[Expressions] Add support of expressions evaluation in some object's context
Summary:
This patch adds support of expression evaluation in a context of some object.
Consider the following example:
```
struct S {
int a = 11;
int b = 12;
};
int main() {
S s;
int a = 1;
int b = 2;
// We have stopped here
return 0;
}
```
This patch allows to do something like that:
```
lldb.frame.FindVariable("s").EvaluateExpression("a + b")
```
and the result will be `33` (not `3`) because fields `a` and `b` of `s` will be
used (not locals `a` and `b`).
This is achieved by replacing of `this` type and object for the expression. This
has some limitations: an expression can be evaluated only for values located in
the debuggee process memory (they must have an address of `eAddressTypeLoad`
type).
Reviewers: teemperor, clayborg, jingham, zturner, labath, davide, spyffe, serge-sans-paille
Reviewed By: jingham
Subscribers: abidh, lldb-commits, leonid.mashinskiy
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D55318
llvm-svn: 353149
26 files changed