Add uplevel keyword to Kernel#warn and use it

If uplevel keyword is given, the warning message is prepended
with caller file and line information and the string "warning: ".
The use of the uplevel keyword makes Kernel#warn format output
similar to how rb_warn formats output.

This patch modifies net/ftp and net/imap to use Kernel#warn
instead of $stderr.puts or $stderr.printf, since they are used
for printing warnings.

This makes lib/cgi/core and tempfile use $stderr.puts instead of
warn for debug logging, since they are used for debug printing
and not for warning.

This does not modify bundler, rubygems, or rdoc, as those are
maintained outside of ruby and probably wish to remain backwards
compatible with older ruby versions.

rb_warn_m code is originally from nobu, but I've changed it
so that it only includes the path and lineno from uplevel
(not the method), and also prepends the string "warning: ",
to make it more similar to rb_warn.

From: Jeremy Evans code@jeremyevans.net
Signed-off-by: Urabe Shyouhei shyouhei@ruby-lang.org


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61155 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

32 files changed, 92 insertions, 63 deletions

diff --git a/error.c b/error.c
index 4b921f99ff..075cb1dfb1 100644
--- a/error.c
+++ b/error.c
@@ -327,10 +327,39 @@ warning_write(int argc, VALUE *argv, VALUE buf)
 static VALUE
 rb_warn_m(int argc, VALUE *argv, VALUE exc)
 {
-    if (!NIL_P(ruby_verbose) && argc > 0) {
+    VALUE opts, uplevel = Qnil;
+
+    if (!NIL_P(ruby_verbose) && argc > 0 &&
+	    (argc = rb_scan_args(argc, argv, "*:", NULL, &opts)) > 0) {
 	VALUE str = argv[0];
-	if (argc > 1 || !end_with_asciichar(str, '\n')) {
-	    str = rb_str_tmp_new(0);
+	if (!NIL_P(opts)) {
+	    static ID kwds[1];
+	    if (!kwds[0]) {
+		CONST_ID(kwds[0], "uplevel");
+	    }
+	    rb_get_kwargs(opts, kwds, 0, 1, &uplevel);
+	    if (uplevel == Qundef) {
+		uplevel = Qnil;
+	    }
+	    else if (!NIL_P(uplevel)) {
+		uplevel = LONG2NUM((long)NUM2ULONG(uplevel) + 1);
+		uplevel = rb_vm_thread_backtrace_locations(1, &uplevel, GET_THREAD()->self);
+		if (!NIL_P(uplevel)) {
+		    uplevel = rb_ary_entry(uplevel, 0);
+		}
+	    }
+	}
+	if (argc > 1 || !NIL_P(uplevel) || !end_with_asciichar(str, '\n')) {
+	    if (NIL_P(uplevel)) {
+		str = rb_str_tmp_new(0);
+	    }
+	    else {
+		VALUE path;
+		path = rb_funcall(uplevel, rb_intern("path"), 0);
+		str = rb_sprintf("%s:%li: warning: ",
+		    rb_string_value_ptr(&path),
+		    NUM2LONG(rb_funcall(uplevel, rb_intern("lineno"), 0)));
+	    }
 	    RBASIC_SET_CLASS(str, rb_cWarningBuffer);
 	    rb_io_puts(argc, argv, str);
 	    RBASIC_SET_CLASS(str, rb_cString);
