Backport public support to release-3 (#808)

Project.toml

@@ -1,6 +1,6 @@
 name = "Compat"
 uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
-version = "3.46.2"
+version = "3.47.0"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"

README.md

@@ -69,6 +69,9 @@ changes in `julia`.
 
 ## Supported features
 
+
+* `@compat public foo, bar` marks `foo` and `bar` as public in Julia 1.11+ and is a no-op in Julia 1.10 and earlier. ([#50105]) (since Compat 3.47.0)
+
 * `popat!` removes the item at the given `i` and returns it ([#36070]). (since
   Compat 3.45.0)
 
@@ -325,3 +328,4 @@ Note that you should specify the correct minimum version for `Compat` in the
 [#39245]: https://github.com/JuliaLang/julia/issues/39245
 [#42351]: https://github.com/JuliaLang/julia/issues/42351
 [#43334]: https://github.com/JuliaLang/julia/issues/43334
+[#50105]: https://github.com/JuliaLang/julia/issues/50105

src/compatmacro.jl

@@ -20,11 +20,11 @@ function _compat(ex::Expr)
     @static if VERSION < v"1.7.0-DEV.364"
         if Meta.isexpr(ex, :(=)) && Meta.isexpr(ex.args[1], :tuple) &&
             Meta.isexpr(ex.args[1].args[1], :parameters)
-            
+
             ex = _destructure_named_tuple(ex)
         end
     end
-    
+
     return Expr(ex.head, map(_compat, ex.args)...)
 end
 
@@ -116,3 +116,46 @@ function _destructure_named_tuple(ex::Expr)
     push!(ex.args, values)
     return ex
 end
+
+# https://github.com/JuliaLang/julia/pull/50105
+# No ambiguity with import because this requires the first argument to be a symbol.
+macro compat(public::Symbol, symbols_expr::Union{Expr, Symbol})
+    public == :public || throw(ArgumentError("Invalid Syntax: `@compat $public $symbols_expr`"))
+    symbols = _get_symbols(symbols_expr)
+    if VERSION >= v"1.11.0-DEV.469"
+        esc(Expr(:public, symbols...))
+    end
+end
+
+"""
+    _valid_macro(expr)
+
+Check if `expr` is a valid macro call with no arguments.
+"""
+_valid_macro(expr) = Meta.isexpr(expr, :macrocall) && length(expr.args) == 2 &&
+    expr.args[1] isa Symbol && string(expr.args[1])[1] == '@' &&
+    expr.args[2] isa LineNumberNode
+
+_var_str_macro(expr) = Meta.isexpr(expr, :macrocall) && length(expr.args) == 3 &&
+    expr.args[1] === Symbol("@var_str") &&
+    expr.args[2] isa LineNumberNode
+
+_get_symbols(symbol::Symbol) = [symbol]
+function _get_symbols(expr::Expr)
+    _valid_macro(expr) && return [expr.args[1]]
+    _var_str_macro(expr) && return [Symbol(expr.args[3])]
+    expr.head == :tuple || throw(ArgumentError("cannot mark `$expr` as public. Try `@compat public foo, bar`."))
+    symbols = Vector{Symbol}(undef, length(expr.args))
+    for (i, arg) in enumerate(expr.args)
+        if arg isa Symbol
+            symbols[i] = arg
+        elseif _valid_macro(arg)
+            symbols[i] = arg.args[1]
+        elseif _var_str_macro(arg)
+            symbols[i] = Symbol(expr.args[3])
+        else
+            throw(ArgumentError("cannot mark `$arg` as public. Try `@compat public foo, bar`."))
+        end
+    end
+    symbols
+end

test/runtests.jl

@@ -1585,3 +1585,35 @@ end
     @test_throws ArgumentError stack([])
     @test_throws ArgumentError stack(x for x in 1:3 if false)
 end
+
+
+module Mod50105
+    using Compat
+    @compat public foo, var"#", baz
+    @compat public var"blah"
+    @compat public @mac1
+    @compat public f00, @mac2, @mac3
+    @compat public @mac4, @mac5
+end
+
+# https://github.com/JuliaLang/julia/pull/50105
+@testset "@compat public" begin
+    @compat public foo_50105
+    # foo_50105 = 4 # Uncommenting this line would cause errors due to https://github.com/JuliaLang/julia/issues/51325
+    @test Base.isexported(@__MODULE__, :foo_50105) === false
+    VERSION >= v"1.11.0-DEV.469" && @test Base.ispublic(@__MODULE__, :foo_50105)
+    for sym in [:foo, Symbol("#"), :baz, Symbol("@mac1"), :f00, Symbol("@mac2"), Symbol("@mac3"), Symbol("@mac4"), Symbol("@mac5")]
+        @test Base.isexported(Mod50105, sym) === false
+        VERSION >= v"1.11.0-DEV.469" && @test Base.ispublic(Mod50105, sym)
+    end
+
+    @test_throws LoadError @eval @compat public 4, bar
+    @test_throws LoadError @eval @compat public foo bar
+    @test_throws LoadError @eval @compat publac foo, bar
+    @test_throws LoadError @eval @compat public 4, @bar
+    @test_throws LoadError @eval @compat public foo @bar
+    @test_throws LoadError @eval @compat publac foo, @bar
+    @test_throws LoadError @eval @compat public @bar, 4
+    @test_throws LoadError @eval @compat public @bar foo
+    @test_throws LoadError @eval @compat publac @bar, foo
+end