Distinguish `__block` variables that are captured by escaping blocks

from those that aren't.

This patch changes the way __block variables that aren't captured by
escaping blocks are handled:

- Since non-escaping blocks on the stack never get copied to the heap
  (see https://reviews.llvm.org/D49303), Sema shouldn't error out when
  the type of a non-escaping __block variable doesn't have an accessible
  copy constructor.

- IRGen doesn't have to use the specialized byref structure (see
  https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
  non-escaping __block variable anymore. Instead IRGen can emit the
  variable as a normal variable and copy the reference to the block
  literal. Byref copy/dispose helpers aren't needed either.

rdar://problem/39352313

Differential Revision: https://reviews.llvm.org/D51564

llvm-svn: 341754

4 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/CodeGen/block-byref-aggr.c b/clang/test/CodeGen/block-byref-aggr.c
index 962f100638f..db105768993 100644
--- a/clang/test/CodeGen/block-byref-aggr.c
+++ b/clang/test/CodeGen/block-byref-aggr.c
@@ -9,11 +9,13 @@ Agg makeAgg(void);
 // cause a block copy.  rdar://9309454
 void test0() {
   __block Agg a = {100};
+  ^{ (void)a; };
 
  a = makeAgg();
 }
 // CHECK-LABEL:    define void @test0()
 // CHECK:      [[A:%.*]] = alloca [[BYREF:%.*]], align 8
+// CHECK-NEXT: alloca <{ i8*, i32, i32, i8*, %{{.*}}*, i8* }>, align 8
 // CHECK-NEXT: [[TEMP:%.*]] = alloca [[AGG]], align 4
 // CHECK:      [[RESULT:%.*]] = call i32 @makeAgg()
 // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [[AGG]], [[AGG]]* [[TEMP]], i32 0, i32 0
@@ -35,11 +37,13 @@ void test0() {
 // rdar://11757470
 void test1() {
   __block Agg a, b;
+  ^{ (void)a; (void)b; };
   a = b = makeAgg();
 }
 // CHECK-LABEL:    define void @test1()
 // CHECK:      [[A:%.*]] = alloca [[A_BYREF:%.*]], align 8
 // CHECK-NEXT: [[B:%.*]] = alloca [[B_BYREF:%.*]], align 8
+// CHECK-NEXT: alloca <{ i8*, i32, i32, i8*, %{{.*}}*, i8*, i8* }>, align 8
 // CHECK-NEXT: [[TEMP:%.*]] = alloca [[AGG]], align 4
 // CHECK:      [[RESULT:%.*]] = call i32 @makeAgg()
 // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [[AGG]], [[AGG]]* [[TEMP]], i32 0, i32 0
diff --git a/clang/test/CodeGen/blocks-seq.c b/clang/test/CodeGen/blocks-seq.c
index b3e672976ca..9b47fbf783d 100644
--- a/clang/test/CodeGen/blocks-seq.c
+++ b/clang/test/CodeGen/blocks-seq.c
@@ -11,6 +11,7 @@ int rhs();
 
 void foo() {
   __block int i;
+  ^{ (void)i; };
   i = rhs();
   i += rhs();
 }
diff --git a/clang/test/CodeGen/exceptions.c b/clang/test/CodeGen/exceptions.c
index 039ec84d2e5..57b869196ba 100644
--- a/clang/test/CodeGen/exceptions.c
+++ b/clang/test/CodeGen/exceptions.c
@@ -23,6 +23,7 @@ void test1() {
 void test2_helper();
 void test2() {
   __block int x = 10;
+  ^{ (void)x; };
   test2_helper(5, 6, 7);
 }
 void test2_helper(int x, int y) {
diff --git a/clang/test/CodeGen/personality.c b/clang/test/CodeGen/personality.c
index 1c533ce786c..59a6a9ccd69 100644
--- a/clang/test/CodeGen/personality.c
+++ b/clang/test/CodeGen/personality.c
@@ -26,6 +26,7 @@ extern void i(void);
 
 void f(void) {
   __block int i;
+  ^{ (void)i; };
   g(^ { });
 }