diff --git a/lib/cgi/core.rb b/lib/cgi/core.rb
index 1b5f7ed390..d510b80628 100644
--- a/lib/cgi/core.rb
+++ b/lib/cgi/core.rb
@@ -267,7 +267,7 @@ class CGI
   def _header_for_modruby(buf)  #:nodoc:
     request = Apache::request
     buf.scan(/([^:]+): (.+)#{EOL}/o) do |name, value|
-      warn sprintf("name:%s value:%s\n", name, value) if $DEBUG
+      $stderr.puts sprintf("name:%s value:%s\n", name, value) if $DEBUG
       case name
       when 'Set-Cookie'
         request.headers_out.add(name, value)
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 4f327fd188..7dbd65e799 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -50,7 +50,7 @@ module CMath
     atanh
   ].each do |meth|
     define_method(meth + '!') do |*args, &block|
-      warn("CMath##{meth}! is deprecated; use CMath##{meth} or Math##{meth}") if $VERBOSE
+      warn("CMath##{meth}! is deprecated; use CMath##{meth} or Math##{meth}", uplevel: 1) if $VERBOSE
       RealMath.send(meth, *args, &block)
     end
   end
diff --git a/lib/delegate.rb b/lib/delegate.rb
index 71aff40f7f..37819a28f4 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -97,7 +97,7 @@ class Delegator < BasicObject
     target = self.__getobj__ {r = false}
     r &&= target.respond_to?(m, include_private)
     if r && include_private && !target.respond_to?(m, false)
-      warn "#{caller(3, 1)[0]}: delegator does not forward private method \##{m}"
+      warn "delegator does not forward private method \##{m}", uplevel: 3
       return false
     end
     r
diff --git a/lib/drb/ssl.rb b/lib/drb/ssl.rb
index 8d2724e736..45fe4f1f74 100644
--- a/lib/drb/ssl.rb
+++ b/lib/drb/ssl.rb
@@ -336,7 +336,7 @@ module DRb
       end
       self.class.new(uri, ssl, @config, true)
       rescue OpenSSL::SSL::SSLError
-        warn("#{__FILE__}:#{__LINE__}: warning: #{$!.message} (#{$!.class})") if @config[:verbose]
+        warn("#{$!.message} (#{$!.class})", uplevel: 0) if @config[:verbose]
         retry
       end
     end
diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index 3662f56011..a8e5aa1d5a 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -206,7 +206,7 @@ module Forwardable
       method_call = "#{<<-"begin;"}\n#{<<-"end;".chomp}"
         begin;
           unless defined? _.#{method}
-            ::Kernel.warn "\#{caller_locations(1)[0]}: "#{mesg.dump}"\#{_.class}"'##{method}'
+            ::Kernel.warn #{mesg.dump}"\#{_.class}"'##{method}', uplevel: 1
             _#{method_call}
           else
             _.#{method}(*args, &block)
diff --git a/lib/ipaddr.rb b/lib/ipaddr.rb
index 0f3a5e2878..60f102d4e6 100644
--- a/lib/ipaddr.rb
+++ b/lib/ipaddr.rb
@@ -310,7 +310,7 @@ class IPAddr
 
