[gcc/devel/rust/master] Allow rustc_const_stable and rustc_const_unstable

[Thomas Schwinge via Gcc-cvs]

https://gcc.gnu.org/g:646046091b703621c4ba63adb76179c11a1dbb92

commit 646046091b703621c4ba63adb76179c11a1dbb92
Author: Owen Avery <powerboat9.ga...@gmail.com>
Date:   Wed Feb 28 21:00:08 2024 -0500

    Allow rustc_const_stable and rustc_const_unstable
    
    gcc/rust/ChangeLog:
    
            * expand/rust-macro-builtins.cc
            (MacroBuiltin::builtin_transcribers):
            Add entries for "rustc_const_stable" and "rustc_const_unstable".
            * util/rust-attributes.cc
            (__definitions): Add entries for RUSTC_CONST_STABLE and
            RUSTC_CONST_UNSTABLE.
            * util/rust-attribute-values.h
            (Attributes::RUSTC_CONST_STABLE): New.
            (Attributes::RUSTC_CONST_UNSTABLE): New.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/rustc_const_stable.rs:
            Enable feature rustc_attrs, expect no errors.
            * rust/compile/rustc_const_unstable.rs: New test.
    
    Signed-off-by: Owen Avery <powerboat9.ga...@gmail.com>

Diff:
---
 gcc/rust/expand/rust-macro-builtins.cc             | 2 ++
 gcc/rust/util/rust-attribute-values.h              | 2 ++
 gcc/rust/util/rust-attributes.cc                   | 5 ++++-
 gcc/testsuite/rust/compile/rustc_const_stable.rs   | 4 +++-
 gcc/testsuite/rust/compile/rustc_const_unstable.rs | 4 ++++
 5 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/expand/rust-macro-builtins.cc 
b/gcc/rust/expand/rust-macro-builtins.cc
index bc5bc944e772..a6816cf1603a 100644
--- a/gcc/rust/expand/rust-macro-builtins.cc
+++ b/gcc/rust/expand/rust-macro-builtins.cc
@@ -123,6 +123,8 @@ std::unordered_map<std::string, AST::MacroTranscriberFunc>
     {"test_case", MacroBuiltin::sorry},
     {"global_allocator", MacroBuiltin::sorry},
     {"cfg_accessible", MacroBuiltin::sorry},
+    {"rustc_const_stable", MacroBuiltin::sorry},
+    {"rustc_const_unstable", MacroBuiltin::sorry},
     /* Derive builtins do not need a real transcriber, but still need one. It
        should however never be called since builtin derive macros get expanded
        differently, and benefit from knowing on what kind of items they are
diff --git a/gcc/rust/util/rust-attribute-values.h 
b/gcc/rust/util/rust-attribute-values.h
index a8551c07dba6..a7eaf9ffa70c 100644
--- a/gcc/rust/util/rust-attribute-values.h
+++ b/gcc/rust/util/rust-attribute-values.h
@@ -53,6 +53,8 @@ public:
     = "rustc_inherit_overflow_checks";
   static constexpr auto &STABLE = "stable";
   static constexpr auto &UNSTABLE = "unstable";
+  static constexpr auto &RUSTC_CONST_STABLE = "rustc_const_stable";
+  static constexpr auto &RUSTC_CONST_UNSTABLE = "rustc_const_unstable";
 };
 } // namespace Values
 } // namespace Rust
diff --git a/gcc/rust/util/rust-attributes.cc b/gcc/rust/util/rust-attributes.cc
index 84d1781d0b36..33166673c28a 100644
--- a/gcc/rust/util/rust-attributes.cc
+++ b/gcc/rust/util/rust-attributes.cc
@@ -61,7 +61,10 @@ static const BuiltinAttrDefinition __definitions[]
      {Attrs::RUSTC_DEPRECATED, STATIC_ANALYSIS},
      {Attrs::RUSTC_INHERIT_OVERFLOW_CHECKS, CODE_GENERATION},
      {Attrs::STABLE, STATIC_ANALYSIS},
-     {Attrs::UNSTABLE, STATIC_ANALYSIS}};
+     {Attrs::UNSTABLE, STATIC_ANALYSIS},
+     // assuming we keep these for static analysis
+     {Attrs::RUSTC_CONST_STABLE, STATIC_ANALYSIS},
+     {Attrs::RUSTC_CONST_UNSTABLE, STATIC_ANALYSIS}};
 
 BuiltinAttributeMappings *
 BuiltinAttributeMappings::get ()
diff --git a/gcc/testsuite/rust/compile/rustc_const_stable.rs 
b/gcc/testsuite/rust/compile/rustc_const_stable.rs
index 9208b1ab3b62..a45355de6b37 100644
--- a/gcc/testsuite/rust/compile/rustc_const_stable.rs
+++ b/gcc/testsuite/rust/compile/rustc_const_stable.rs
@@ -1,2 +1,4 @@
+#![feature(rustc_attrs)]
+
 #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = 
"1.47.0")]
-pub fn foo() {} // { dg-error "macro not found" "" { target *-*-* } .-1 }
+pub fn foo() {}
diff --git a/gcc/testsuite/rust/compile/rustc_const_unstable.rs 
b/gcc/testsuite/rust/compile/rustc_const_unstable.rs
new file mode 100644
index 000000000000..6cedefade720
--- /dev/null
+++ b/gcc/testsuite/rust/compile/rustc_const_unstable.rs
@@ -0,0 +1,4 @@
+#![feature(rustc_attrs)]
+
+#[rustc_const_unstable(feature = "const_ascii_ctype_on_intrinsics", issue = 
"1234")]
+pub fn foo() {}