c548c47476
This corrects the codegen for the final class optimization to correct handle the case where there is no path to perform the cast, and also corrects the codegen to handle ptrauth protected vtable pointers. As part of this fix we separate out the path computation as that makes it easier to reason about the failure code paths and more importantly means we can know what the type of the this object is during the cast. The allows us to use the GetVTablePointer interface which correctly performs the authentication operations required when pointer authentication is enabled. This still leaves incorrect authentication behavior in the multiple inheritance case but currently the optimization is disabled entirely if pointer authentication is enabled. Fixes #137518
128 lines
4.7 KiB
C++
128 lines
4.7 KiB
C++
// RUN: %clang_cc1 -I%S %s -triple x86_64-apple-darwin10 -emit-llvm -fcxx-exceptions -fexceptions -std=c++11 -o - -O1 -disable-llvm-passes | FileCheck %s --implicit-check-not='call {{.*}} @__dynamic_cast'
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struct Offset { virtual ~Offset(); };
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struct A { virtual ~A(); };
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struct B final : Offset, A { };
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struct C { virtual ~C(); int c; };
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struct D : A { int d; };
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struct E : A { int e; };
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struct F : virtual A { int f; };
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struct G : virtual A { int g; };
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struct H final : C, D, E, F, G { int h; };
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struct H1 final: C, private D { int h1; };
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// CHECK-LABEL: @_Z7inexactP1A
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C *inexact(A *a) {
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// CHECK: call {{.*}} @__dynamic_cast
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return dynamic_cast<C*>(a);
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}
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// CHECK-LABEL: @_Z12exact_singleP1A
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B *exact_single(A *a) {
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// CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
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// CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
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// CHECK: [[LABEL_NOTNULL]]:
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// CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
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// CHECK: %[[MATCH:.*]] = icmp eq ptr %[[VPTR]], getelementptr inbounds inrange(-16, 16) ({ [4 x ptr], [4 x ptr] }, ptr @_ZTV1B, i32 0, i32 1, i32 2)
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// CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 -8
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// CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
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// CHECK: [[LABEL_FAILED]]:
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// CHECK: br label %[[LABEL_END]]
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// CHECK: [[LABEL_END]]:
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// CHECK: phi ptr [ %[[RESULT]], %[[LABEL_NOTNULL]] ], [ null, %[[LABEL_FAILED]] ]
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return dynamic_cast<B*>(a);
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}
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// CHECK-LABEL: @_Z9exact_refR1A
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B &exact_ref(A &a) {
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// CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
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// CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
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// CHECK: [[LABEL_NOTNULL]]:
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// CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
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// CHECK: %[[MATCH:.*]] = icmp eq ptr %[[VPTR]], getelementptr inbounds inrange(-16, 16) ({ [4 x ptr], [4 x ptr] }, ptr @_ZTV1B, i32 0, i32 1, i32 2)
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// CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 -8
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// CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
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// CHECK: [[LABEL_FAILED]]:
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// CHECK: call {{.*}} @__cxa_bad_cast
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// CHECK: unreachable
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// CHECK: [[LABEL_END]]:
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// CHECK: ret ptr %[[RESULT]]
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return dynamic_cast<B&>(a);
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}
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// CHECK-LABEL: @_Z11exact_multiP1A
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H *exact_multi(A *a) {
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// CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
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// CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
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// CHECK: [[LABEL_NOTNULL]]:
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// CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
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// CHECK: %[[OFFSET_TO_TOP_SLOT:.*]] = getelementptr inbounds i64, ptr %[[VPTR]], i64 -2
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// CHECK: %[[OFFSET_TO_TOP:.*]] = load i64, ptr %[[OFFSET_TO_TOP_SLOT]]
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// CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 %[[OFFSET_TO_TOP]]
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// CHECK: %[[DERIVED_VPTR:.*]] = load ptr, ptr %[[RESULT]]
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// CHECK: %[[MATCH:.*]] = icmp eq ptr %[[DERIVED_VPTR]], getelementptr inbounds inrange(-24, 16) ({ [5 x ptr], [4 x ptr], [4 x ptr], [6 x ptr], [6 x ptr] }, ptr @_ZTV1H, i32 0, i32 0, i32 3)
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// CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
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// CHECK: [[LABEL_FAILED]]:
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// CHECK: br label %[[LABEL_END]]
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// CHECK: [[LABEL_END]]:
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// CHECK: phi ptr [ %[[RESULT]], %[[LABEL_NOTNULL]] ], [ null, %[[LABEL_FAILED]] ]
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return dynamic_cast<H*>(a);
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}
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// CHECK-LABEL: @_Z19exact_invalid_multiP1D
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H1 *exact_invalid_multi(D* d) {
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// CHECK: entry:
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// CHECK-NEXT: %d.addr = alloca ptr
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// CHECK-NEXT: store ptr %d, ptr %d.addr
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// CHECK-NEXT: load ptr, ptr %d.addr
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// CHECK-NEXT: ret ptr null
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return dynamic_cast<H1*>(d);
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}
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// CHECK-LABEL: @_Z19exact_invalid_multiR1D
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H1 &exact_invalid_multi(D& d) {
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// CHECK: entry:
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// CHECK-NEXT: %d.addr = alloca ptr
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// CHECK-NEXT: store ptr %d, ptr %d.addr
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// CHECK-NEXT: load ptr, ptr %d.addr
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// CHECK-NEXT: call void @__cxa_bad_cast()
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// CHECK-NEXT: unreachable
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// CHECK: dynamic_cast.unreachable:
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// CHECK-NEXT: ret ptr poison
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return dynamic_cast<H1&>(d);
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}
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namespace GH137518 {
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class base { virtual void fn() = 0; };
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class test final : base { virtual void fn() { } };
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test* new_test() { return new test(); }
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// CHECK-LABEL: @_ZN8GH1375184castEPNS_4baseE(
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test* cast(base* b) {
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// CHECK: entry:
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// CHECK-NEXT: %b.addr = alloca ptr
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// CHECK-NEXT: store ptr %b, ptr %b.addr
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// CHECK-NEXT: load ptr, ptr %b.addr
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// CHECK-NEXT: ret ptr null
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return dynamic_cast<test*>(b);
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}
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}
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namespace GH64088 {
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// Ensure we mark the B vtable as used here, because we're going to emit a
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// reference to it.
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// CHECK: define {{.*}} void @_ZN7GH640881BD0Ev(
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struct A { virtual ~A(); };
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struct B final : A { virtual ~B() = default; };
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B *cast(A *p) { return dynamic_cast<B*>(p); }
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}
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