RFC: solve Ada-specific problem with linespec patches

[Tom Tromey <tromey at redhat dot com>]

This is the patch I mentioned in the other thread.

It applies on top of the other ambiguous linespec patches, and fixes a
couple of Ada-specific problems.

I added a couple of tests so you can readily see the problems.
The first problem is that we needed a way to find all the Ada symbols
corresponding to the linespec the user gave.  I implemented this by
adding a new language method that is called by linespec.  This is just a
thin wrapper around ada_lookup_symbol_list.

The other problem was that special Ada quoting (the <name> form) wasn't
handled.  I fixed this directly in the new Ada method.

I'm looking for feedback from the Ada-knowledgeable.

Tom

2011-11-22  Tom Tromey  <tromey@redhat.com>

	* linespec.c (iterate_over_all_matching_symtabs): Call
	la_iterate_over_symbols.
	(find_function_symbols, decode_variable): Remove Ada special
	case.
	* language.h (struct language_defn) <la_iterate_over_symbols>: New
	field.
	* language.c (unknown_language_defn, auto_language_defn)
	(local_language_defn): Update.
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Update.
	* d-lang.c (d_language_defn): Update.
	* f-lang.c (f_language_defn): Update.
	* jv-lang.c (java_language_defn): Update.
	* m2-lang.c (m2_language_defn): Update.
	* objc-lang.c (objc_language_defn): Update.
	* opencl-lang.c (opencl_language_defn): Update.
	* p-lang.c (pascal_language_defn): Update.
	* ada-lang.c (ada_iterate_over_symbols): New function.
	(ada_language_defn): Update.

2011-11-22  Tom Tromey  <tromey@redhat.com>

	* gdb.ada/homonym.exp: Add two breakpoint tests.

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 2edbe7f..18cb954 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -5052,6 +5052,35 @@ done:
   return ndefns;
 }
 
+/* Implementation of the la_iterate_over_symbols method.  */
+
+static void
+ada_iterate_over_symbols (const char *name, domain_enum domain,
+			  int (*callback) (struct symbol *, void *),
+			  void *data)
+{
+  int ndefs, i;
+  struct ada_symbol_info *results;
+  char *canon;
+  int nlen = strlen (name);
+
+  if (name[0] == '<' && name[nlen - 1] == '>')
+    {
+      canon = alloca (nlen - 1);
+      memcpy (canon, name + 1, nlen - 2);
+      canon[nlen - 2] = '\0';
+    }
+  else
+    canon = ada_encode (ada_fold_name (name));
+
+  ndefs = ada_lookup_symbol_list (canon, NULL, domain, &results);
+  for (i = 0; i < ndefs; ++i)
+    {
+      if (! (*callback) (results[i].sym, data))
+	break;
+    }
+}
+
 struct symbol *
 ada_lookup_encoded_symbol (const char *name, const struct block *block0,
 			   domain_enum namespace, struct block **block_found)
@@ -12284,6 +12313,7 @@ const struct language_defn ada_language_defn = {
   ada_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  ada_iterate_over_symbols,
   LANG_MAGIC
 };
 
diff --git a/gdb/c-lang.c b/gdb/c-lang.c
index 3a35a78..b9101d3 100644
--- a/gdb/c-lang.c
+++ b/gdb/c-lang.c
@@ -863,6 +863,7 @@ const struct language_defn c_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
@@ -984,6 +985,7 @@ const struct language_defn cplus_language_defn =
   default_print_array_index,
   cp_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
@@ -1023,6 +1025,7 @@ const struct language_defn asm_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
@@ -1067,6 +1070,7 @@ const struct language_defn minimal_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/d-lang.c b/gdb/d-lang.c
index c0599a5..44ff68a 100644
--- a/gdb/d-lang.c
+++ b/gdb/d-lang.c
@@ -273,6 +273,7 @@ static const struct language_defn d_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/f-lang.c b/gdb/f-lang.c
index f538eee..fb48069 100644
--- a/gdb/f-lang.c
+++ b/gdb/f-lang.c
@@ -309,6 +309,7 @@ const struct language_defn f_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/jv-lang.c b/gdb/jv-lang.c
index 4eae356..e957255 100644
--- a/gdb/jv-lang.c
+++ b/gdb/jv-lang.c
@@ -1197,6 +1197,7 @@ const struct language_defn java_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/language.c b/gdb/language.c
index 825c02d..d798c38 100644
--- a/gdb/language.c
+++ b/gdb/language.c
@@ -1200,6 +1200,7 @@ const struct language_defn unknown_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
@@ -1241,6 +1242,7 @@ const struct language_defn auto_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
@@ -1280,6 +1282,7 @@ const struct language_defn local_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/language.h b/gdb/language.h
index 1ff575f..ede6a92 100644
--- a/gdb/language.h
+++ b/gdb/language.h
@@ -318,6 +318,19 @@ struct language_defn
     void (*la_get_string) (struct value *value, gdb_byte **buffer, int *length,
 			   struct type **chartype, const char **charset);
 
