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.
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*
