We don't want cast and dyn_cast to work on temporaries. They don't extend
lifetime like a direct bind to a reference would, so they can introduce
hard to find bugs.
I added tests to make sure we don't regress this. Thanks to Eli Friedman for
noticing this and for his suggestions on how to test it.
llvm-svn: 186559
As far as simplify_type is concerned, there are 3 kinds of smart pointers:
* const correct: A 'const MyPtr<int> &' produces a 'const int*'. A
'MyPtr<int> &' produces a 'int *'.
* always const: Even a 'MyPtr<int> &' produces a 'const int*'.
* no const: Even a 'const MyPtr<int> &' produces a 'int*'.
This patch then does the following:
* Removes the unused specializations. Since they are unused, it is hard
to know which kind should be implemented.
* Make sure we don't drop const.
* Fix the default forwarding so that const correct pointer only need
one specialization.
* Simplifies the existing specializations.
llvm-svn: 178147
After cleaning up the following type hierarchies:
* TypeLoc: r175462
* SVal: r175594
* CFGElement: r175462
* ProgramPoint: r175812
that all invoked undefined behavior by causing a derived copy construction of a
base object through an invalid cast (thus supporting code that relied on
casting temporaries that were direct base objects) Clang/LLVM is now clean of
casts of temporaries. So here's some fun SFINAE machinery (courtesy of Eli
Friedman, with some porting back from C++11 to LLVM's traits by me) to cause
compile-time failures if llvm::cast & friends are ever passed an rvalue.
This should avoid a repeat of anything even remotely like PR14321/r168124.
Thanks to Jordan Rose for the help with the various Static Analyzer related
hierarchies that needed cleaning up, Eli for the SFINAE, Richard Smith, John
McCall, Ted Kremenek, and Anna Zaks for their input/reviews/patience along the
way.
llvm-svn: 175819
Additionally, all such cases are handled with no dynamic check.
All `classof()` of the form
class Foo {
[...]
static bool classof(const Bar *) { return true; }
[...]
}
where Foo is an ancestor of Bar are no longer necessary.
Don't write them!
Note: The exact test is `is_base_of<Foo, Bar>`, which is non-strict, so
that Foo is considered an ancestor of itself.
This leads to the following rule of thumb for LLVM-style RTTI:
The argument type of `classof()` should be a strict ancestor.
For more information about implementing LLVM-style RTTI, see
docs/HowToSetUpLLVMStyleRTTI.rst
llvm-svn: 165765
This silences several analyzer warnings within LLVM, and provides a slightly
nicer crash experience when someone calls isa<>, cast<>, or dyn_cast<> with
a null pointer.
llvm-svn: 164439
cast needs to adjust for a vtable pointer when going from base to
derived type (when the base doesn't have a vtable but the
derived type does).
llvm-svn: 95585
In order for the changes in r78424 to work properly, cast_retty<X,Y> should return an object instead of a reference, and it's not clear that this approach has real advantages.
llvm-svn: 79023
The use case is if you have a wrapper class:
class Base {
void *Ptr;
public:
Base() : Ptr(0) { }
operator bool() const { return Ptr; }
.....
}
and sub-wrappers that have exactly the same size:
class Sub : public Base {
public:
....
static bool classof(const Base*);
}
and in the code you would do:
void f(Base b) {
Sub sub = dyn_cast<Sub>(b);
if (sub) {
....
}
}
llvm-svn: 78424
NULL-based reference.
Note: Encountered this a few times on Tiger + gcc 4.0.1. Might just be a
platform-specific compiler issue, but it's good defensive programming in any
case.
llvm-svn: 59890
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.
llvm-svn: 16137
