[IR][Object][NFC] Move ARM64EC name mangling helpers to Mangler.h. (llvm#87191)

Move the implementation to llvm:Core to avoids including `COFF.h` in `Mangler.cpp`.

Author: cjacek

llvm/include/llvm/IR/Mangler.h

@@ -14,6 +14,7 @@
 #define LLVM_IR_MANGLER_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace llvm {
 
@@ -52,6 +53,9 @@ void emitLinkerFlagsForGlobalCOFF(raw_ostream &OS, const GlobalValue *GV,
 void emitLinkerFlagsForUsedCOFF(raw_ostream &OS, const GlobalValue *GV,
                                 const Triple &T, Mangler &M);
 
+std::optional<std::string> getArm64ECMangledFunctionName(StringRef Name);
+std::optional<std::string> getArm64ECDemangledFunctionName(StringRef Name);
+
 } // End llvm namespace
 
 #endif

llvm/include/llvm/Object/COFF.h

@@ -1362,47 +1362,6 @@ class SectionStrippedError
   SectionStrippedError() { setErrorCode(object_error::section_stripped); }
 };
 
-inline std::optional<std::string>
-getArm64ECMangledFunctionName(StringRef Name) {
-  bool IsCppFn = Name[0] == '?';
-  if (IsCppFn && Name.find("$$h") != std::string::npos)
-    return std::nullopt;
-  if (!IsCppFn && Name[0] == '#')
-    return std::nullopt;
-
-  StringRef Prefix = "$$h";
-  size_t InsertIdx = 0;
-  if (IsCppFn) {
-    InsertIdx = Name.find("@@");
-    size_t ThreeAtSignsIdx = Name.find("@@@");
-    if (InsertIdx != std::string::npos && InsertIdx != ThreeAtSignsIdx) {
-      InsertIdx += 2;
-    } else {
-      InsertIdx = Name.find("@");
-      if (InsertIdx != std::string::npos)
-        InsertIdx++;
-    }
-  } else {
-    Prefix = "#";
-  }
-
-  return std::optional<std::string>(
-      (Name.substr(0, InsertIdx) + Prefix + Name.substr(InsertIdx)).str());
-}
-
-inline std::optional<std::string>
-getArm64ECDemangledFunctionName(StringRef Name) {
-  if (Name[0] == '#')
-    return std::string(Name.substr(1));
-  if (Name[0] != '?')
-    return std::nullopt;
-
-  std::pair<StringRef, StringRef> Pair = Name.split("$$h");
-  if (Pair.second.empty())
-    return std::nullopt;
-  return (Pair.first + Pair.second).str();
-}
-
 } // end namespace object
 
 } // end namespace llvm

llvm/include/llvm/Object/COFFImportFile.h

@@ -17,6 +17,7 @@
 #define LLVM_OBJECT_COFFIMPORTFILE_H
 
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/IR/Mangler.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Object/SymbolicFile.h"

llvm/lib/IR/Mangler.cpp

@@ -18,7 +18,6 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Module.h"
-#include "llvm/Object/COFF.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TargetParser/Triple.h"
 
@@ -242,7 +241,7 @@ void llvm::emitLinkerFlagsForGlobalCOFF(raw_ostream &OS, const GlobalValue *GV,
       // typically functions correctly; the linker can resolve the export
       // with the demangled alias.
       if (std::optional<std::string> demangledName =
-              object::getArm64ECDemangledFunctionName(GV->getName()))
+              getArm64ECDemangledFunctionName(GV->getName()))
         OS << ",EXPORTAS," << *demangledName;
     }
     if (NeedQuotes)
@@ -291,3 +290,42 @@ void llvm::emitLinkerFlagsForUsedCOFF(raw_ostream &OS, const GlobalValue *GV,
     OS << "\"";
 }
 
+std::optional<std::string> llvm::getArm64ECMangledFunctionName(StringRef Name) {
+  bool IsCppFn = Name[0] == '?';
+  if (IsCppFn && Name.find("$$h") != std::string::npos)
+    return std::nullopt;
+  if (!IsCppFn && Name[0] == '#')
+    return std::nullopt;
+
+  StringRef Prefix = "$$h";
+  size_t InsertIdx = 0;
+  if (IsCppFn) {
+    InsertIdx = Name.find("@@");
+    size_t ThreeAtSignsIdx = Name.find("@@@");
+    if (InsertIdx != std::string::npos && InsertIdx != ThreeAtSignsIdx) {
+      InsertIdx += 2;
+    } else {
+      InsertIdx = Name.find("@");
+      if (InsertIdx != std::string::npos)
+        InsertIdx++;
+    }
+  } else {
+    Prefix = "#";
+  }
+
+  return std::optional<std::string>(
+      (Name.substr(0, InsertIdx) + Prefix + Name.substr(InsertIdx)).str());
+}
+
+std::optional<std::string>
+llvm::getArm64ECDemangledFunctionName(StringRef Name) {
+  if (Name[0] == '#')
+    return std::optional<std::string>(Name.substr(1));
+  if (Name[0] != '?')
+    return std::nullopt;
+
+  std::pair<StringRef, StringRef> Pair = Name.split("$$h");
+  if (Pair.second.empty())
+    return std::nullopt;
+  return std::optional<std::string>((Pair.first + Pair.second).str());
+}

llvm/lib/Target/AArch64/AArch64Arm64ECCallLowering.cpp

@@ -23,6 +23,7 @@
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Instruction.h"
+#include "llvm/IR/Mangler.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Pass.h"
@@ -31,7 +32,6 @@
 
 using namespace llvm;
 using namespace llvm::COFF;
-using namespace llvm::object;
 
 using OperandBundleDef = OperandBundleDefT<Value *>;