MIR Serialization: Start serializing the CFI operands with .cfi_def_cfa_offset.

This commit begins serialization of the CFI index machine operands by
serializing one kind of CFI instruction - the .cfi_def_cfa_offset instruction.

Reviewers: Duncan P. N. Exon Smith
llvm-svn: 242845

1 files changed, 28 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index ca98ae3c97f..498ca0615d5 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -20,6 +20,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/raw_ostream.h"
@@ -111,6 +112,8 @@ public:
   bool parseConstantPoolIndexOperand(MachineOperand &Dest);
   bool parseJumpTableIndexOperand(MachineOperand &Dest);
   bool parseExternalSymbolOperand(MachineOperand &Dest);
+  bool parseCFIOffset(int &Offset);
+  bool parseCFIOperand(MachineOperand &Dest);
   bool parseMachineOperand(MachineOperand &Dest);
 
 private:
@@ -572,6 +575,29 @@ bool MIParser::parseExternalSymbolOperand(MachineOperand &Dest) {
   return false;
 }
 
+bool MIParser::parseCFIOffset(int &Offset) {
+  if (Token.isNot(MIToken::IntegerLiteral))
+    return error("expected a cfi offset");
+  if (Token.integerValue().getMinSignedBits() > 32)
+    return error("expected a 32 bit integer (the cfi offset is too large)");
+  Offset = (int)Token.integerValue().getExtValue();
+  lex();
+  return false;
+}
+
+bool MIParser::parseCFIOperand(MachineOperand &Dest) {
+  // TODO: Parse the other CFI operands.
+  assert(Token.is(MIToken::kw_cfi_def_cfa_offset));
+  lex();
+  int Offset;
+  if (parseCFIOffset(Offset))
+    return true;
+  // NB: MCCFIInstruction::createDefCfaOffset negates the offset.
+  Dest = MachineOperand::CreateCFIIndex(MF.getMMI().addFrameInst(
+      MCCFIInstruction::createDefCfaOffset(nullptr, -Offset)));
+  return false;
+}
+
 bool MIParser::parseMachineOperand(MachineOperand &Dest) {
   switch (Token.kind()) {
   case MIToken::kw_implicit:
@@ -602,6 +628,8 @@ bool MIParser::parseMachineOperand(MachineOperand &Dest) {
   case MIToken::ExternalSymbol:
   case MIToken::QuotedExternalSymbol:
     return parseExternalSymbolOperand(Dest);
+  case MIToken::kw_cfi_def_cfa_offset:
+    return parseCFIOperand(Dest);
   case MIToken::Error:
     return true;
   case MIToken::Identifier: