Improve Ruby support in 'etags'

* lib-src/etags.c (Ruby_functions): Tag constants.  Don't tag
singleton classes.  Remove class qualifiers from tags generated
for method and constant names.  (Bug#22241)

* doc/emacs/maintaining.texi (Tag Syntax): Mention that constants
are tagged by etags in Ruby.

* etc/NEWS: Mention that constants are tagged by etags in Ruby.

* test/etags/ruby-src/test1.ruby: Add more tests.
* test/etags/ETAGS.good_1:
* test/etags/ETAGS.good_2:
* test/etags/ETAGS.good_3:
* test/etags/ETAGS.good_4:
* test/etags/ETAGS.good_5:
* test/etags/ETAGS.good_6:
* test/etags/CTAGS.good: Adapt to the changes in etags and in Ruby
tests.

11 files changed, 154 insertions, 33 deletions

diff --git a/doc/emacs/maintaining.texi b/doc/emacs/maintaining.texi
index 471a16b57de..7039de63e53 100644
--- a/doc/emacs/maintaining.texi
+++ b/doc/emacs/maintaining.texi
@@ -2264,7 +2264,7 @@ generate a tag.
 
 @item
 In Ruby code, @code{def} or @code{class} or @code{module} at the
-beginning of a line generate a tag.
+beginning of a line generate a tag.  Constants also generate tags.
 @end itemize
 
   You can also generate tags based on regexp matching (@pxref{Etags
diff --git a/etc/NEWS b/etc/NEWS
index af2dee931f3..78dce166b43 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1830,8 +1830,8 @@ qualified names by hand.
 +++
 *** New language Ruby
 
-Names of modules, classes, methods, and functions are tagged.
-Overloaded operators are also tagged.
+Names of modules, classes, methods, functions, and constants are
+tagged.  Overloaded operators are also tagged.
 
 +++
 *** Improved support for Lua
diff --git a/lib-src/etags.c b/lib-src/etags.c
index 54ed1b428e9..adc08a23678 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -4550,18 +4550,68 @@ Ruby_functions (FILE *inf)
 
   LOOP_ON_INPUT_LINES (inf, lb, cp)
     {
+      bool is_class = false;
+      bool is_method = false;
+      char *name;
+
       cp = skip_spaces (cp);
-      if (LOOKING_AT (cp, "def")
-	  || LOOKING_AT (cp, "class")
-	  || LOOKING_AT (cp, "module"))
+      if (c_isalpha (*cp) && c_isupper (*cp)) /* constants */
 	{
-	  char *name = cp;
+	  char *bp, *colon = NULL;
+
+	  name = cp;
+
+	  for (cp++; c_isalnum (*cp) || *cp == '_' || *cp == ':'; cp++)
+	    {
+	      if (*cp == ':')
+		colon = cp;
+	    }
+	  if (cp > name + 1)
+	    {
+	      bp = skip_spaces (cp);
+	      if (*bp == '=' && c_isspace (bp[1]))
+		{
+		  if (colon && !c_isspace (colon[1]))
+		    name = colon + 1;
+		  make_tag (name, cp - name, false,
+			    lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
+		}
+	    }
+	}
+      else if ((is_method = LOOKING_AT (cp, "def")) /* module/class/method */
+	       || (is_class = LOOKING_AT (cp, "class"))
+	       || LOOKING_AT (cp, "module"))
+	{
+	  const char self_name[] = "self.";
+	  const size_t self_size1 = sizeof ("self.") - 1;
+
+	  name = cp;
 
 	 /* Ruby method names can end in a '='.  Also, operator overloading can
 	    define operators whose names include '='.  */
 	  while (!notinname (*cp) || *cp == '=')
 	    cp++;
 
