[gcc/devel/rust/master] Merge #1608

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:490aa25d5564313c1957bf28533fe902a0aaa1f2

commit 490aa25d5564313c1957bf28533fe902a0aaa1f2
Merge: 60b21d2f58f 05bd0555fa3
Author: bors[bot] <26634292+bors[bot]@users.noreply.github.com>
Date:   Fri Oct 21 14:13:47 2022 +0000

    Merge #1608
    
    1608: Initial support for closures r=philberty a=philberty
    
    This patch series introduces initial support for closures. Rust's implementation
    of closures is actually pretty clever, the function signatures for closures is driven
    by the specific FnTrait that the closure implements, this means a CallExpr to a closure
    becomes a method-call expr with the receiver type being the closure itself using the
    normal autoderef mechanism to do method selection for an implicit impl block.
    
    See https://github.com/rust-lang/rust/blob/7807a694c2f079fd3f395821bcc357eee8650071/library/core/src/ops/function.rs#L54-L71
    
    The other implicit part of this is that arguments being passed to a closure _must_
    be passed as a tuple. The down side of allowing libcore to specify the signatures
    of the closure functions is that we are limited in how we pass arguments, but
    using a tuple and then using similar machinery from the match-expr to restructure
    the parameter access to become the tuple accessors makes it look seamless. For
    example:
    
    ```rust
      let closure_annotated = |i: i32| -> i32 { i + 123 };
      let i = 1;
      closure_annotated(i);
    ```
    
    Wil generate a function and call-expr such as:
    
    ```c
    i32 test::main::{{closure}} (struct {{closure}} $closure, struct (i32) args)
    {
      _1 = args.__0; // this is 'i'
      return _1 + 123;
    }
    
    
    __attribute__((cdecl))
    i32 test::main ()
    {
      struct
    {
      i32 __0;
    } D.137;
      i32 D.140;
      const i32 a;
      const struct{{closure}} closure_annotated;
      const i32 i;
    
      try
        {
          a = 1;
          i = 1;
          D.137.__0 = i;
          _1 = test::main::{{closure}} (closure_annotated, D.137);
         <...>
        }
      finally
        {
          closure_annotated = {CLOBBER(eol)};
        }
    }
    
    ```
    
    Note this patch series does not implement the argument capture yet but this patch set is
    good start to the implementation so far.
    
    Addresses #195
    
    Co-authored-by: Philip Herron <philip.herron@embecosm.com>

Diff:

 gcc/rust/Make-lang.in                              |   2 +
 gcc/rust/ast/rust-expr.h                           |   9 +-
 gcc/rust/ast/rust-path.h                           |   2 +
 gcc/rust/backend/rust-compile-block.h              |   6 +-
 gcc/rust/backend/rust-compile-context.h            |  31 +
 gcc/rust/backend/rust-compile-expr.cc              | 306 +++++++-
 gcc/rust/backend/rust-compile-expr.h               |  16 +-
 gcc/rust/backend/rust-compile-type.cc              |  10 +-
 gcc/rust/backend/rust-mangle.cc                    |   6 +
 gcc/rust/backend/rust-tree.h                       |   5 +
 .../checks/errors/privacy/rust-privacy-reporter.cc |   8 +-
 .../checks/errors/privacy/rust-privacy-reporter.h  |   3 +-
 gcc/rust/checks/errors/rust-const-checker.cc       |  10 +-
 gcc/rust/checks/errors/rust-const-checker.h        |   3 +-
 gcc/rust/checks/errors/rust-unsafe-checker.cc      |  10 +-
 gcc/rust/checks/errors/rust-unsafe-checker.h       |   3 +-
 gcc/rust/checks/lints/rust-lint-marklive.h         |   5 +
 gcc/rust/hir/rust-ast-lower-base.cc                | 113 ---
 gcc/rust/hir/rust-ast-lower-base.h                 |   2 +
 gcc/rust/hir/rust-ast-lower-expr.cc                | 810 +++++++++++++++++++++
 gcc/rust/hir/rust-ast-lower-expr.h                 | 746 ++-----------------
 gcc/rust/hir/rust-ast-lower-pattern.cc             |  18 +
 gcc/rust/hir/rust-ast-lower-pattern.h              |  24 +-
 gcc/rust/hir/rust-ast-lower-type.cc                | 232 ++++++
 gcc/rust/hir/rust-ast-lower-type.h                 |  63 +-
 gcc/rust/hir/rust-ast-lower.cc                     |  23 +
 gcc/rust/hir/rust-hir-dump.cc                      |   6 +-
 gcc/rust/hir/rust-hir-dump.h                       |   3 +-
 gcc/rust/hir/tree/rust-hir-expr.h                  | 213 +++---
 gcc/rust/hir/tree/rust-hir-full-decls.h            |   2 -
 gcc/rust/hir/tree/rust-hir-full-test.cc            |  37 +-
 gcc/rust/hir/tree/rust-hir-path.h                  |  68 +-
 gcc/rust/hir/tree/rust-hir-visitor.h               |   9 +-
 gcc/rust/hir/tree/rust-hir.h                       |   1 +
 gcc/rust/resolve/rust-ast-resolve-expr.cc          |  58 ++
 gcc/rust/resolve/rust-ast-resolve-expr.h           |  48 +-
 gcc/rust/resolve/rust-ast-resolve-type.cc          |  15 +-
 gcc/rust/typecheck/rust-hir-type-check-expr.cc     | 315 +++++++-
 gcc/rust/typecheck/rust-hir-type-check-expr.h      |  10 +-
 gcc/rust/typecheck/rust-hir-type-check.h           |   2 +
 gcc/rust/typecheck/rust-tyctx.cc                   |  32 +
 gcc/rust/typecheck/rust-tyty-bounds.cc             |  69 +-
 gcc/rust/typecheck/rust-tyty-call.cc               |  98 ++-
 gcc/rust/typecheck/rust-tyty-call.h                |  79 +-
 gcc/rust/typecheck/rust-tyty-cmp.h                 |  23 +
 gcc/rust/typecheck/rust-tyty-rules.h               |  40 +-
 gcc/rust/typecheck/rust-tyty.cc                    |  71 +-
 gcc/rust/typecheck/rust-tyty.h                     |  38 +-
 gcc/rust/util/rust-lang-item.h                     |   7 +
 gcc/testsuite/rust/execute/torture/closure1.rs     |  18 +
 gcc/testsuite/rust/execute/torture/closure2.rs     |  32 +
 51 files changed, 2455 insertions(+), 1305 deletions(-)