Implement __LINE__ and __FILE__ magic macros

Fixes #8066

NEWS.md

@@ -53,6 +53,7 @@ New language features
  Default continues to be of length 1 ([#12385]).
  See http:https://docs.julialang.org/en/latest/manual/parallel-computing/#remoterefs-and-abstractchannels for details.
 
+ * `@__LINE__` special macro now available to reflect invocation source line number ([#12727]).
 
 Language changes
 ----------------

base/docs/helpdb.jl

@@ -2,6 +2,8 @@
 
 # Base.LinAlg.BLAS
 
+import .Docs: keywords
+
 doc"""
  ger!(alpha, x, y, A)
 
@@ -9531,12 +9533,20 @@ Returns an iterator over substrings of `s` that correspond to the extended graph
 """
 graphemes
 
-doc"""
+keywords[symbol("@__FILE__")] = doc"""
+
  @__FILE__() -> AbstractString
 
-`@__FILE__` expands to a string with the absolute path and file name of the script being run. Returns `nothing` if run from a REPL or an empty string if evaluated by `julia -e <expr>`.
+`@__FILE__` expands to a string with the absolute path and file name of the script being run.
+Returns `"none"` if run from a REPL or command-line context.
+"""
+
+keywords[symbol("@__LINE__")] = doc"""
+
+ @__LINE__() -> Int
+
+`@__LINE__` expands to the line number of the call-site.
 """
-:@__FILE__
 
 doc"""
  charwidth(c)

base/exports.jl

@@ -1343,7 +1343,6 @@ export
 
 # Macros
  # parser internal
- @__FILE__,
  @int128_str,
  @uint128_str,
  @big_str,

base/loading.jl

@@ -253,8 +253,6 @@ function source_dir()
  p === nothing ? p : dirname(p)
 end
 
-macro __FILE__() source_path() end
-
 function include_from_node1(_path::AbstractString)
  path, prev = _include_dependency(_path)
  tls = task_local_storage()

src/julia-parser.scm

@@ -2039,14 +2039,18 @@
  (with-space-sensitive
  (let* ((head (parse-unary-prefix s))
  (t (peek-token s)))
- (if (ts:space? s)
+ (cond
+ ((eqv? head '__LINE__) (input-port-line (ts:port s)))
+ ((eqv? head '__FILE__) (string current-filename))
+ ((ts:space? s)
  `(macrocall ,(macroify-name head)
- ,@(parse-space-separated-exprs s))
- (let ((call (parse-call-chain s head #t)))
- (if (and (pair? call) (eq? (car call) 'call))
+ ,@(parse-space-separated-exprs s)))
+ (else
+ (let ((call (parse-call-chain s head #t)))
+ (if (and (pair? call) (eq? (car call) 'call))
  `(macrocall ,(macroify-name (cadr call)) ,@(cddr call))
  `(macrocall ,(macroify-name call)
- ,@(parse-space-separated-exprs s))))))))
+ ,@(parse-space-separated-exprs s)))))))))
 
  ;; command syntax
  ((eqv? t #\`)

test/loading.jl

@@ -3,8 +3,10 @@
 using Base.Test
 
 include("test_sourcepath.jl")
-thefname = "the fname!//\\&\0\1*"
-@test include_string("include_string_test() = @__FILE__", thefname)() == Base.source_path()
+thefname = "the fname!//\\&\1*"
+# passing a second argument to include_string should be reflected by @__FILE__
+@test include_string("test_atsign_file() = @__FILE__", thefname)() == thefname
+@test include_string("test_atsign_file() = @__FILE__")() == "string"
 @test include_string("Base.source_path()", thefname) == Base.source_path()
 @test basename(@__FILE__) == "loading.jl"
 @test isabspath(@__FILE__)