+	  /* Remove "self." from the method name.  */
+	  if (cp - name > self_size1
+	      && strneq (name, self_name, self_size1))
+	    name += self_size1;
+
+	  /* Remove the class/module qualifiers from method names.  */
+	  if (is_method)
+	    {
+	      char *q;
+
+	      for (q = name; q < cp && *q != '.'; q++)
+		;
+	      if (q < cp - 1)	/* punt if we see just "FOO." */
+		name = q + 1;
+	    }
+
+	  /* Don't tag singleton classes.  */
+	  if (is_class && strneq (name, "<<", 2) && cp == name + 2)
+	    continue;
+
 	  make_tag (name, cp - name, true,
 		    lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
 	}
diff --git a/test/etags/CTAGS.good b/test/etags/CTAGS.good
index 1c494d64277..86eb9f85cf3 100644
--- a/test/etags/CTAGS.good
+++ b/test/etags/CTAGS.good
@@ -227,6 +227,8 @@ A	cp-src/c.C	117
 A	cp-src/fail.C	7
 A	cp-src/fail.C	23
 A	ruby-src/test1.ruby	/^class A$/
+A	ruby-src/test1.ruby	/^module A$/
+ABC	ruby-src/test1.ruby	11
 ADDRESS	c-src/emacs/src/gmalloc.c	/^#define ADDRESS(B)	((void *) (((B) - 1) * BLOCKSIZ/
 ALIGNOF_STRUCT_LISP_VECTOR	c-src/emacs/src/lisp.h	1378
 ALLOCATED_BEFORE_DUMPING	c-src/emacs/src/gmalloc.c	/^#define ALLOCATED_BEFORE_DUMPING(P) \\$/
@@ -289,6 +291,7 @@ B	cp-src/c.C	/^void B::B() {}$/
 B	cp-src/c.C	122
 B	cp-src/fail.C	8
 B	cp-src/fail.C	24
+B	ruby-src/test1.ruby	/^  class B$/
 BE_Node	cp-src/c.C	/^void BE_Node::BE_Node() {}$/
 BE_Node	cp-src/c.C	77
 BITS_PER_BITS_WORD	c-src/emacs/src/lisp.h	125
@@ -438,7 +441,6 @@ Cjava_entries	c-src/etags.c	/^Cjava_entries (FILE *inf)$/
 Cjava_help	c-src/etags.c	551
 Cjava_suffixes	c-src/etags.c	549
 ClassExample	ruby-src/test.rb	/^    class ClassExample$/
-ClassExample.class_method	ruby-src/test.rb	/^        def ClassExample.class_method$/
 Clear/p	ada-src/2ataspri.adb	/^   procedure Clear (Cell : in out TAS_Cell) is$/
 Clear/p	ada-src/2ataspri.ads	/^   procedure Clear        (Cell : in out TAS_Cell)/
 Cobol_help	c-src/etags.c	558
@@ -458,6 +460,7 @@ Condition_Variable/t	ada-src/2ataspri.ads	/^   type Condition_Variable is privat
 Condition_Variable/t	ada-src/2ataspri.ads	/^   type Condition_Variable is$/
 Configure	pyt-src/server.py	/^class Configure(Frame, ControlEdit):$/
 ConfirmQuit	pyt-src/server.py	/^def ConfirmQuit(frame, context):$/
+Constant	ruby-src/test1.ruby	26
 ControlEdit	pyt-src/server.py	/^class ControlEdit(Frame):$/
 Controls	pyt-src/server.py	/^class Controls:$/
 CopyTextString	pas-src/common.pas	/^function CopyTextString;(*($/
@@ -939,7 +942,6 @@ Metags	c-src/etags.c	/^main (int argc, char **argv)$/
 Mfail	cp-src/fail.C	/^main()$/
 Mkai-test.pl	perl-src/kai-test.pl	/^package main;$/
 ModuleExample	ruby-src/test.rb	/^module ModuleExample$/
-ModuleExample.module_class_method	ruby-src/test.rb	/^    def ModuleExample.module_class_method$/
 More_Lisp_Bits	c-src/emacs/src/lisp.h	801
 MoveLayerAfter	lua-src/allegro.lua	/^function MoveLayerAfter (this_one)$/
 MoveLayerBefore	lua-src/allegro.lua	/^function MoveLayerBefore (this_one)$/
@@ -2351,6 +2353,7 @@ __str__	pyt-src/server.py	/^    def __str__(self):$/
 __up	c.c	160
 _aligned_blocks	c-src/emacs/src/gmalloc.c	1004
 _aligned_blocks_mutex	c-src/emacs/src/gmalloc.c	518
+_bar?	ruby-src/test1.ruby	/^    def self._bar?(abc)$/
 _bytes_free	c-src/emacs/src/gmalloc.c	376
 _bytes_used	c-src/emacs/src/gmalloc.c	374
 _chunks_free	c-src/emacs/src/gmalloc.c	375
@@ -2620,6 +2623,7 @@ childDidExit	objc-src/Subprocess.m	/^- childDidExit$/
 chunks_free	c-src/emacs/src/gmalloc.c	313
 chunks_used	c-src/emacs/src/gmalloc.c	311
 cjava	c-src/etags.c	2936
+class_method	ruby-src/test.rb	/^        def ClassExample.class_method$/
 classifyLine	php-src/lce_functions.php	/^      function classifyLine($line)$/
 clear	cp-src/conway.hpp	/^    void clear(void) { alive = 0; }$/
 clear-abbrev-table	c-src/abbrev.c	/^DEFUN ("clear-abbrev-table", Fclear_abbrev_table, /
@@ -2952,6 +2956,7 @@ foo	f-src/entry.for	/^       character*(*) function foo()$/
 foo	f-src/entry.strange_suffix	/^       character*(*) function foo()$/
 foo	f-src/entry.strange	/^       character*(*) function foo()$/
 foo	php-src/ptest.php	/^foo()$/
+foo!	ruby-src/test1.ruby	/^    def foo!$/
 foobar	c-src/c.c	/^int foobar() {;}$/
 foobar	c.c	/^extern void foobar (void) __attribute__ ((section /
 foobar2	c-src/h.h	20
@@ -3450,6 +3455,7 @@ miti	html-src/softwarelibero.html	/^Sfatiamo alcuni miti$/
 modifier_names	c-src/emacs/src/keyboard.c	6319
 modifier_symbols	c-src/emacs/src/keyboard.c	6327
 modify_event_symbol	c-src/emacs/src/keyboard.c	/^modify_event_symbol (ptrdiff_t symbol_num, int mod/
+module_class_method	ruby-src/test.rb	/^    def ModuleExample.module_class_method$/
 module_instance_method	ruby-src/test.rb	/^    def module_instance_method$/
 more_aligned_int	c.c	165
 morecore_nolock	c-src/emacs/src/gmalloc.c	/^morecore_nolock (size_t size)$/
@@ -3812,6 +3818,7 @@ quantizing	html-src/algrthms.html	/^Quantizing the Received$/
 questo	../c/c.web	34
 quit_char	c-src/emacs/src/keyboard.c	192
 quit_throw_to_read_char	c-src/emacs/src/keyboard.c	/^quit_throw_to_read_char (bool from_signal)$/
+qux=	ruby-src/test1.ruby	/^      def qux=(tee)$/
 r0	c-src/sysdep.h	54
 r1	c-src/sysdep.h	55
 r_alloc	c-src/emacs/src/lisp.h	/^extern void *r_alloc (void **, size_t) ATTRIBUTE_A/
diff --git a/test/etags/ETAGS.good_1 b/test/etags/ETAGS.good_1
index 52ded46e28a..44ac091066b 100644
--- a/test/etags/ETAGS.good_1
+++ b/test/etags/ETAGS.good_1
@@ -2977,11 +2977,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -2995,12 +2995,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ETAGS.good_2 b/test/etags/ETAGS.good_2
index ea10012669c..8a93e3b0656 100644
--- a/test/etags/ETAGS.good_2
+++ b/test/etags/ETAGS.good_2
@@ -3548,11 +3548,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -3566,12 +3566,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ETAGS.good_3 b/test/etags/ETAGS.good_3
index 3b3650f8fa8..e575b40ab0d 100644
--- a/test/etags/ETAGS.good_3
+++ b/test/etags/ETAGS.good_3
@@ -3321,11 +3321,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -3339,12 +3339,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ETAGS.good_4 b/test/etags/ETAGS.good_4
index 0415c17bff3..28258060517 100644
--- a/test/etags/ETAGS.good_4
+++ b/test/etags/ETAGS.good_4
@@ -3141,11 +3141,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -3159,12 +3159,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ETAGS.good_5 b/test/etags/ETAGS.good_5
index 8dc814e5ac8..35bb353c767 100644
--- a/test/etags/ETAGS.good_5
+++ b/test/etags/ETAGS.good_5
@@ -4056,11 +4056,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -4074,12 +4074,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ETAGS.good_6 b/test/etags/ETAGS.good_6
index 322c1651984..8add300784f 100644
--- a/test/etags/ETAGS.good_6
+++ b/test/etags/ETAGS.good_6
@@ -4056,11 +4056,11 @@ class Configure(760,24879
     def save(797,26022
     def nosave(807,26310
 
