DemangleInitRAII saves and restores NumWords but not the Words[] array
itself. When a nested demangleSymbol/demangleType call processes
identifiers, it overwrites Words[] entries with StringRefs pointing
into its own Text buffer. After ~DemangleInitRAII restores the outer
NumWords, those entries still reference the inner (now-destroyed)
buffer. The outer demangling then hits a word substitution and reads
freed memory through the stale StringRef.
In practice this is triggered by MetadataReader::demangle(): the
symbolic reference resolver calls buildContextManglingForSymbol which
calls dem.demangleSymbol() on the same Demangler. The inner symbol's
identifiers overwrite Words[] with pointers into the
ParentContextDescriptorRef's temporary string. When the resolver
returns and the PCCDR is destroyed, the outer demangleType accesses
dangling Words[] entries via word substitution identifiers.
The fix adds Words[] to DemangleInitRAII's saved/restored state.
rdar://172223904
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
`OpaqueReturnTypeParent` node now references the parent with a mangled parent name, rather than a parent pointer. This makes trees obtained from different demanglers (or calls to `Demangler::demangleSymbol`) for the same symbol equal.
LLDB would like to substitute the original Archetype names from the
source code when demangling symbols instead of the confusing generic
'A', 'B', ...
<rdar://problem/48259889>
This function can be queried to find out whether the passed
mangled name is an Objective-C symbol. This will be used
in the debugger to replace an hardcoded check that would
break if the mangling prefix changed.
<rdar://problem/44467875>
Previously it was part of swiftBasic.
The demangler library does not depend on llvm (except some header-only utilities like StringRef). Putting it into its own library makes sure that no llvm stuff will be linked into clients which use the demangler library.
This change also contains other refactoring, like moving demangler code into different files. This makes it easier to remove the old demangler from the runtime library when we switch to the new symbol mangling.
Also in this commit: remove some unused API functions from the demangler Context.
fixes rdar://problem/30503344
Fred Riss
Dmitrii Galimzianov
Adrian Prantl
Erik Eckstein
Davide Italiano
Michael Gottesman