This test was failing due to a semantic merge conflict between #509,
which added `UninitializedInstruction`, and #517, which added new test
code that would get `UninitializedInstruction`s in it after merging with #509.
This adds a `NewOrNewArrayExpr.getPlacementPointer` predicate and uses
it in `Alloc.qll` to detect when a `new`-expression is not an
allocation.
User-defined replacements for `operator new` may not be allocations
either, but the code continues to assume that they are. It's possible
that we want to change this assumption in the future or leave it up to
individual queries to decide on which side to err. It's hard to
statically tell whether `operator new` has been overloaded in a
particular file because it can be overloaded by a definition that is not
in scope but is only linked together with that file.
This commit inserts an `Uninitialized` instruction to "initialize" a local variable when that variable is initialized with an initializer list. This ensures that there is always a definition of the whole variable before any read or write to part of that variable.
This change appears in a different form in @rdmarsh2's Chi node PR, but I needed to refactor the initialization code anyway to handle ConditionDeclExpr.
@rdmarsh2 has been working on various queries and libraries on top of the IR, and has pointed out that having to always refer to an operand of an instruction by the pair of (instruction, operandTag) makes using the IR a bit clunky. This PR adds a new `Operand` IPA type that represents an operand of an instruction. `OperandTag` still exists, but is now an internal type used only in the IR implementation.
This is motivated by test performance; IR compilation happens separately
for each test and takes a bit over a minute, so combining these 8 tests
saves about 10 minutes of test running.
The IR for the conversion to bool results in a comparison where the left
hand side is not the result of any expression in the AST, so they can't
be usefully converted back to the AST
For ease of reviewing, I've checked in the .expected files from the
AST-based guards library. The next commit accepts output for these tests
and adds tests that use getAST rather than the translation layer.