Add support for attribute 'noescape'.

The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32520

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@313720 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 71 insertions, 0 deletions

diff --git a/test/CodeGenObjC/noescape.m b/test/CodeGenObjC/noescape.m
new file mode 100644
index 0000000000..8ea2aa94e0
--- /dev/null
+++ b/test/CodeGenObjC/noescape.m
@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 -fblocks -emit-llvm -o - %s | FileCheck %s
+
+typedef void (^BlockTy)(void);
+
+union U {
+  int *i;
+  long long *ll;
+} __attribute__((transparent_union));
+
+void noescapeFunc0(id, __attribute__((noescape)) BlockTy);
+void noescapeFunc1(__attribute__((noescape)) int *);
+void noescapeFunc2(__attribute__((noescape)) id);
+void noescapeFunc3(__attribute__((noescape)) union U);
+
+// CHECK-LABEL: define void @test0(
+// CHECK: call void @noescapeFunc0({{.*}}, {{.*}} nocapture {{.*}})
+// CHECK: declare void @noescapeFunc0(i8*, {{.*}} nocapture)
+void test0(BlockTy b) {
+  noescapeFunc0(0, b);
+}
+
+// CHECK-LABEL: define void @test1(
+// CHECK: call void @noescapeFunc1({{.*}} nocapture {{.*}})
+// CHECK: declare void @noescapeFunc1({{.*}} nocapture)
+void test1(int *i) {
+  noescapeFunc1(i);
+}
+
+// CHECK-LABEL: define void @test2(
+// CHECK: call void @noescapeFunc2({{.*}} nocapture {{.*}})
+// CHECK: declare void @noescapeFunc2({{.*}} nocapture)
+void test2(id i) {
+  noescapeFunc2(i);
+}
+
+// CHECK-LABEL: define void @test3(
+// CHECK: call void @noescapeFunc3({{.*}} nocapture {{.*}})
+// CHECK: declare void @noescapeFunc3({{.*}} nocapture)
+void test3(union U u) {
+  noescapeFunc3(u);
+}
+
+// CHECK: define internal void @"\01-[C0 m0:]"({{.*}}, {{.*}}, {{.*}} nocapture {{.*}})
+
+// CHECK-LABEL: define void @test4(
+// CHECK: call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, i32*)*)(i8* {{.*}}, i8* {{.*}}, i32* nocapture {{.*}})
+
+@interface C0
+-(void) m0:(int*)__attribute__((noescape)) p0;
+@end
+
+@implementation C0
+-(void) m0:(int*)__attribute__((noescape)) p0 {
+}
+@end
+
+void test4(C0 *c0, int *p) {
+  [c0 m0:p];
+}
+
+// CHECK-LABEL: define void @test5(
+// CHECK: call void {{.*}}(i8* bitcast ({ i8**, i32, i32, i8*, {{.*}} }* @{{.*}} to i8*), i32* nocapture {{.*}})
+// CHECK: call void {{.*}}(i8* {{.*}}, i32* nocapture {{.*}})
+// CHECK: define internal void @{{.*}}(i8* {{.*}}, i32* nocapture {{.*}})
+
+typedef void (^BlockTy2)(__attribute__((noescape)) int *);
+
+void test5(BlockTy2 b, int *p) {
+  ^(int *__attribute__((noescape)) p0){}(p);
+  b(p);
+}