[all-commits] [llvm/llvm-project] fa8080: [AST][SVE] Add new Type queries for sizeless types

[rsandifo-arm via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: fa8080376e739e2148aa53715dc93e5406f53fd2
      https://github.com/llvm/llvm-project/commit/fa8080376e739e2148aa53715dc93e5406f53fd2
  Author: Richard Sandiford <richard.sandiford at arm.com>
  Date:   2020-03-12 (Thu, 12 Mar 2020)

  Changed paths:
    M clang/include/clang/AST/CanonicalType.h
    M clang/include/clang/AST/Type.h
    M clang/lib/AST/Type.cpp
    M clang/unittests/AST/CMakeLists.txt
    A clang/unittests/AST/SizelessTypesTest.cpp

  Log Message:
  -----------
  [AST][SVE] Add new Type queries for sizeless types

One of the defining features of the SVE ACLE types is that they
are "sizeless"; see the SVE ACLE spec:

    https://developer.arm.com/docs/100987/0000/arm-c-language-extensions-for-sve

or the email message:

    http://lists.llvm.org/pipermail/cfe-dev/2019-June/062523.html

for a fuller definition of what that means.

This patch adds two associated type queries:

- isSizelessBuiltinType asks specifically about types that are built
  into clang.  It is effectively an enum range check.

- isSizelessType instead tests for any type that has the "sizeless" type
  property.  At the moment it only returns true for the built-in types,
  but it seems better not to hard-code that assumption throughout
  the codebase.  (E.g. we could in principle support some form of
  user-defined sizeless types in future.  Even if that seems unlikely
  and never actually happens, the possibility at least exists.)

Differential Revision: https://reviews.llvm.org/D75570