[MIRParser][nfc] Factor out code parsing debug MD nodes

This commit splits a function that both parses MD nodes from YAML into
DI{Expr,Loc,Variable} objects AND adds an entry to the MF variable table, so
that each of those jobs is done separately.

It will enable subsequent patches to reuse the MD node parsing code.

Differential Revision: https://reviews.llvm.org/D149870

diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 4fffd62..5488824 100644 (file)
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -130,6 +130,16 @@ public:
                                 const yaml::StringValue &RegisterSource,
                                 bool IsRestored, int FrameIdx);
 
+  struct VarExprLoc {
+    DILocalVariable *DIVar = nullptr;
+    DIExpression *DIExpr = nullptr;
+    DILocation *DILoc = nullptr;
+  };
+
+  std::optional<VarExprLoc> parseVarExprLoc(PerFunctionMIParsingState &PFS,
+                                            const yaml::StringValue &VarStr,
+                                            const yaml::StringValue &ExprStr,
+                                            const yaml::StringValue &LocStr);
   template <typename T>
   bool parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
                                   const T &Object,
@@ -888,26 +898,37 @@ static bool typecheckMDNode(T *&Result, MDNode *Node,
   return false;
 }
 
-template <typename T>
-bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
-    const T &Object, int FrameIdx) {
-  // Debug information can only be attached to stack objects; Fixed stack
-  // objects aren't supported.
-  MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
-  if (parseMDNode(PFS, Var, Object.DebugVar) ||
-      parseMDNode(PFS, Expr, Object.DebugExpr) ||
-      parseMDNode(PFS, Loc, Object.DebugLoc))
-    return true;
-  if (!Var && !Expr && !Loc)
-    return false;
+std::optional<MIRParserImpl::VarExprLoc> MIRParserImpl::parseVarExprLoc(
+    PerFunctionMIParsingState &PFS, const yaml::StringValue &VarStr,
+    const yaml::StringValue &ExprStr, const yaml::StringValue &LocStr) {
+  MDNode *Var = nullptr;
+  MDNode *Expr = nullptr;
+  MDNode *Loc = nullptr;
+  if (parseMDNode(PFS, Var, VarStr) || parseMDNode(PFS, Expr, ExprStr) ||
+      parseMDNode(PFS, Loc, LocStr))
+    return std::nullopt;
   DILocalVariable *DIVar = nullptr;
   DIExpression *DIExpr = nullptr;
   DILocation *DILoc = nullptr;
-  if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
-      typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
-      typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
+  if (typecheckMDNode(DIVar, Var, VarStr, "DILocalVariable", *this) ||
+      typecheckMDNode(DIExpr, Expr, ExprStr, "DIExpression", *this) ||
+      typecheckMDNode(DILoc, Loc, LocStr, "DILocation", *this))
+    return std::nullopt;
+  return VarExprLoc{DIVar, DIExpr, DILoc};
+}
+
+template <typename T>
+bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
+                                               const T &Object, int FrameIdx) {
+  std::optional<VarExprLoc> MaybeInfo =
+      parseVarExprLoc(PFS, Object.DebugVar, Object.DebugExpr, Object.DebugLoc);
+  if (!MaybeInfo)
     return true;
-  PFS.MF.setVariableDbgInfo(DIVar, DIExpr, FrameIdx, DILoc);
+  // Debug information can only be attached to stack objects; Fixed stack
+  // objects aren't supported.
+  if (MaybeInfo->DIVar || MaybeInfo->DIExpr || MaybeInfo->DILoc)
+    PFS.MF.setVariableDbgInfo(MaybeInfo->DIVar, MaybeInfo->DIExpr, FrameIdx,
+                              MaybeInfo->DILoc);
   return false;
 }