Previously, where we had a function-scoped `DeclarationEntry` for an extern variable or function, we would generate a `NoOp` instruction for it. There's nothing wrong with this by itself, although it was unnecessary. However, I've hit an extractor issue (Jira ticket already opened) that commonly causes multiple `DeclStmt`s to share a single `DeclarationEntry` child on extern declarations, so removing the `NoOp` instructions is an easy way to work around the extractor issue.
The previous version of the test used `0 = 1;` to test an lvalue-typed
`ErrorExpr`, but the extractor replaced the whole assignment expression
with `ErrorExpr` instead of just the LHS. This variation of the test
only leads to an `ErrorExpr` for the part of the syntax that's supposed
to be an lvalue-typed expression, so that's an improvement.
Unfortunately it still doesn't demonstrate that we can `Store` into an
address computed by an `ErrorExpr`.
Before this change, `delete` and `delete[]` expressions had no control
flow after them, which caused the reachability analysis to remove all
code after a delete expression. This commit adds placeholder support for
delete expression by translating them to `NoOp` instructions so their
presence doesn't cause large chunks of the program to be removed.
IR construction was missing support for C++ 11 range-based `for` loops. The extractor generates ASTs for the compiler-generated implementation already, so I had enough information to generate IR. I've expanded on some of the predicates in `RangeBasedForStmt` to access the desugared information.
One complication was that the `DeclStmt`s for the compiler-generated variables seem to have results for `getDeclaration()` but not for `getDeclarationEntry()`. This required handling these slightly differently than we do for other `DeclStmt`s.
The flow for range-based `for` is actually easier than for a regular `for`, because all three components (init, condition, and update) are always present.
I kept forgetting which operand on a Chi instruction was which, so I added dump labels. I added labels for the function target of a `Call`, for positional arguments, and for address operands as well.
The IR construction code wasn't handling lambda expressions, so I added `TranslatedLambdaExpression`. It's pretty straightforward: it creates a temporary variable, initializes it with an `Uninitialized` instruction, then initializes the individual captured fields with the initializer list supplied in the AST.
When testing the case of a lambda with no captures, I noticed that we weren't handling initialization of empty structs with an initializer list correctly, so I fixed that along the way.
I was getting confused by the bad indentation for wrapped lines in
TranslatedInitialization.qll, so I fixed that up in a separate commit.
