteFunctionMappingsToBuffer(
         Region.Span.ColumnStart, Region.Span.LineEnd, Region.Span.ColumnEnd));
   }
 
+  // Expansion regions:
+  for (const auto &Region : ArrayRef(ExpansionRegions, NumExpansionRegions)) {
+    MappingRegions.push_back(coverage::CounterMappingRegion::makeExpansion(
+        Region.Span.FileID, Region.ExpandedFileID, Region.Span.LineStart,
+        Region.Span.ColumnStart, Region.Span.LineEnd, Region.Span.ColumnEnd));
+  }
+
   // Branch regions:
   for (const auto &Region : ArrayRef(BranchRegions, NumBranchRegions)) {
     MappingRegions.push_back(coverage::CounterMappingRegion::makeBranchRegion(
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index bc3d4d6f83a..86f1bcc46ee 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -1682,12 +1682,21 @@ extern "C" void LLVMRustComputeLTOCacheKey(RustStringRef KeyOut,
 #endif
 
   // Based on the 'InProcessThinBackend' constructor in LLVM
+#if LLVM_VERSION_GE(21, 0)
+  for (auto &Name : Data->Index.cfiFunctionDefs().symbols())
+    CfiFunctionDefs.insert(
+        GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name)));
+  for (auto &Name : Data->Index.cfiFunctionDecls().symbols())
+    CfiFunctionDecls.insert(
+        GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name)));
+#else
   for (auto &Name : Data->Index.cfiFunctionDefs())
     CfiFunctionDefs.insert(
         GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name)));
   for (auto &Name : Data->Index.cfiFunctionDecls())
     CfiFunctionDecls.insert(
         GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name)));
+#endif
 
 #if LLVM_VERSION_GE(20, 0)
   Key = llvm::computeLTOCacheKey(conf, Data->Index, ModId, ImportList,