added log{info,warn} for redirection of messages

NEWS.md

@@ -48,6 +48,9 @@ Language changes
   * The built-in `NTuple` type has been removed; `NTuple{N,T}` is now
     implemented internally as `Tuple{Vararg{T,N}}` ([#11242]).
 
+  * `loginfo` and `logwarn` can be used to redirect `info` and `warn` messages,
+    respectively, either universally or on a per-module/function basis ([#16213]).
+
 Command-line option changes
 ---------------------------
 

base/docs/helpdb/Base.jl

@@ -3599,13 +3599,6 @@ behavior, including program corruption or segfaults, at any later time.
 """
 unsafe_convert
 
-"""
-    warn(msg)
-
-Display a warning. Argument `msg` is a string describing the warning to be displayed.
-"""
-warn
-
 """
     erfinv(x)
 
@@ -4648,13 +4641,6 @@ multiple of four, this is equivalent to a `copy`.
 """
 rotl90(A, k)
 
-"""
-    info(msg)
-
-Display an informational message. Argument `msg` is a string describing the information to be displayed.
-"""
-info
-
 """
     eigmin(A)
 

base/util.jl

@@ -332,18 +332,77 @@ println_with_color(color::Symbol, msg::AbstractString...) =
 
 ## warnings and messages ##
 
+"""
+    info(msg...)
+
+Display an informational message. Argument `msg` is a string describing the information to be displayed.
+
+See also `loginfo`.
+"""
 function info(io::IO, msg...; prefix="INFO: ")
-    println_with_color(info_color(), io, prefix, chomp(string(msg...)))
+    st = StackTraces.remove_frames!(stacktrace(), :info)[1]
+    mo = st.outer_linfo.value.def.module
+    fu = st.func
+    if !isempty(log_info_to)
+        if haskey(log_info_to, (mo,fu))
+            io = log_info_to[(mo,fu)]
+        elseif haskey(log_info_to, mo)
+            io = log_info_to[mo]
+        elseif haskey(log_info_to, nothing)
+            io = log_info_to[nothing]
+        end
+    end
+    println_with_color(info_color(), io, prefix, chomp(string(msg...)), " ($mo.$fu)")
 end
 info(msg...; prefix="INFO: ") = info(STDERR, msg..., prefix=prefix)
 
 # print a warning only once
 
 const have_warned = Set()
+const log_warn_to = Dict()
+const log_info_to = Dict()
+
+"""
+    logwarn([io [, m [, f]]])
+
+Stream output of warnings to `io`, overriding what was otherwise specified.
+Optionally, divert stream only for module `m`, or specifically function `f`
+within `m`.  See `Base.log_warn_to` for the current set of redirections.  Call
+`logwarn` with no arguments to reset everything.
+"""
+logwarn(io::IO, m::Module, f::Symbol) = log_warn_to[(m,f)]=io
+logwarn(io::IO, m::Module) = log_warn_to[m]=io
+logwarn(io::IO) = log_warn_to[nothing]=io
+logwarn() = empty!(log_warn_to)
+
+"""
+    loginfo([io [, m [, f]]])
+
+Stream output of informational messages to `io`, overriding what was otherwise
+specified.  Optionally, divert stream only for module `m`, or specifically
+function `f` within `m`.  See `Base.log_warn_to` for the current set of
+redirections.  Call `loginfo` with no arguments to reset everything.
+"""
+loginfo(io::IO, m::Module, f::Symbol) = log_info_to[(m,f)]=io
+loginfo(io::IO, m::Module) = log_info_to[m]=io
+loginfo(io::IO) = log_info_to[nothing]=io
+loginfo() = empty!(log_info_to)
+
+export logwarn, loginfo
 
 warn_once(io::IO, msg...) = warn(io, msg..., once=true)
 warn_once(msg...) = warn(STDERR, msg..., once=true)
 
+"""
+    warn(msg..., [prefix="WARNING: ", once=false, key=nothing, bt=nothing, filename=nothing, lineno::Int=0])
+
+Display a warning. Argument `msg` is a string describing the warning to be
+displayed.  Set `once` to true and specify a `key` to only display `msg` the
+first time `warn` is called.  If `bt` is not nothing a backtrace is displayed.
+If `filename` is not nothing both it and `lineno` are displayed.
+
+See also `logwarn`.
+"""
 function warn(io::IO, msg...;
               prefix="WARNING: ", once=false, key=nothing, bt=nothing,
               filename=nothing, lineno::Int=0)
@@ -355,7 +414,19 @@ function warn(io::IO, msg...;
         (key in have_warned) && return
         push!(have_warned, key)
     end
-    print_with_color(warn_color(), io, prefix, str)
+    st = StackTraces.remove_frames!(stacktrace(), :warn)[1]
+    mo = st.outer_linfo.value.def.module
+    fu = st.func
+    if !isempty(log_warn_to)
+        if haskey(log_warn_to, (mo,fu))
+            io = log_warn_to[(mo,fu)]
+        elseif haskey(log_warn_to, mo)
+            io = log_warn_to[mo]
+        elseif haskey(log_warn_to, nothing)
+            io = log_warn_to[nothing]
+        end
+    end
+    print_with_color(warn_color(), io, prefix, str, " ($mo.$fu)")
     if bt !== nothing
         show_backtrace(io, bt)
     end

doc/stdlib/io-network.rst

@@ -464,17 +464,33 @@ Text I/O
 
    ``color`` may take any of the values ``:normal``\ , ``:bold``\ , ``:black``\ , ``:blue``\ , ``:cyan``\ , ``:green``\ , ``:magenta``\ , ``:red``\ , ``:white``\ , or  ``:yellow``\ .
 