   # Returns true if the ipaddr is an IPv4-compatible IPv6 address.
   def ipv4_compat?
-    warn "#{caller(1, 1)[0]}: warning: IPAddr\##{__callee__} is obsolete" if $VERBOSE
+    warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
     _ipv4_compat?
   end
 
@@ -336,7 +336,7 @@ class IPAddr
   # Returns a new ipaddr built by converting the native IPv4 address
   # into an IPv4-compatible IPv6 address.
   def ipv4_compat
-    warn "#{caller(1, 1)[0]}: warning: IPAddr\##{__callee__} is obsolete" if $VERBOSE
+    warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
     if !ipv4?
       raise InvalidAddressError, "not an IPv4 address"
     end
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index db03340a69..c50e3421ec 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -277,7 +277,7 @@ module IRB # :nodoc:
       begin
         require m
       rescue LoadError => err
-        warn err.backtrace[0] << ":#{err.class}: #{err}"
+        warn ":#{err.class}: #{err}", uplevel: 0
       end
     end
   end
diff --git a/lib/irb/locale.rb b/lib/irb/locale.rb
index df540c8cbb..b713f50e76 100644
--- a/lib/irb/locale.rb
+++ b/lib/irb/locale.rb
@@ -31,7 +31,7 @@ module IRB # :nodoc:
         if @encoding_name
           begin load 'irb/encoding_aliases.rb'; rescue LoadError; end
           if @encoding = @@legacy_encoding_alias_map[@encoding_name]
-            warn "%s is obsolete. use %s" % ["#{@lang}_#{@territory}.#{@encoding_name}", "#{@lang}_#{@territory}.#{@encoding.name}"]
+            warn(("%s is obsolete. use %s" % ["#{@lang}_#{@territory}.#{@encoding_name}", "#{@lang}_#{@territory}.#{@encoding.name}"]), uplevel: 1)
           end
           @encoding = Encoding.find(@encoding_name) rescue nil
         end
diff --git a/lib/matrix.rb b/lib/matrix.rb
index ca4424f4b1..923e716b35 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -1184,7 +1184,7 @@ class Matrix
   # deprecated; use Matrix#determinant
   #
   def determinant_e
-    warn "#{caller(1, 1)[0]}: warning: Matrix#determinant_e is deprecated; use #determinant"
+    warn "Matrix#determinant_e is deprecated; use #determinant", uplevel: 1
     determinant
   end
   alias det_e determinant_e
@@ -1242,7 +1242,7 @@ class Matrix
   # deprecated; use Matrix#rank
   #
   def rank_e
-    warn "#{caller(1, 1)[0]}: warning: Matrix#rank_e is deprecated; use #rank"
+    warn "Matrix#rank_e is deprecated; use #rank", uplevel: 1
     rank
   end
 
@@ -1435,17 +1435,17 @@ class Matrix
   end
 
   def elements_to_f
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_f is deprecated, use map(&:to_f)"
+    warn "Matrix#elements_to_f is deprecated, use map(&:to_f)", uplevel: 1
     map(&:to_f)
   end
 
   def elements_to_i
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_i is deprecated, use map(&:to_i)"
+    warn "Matrix#elements_to_i is deprecated, use map(&:to_i)", uplevel: 1
     map(&:to_i)
   end
 
   def elements_to_r
-    warn "#{caller(1, 1)[0]}: warning: Matrix#elements_to_r is deprecated, use map(&:to_r)"
+    warn "Matrix#elements_to_r is deprecated, use map(&:to_r)", uplevel: 1
     map(&:to_r)
   end
 
@@ -2098,17 +2098,17 @@ class Vector
   end
 
   def elements_to_f
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_f is deprecated"
+    warn "Vector#elements_to_f is deprecated", uplevel: 1
     map(&:to_f)
   end
 
   def elements_to_i
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_i is deprecated"
+    warn "Vector#elements_to_i is deprecated", uplevel: 1
     map(&:to_i)
   end
 
   def elements_to_r
-    warn "#{caller(1, 1)[0]}: warning: Vector#elements_to_r is deprecated"
+    warn "Vector#elements_to_r is deprecated", uplevel: 1
     map(&:to_r)
   end
 
diff --git a/lib/net/ftp.rb b/lib/net/ftp.rb
index cfd72ee4e0..a7915189bd 100644
--- a/lib/net/ftp.rb
+++ b/lib/net/ftp.rb
@@ -310,13 +310,13 @@ module Net
 
     # Obsolete
     def return_code # :nodoc:
-      $stderr.puts("warning: Net::FTP#return_code is obsolete and do nothing")
+      warn("Net::FTP#return_code is obsolete and do nothing", uplevel: 1)
       return "\n"
     end
 
     # Obsolete
     def return_code=(s) # :nodoc:
-      $stderr.puts("warning: Net::FTP#return_code= is obsolete and do nothing")
+      warn("Net::FTP#return_code= is obsolete and do nothing", uplevel: 1)
     end
 
