llvm/unittests
Chandler Carruth 33d568124e [PM] Change the static object whose address is used to uniquely identify
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.

This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.

However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.

And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.

This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.

We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.

Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!

While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.

Differential Revision: https://reviews.llvm.org/D27031

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287783 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-23 17:53:26 +00:00
..
ADT Add some searching functions for ArrayRef<T>. 2016-11-22 23:22:19 +00:00
Analysis [PM] Change the static object whose address is used to uniquely identify 2016-11-23 17:53:26 +00:00
AsmParser Remove every uses of getGlobalContext() in LLVM (but the C API) 2016-04-14 21:59:01 +00:00
Bitcode Bitcode: Change module reader functions to return an llvm::Expected. 2016-11-13 07:00:17 +00:00
CodeGen GlobalISel: rename legalizer components to match others. 2016-10-14 22:18:18 +00:00
DebugInfo Clean up DWARFFormValue by reducing duplicated code and removing DWARFFormValue::getFixedFormSizes() 2016-11-11 16:21:37 +00:00
ExecutionEngine Remove a stale test case. 2016-11-17 01:02:52 +00:00
IR [PM] Change the static object whose address is used to uniquely identify 2016-11-23 17:53:26 +00:00
LineEditor Remove autoconf support 2016-01-26 21:29:08 +00:00
Linker Remangle intrinsics names when types are renamed 2016-06-24 15:10:29 +00:00
MC Fix static initialization order fiasco in MCTests 2016-11-11 22:18:42 +00:00
MI CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses 2016-08-24 01:52:46 +00:00
Object Fix llvm-symbolizer to correctly sort a symbol array and calculate symbol sizes 2016-11-15 21:07:03 +00:00
ObjectYAML Move ObjectYAML code to a new library. 2016-03-01 19:15:06 +00:00
Option Option parser: class for consuming a joined arg in addition to all remaining args 2016-04-15 00:23:30 +00:00
ProfileData Fix spelling mistakes in Tools/Tests comments. NFC. 2016-11-20 13:31:13 +00:00
Support Add convenient functions to compute hashes of byte vectors. 2016-11-23 00:46:09 +00:00
Target Remove a FIXME that I forgot about. NFC. 2016-10-13 05:28:55 +00:00
Transforms Make the FunctionComparator of the MergeFunctions pass a stand-alone utility. 2016-11-11 21:15:13 +00:00
CMakeLists.txt Fix llvm-symbolizer to correctly sort a symbol array and calculate symbol sizes 2016-11-15 21:07:03 +00:00