We introduce a new LLVM Pass that should detect implicit
casts, by marking the 3rd argument of ModelCast as `true`.
The backend will omit printing a cast expression if the
ModelCast is implicit one.
Currently, some non-determinism upstream in the ABI detection pipeline
causes the return type of the `compute` function to be misdetected, even
if only very rarely.
Exclud this return type from tests for now.
Consider to re-add it in the future if we enforce stricter determinism,
or when EFA 4 is ready.
Many old unit tests were too rigid, using the model and the LLVM IR.
This commit drops them, and replaces them with decompilation tests based
on revng-qa, relying on `revng model compare` to test model properties,
and on `FileCheck` to test that we emit specific constructs in C.
The new tests cover various features of the decompiler.
* DLA capability to recover complex data structure like linked-lists and
arrays.
* DLA capability to update segment and section types, so that we emit
nice looking accesses to segments in C.
* Capability to emit nice looking integer literals in C
* Capability to emit inline string literals in C and update the model
types of the segments containg such string literals.
This pass is dedicated to applying a bunch of peephole optimizations
that are useful for decompilation and haven't been implemented in LLVM
for whatever reason.
At the moment it only runs an optimization that tries to reduce the uses
of incoming values of PHINodes, under very specific condidtions, which
enables emitting less LocalVariables.
Since pointer to copy system got straightenned up, the old way of
marking them (`abi::Definition::UsePointerToCopyForStackArguments`)
is no longer needed.
This does not change anything about the "successful" tests, but does
make "failing" ones slightly easier to debug - since "compatibility"
failures are generally easier to work with (they provide more explicit
information about the failure) that "equivalence" ones.
A class or a struct type A can be a forward declaration and refer
to another type B in PDB, so we need to follow the references.
We pre-create type for B, when we face type A, and then, when we
visit type B, we populate the fields for the model::type we
pre-created.
In addition, this patch fixes some minor/side bugs:
- Handle SHORT/Int16Short simple type
- Do not delete model::Function if Prototype is invalid.
Djordje Todorovic