     # Constructs a socket with +host+ and +port+.
diff --git a/lib/net/http.rb b/lib/net/http.rb
index 6aa3839011..c2d33018a2 100644
--- a/lib/net/http.rb
+++ b/lib/net/http.rb
@@ -708,7 +708,7 @@ module Net   #:nodoc:
     #   http.start { .... }
     #
     def set_debug_output(output)
-      warn 'Net::HTTP#set_debug_output called after HTTP started' if started?
+      warn 'Net::HTTP#set_debug_output called after HTTP started', uplevel: 1 if started?
       @debug_output = output
     end
 
diff --git a/lib/net/http/generic_request.rb b/lib/net/http/generic_request.rb
index 6c5ceafe61..526cc333fc 100644
--- a/lib/net/http/generic_request.rb
+++ b/lib/net/http/generic_request.rb
@@ -82,7 +82,7 @@ class Net::HTTPGenericRequest
   end
 
   def body_exist?
-    warn "Net::HTTPRequest#body_exist? is obsolete; use response_body_permitted?" if $VERBOSE
+    warn "Net::HTTPRequest#body_exist? is obsolete; use response_body_permitted?", uplevel: 1 if $VERBOSE
     response_body_permitted?
   end
 
@@ -299,7 +299,7 @@ class Net::HTTPGenericRequest
 
   def supply_default_content_type
     return if content_type()
-    warn 'net/http: warning: Content-Type did not set; using application/x-www-form-urlencoded' if $VERBOSE
+    warn 'net/http: Content-Type did not set; using application/x-www-form-urlencoded', uplevel: 1 if $VERBOSE
     set_content_type 'application/x-www-form-urlencoded'
   end
 
diff --git a/lib/net/http/header.rb b/lib/net/http/header.rb
index 3484b5b681..5c543e769d 100644
--- a/lib/net/http/header.rb
+++ b/lib/net/http/header.rb
@@ -14,9 +14,9 @@ module Net::HTTPHeader
     @header = {}
     return unless initheader
     initheader.each do |key, value|
-      warn "net/http: warning: duplicated HTTP header: #{key}" if key?(key) and $VERBOSE
+      warn "net/http: duplicated HTTP header: #{key}", uplevel: 1 if key?(key) and $VERBOSE
       if value.nil?
-        warn "net/http: warning: nil HTTP header: #{key}" if $VERBOSE
+        warn "net/http: nil HTTP header: #{key}", uplevel: 1 if $VERBOSE
       else
         @header[key.downcase] = [value.strip]
       end
diff --git a/lib/net/http/response.rb b/lib/net/http/response.rb
index ee02f4be4a..6a78272ac8 100644
--- a/lib/net/http/response.rb
+++ b/lib/net/http/response.rb
@@ -140,17 +140,17 @@ class Net::HTTPResponse
   #
 
   def response   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#response is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#response is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
   def header   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#header is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#header is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
   def read_header   #:nodoc:
-    warn "#{caller(1, 1)[0]}: warning: Net::HTTPResponse#read_header is obsolete" if $VERBOSE
+    warn "Net::HTTPResponse#read_header is obsolete", uplevel: 1 if $VERBOSE
     self
   end
 
diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index bb6754c732..3d33b94fdd 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -2032,8 +2032,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2060,8 +2059,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2090,8 +2088,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
@@ -2151,8 +2148,7 @@ module Net
       # generate a warning message to +stderr+, then return
       # the value of +subtype+.
       def media_subtype
-        $stderr.printf("warning: media_subtype is obsolete.\n")
-        $stderr.printf("         use subtype instead.\n")
+        warn("media_subtype is obsolete, use subtype instead.\n", uplevel: 1)
         return subtype
       end
     end
diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index 6cf0ecefc3..28890304e4 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -162,7 +162,7 @@ class OpenStruct
   end
   private :modifiable?
 
-  # ::Kernel.warn("#{caller(1, 1)[0]}: do not use OpenStruct#modifiable")
+  # ::Kernel.warn("do not use OpenStruct#modifiable", uplevel: 1)
   alias modifiable modifiable? # :nodoc:
   protected :modifiable
 
@@ -181,7 +181,7 @@ class OpenStruct
   end
   private :new_ostruct_member!
 
