[gcc/devel/rust/master] Merge #1545

[gcc/devel/rust/master] Merge #1545

[Thomas Schwinge]

https://gcc.gnu.org/g:b71e3dc02a8fd3141080419b7fb1a24d2c4133d0

commit b71e3dc02a8fd3141080419b7fb1a24d2c4133d0
Merge: cecd314884a b17e69852ea
Author: bors[bot] <26634292+bors[bot]@users.noreply.github.com>
Date:   Tue Sep 27 14:06:08 2022 +0000

    Merge #1545
    
    1545: Refactor TypeResolution to be a simple query based system r=philberty a=philberty
    
    This patch refactors the type resolution system to introduce a new
    interface
    
      bool query_type (HirId, TyTy::BaseType** result)
    
    This is needed in order to properly support forward declared items. Our
    name resolution system has two parts:
    
      1. Toplevel scan
      2. Item resolution
    
    The toplevel scan gathers all the nesseacry 'names' into their respective
    namespace by doing a full toplevel scan and generate canonical paths for
    each item. The second pass is responsible for drilling down into each
    structure or function to resolve each field or variable etc. This means
    our name resolution system supports forward decalred items but our type
    resolution system did not.
    
    This patch removes the toplevel scan from our type resolution pass which
    is not able to handle all cases such as a function with return type and
    the type is decalred after the fact or a type alias to a type declared
    after the fact. The name resolution mappings are resolved so when errors
    occured here we got errors such as unable to lookup HirId 1234, which meant
    yes we have 'resolved' this reference to this HirId but we are unable to
    find any type information for it. This means we needed a new way to figure
    out the type in a query based way.
    
    This is where the new query_type inferface comes in so when we have an
    HirId we want to resolve the mappings class allows us to figure out what
    item this is such as:
    
      1. HIR::Item (normal HIR::Function, Struct, TypeAlias, ...)
      2. HIR::ImplItem (function, constant, ... within an impl-block)
      3. HIR::ImplBlock (Self type on an impl-block)
      4. HIR::ExternalItem (extern-block item)
    
    The mappings class allows us to simply lookup these HIR nodes and then
    call the relevant resolver class to compute the type. This patch does not
    add support for self-referencial types but is the starting point to be able to support such types.
    
    Fixes #1455
    Fixes #1006
    Fixes #1073
    Fixes #1272
    
    
    Co-authored-by: Philip Herron <philip.herron@embecosm.com>

Diff:

 gcc/rust/Make-lang.in                              |   2 +-
 gcc/rust/backend/rust-compile-context.h            |  21 +-
 gcc/rust/backend/rust-compile-expr.h               |  17 +-
 gcc/rust/backend/rust-compile-item.cc              |  14 +-
 gcc/rust/backend/rust-constexpr.cc                 |  16 +-
 gcc/rust/checks/lints/rust-lint-marklive.cc        |   7 +-
 gcc/rust/resolve/rust-name-resolver.cc             |  20 +
 gcc/rust/resolve/rust-name-resolver.h              |   6 +
 gcc/rust/typecheck/rust-hir-dot-operator.cc        |   8 +-
 gcc/rust/typecheck/rust-hir-dot-operator.h         |   6 +-
 gcc/rust/typecheck/rust-hir-path-probe.cc          |  46 ++
 gcc/rust/typecheck/rust-hir-path-probe.h           |  24 +-
 gcc/rust/typecheck/rust-hir-type-check-base.cc     |  76 +++
 gcc/rust/typecheck/rust-hir-type-check-base.h      |   2 +
 gcc/rust/typecheck/rust-hir-type-check-expr.cc     |   3 +
 gcc/rust/typecheck/rust-hir-type-check-implitem.cc | 181 +++----
 gcc/rust/typecheck/rust-hir-type-check-implitem.h  |  42 +-
 gcc/rust/typecheck/rust-hir-type-check-item.cc     | 554 +++++++++++++++++----
 gcc/rust/typecheck/rust-hir-type-check-item.h      |  47 +-
 gcc/rust/typecheck/rust-hir-type-check-path.cc     |   9 +-
 gcc/rust/typecheck/rust-hir-type-check-stmt.cc     | 387 ++------------
 gcc/rust/typecheck/rust-hir-type-check-stmt.h      |  62 +--
 gcc/rust/typecheck/rust-hir-type-check-toplevel.cc | 378 --------------
 gcc/rust/typecheck/rust-hir-type-check-toplevel.h  |  56 ---
 gcc/rust/typecheck/rust-hir-type-check-type.cc     | 110 ++--
 gcc/rust/typecheck/rust-hir-type-check.cc          |   9 +-
 gcc/rust/typecheck/rust-hir-type-check.h           |  41 ++
 gcc/rust/typecheck/rust-substitution-mapper.h      |   2 +-
 gcc/rust/typecheck/rust-tyty-bounds.cc             |  24 +-
 gcc/rust/typecheck/rust-tyty-cmp.h                 |   2 +
 gcc/rust/typecheck/rust-tyty.cc                    |  45 +-
 gcc/rust/typecheck/rust-tyty.h                     |  34 +-
 gcc/rust/util/rust-hir-map.cc                      |  13 +
 gcc/rust/util/rust-hir-map.h                       |   2 +
 gcc/testsuite/rust/compile/const_generics_5.rs     |  13 +-
 gcc/testsuite/rust/compile/issue-1006.rs           |  10 +
 gcc/testsuite/rust/compile/issue-1073.rs           |   4 +
 gcc/testsuite/rust/compile/issue-1272.rs           |   8 +
 .../rust/compile/unconstrained_type_param.rs       |   2 +
 39 files changed, 1058 insertions(+), 1245 deletions(-)