llvm-mirror/test/Transforms/WholeProgramDevirt/constant-arg.ll
Peter Collingbourne 41f4d00801 IR: Introduce llvm.type.checked.load intrinsic.
This intrinsic safely loads a function pointer from a virtual table pointer
using type metadata. This intrinsic is used to implement control flow integrity
in conjunction with virtual call optimization. The virtual call optimization
pass will optimize away llvm.type.checked.load intrinsics associated with
devirtualized calls, thereby removing the type check in cases where it is
not needed to enforce the control flow integrity constraint.

This patch also introduces the capability to copy type metadata between
global variables, and teaches the virtual call optimization pass to do so.

Differential Revision: http://reviews.llvm.org/D21121

llvm-svn: 273756
2016-06-25 00:23:04 +00:00

78 lines
3.0 KiB
LLVM

; RUN: opt -S -wholeprogramdevirt %s | FileCheck %s
; RUN: opt -S -passes=wholeprogramdevirt %s | FileCheck %s
target datalayout = "e-p:64:64"
target triple = "x86_64-unknown-linux-gnu"
; CHECK: private constant { [8 x i8], [1 x i8*], [0 x i8] } { [8 x i8] c"\00\00\00\00\00\00\00\01", [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf1 to i8*)], [0 x i8] zeroinitializer }, !type [[T8:![0-9]+]]
; CHECK: private constant { [8 x i8], [1 x i8*], [0 x i8] } { [8 x i8] c"\00\00\00\00\00\00\00\02", [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf2 to i8*)], [0 x i8] zeroinitializer }, !type [[T8]]
; CHECK: private constant { [8 x i8], [1 x i8*], [0 x i8] } { [8 x i8] c"\00\00\00\00\00\00\00\01", [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf4 to i8*)], [0 x i8] zeroinitializer }, !type [[T8]]
; CHECK: private constant { [8 x i8], [1 x i8*], [0 x i8] } { [8 x i8] c"\00\00\00\00\00\00\00\02", [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf8 to i8*)], [0 x i8] zeroinitializer }, !type [[T8]]
@vt1 = constant [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf1 to i8*)], !type !0
@vt2 = constant [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf2 to i8*)], !type !0
@vt4 = constant [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf4 to i8*)], !type !0
@vt8 = constant [1 x i8*] [i8* bitcast (i1 (i8*, i32)* @vf8 to i8*)], !type !0
define i1 @vf1(i8* %this, i32 %arg) readnone {
%and = and i32 %arg, 1
%cmp = icmp ne i32 %and, 0
ret i1 %cmp
}
define i1 @vf2(i8* %this, i32 %arg) readnone {
%and = and i32 %arg, 2
%cmp = icmp ne i32 %and, 0
ret i1 %cmp
}
define i1 @vf4(i8* %this, i32 %arg) readnone {
%and = and i32 %arg, 4
%cmp = icmp ne i32 %and, 0
ret i1 %cmp
}
define i1 @vf8(i8* %this, i32 %arg) readnone {
%and = and i32 %arg, 8
%cmp = icmp ne i32 %and, 0
ret i1 %cmp
}
; CHECK: define i1 @call1
define i1 @call1(i8* %obj) {
%vtableptr = bitcast i8* %obj to [1 x i8*]**
%vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
%vtablei8 = bitcast [1 x i8*]* %vtable to i8*
%p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid")
call void @llvm.assume(i1 %p)
%fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
%fptr = load i8*, i8** %fptrptr
%fptr_casted = bitcast i8* %fptr to i1 (i8*, i32)*
; CHECK: getelementptr {{.*}} -1
; CHECK: and {{.*}}, 1
%result = call i1 %fptr_casted(i8* %obj, i32 5)
ret i1 %result
}
; CHECK: define i1 @call2
define i1 @call2(i8* %obj) {
%vtableptr = bitcast i8* %obj to [1 x i8*]**
%vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
%vtablei8 = bitcast [1 x i8*]* %vtable to i8*
%p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid")
call void @llvm.assume(i1 %p)
%fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
%fptr = load i8*, i8** %fptrptr
%fptr_casted = bitcast i8* %fptr to i1 (i8*, i32)*
; CHECK: getelementptr {{.*}} -1
; CHECK: and {{.*}}, 2
%result = call i1 %fptr_casted(i8* %obj, i32 10)
ret i1 %result
}
declare i1 @llvm.type.test(i8*, metadata)
declare void @llvm.assume(i1)
; CHECK: [[T8]] = !{i32 8, !"typeid"}
!0 = !{i32 0, !"typeid"}