Revert "[Attr] Add support for the `ms_hook_prologue` attribute."

This reverts commit r278050. It depends on r278048, which will be
reverted.

llvm-svn: 278052

clang/include/clang/Basic/Attr.td

@@ -257,7 +257,6 @@ def TargetMips : TargetArch<["mips", "mipsel"]>;
 def TargetMSP430 : TargetArch<["msp430"]>;
 def TargetX86 : TargetArch<["x86"]>;
 def TargetAnyX86 : TargetArch<["x86", "x86_64"]>;
-def TargetWindowsArches : TargetArch<["x86", "x86_64", "arm", "thumb"]>;
 def TargetWindows : TargetArch<["x86", "x86_64", "arm", "thumb"]> {
   let OSes = ["Win32"];
 }
@@ -2070,12 +2069,6 @@ def TypeTagForDatatype : InheritableAttr {
 
 // Microsoft-related attributes
 
-def MSHookPrologue : InheritableAttr, TargetSpecificAttr<TargetWindowsArches> {
-  let Spellings = [GCC<"ms_hook_prologue">];
-  let Subjects = SubjectList<[Function]>;
-  let Documentation = [MSHookPrologueDocs];
-}
-
 def MSNoVTable : InheritableAttr, TargetSpecificAttr<TargetMicrosoftCXXABI> {
   let Spellings = [Declspec<"novtable">];
   let Subjects = SubjectList<[CXXRecord]>;

clang/include/clang/Basic/AttrDocs.td

@@ -548,22 +548,6 @@ Query for this feature with ``__has_attribute(objc_method_family)``.
   }];
 }
 
-def MSHookPrologueDocs : Documentation {
-  let Category = DocCatFunction;
-  let Content = [{
-The ``ms_hook_prologue`` attribute marks a function as "hotpatchable" according
-to conventions used on Windows. Specifically, enough space will be ensured
-in the prologue for a short jump, and an architecturally dependently sized
-patch space will be reserved prior to the entry point. See the documentation
-for the `/HOTPATCH`_ switch on MSDN.
-
-This attribute cannot be used in conjunction with the ``naked``,
-``always_inline``, or ``__forceinline`` attributes.
-
-.. _`/HOTPATCH`: https://msdn.microsoft.com/en-us/library/ms173507.aspx
-  }];
-}
-
 def NoDebugDocs : Documentation {
   let Category = DocCatVariable;
   let Content = [{

clang/lib/CodeGen/TargetInfo.cpp

@@ -1779,10 +1779,6 @@ void X86_32TargetCodeGenInfo::setTargetAttributes(const Decl *D,
       llvm::Function *Fn = cast<llvm::Function>(GV);
       Fn->setCallingConv(llvm::CallingConv::X86_INTR);
     }
-    if (FD->hasAttr<MSHookPrologueAttr>()) {
-      llvm::Function *Fn = cast<llvm::Function>(GV);
-      Fn->addFnAttr("patchable-function", "ms-hotpatch");
-    }
   }
 }
 
@@ -2113,10 +2109,6 @@ public:
         llvm::Function *Fn = cast<llvm::Function>(GV);
         Fn->setCallingConv(llvm::CallingConv::X86_INTR);
       }
-      if (FD->hasAttr<MSHookPrologueAttr>()) {
-        llvm::Function *Fn = cast<llvm::Function>(GV);
-        Fn->addFnAttr("patchable-function", "ms-hotpatch");
-      }
     }
   }
 };

clang/lib/Sema/SemaDeclAttr.cpp

@@ -1664,6 +1664,15 @@ static void handleCommonAttr(Sema &S, Decl *D, const AttributeList &Attr) {
     D->addAttr(CA);
 }
 
+static void handleNakedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
+  if (checkAttrMutualExclusion<DisableTailCallsAttr>(S, D, Attr.getRange(),
+                                                     Attr.getName()))
+    return;
+
+  D->addAttr(::new (S.Context) NakedAttr(Attr.getRange(), S.Context,
+                                         Attr.getAttributeSpellingListIndex()));
+}
+
 static void handleNoReturnAttr(Sema &S, Decl *D, const AttributeList &attr) {
   if (hasDeclarator(D)) return;
 
