Merge pull request JuliaLang#14404 from JuliaLang/jcb/fixannoyingdocb…

…indingerror

Fix exception being thrown when a binding is not defined

base/docs/Docs.jl

@@ -90,8 +90,11 @@ end
 
 function get_obj_meta(obj)
  for mod in modules
- haskey(meta(mod), obj) && return meta(mod)[obj]
+ if haskey(meta(mod), obj)
+ return meta(mod)[obj]
+ end
  end
+ nothing
 end
 
 "`doc(obj)`: Get the metadata associated with `obj`."
@@ -146,38 +149,60 @@ function functionsummary(func::Function)
  return Markdown.parse(takebuf_string(io))
 end
 
+function qualified_name(b::Binding)
+ if b.mod === Main
+ string(b.var)
+ else
+ join((b.mod, b.var), '.')
+ end
+end
+
 function doc(b::Binding)
  d = get_obj_meta(b)
- if d === nothing
- v = getfield(b.mod,b.var)
- d = doc(v)
- if d === nothing
- if startswith(string(b.var),'@')
- # check to see if the binding var is a macro
- d = catdoc(Markdown.parse("""
- No documentation found.
-
- """), macrosummary(b.var, v))
- elseif isa(v,Function)
- d = catdoc(Markdown.parse("""
- No documentation found.
-
- `$(b.mod === Main ? b.var : join((b.mod, b.var),'.'))` is $(isgeneric(v) ? "a generic" : "an anonymous") `Function`.
- """), functionsummary(v))
- elseif isa(v,DataType)
- d = catdoc(Markdown.parse("""
- No documentation found.
-
- """), typesummary(v))
- else
- T = typeof(v)
- d = catdoc(Markdown.parse("""
- No documentation found.
+ if d !== nothing
+ return d
+ end
+ if !(b.defined)
+ return Markdown.parse("""
 
- `$(b.mod === Main ? b.var : join((b.mod, b.var),'.'))` is of type `$T`:
- """), typesummary(typeof(v)))
- end
- end
+ No documentation found.
+
+ Binding `$(qualified_name(b))` does not exist.
+ """)
+ end
+ v = getfield(b.mod,b.var)
+ d = doc(v)
+ if d !== nothing
+ return d
+ end
+ if startswith(string(b.var),'@')
+ # check to see if the binding var is a macro
+ d = catdoc(Markdown.parse("""
+
+ No documentation found.
+
+ """), macrosummary(b.var, v))
+ elseif isa(v,Function)
+ d = catdoc(Markdown.parse("""
+
+ No documentation found.
+
+ `$(qualified_name(b))` is $(isgeneric(v) ? "a generic" : "an anonymous") `Function`.
+ """), functionsummary(v))
+ elseif isa(v,DataType)
+ d = catdoc(Markdown.parse("""
+
+ No documentation found.
+
+ """), typesummary(v))
+ else
+ T = typeof(v)
+ d = catdoc(Markdown.parse("""
+
+ No documentation found.
+
+ `$(qualified_name(b))` is of type `$T`:
+ """), typesummary(typeof(v)))
  end
  return d
 end
@@ -518,8 +543,9 @@ function docm(meta, def, define = true)
 
  def′ = unblock(def)
 
- isexpr(def′, :quote) && isexpr(def′.args[1], :macrocall) &&
+ if isexpr(def′, :quote) && isexpr(def′.args[1], :macrocall)
  return vardoc(meta, nothing, namify(def′.args[1]))
+ end
 
  ex = def # Save unexpanded expression for error reporting.
  def = macroexpand(def)

base/docs/bindings.jl

@@ -5,7 +5,15 @@ export @var
 immutable Binding
  mod::Module
  var::Symbol
- Binding(m, v) = new(Base.which_module(m, v), v)
+ defined::Bool
+
+ function Binding(m, v)
+ if !isdefined(m, v)
+ new(m, v, false)
+ else
+ new(Base.binding_module(m, v), v, true)
+ end
+ end
 end
 
 function splitexpr(x::Expr)

test/docs.jl

@@ -497,6 +497,12 @@ undocumented(x,y) = 3
 
 end
 
+@test docstrings_equal(@doc(Undocumented.bindingdoesnotexist), doc"""
+No documentation found.
+
+Binding `Undocumented.bindingdoesnotexist` does not exist.
+""")
+
 @test docstrings_equal(@doc(Undocumented.A), doc"""
 No documentation found.
 
@@ -577,32 +583,47 @@ end
 import Base.Docs: @var, Binding
 
 let x = Binding(Base, symbol("@time"))
+ @test x.defined == true
  @test @var(@time) == x
  @test @var(Base.@time) == x
  @test @var(Base.Pkg.@time) == x
 end
 
 let x = Binding(Base.LinAlg, :norm)
+ @test x.defined == true
  @test @var(norm) == x
  @test @var(Base.norm) == x
  @test @var(Base.LinAlg.norm) == x
  @test @var(Base.Pkg.Dir.norm) == x
 end
 
 let x = Binding(Core, :Int)
+ @test x.defined == true
  @test @var(Int) == x
  @test @var(Base.Int) == x
  @test @var(Core.Int) == x
  @test @var(Base.Pkg.Resolve.Int) == x
 end
 
 let x = Binding(Base, :Pkg)
+ @test x.defined == true
  @test @var(Pkg) == x
  @test @var(Base.Pkg) == x
  @test @var(Main.Pkg) == x
 end
 
 let x = Binding(Base, :VERSION)
+ @test x.defined == true
  @test @var(VERSION) == x
  @test @var(Base.VERSION) == x
 end
+
+let x = Binding(Base, :bindingdoesnotexist)
+ @test x.defined == false
+ @test @var(Base.bindingdoesnotexist) == x
+end
+
+let x = Binding(Main, :bindingdoesnotexist)
+ @test x.defined == false
+ @test @var(bindingdoesnotexist) == x
+end