-  # ::Kernel.warn("#{caller(1, 1)[0]}: do not use OpenStruct#new_ostruct_member")
+  # ::Kernel.warn("do not use OpenStruct#new_ostruct_member", uplevel: 1)
   alias new_ostruct_member new_ostruct_member! # :nodoc:
   protected :new_ostruct_member
 
diff --git a/lib/rexml/cdata.rb b/lib/rexml/cdata.rb
index fe9b49b5f7..2238446dc4 100644
--- a/lib/rexml/cdata.rb
+++ b/lib/rexml/cdata.rb
@@ -58,7 +58,7 @@ module REXML
     #  c = CData.new( " Some text " )
     #  c.write( $stdout )     #->  <![CDATA[ Some text ]]>
     def write( output=$stdout, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn( "#{self.class.name}.write is deprecated" )
+      Kernel.warn( "#{self.class.name}.write is deprecated", uplevel: 1)
       indent( output, indent )
       output << START
       output << @string
diff --git a/lib/rexml/comment.rb b/lib/rexml/comment.rb
index 746af77296..822fe0d586 100644
--- a/lib/rexml/comment.rb
+++ b/lib/rexml/comment.rb
@@ -48,7 +48,7 @@ module REXML
     # ie_hack::
     #    Needed for conformity to the child API, but not used by this class.
     def write( output, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn("Comment.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("Comment.write is deprecated.  See REXML::Formatters", uplevel: 1)
       indent( output, indent )
       output << START
       output << @string
diff --git a/lib/rexml/element.rb b/lib/rexml/element.rb
index a9811bcba3..ac9b10872c 100644
--- a/lib/rexml/element.rb
+++ b/lib/rexml/element.rb
@@ -710,7 +710,7 @@ module REXML
     #  doc.write( out )     #-> doc is written to the string 'out'
     #  doc.write( $stdout ) #-> doc written to the console
     def write(output=$stdout, indent=-1, transitive=false, ie_hack=false)
-      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters", uplevel: 1)
       formatter = if indent > -1
           if transitive
             require "rexml/formatters/transitive"
diff --git a/lib/rexml/instruction.rb b/lib/rexml/instruction.rb
index 576939ca2b..c4f65eefc1 100644
--- a/lib/rexml/instruction.rb
+++ b/lib/rexml/instruction.rb
@@ -43,7 +43,7 @@ module REXML
     # See the rexml/formatters package
     #
     def write writer, indent=-1, transitive=false, ie_hack=false
-      Kernel.warn( "#{self.class.name}.write is deprecated" )
+      Kernel.warn( "#{self.class.name}.write is deprecated", uplevel: 1)
       indent(writer, indent)
       writer << START.sub(/\\/u, '')
       writer << @target
diff --git a/lib/rexml/node.rb b/lib/rexml/node.rb
index c7a3936799..52337ade44 100644
--- a/lib/rexml/node.rb
+++ b/lib/rexml/node.rb
@@ -26,7 +26,7 @@ module REXML
     #   REXML::Formatters package for changing the output style.
     def to_s indent=nil
       unless indent.nil?
-        Kernel.warn( "#{self.class.name}.to_s(indent) parameter is deprecated" )
+        Kernel.warn( "#{self.class.name}.to_s(indent) parameter is deprecated", uplevel: 1)
         f = REXML::Formatters::Pretty.new( indent )
         f.write( self, rv = "" )
       else
diff --git a/lib/rexml/text.rb b/lib/rexml/text.rb
index 9ea8ba9df3..86269dea1e 100644
--- a/lib/rexml/text.rb
+++ b/lib/rexml/text.rb
@@ -293,7 +293,7 @@ module REXML
     # See REXML::Formatters
     #
     def write( writer, indent=-1, transitive=false, ie_hack=false )
-      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters")
+      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters", uplevel: 1)
       formatter = if indent > -1
           REXML::Formatters::Pretty.new( indent )
         else
diff --git a/lib/rss/rss.rb b/lib/rss/rss.rb
index f88bb3c1ba..db87e11ad5 100644
--- a/lib/rss/rss.rb
+++ b/lib/rss/rss.rb
@@ -596,11 +596,10 @@ EOC
 
