This commit makes sure that GeneratedCodeBasicInfo can be used even in
absence of the `root`.
This also ensure that no time is wasted on brief/focused pipelines that
do not care about analyzing each basic block in the `root` function.
Integrate results of ABIAnalyses in EarlyFunctionAnalysis
and refine such results by suppressing stack pointer
and callee-saved registers from the analyses.
Architecture-agnostic and ABI-independent data-flow analyses that
traverse the recovered functions in order to detect arguments and
return values registers.
An architecture-agnostic analysis that attempts to detect
boundaries of functions, recover the control-flow graph as
well as function prototypes (arguments and return values)
of the original program. The analysis determines whether
the function jumps to its return address (namely, it is a
regular function), it tracks the evolution of the stack
by determining its height (in order to say if the stack is
left in a correct position upon stackframe destruction),
and it identifies callee-saved registers.
A pass which segregates direct stack accesses from all other
memory accesses through appropriate alias information metadata.
By doing so, we provide a way to say that stack accesses reasonably
do not interfere with any other memory access. This pass also tries
to canonicalize `inttoptr` + `add` instructions into `getelementptr`s
so as to avoid the use of `inttoptr`, which would otherwise inhibit
compiler optimizations.
These functions can be used in conjunction to dump the Model on a
file during a gdb session, for example:
```
(gdb) p writeToFile(Model->toString(), "/tmp/model.yaml")
```
Add `MakeModelTypes` and `UpdateFuncPrototypes` to the DLA backend:
* `MakeModelTypes` adds to the model all the types recovered by the DLA
* `UpdateFuncPrototypes` updates function prototypes in the model that
have generic return values or arguments to use the types recovered by
the DLA
* Changes to the `LayoutTypeSystem` graph
Pointers are identified in the TypeSystem graph as leaf nodes which
have a new type of edge (PointerEdge) that connects them to another
node of the graph. The destination of the edge represents the layout of
the pointed type.
* Changes to the Front-end
Pointer edges, and their destination nodes, are created by the DLA
front-end (`DLACreateIntraProceduralTypes`) whenever an access node has
a size that is compatible with the size of a pointer in the current
Architecture.
Successors might then be added to the newly generated node, if any,
by looking up the llvm::Value it is attached to.
* Changes to the Middle-end
Most of the DLA passes should ignore Pointer Edges, so they are modified
accordingly. Most notably, nodes that represent pointed layouts should
never be merged/pruned-off.
* Changes to the Back-end
The `TypeDeclCreationAction` of the decompiler and the `DLAMakeLayouts`
step of the DLA back-end are modified to take into account the new
information about pointers.
⚠️ There is a known issue with this version of the decompiler,
namely the fact that type loops are not detected and can cause the
emitter to enter an infinite loop.
We introduce a new tile, for matching if node with a single and inlined
then/else. In these case, the not inlined successor should be connected
with the tile node.
Handle switch nodes with all but one case edges inlined, by electing the
not inlined edge as the path conducting to the postdominator, and
avoiding parts of the graph disconnecting during the tiling procedure.
Massimo Fioravanti