-ruby-src/test.rb,604
+ruby-src/test.rb,637
 module ModuleExample1,0
     class ClassExample2,21
         def instance_method3,44
-        def ClassExample.class_method6,121
+        def ClassExample.class_methodclass_method
6,121
         def instance_method_exclamation!9,206
         def instance_method_question?12,310
         def instance_method_equals=instance_method_equals=
15,408
@@ -4074,12 +4074,19 @@ module ModuleExample1,0
         def <=>(<=>
39,943
         def ===(===
42,990
     def module_instance_method46,1051
-    def ModuleExample.module_class_method49,1131
+    def ModuleExample.module_class_methodmodule_class_method
49,1131
 
-ruby-src/test1.ruby,37
+ruby-src/test1.ruby,191
 class A1,0
  def a(2,8
  def b(5,38
+module A9,57
+  class B10,66
+    ABC 11,76
+    def foo!13,89
+    def self._bar?(_bar?
16,111
+      def qux=(qux=
20,162
+A::Constant Constant
26,211
 
 tex-src/testenv.tex,52
 \newcommand{\nm}\nm
4,77
diff --git a/test/etags/ruby-src/test1.ruby b/test/etags/ruby-src/test1.ruby
index 43b1a14b95e..26b7d538b64 100644
--- a/test/etags/ruby-src/test1.ruby
+++ b/test/etags/ruby-src/test1.ruby
@@ -5,3 +5,25 @@ class A
  def b()
  end
 end
+
+module A
+  class B
+    ABC = 4
+
+    def foo!
+    end
+
+    def self._bar?(abc)
+    end
+
+    class << self
+      def qux=(tee)
+      end
+    end
+  end
+end
+
+A::Constant = 5
+
+# def foo_in_comment
+# end