       def #{accessor_name}=(*args)
         receiver = self.class.name
-        warn("Warning:\#{caller.first.sub(/:in `.*'\z/, '')}: " \
-             "Don't use `\#{receiver}\##{accessor_name} = XXX'/" \
+        warn("Don't use `\#{receiver}\##{accessor_name} = XXX'/" \
              "`\#{receiver}\#set_#{accessor_name}(XXX)'. " \
              "Those APIs are not sense of Ruby. " \
-             "Use `\#{receiver}\##{plural_name} << XXX' instead of them.")
+             "Use `\#{receiver}\##{plural_name} << XXX' instead of them.", uplevel: 1)
         if args.size == 1
           @#{accessor_name}.push(args[0])
         else
diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index 5489ac044f..671ac7b83b 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -124,7 +124,7 @@ class Tempfile < DelegateClass(File)
   # If Tempfile.new cannot find a unique filename within a limited
   # number of tries, then it will raise an exception.
   def initialize(basename="", tmpdir=nil, mode: 0, **options)
-    warn "Tempfile.new doesn't call the given block." if block_given?
+    warn "Tempfile.new doesn't call the given block.", uplevel: 1 if block_given?
 
     @unlinked = false
     @mode = mode|File::RDWR|File::CREAT|File::EXCL
@@ -250,7 +250,7 @@ class Tempfile < DelegateClass(File)
     def call(*args)
       return if @pid != Process.pid
 
-      warn "removing #{@tmpfile.path}..." if $DEBUG
+      $stderr.puts "removing #{@tmpfile.path}..." if $DEBUG
 
       @tmpfile.close
       begin
@@ -258,7 +258,7 @@ class Tempfile < DelegateClass(File)
       rescue Errno::ENOENT
       end
 
-      warn "done" if $DEBUG
+      $stderr.puts "done" if $DEBUG
     end
   end
 
diff --git a/lib/timeout.rb b/lib/timeout.rb
index 057dd7fe68..a33bb4ce65 100644
--- a/lib/timeout.rb
+++ b/lib/timeout.rb
@@ -118,7 +118,7 @@ module Timeout
 end
 
 def timeout(*args, &block)
-  warn "#{caller_locations(1, 1)[0]}: Object##{__method__} is deprecated, use Timeout.timeout instead."
+  warn "Object##{__method__} is deprecated, use Timeout.timeout instead.", uplevel: 1
   Timeout.timeout(*args, &block)
 end
 
diff --git a/lib/uri/common.rb b/lib/uri/common.rb
index a082c2a918..764f89d810 100644
--- a/lib/uri/common.rb
+++ b/lib/uri/common.rb
@@ -100,7 +100,7 @@ module URI
     #   # => "@%3F@%21"
     #
     def escape(*arg)
-      warn "#{caller(1, 1)[0]}: warning: URI.escape is obsolete" if $VERBOSE
+      warn "URI.escape is obsolete", uplevel: 1 if $VERBOSE
       DEFAULT_PARSER.escape(*arg)
     end
     alias encode escape
@@ -132,7 +132,7 @@ module URI
     #   # => "http://example.com/?a=\t\r"
     #
     def unescape(*arg)
-      warn "#{caller(1, 1)[0]}: warning: URI.unescape is obsolete" if $VERBOSE
+      warn "URI.unescape is obsolete", uplevel: 1 if $VERBOSE
       DEFAULT_PARSER.unescape(*arg)
     end
     alias decode unescape
@@ -300,7 +300,7 @@ module URI
   #   # => ["http://foo.example.com/bla", "mailto:test@example.com"]
   #
   def self.extract(str, schemes = nil, &block)
-    warn "#{caller(1, 1)[0]}: warning: URI.extract is obsolete" if $VERBOSE
+    warn "URI.extract is obsolete", uplevel: 1 if $VERBOSE
     DEFAULT_PARSER.extract(str, schemes, &block)
   end
 
