Introduce the `ScopeCloser` and `GotoTarget` annotations in the IR, and
the relative necessary machinery, needed to handle scope closer and goto
edges for the new backend.
A specialization of the `llvm::GraphTraits`, called `ScopeGraph`, that
is able to handle both the above mentioned annotations is provided.
For the `llvm::GraphTraits` implementation, we introduce the
`GeneratorIterator` class, which uses a coroutine to store the status of
the iteration.
A debug logger pass is added, so that we are able to test the
functionality with `FileCheck`.
Before this commit, we used to attach to call site a metadata to trace
back the call site to the CFG (i.e., `FunctionMetadata`).
This led several passes in revng-c to depend on `FunctionMetadata` just
for this.
This commit, attaches to call sites a reference to the prototype itself
(on the `revng.prototype` metadata), breaking many of such dependencies.
Various parts of revng replace `llvm::GlobalVariable`s representing CSVs
with Allocal/Load/Store. In particular, these are PromoteCSV,
RootAnalyzer and PromoteGlobalToLocalVars.
Before this commit, those places were sloppy when replacing CSVs with
Alloca/Load/Store, and did that iterating on a container sorted by
pointers. This caused Alloca/Load/Store to be emitted in different order
accross runs, which in turn caused more non-determinism down the
pipeline.
This commit fixes the non-deterministic behavior, sorting CSVs based on
their names, which should always be present and deterministic.
getJumpTargetBlock takes llvm::BasicBlock * as argument, but doesn't
need to modify it, so const it adds const to it and other functions that
are used by getJumpTargetBlock: findJumpTarget, isTranslated, getType,
isJumpTarget.
`ValueMaterializer` is a rewrite of what was called `AdvancedValueInfo`
which follows the same principles.
The main benefits over the old version is:
* We materialize the data-flow graph and the CFG of the relevant part of
root. This makes debugging significantly easier.
* We drop the old MonotoneFramework infrastructure in favor of
getMaximalFixedPoint.
* We significantly reduce the amount of queries we make to
AdvancedValueInfo.
`getUniqueString` returns a dedup'd char array `GlobalVariable` given a
string. We used to rely on named metadata to dedup them. However, this
lead to issues with `LLVMContainer` cloning and linking.
The new implementation uses the name of the variable as the
de-decuplication key, circumventing the problem entirely and improving
performance.
This commit introduces `BasicBlockID` as the unique identifier for a
`efa::BasicBlock` into the CFG. A `BasicBlockID` is defined by a
`MetaAddress` plus an incremental integer. This enables us to have
multiple instances of the same block in a single function, which is
particularly useful when inlining multiple times the same function.
Apart from this, the commit also does the following:
* It drops representing `MetaAddress`es a `structs` in the IR. This created
several issues related to ABI. We now represent them as strings.
* It defines more functions in `support.h`, instead of defining prototypes
by hand in `CodeGenerator.cpp` and the like. Specifically, `unknownPC`
and `raise_exception_helper`. We also introduce a C "constructor" for
`PlainMetaAddress`.
* It significantly reduces the API of `GeneratedCodeBasicInfo`, which
was supposed to be put on a diet since a long time. Specifically,
many jump target related methods have been moved to free functions in
`IRHelpers.h`. Also `GCBI::getSuccessors` has been pushed into its
only user, `PruneRetSuccessors`, to prevent further usage of a
deprecated API. In the future, it would be nice to drop it entirely.
* It introduces `efa::BasicBlock::InlinedFrom`.
* Introduce an enum to represent named argument indices for `newpc`.
This enables us to more effectively manipulate its argument list.
* It improves the verification and error reporting for
`efa::FunctionMetadata`.
* Update tests.
This commit is preliminary to another piece of work to improve the
generality of inlining beyond the simple "fake function" scenario, for
which the feature was originally conceived.
The control-flow graph and all its hierarchy components
have been moved from `model` to `efa`. The CFG is now
serialized onto the LLVM IR module as a metadata.
Ivan Krysak