1 files changed, 23 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 1ba7f1f1df2..57ecacf7dce 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -84,6 +84,10 @@ public:
                                    const yaml::MachineBasicBlock &YamlMBB);
 
 private:
+  /// Return a MIR diagnostic converted from an MI string diagnostic.
+  SMDiagnostic diagFromMIStringDiag(const SMDiagnostic &Error,
+                                    SMRange SourceRange);
+
   /// Return a MIR diagnostic converted from an LLVM assembly diagnostic.
   SMDiagnostic diagFromLLVMAssemblyDiag(const SMDiagnostic &Error,
                                         SMRange SourceRange);
@@ -129,6 +133,7 @@ static void handleYAMLDiag(const SMDiagnostic &Diag, void *Context) {
 std::unique_ptr<Module> MIRParserImpl::parse() {
   yaml::Input In(SM.getMemoryBuffer(SM.getMainFileID())->getBuffer(),
                  /*Ctxt=*/nullptr, handleYAMLDiag, this);
+  In.setContext(&In);
 
   if (!In.setCurrentDocument()) {
     if (In.error())
@@ -235,16 +240,32 @@ bool MIRParserImpl::initializeMachineBasicBlock(
   // Parse the instructions.
   for (const auto &MISource : YamlMBB.Instructions) {
     SMDiagnostic Error;
-    if (auto *MI = parseMachineInstr(SM, MF, MISource, Error)) {
+    if (auto *MI = parseMachineInstr(SM, MF, MISource.Value, Error)) {
       MBB.insert(MBB.end(), MI);
       continue;
     }
-    reportDiagnostic(Error);
+    reportDiagnostic(diagFromMIStringDiag(Error, MISource.SourceRange));
     return true;
   }
   return false;
 }
 
+SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
+                                                 SMRange SourceRange) {
+  assert(SourceRange.isValid() && "Invalid source range");
+  SMLoc Loc = SourceRange.Start;
+  bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
+                  *Loc.getPointer() == '\'';
+  // Translate the location of the error from the location in the MI string to
+  // the corresponding location in the MIR file.
+  Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
+                           (HasQuote ? 1 : 0));
+
+  // TODO: Translate any source ranges as well.
+  return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
+                       Error.getFixIts());
+}
+
 SMDiagnostic MIRParserImpl::diagFromLLVMAssemblyDiag(const SMDiagnostic &Error,
                                                      SMRange SourceRange) {
   assert(SourceRange.isValid());