Docsystem: unwrap nospecialize (fixes #34122)

Author: timholy

base/docs/Docs.jl

@@ -120,6 +120,12 @@ signature(@nospecialize other) = signature!([], other)
 function argtype(expr::Expr)
     isexpr(expr, :(::))  && return expr.args[end]
     isexpr(expr, :(...)) && return :(Vararg{$(argtype(expr.args[1]))})
+    if isexpr(expr, :meta) && length(expr.args) == 2
+        a1 = expr.args[1]
+        if a1 === :nospecialize || a1 === :specialize
+            return argtype(expr.args[2])
+        end
+    end
     return argtype(expr.args[1])
 end
 argtype(@nospecialize other) = :Any

test/docs.jl

@@ -211,6 +211,13 @@ function returntype(x::Int)::Int
     x
 end
 
+# @nospecialize (issue #34122)
+"`fnospecialize` for Numbers"
+fnospecialize(@nospecialize(x::Number)) = 1
+
+"`fnospecialize` for arrays"
+fnospecialize(@nospecialize(x::AbstractArray)) = 2
+
 end
 
 let md = meta(DocsTest)[@var(DocsTest)]
@@ -284,6 +291,14 @@ let rt = @var(DocsTest.returntype)
     @test md.order == [Tuple{Float64}, Tuple{Int}]
 end
 
+let fns = @var(DocsTest.fnospecialize)
+    md = meta(DocsTest)[fns]
+    d = md.docs[Tuple{Number}]
+    @test docstrings_equal(d, doc"`fnospecialize` for Numbers")
+    d = md.docs[Tuple{AbstractArray}]
+    @test docstrings_equal(d, doc"`fnospecialize` for arrays")
+end
+
 @test docstrings_equal(@doc(DocsTest.TA), doc"TA")
 
 @test docstrings_equal(@doc(DocsTest.@mac), doc"@mac()")