-.. function:: info(msg)
+.. function:: info(msg...)
 
    .. Docstring generated from Julia source
 
    Display an informational message. Argument ``msg`` is a string describing the information to be displayed.
 
-.. function:: warn(msg)
+   See also ``loginfo``\ .
+
+.. function:: warn(msg..., [prefix="WARNING: ", once=false, key=nothing, bt=nothing, filename=nothing, lineno::Int=0])
+
+   .. Docstring generated from Julia source
+
+   Display a warning. Argument ``msg`` is a string describing the warning to be displayed.  Set ``once`` to true and specify a ``key`` to only display ``msg`` the first time ``warn`` is called.  If ``bt`` is not nothing a backtrace is displayed. If ``filename`` is not nothing both it and ``lineno`` are displayed.
+
+   See also ``logwarn``\ .
+
+.. function:: loginfo([io [, m [, f]]])
+
+   .. Docstring generated from Julia source
+
+   Stream output of informational messages to ``io``\ , overriding what was otherwise specified.  Optionally, divert stream only for module ``m``\ , or specifically function ``f`` within ``m``\ .  See ``Base.log_warn_to`` for the current set of redirections.  Call ``loginfo`` with no arguments to reset everything.
+
+.. function:: logwarn([io [, m [, f]]])
 
    .. Docstring generated from Julia source
 
-   Display a warning. Argument ``msg`` is a string describing the warning to be displayed.
+   Stream output of warnings to ``io``\ , overriding what was otherwise specified. Optionally, divert stream only for module ``m``\ , or specifically function ``f`` within ``m``\ .  See ``Base.log_warn_to`` for the current set of redirections.  Call ``logwarn`` with no arguments to reset everything.
 
 .. function:: @printf([io::IOStream], "%Fmt", args...)
 

test/misc.jl

@@ -28,6 +28,53 @@ let bt = backtrace()
     end
 end
 
+module Foo
+    barw(io) = warn(io,"barw")
+    poohw(io) = warn(io,"poohw")
+    bari(io) = info(io,"bari")
+    poohi(io) = info(io,"poohi")
+end
+
+@test contains(sprint(Foo.barw), "WARNING: barw (Foo.barw)")
+@test contains(sprint(Foo.poohw), "WARNING: poohw (Foo.poohw)")
+@test contains(sprint(io->warn(io,"test")), "WARNING: test (Main")
+logwarn(DevNull, Foo, :barw)
+@test sprint(Foo.barw) == ""
+@test contains(sprint(Foo.poohw), "WARNING: poohw (Foo.poohw)")
+@test contains(sprint(io->warn(io,"test")), "WARNING: test (Main")
+logwarn(DevNull, Foo)
+@test sprint(Foo.barw) == ""
+@test sprint(Foo.poohw) == ""
+@test contains(sprint(io->warn(io,"test")), "WARNING: test (Main")
+logwarn(DevNull)
+@test sprint(Foo.barw) == ""
+@test sprint(Foo.poohw) == ""
+@test sprint(io->warn(io,"test")) == ""
+logwarn()
+@test contains(sprint(Foo.barw), "WARNING: barw (Foo.barw)")
+@test contains(sprint(Foo.poohw), "WARNING: poohw (Foo.poohw)")
+@test contains(sprint(io->warn(io,"test")), "WARNING: test (Main")
+
+@test contains(sprint(Foo.bari), "INFO: bari (Foo.bari)")
+@test contains(sprint(Foo.poohi), "INFO: poohi (Foo.poohi)")
+@test contains(sprint(io->info(io,"test")), "INFO: test (Main")
+loginfo(DevNull, Foo, :bari)
+@test sprint(Foo.bari) == ""
+@test contains(sprint(Foo.poohi), "INFO: poohi (Foo.poohi)")
+@test contains(sprint(io->info(io,"test")), "INFO: test (Main")
+loginfo(DevNull, Foo)
+@test sprint(Foo.bari) == ""
+@test sprint(Foo.poohi) == ""
+@test contains(sprint(io->info(io,"test")), "INFO: test (Main")
+loginfo(DevNull)
+@test sprint(Foo.bari) == ""
+@test sprint(Foo.poohi) == ""
+@test sprint(io->info(io,"test")) == ""
+loginfo()
+@test contains(sprint(Foo.bari), "INFO: bari (Foo.bari)")
+@test contains(sprint(Foo.poohi), "INFO: poohi (Foo.poohi)")
+@test contains(sprint(io->info(io,"test")), "INFO: test (Main")
+
 # test assert() method
 @test_throws AssertionError assert(false)
 let res = assert(true)