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.
llvm-svn: 95167
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
"integer promotion" type associated with an enum decl, and use this type to
determine which type to promote to. This type obeys C++ [conv.prom]p2 and
is therefore generally signed unless the range of the enumerators forces
it to be unsigned.
Kills off a lot of false positives from -Wsign-compare in C++, addressing
rdar://7455616
llvm-svn: 90965
struct B;
B f();
void g() {
f();
}
We now get
t.cpp:6:3: error: calling 'f' with incomplete return type 'struct B'
f();
^~~
t.cpp:3:3: note: 'f' declared here
B f();
^
t.cpp:1:8: note: forward declaration of 'struct B'
struct B;
^
llvm-svn: 83692
Douglas Gregor