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