+    /* Find all symbols in the current program space matching NAME in
+       DOMAIN, according to this language's rules.  For each one, call
+       CALLBACK with the symbol and the DATA argument.  If CALLBACK
+       returns zero, the iteration ends at that point.
+
+       This field can be NULL, meaning that this language doesn't need
+       any special code aside from ordinary searches of the symbol
+       table.  */
+    void (*la_iterate_over_symbols) (const char *name,
+				     domain_enum domain,
+				     int (*callback) (struct symbol *, void *),
+				     void *data);
+
     /* Add fields above this point, so the magic number is always last.  */
     /* Magic number for compat checking.  */
 
diff --git a/gdb/linespec.c b/gdb/linespec.c
index 3e06f09..c07198a 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -376,6 +376,10 @@ iterate_over_all_matching_symtabs (const char *name,
 	    }
 	}
     }
+
+    if (current_language->la_iterate_over_symbols)
+      (*current_language->la_iterate_over_symbols) (name, domain,
+						    callback, data);
   }
 }
 
@@ -2225,28 +2229,6 @@ find_function_symbols (char **argptr, char *p, int is_quote_enclosed,
   iterate_over_all_matching_symtabs (copy, VAR_DOMAIN,
 				     collect_function_symbols, &result, NULL);
 
-  /* If looking up the given name failed, try using the current
-     language to look up a symbol.  This may augment the search.  If a
-     symbol is found this way, repeat the iteration, but using the
-     discovered name.  */
-  if (VEC_empty (symbolp, result)
-      && current_language->la_language == language_ada)
-    {
-      struct symbol *function_symbol;
-
-      function_symbol = lookup_symbol (copy, get_selected_block (0),
-				       VAR_DOMAIN, 0);
-      if (function_symbol && SYMBOL_CLASS (function_symbol) == LOC_BLOCK)
-	{
-	  xfree (copy);
-	  copy = xstrdup (SYMBOL_SEARCH_NAME (function_symbol));
-	  *user_function = copy;
-	  iterate_over_all_matching_symtabs (copy, VAR_DOMAIN,
-					     collect_function_symbols,
-					     &result, NULL);
-	}
-    }
-
   if (VEC_empty (symbolp, result))
     VEC_free (symbolp, result);
   else
@@ -2781,22 +2763,6 @@ decode_variable (struct linespec_state *self, char *copy)
 
   add_matching_symbols_to_info (lookup_name, &info, NULL);
 
-  /* If looking up the given name failed, try using the current
-     language to look up a symbol.  This may augment the search.  If a
-     symbol is found this way, repeat the iteration, but using the
-     discovered name.  */
-  if (info.result.nelts == 0 && current_language->la_language == language_ada)
-    {
-      struct symbol *sym;
-
-      sym = lookup_symbol (lookup_name, get_selected_block (0), VAR_DOMAIN, 0);
-      if (sym)
-	{
-	  copy = SYMBOL_SEARCH_NAME (sym);
-	  add_matching_symbols_to_info (copy, &info, NULL);
-	}
-    }
-
   if (info.result.nelts > 0)
     {
       if (self->canonical)
diff --git a/gdb/m2-lang.c b/gdb/m2-lang.c
index f83c622..52c592a 100644
--- a/gdb/m2-lang.c
+++ b/gdb/m2-lang.c
@@ -401,6 +401,7 @@ const struct language_defn m2_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/objc-lang.c b/gdb/objc-lang.c
index dcf9459..b5024b6 100644
--- a/gdb/objc-lang.c
+++ b/gdb/objc-lang.c
@@ -541,6 +541,7 @@ const struct language_defn objc_language_defn = {
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/opencl-lang.c b/gdb/opencl-lang.c
index 05955b4..43791ea 100644
--- a/gdb/opencl-lang.c
+++ b/gdb/opencl-lang.c
@@ -1024,6 +1024,7 @@ const struct language_defn opencl_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   c_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/p-lang.c b/gdb/p-lang.c
index 655279b..76ec4b9 100644
--- a/gdb/p-lang.c
+++ b/gdb/p-lang.c
@@ -459,6 +459,7 @@ const struct language_defn pascal_language_defn =
   default_print_array_index,
   default_pass_by_reference,
   default_get_string,
+  NULL,
   LANG_MAGIC
 };
 
diff --git a/gdb/testsuite/gdb.ada/homonym.exp b/gdb/testsuite/gdb.ada/homonym.exp
index b5dff1b..c58657a 100644
--- a/gdb/testsuite/gdb.ada/homonym.exp
+++ b/gdb/testsuite/gdb.ada/homonym.exp
@@ -31,6 +31,20 @@ if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug]] != "" }
 
 clean_restart ${testfile}
 
+
+# Do these tests before running, so we are operating in a known
+# environment.
+
+gdb_test "break Get_Value" \
+    "Breakpoint \[0-9\]+ at $hex: Get_Value. .2 locations." \
+    "set breakpoint at Get_Value"
+
+gdb_test "break <homonym__get_value>" \
+    "Breakpoint \[0-9\]+ at $hex: <homonym__get_value>. .2 locations." \
+    "set breakpoint at <homonym__get_value>"
+
+delete_breakpoints
+
 set bp_location [gdb_get_line_number "BREAK_1" ${testdir}/homonym.adb]
 runto "homonym.adb:$bp_location"
 
@@ -86,6 +100,3 @@ gdb_test "ptype lcl" \
 gdb_test "print lcl" \
          "= 17" \
          "print lcl at BREAK_2"
-
-
-