Only allow captures attribute on pointer types

Author: nikic

llvm/lib/IR/Attributes.cpp

@@ -2381,7 +2381,8 @@ AttributeMask AttributeFuncs::typeIncompatible(Type *Ty, AttributeSet AS,
           .addAttribute(Attribute::DereferenceableOrNull)
           .addAttribute(Attribute::Writable)
           .addAttribute(Attribute::DeadOnUnwind)
-          .addAttribute(Attribute::Initializes);
+          .addAttribute(Attribute::Initializes)
+          .addAttribute(Attribute::Captures);
     if (ASK & ASK_UNSAFE_TO_DROP)
       Incompatible.addAttribute(Attribute::Nest)
           .addAttribute(Attribute::SwiftError)

llvm/test/Assembler/captures-errors.ll

@@ -7,6 +7,7 @@
 ; RUN: not llvm-as < %t/duplicate-ret.ll 2>&1 | FileCheck %s --check-prefix=CHECK-DUPLICATE-RET
 ; RUN: not llvm-as < %t/none-after.ll 2>&1 | FileCheck %s --check-prefix=CHECK-NONE-AFTER
 ; RUN: not llvm-as < %t/none-before.ll 2>&1 | FileCheck %s --check-prefix=CHECK-NONE-BEFORE
+; RUN: not opt -disable-output < %t/non-pointer-type.ll 2>&1 | FileCheck %s --check-prefix=CHECK-NON-POINTER-TYPE
 
 ;--- missing-lparen.ll
 
@@ -63,3 +64,10 @@ define void @test(ptr captures(address, none) %p) {
 define void @test(ptr captures(none, address) %p) {
   ret void
 }
+
+;--- non-pointer-type.ll
+
+; CHECK-NON-POINTER-TYPE: Attribute 'captures(none)' applied to incompatible type!
+define void @test(i32 captures(none) %p) {
+  ret void
+}