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.
This changes all the getters on `Instruction` to use `getDef` instead of
`getAnyDef`, with the result that these getters now only have a result
if the definition is exact.
This is a backwards-INCOMPATIBLE change.
This renames `getDefinitionInstruction` to `getAnyDef`, reflecting that
it includes definitions without exact overlap. It renames
`getUseInstruction` to `getUse` for consistency.
perl -p -i -e 's/\bgetUseInstruction\b/getUse/g; s/\bgetDefinitionInstruction\b/getAnyDef/g' \
cpp/ql/src/semmle/code/cpp/ir/**/*.ql* \
cpp/ql/test/**/*.ql* \
cpp/ql/src/semmle/code/cpp/rangeanalysis/**/*.ql*
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.
