We can end up querying the pointer size and similar things very frequently, which can be slow. These values don't change for any given reader, so call them once and cache the values locally instead.
rdar://150221008
This patch changes RemoteAbsolutePointer to store both the symbol and
the resolved address. This allows us to retire some ugly workarounds
to deal with non-symbolic addresses and it fixes code paths that would
need these workarounds, but haven't implemented them yet (i.e., the
pack shape handling in the symbolicReferenceResolver in MetadatyaReader.
Addresses parts of rdar://146273066.
rdar://153687085
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
Until recently, `MemoryReader` had a single function `resovlePointer` which did two things, and has a somewhat vague name. The two things were:
1. Tool-specific mapping between real addresses and tagged addresses (first implemented in `swift-reflection-dump` and then later in lldb)
2. Finding a "symbol" for a given address
Recently, `resolvePointerAsSymbol` was added, which overloaded the term "resolve" and it added another way to deal with symbols for addresses. Symbols themselves were a bit muddled, as `swift-reflection-dump` was dealing with dynamic symbols aka bindings, while lldb was dealing in regular (static) symbols.
This change separates these two parts of functionality, and also divides symbol lookup into two cases. The API surface will now be:
1. `resolvePointer` for mapping/tagging addresses
3. `getSymbol` for looking up a symbol for an address
4. `getDynamicSymbol` for looking up a dyld binding for an address
Note: each of these names could be improved. Some alternative terms: `lookup` instead of `get`, `Binding` or `BindingName` instead of `DynamicSymbol`. Maybe even another term instead of "resolve". Suggestions welcome!
Currently, `swift-reflection-dump` supports `getDynamicSymbol` but not `getSymbol`. For lldb it's the reverse, `getSymbol` is supported but `getDynamicSymbol` needs to be implemented.
For everything but lldb, this change is NFC. For lldb it fixes a bug where `LLDBMemoryReader` returns regular symbols where we should instead be returning dynamic symbols.
This commit adds new entry-points to `libSwiftScan` that operate on the new BinaryScanningTool, which reads out Swift type information from object files, starting with a query of all protocol conformances.