@@ -3664,9 +3673,7 @@ OptimizeNoneAttr *Sema::mergeOptimizeNoneAttr(Decl *D, SourceRange Range,
 static void handleAlwaysInlineAttr(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
   if (checkAttrMutualExclusion<NotTailCalledAttr>(S, D, Attr.getRange(),
-                                                  Attr.getName()) ||
-      checkAttrMutualExclusion<MSHookPrologueAttr>(S, D, Attr.getRange(),
-                                                   Attr.getName()))
+                                                  Attr.getName()))
     return;
 
   if (AlwaysInlineAttr *Inline = S.mergeAlwaysInlineAttr(
@@ -5545,8 +5552,7 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
     handleHotAttr(S, D, Attr);
     break;
   case AttributeList::AT_Naked:
-    handleSimpleAttributeWithExclusions<NakedAttr, DisableTailCallsAttr,
-                                        MSHookPrologueAttr>(S, D, Attr);
+    handleNakedAttr(S, D, Attr);
     break;
   case AttributeList::AT_NoReturn:
     handleNoReturnAttr(S, D, Attr);
@@ -5774,9 +5780,6 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
     break;
   case AttributeList::AT_LayoutVersion:
     handleLayoutVersion(S, D, Attr);
-  case AttributeList::AT_MSHookPrologue:
-    handleSimpleAttributeWithExclusions<MSHookPrologueAttr, NakedAttr,
-      AlwaysInlineAttr>(S, D, Attr);
     break;
   case AttributeList::AT_MSNoVTable:
     handleSimpleAttribute<MSNoVTableAttr>(S, D, Attr);

clang/test/CodeGen/function-attributes.c

@@ -108,18 +108,11 @@ void f20(void) {
   _setjmp(0);
 }
 
-// CHECK-LABEL: define void @f21
-// CHECK: [[HOTPATCH:#[0-9]+]]
-// CHECK: {
-void __attribute__((ms_hook_prologue)) f21(void) {
-}
-
 // CHECK: attributes [[NUW]] = { nounwind optsize{{.*}} }
 // CHECK: attributes [[AI]] = { alwaysinline nounwind optsize{{.*}} }
 // CHECK: attributes [[NUW_OS_RN]] = { nounwind optsize readnone{{.*}} }
 // CHECK: attributes [[ALIGN]] = { nounwind optsize alignstack=16{{.*}} }
 // CHECK: attributes [[RT]] = { nounwind optsize returns_twice{{.*}} }
-// CHECK: attributes [[HOTPATCH]] = { nounwind optsize{{.*}}"patchable-function"="ms-hotpatch"{{.*}} }
 // CHECK: attributes [[NR]] = { noreturn optsize }
 // CHECK: attributes [[NUW_RN]] = { nounwind optsize readnone }
 // CHECK: attributes [[RT_CALL]] = { optsize returns_twice }

clang/test/Sema/attr-ms-hook-prologue-wrong-arch.c

@@ -1,6 +0,0 @@
-// RUN: %clang_cc1 -triple s390x-unknown-linux -fms-extensions -fsyntax-only -verify %s
-
-// expected-warning@+1{{unknown attribute 'ms_hook_prologue' ignored}}
-int __attribute__((ms_hook_prologue)) foo(int a, int b) {
-  return a+b;
-}

clang/test/Sema/attr-ms-hook-prologue.c

@@ -1,22 +0,0 @@
-// RUN: %clang_cc1 -triple i386-pc-linux -fms-extensions -fsyntax-only -verify %s
-
-int __attribute__((ms_hook_prologue)) foo(int a, int b) {
-  return a+b;
-}
-
-// expected-note@+2{{conflicting attribute is here}}
-// expected-error@+1{{'naked' and 'ms_hook_prologue' attributes are not compatible}}
-__declspec(naked) int __attribute__((ms_hook_prologue)) bar(int a, int b) {
-}
-
-// expected-note@+2{{conflicting attribute is here}}
-// expected-error@+1{{'__forceinline' and 'ms_hook_prologue' attributes are not compatible}}
-__forceinline int __attribute__((ms_hook_prologue)) baz(int a, int b) {
-  return a-b;
-}
-
-// expected-warning@+1{{'ms_hook_prologue' attribute only applies to functions}}
-int x __attribute__((ms_hook_prologue));
-
-// expected-error@+1{{'ms_hook_prologue' attribute takes no arguments}}
-int f(int a, int b) __attribute__((ms_hook_prologue(2)));