Emit forward declarations and definitions of the opaque-array
artificial structs from the C model header (and from the helpers
header). Definitions are gated on a new DefineOpaqueTypes flag
threaded through PTMLHeaderBuilder::printModelHeader so that the
helpers header keeps emitting only the declarations.
Teach NameBuilder and ModelCBuilder how to produce names and
references for opaque-array types: NameBuilder gains
opaqueTypeName(ByteSize), ModelCBuilder gains the matching
reference and definition tags. Both rely on the new
Configuration::OpaqueTypePrefix.
Type inlining was a feature that allowed type definitions of
structs/unions/enums to be printed in C directly inside the definition
of another parent struct/union, if the inner type was only used once in
the parent type.
This kind of reasoning is inherently global: a type definition of the
subtype can be inlined in the parent type one only if *globally* the
subtype it isn't referred anywhere else.
This caused issues with type inlining inside definitions of stack types
in the body of functions. Indeed, for a given function, due to type
inlining, it was necessary to do global reasoning about what other types
could be inlined in the definition of the function's stack frame type.
This, in turn, had heavy consequences on invalidation, because any
change to any type (even if it wasn't referred in a given function's
body) was causing invalidation of all functions' bodies.
For this reason it was decided to drop the type inlining feature.
This commits wraps all the machinery that can mutate a DependencyGraph
inside the interval factory class DependencyGraph::Builder.
In this way, once a DependencyGraph is created, it cannot be mutated by
accident from outside.
This is important because mutating it from outside makes it easy to
break the consistency of internal maps.
This risk will only increase when supporting artificial struct wrapper
types, so we encapsulate this now to prevent issues in the future.
This data structure is used to bind together a pair of pointers to
TypeDependencyNode, one referring to a declaration of a type and the
other referring to a definition of the same type.
The definition can be null if the type referred to is a type without an
explicit definition (e.g. typedefs), while it's never null for types
for which have forward declaration that is separate from the definition
(e.g. structs and unions).
This commit adds two enum entries to TypeNode::Kind to represent forward
declarations and definitions of artificial struct wrappers, that are not
present in the model but that we're forced to print in C to overcome
its limitations in representing types.
At the moment, this is only going to be used for representing return
types of RawFunctionDefinitions whose Layout returns RegisterSet, which
can't be represented in C without a wrapper.
This commit bans from the model array types in as argument or return
types in CABIFunctionDefinition.
CABIFunctionDefinition implies we're decompiling towards C, and C does
not support array arguments (passed by copy) nor array return types.
Banning these from the model reduces the number of situations where we
have to emit artificial array wrappers (not present in the model) around
types when printing C code, simplifying the handling of such situations
when translating to clift and in general in the decompilation pipeline.
These methods had a misleading name, because they always returned a
ScopeTag, and never indented anything.
As a result they were misused or used in a confusing way in most of
their uses.
They have now both been replaced by two different overloaded methods
with the name getScopeTag.
This commit also fixes all their broken uses.
Before this, commenting is only possible on specific names, with this
the entire supported line is active (unless there are more grannular
comment contexts, for example, in the function prototype).
For example (commentable parts are marked with `^`):
```
// struct whatever {
// ...
// before this
const my_type_name *my_field_name[10];
// ^^^^^^^^^^^^^
// after this
const my_type_name *my_field_name[10];
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// ...
// };
```
It's the same for all the others, like segments, arguments, and so on.
Because of how name builders used to lazy gather namespaces on the first
requested name, the objects were self mutating. As such only non-const
references could be used to pass them around.
Since that is no longer the case, this restores most of lost const
qualifiers.
Pietro Fezzardi