Implement the lvalue-to-rvalue conversion where needed. The

lvalue-to-rvalue conversion adjusts lvalues of qualified, non-class
type to rvalue expressions of the unqualified variant of that
type. For example, given:

  const int i;
  (void)(i + 17);

the lvalue-to-rvalue conversion for the subexpression "i" will turn it
from an lvalue expression (a DeclRefExpr) with type 'const int' into
an rvalue expression with type 'int'. Both C and C++ mandate this
conversion, and somehow we've slid through without implementing it. 

We now have both DefaultFunctionArrayConversion and
DefaultFunctionArrayLvalueConversion, and which gets used depends on
whether we do the lvalue-to-rvalue conversion or not. Generally, we do
the lvalue-to-rvalue conversion, but there are a few notable
exceptions:
  - the left-hand side of a '.' operator
  - the left-hand side of an assignment
  - a C++ throw expression
  - a subscript expression that's subscripting a vector

Making this change exposed two issues with blocks:
  - we were deducing const-qualified return types of non-class type
  from a block return, which doesn't fit well
  - we weren't always setting the known return type of a block when it
  was provided with the ^return-type syntax

Fixes the current Clang-on-Clang compile failure and PR6076.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95167 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 4 deletions

diff --git a/test/Sema/block-return.c b/test/Sema/block-return.c
index 6416545cb7..2385106630 100644
--- a/test/Sema/block-return.c
+++ b/test/Sema/block-return.c
@@ -109,7 +109,7 @@ void foo6() {
 
 void foo7()
 {
- const int (^BB) (void) = ^{ const int i = 1; return i; }; // OK 
+ const int (^BB) (void) = ^{ const int i = 1; return i; }; // expected-error{{incompatible block pointer types initializing 'int (^)(void)', expected 'int const (^)(void)'}}
  const int (^CC) (void)  = ^const int{ const int i = 1; return i; }; // OK
 
   int i;
@@ -123,9 +123,8 @@ void foo7()
   __block const int k;
   const int cint = 100;
 
-  int (^MM) (void)  = ^{ return k; }; // expected-error {{incompatible block pointer types initializing 'int const (^)(void)', expected 'int (^)(void)'}}
-  int (^NN) (void)  = ^{ return cint; }; // expected-error {{incompatible block pointer types initializing 'int const (^)(void)', expected 'int (^)(void)'}}
-
+  int (^MM) (void)  = ^{ return k; };
+  int (^NN) (void)  = ^{ return cint; };
 }