@@ -336,7 +336,7 @@ module URI
   #   end
   #
   def self.regexp(schemes = nil)
-    warn "#{caller(1, 1)[0]}: warning: URI.regexp is obsolete" if $VERBOSE
+    warn "URI.regexp is obsolete", uplevel: 1 if $VERBOSE
     DEFAULT_PARSER.make_regexp(schemes)
   end
 
diff --git a/lib/uri/generic.rb b/lib/uri/generic.rb
index 044d408f50..dc4f9c4c30 100644
--- a/lib/uri/generic.rb
+++ b/lib/uri/generic.rb
@@ -1517,7 +1517,7 @@ module URI
       elsif name == 'http_proxy'
         unless proxy_uri = env[name]
           if proxy_uri = env[name.upcase]
-            warn 'The environment variable HTTP_PROXY is discouraged.  Use http_proxy.'
+            warn 'The environment variable HTTP_PROXY is discouraged.  Use http_proxy.', uplevel: 1
           end
         end
       else
diff --git a/lib/webrick/server.rb b/lib/webrick/server.rb
index 06b7f9fde3..88e160d981 100644
--- a/lib/webrick/server.rb
+++ b/lib/webrick/server.rb
@@ -103,7 +103,7 @@ module WEBrick
       @shutdown_pipe = nil
       unless @config[:DoNotListen]
         if @config[:Listen]
-          warn(":Listen option is deprecated; use GenericServer#listen")
+          warn(":Listen option is deprecated; use GenericServer#listen", uplevel: 1)
         end
         listen(@config[:BindAddress], @config[:Port])
         if @config[:Port] == 0
diff --git a/lib/webrick/utils.rb b/lib/webrick/utils.rb
index 68833af96e..07044876b9 100644
--- a/lib/webrick/utils.rb
+++ b/lib/webrick/utils.rb
@@ -37,7 +37,7 @@ module WEBrick
         Process::Sys::setgid(pw.gid)
         Process::Sys::setuid(pw.uid)
       else
-        warn("WEBrick::Utils::su doesn't work on this platform")
+        warn("WEBrick::Utils::su doesn't work on this platform", uplevel: 1)
       end
     end
     module_function :su
diff --git a/lib/yaml.rb b/lib/yaml.rb
index 0c33305e1d..aa0a1eb470 100644
--- a/lib/yaml.rb
+++ b/lib/yaml.rb
@@ -5,9 +5,9 @@
 begin
   require 'psych'
 rescue LoadError
-  warn "#{caller[0]}:"
-  warn "It seems your ruby installation is missing psych (for YAML output)."
-  warn "To eliminate this warning, please install libyaml and reinstall your ruby."
+  warn "It seems your ruby installation is missing psych (for YAML output).\n" \
+    "To eliminate this warning, please install libyaml and reinstall your ruby.\n",
+    uplevel: 1
   raise
 end
 
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index da1cbd37cf..ce3e98f2c8 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -1003,6 +1003,11 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
     assert_equal(["\n"],     capture_warning_warn {warn ""})
   end
 
+  def test_kernel_warn_uplevel
+    warning = capture_warning_warn {warn("test warning", uplevel: 0)}
+    assert_equal("#{__FILE__}:#{__LINE__-1}: warning: test warning\n", warning[0])
+  end
+
   def test_warning_warn_invalid_argument
     assert_raise(TypeError) do
       ::Warning.warn nil