From 2af3e8f7984572c1ae586c15e2160ebf14f74de7 Mon Sep 17 00:00:00 2001
From: Amaury Sechet <deadalnix@gmail.com>
Date: Wed, 13 Apr 2016 22:51:40 +0000
Subject: [PATCH] Add LLVMGetAttrKindIDInContext in the C API in order to
 facilitate migration away from LLVMAttribute

Summary: LLVMAttribute has outlived its utility and is becoming a problem for C API users that what to use all the LLVM attributes. In order to help moving away from LLVMAttribute in a smooth manner, this diff introduce LLVMGetAttrKindIDInContext, which can be used instead of the enum values.

Reviewers: Wallbraker, whitequark, joker.eph, echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18749

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266257 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm-c/Core.h         |  3 +++
 lib/IR/Core.cpp               | 12 ++++++++++++
 utils/TableGen/Attributes.cpp | 23 +++++++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index d9b6712ac27..114b8788b1b 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -476,6 +476,9 @@ unsigned LLVMGetMDKindIDInContext(LLVMContextRef C, const char *Name,
                                   unsigned SLen);
 unsigned LLVMGetMDKindID(const char *Name, unsigned SLen);
 
+unsigned LLVMGetAttrKindIDInContext(LLVMContextRef C, const char *Name,
+                                    size_t SLen);
+
 /**
  * @}
  */
diff --git a/lib/IR/Core.cpp b/lib/IR/Core.cpp
index 1b4ad203969..147700dea0a 100644
--- a/lib/IR/Core.cpp
+++ b/lib/IR/Core.cpp
@@ -13,6 +13,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm-c/Core.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "AttributeImpl.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/CallSite.h"
@@ -119,6 +121,16 @@ unsigned LLVMGetMDKindID(const char *Name, unsigned SLen) {
   return LLVMGetMDKindIDInContext(LLVMGetGlobalContext(), Name, SLen);
 }
 
+#define GET_ATTR_KIND_FROM_NAME
+#include "AttributesCompatFunc.inc"
+
+unsigned LLVMGetAttrKindIDInContext(LLVMContextRef C, const char *Name,
+                                    size_t SLen) {
+  auto K = getAttrKindFromName(StringRef(Name, SLen));
+  assert(K != Attribute::None && "Invalid attribute");
+  return AttributeImpl::getAttrMask(K);
+}
+
 char *LLVMGetDiagInfoDescription(LLVMDiagnosticInfoRef DI) {
   std::string MsgStorage;
   raw_string_ostream Stream(MsgStorage);
diff --git a/utils/TableGen/Attributes.cpp b/utils/TableGen/Attributes.cpp
index 7b001bf14de..58dbe5767ad 100644
--- a/utils/TableGen/Attributes.cpp
+++ b/utils/TableGen/Attributes.cpp
@@ -27,6 +27,7 @@ public:
 
 private:
   void emitTargetIndependentEnums(raw_ostream &OS);
+  void emitConversionFn(raw_ostream &OS);
   void emitFnAttrCompatCheck(raw_ostream &OS, bool IsStringAttr);
 
   void printEnumAttrClasses(raw_ostream &OS,
@@ -52,6 +53,27 @@ void Attributes::emitTargetIndependentEnums(raw_ostream &OS) {
   OS << "#endif\n";
 }
 
+void Attributes::emitConversionFn(raw_ostream &OS) {
+  OS << "#ifdef GET_ATTR_KIND_FROM_NAME\n";
+  OS << "#undef GET_ATTR_KIND_FROM_NAME\n";
+
+  std::vector<Record*> Attrs =
+      Records.getAllDerivedDefinitions("EnumAttr");
+
+  OS << "static Attribute::AttrKind getAttrKindFromName(StringRef AttrName) {\n";
+  OS << "  return StringSwitch<Attribute::AttrKind>(AttrName)\n";
+
+  for (auto A : Attrs) {
+    OS << "    .Case(\"" << A->getValueAsString("AttrString");
+    OS << "\", Attribute::" << A->getName() << ")\n";
+  }
+
+  OS << "    .Default(Attribute::None);\n";
+  OS << "}\n\n";
+
+  OS << "#endif\n";
+}
+
 void Attributes::emitFnAttrCompatCheck(raw_ostream &OS, bool IsStringAttr) {
   OS << "#ifdef GET_ATTR_COMPAT_FUNC\n";
   OS << "#undef GET_ATTR_COMPAT_FUNC\n";
@@ -144,6 +166,7 @@ void Attributes::printStrBoolAttrClasses(raw_ostream &OS,
 
 void Attributes::emit(raw_ostream &OS) {
   emitTargetIndependentEnums(OS);
+  emitConversionFn(OS);
   emitFnAttrCompatCheck(OS, false);
 }
 
-- 
2.11.0