Change search_symbols to return std::vector

This changes search_symbols to return a std::vector, replacing the
previous linked list approach.  This allows the removal of some
cleanups, as well as the use of std::sort and std::unique, saving some
code and extra allocations in sort_search_symbols_remove_dups.

Regression tested by the buildbot.

gdb/ChangeLog
2017-10-08  Tom Tromey  <tom@tromey.com>

	* symtab.c (free_search_symbols, do_free_search_symbols_cleanup)
	(make_cleanup_free_search_symbols): Remove.
	(search_symbols): Return std::vector.
	(symbol_search::compare_search_syms): Now member of
	symbol_search.  Change arguments.
	(sort_search_symbols_remove_dups): Change arguments.  Rewrite.
	(symtab_symbol_info, rbreak_command): Update.
	* symtab.h (struct symbol_search) <next>: Remove.
	Add constructors.
	(symbol_search::operator<): New function.
	(symbol_search::operator==): New function.
	(search_symbols): Remove std::vector.
	(free_search_symbols, make_cleanup_free_search_symbols): Remove.
	(symbol_search::compare_search_syms): Declare.

1 files changed, 36 insertions, 9 deletions

diff --git a/gdb/symtab.h b/gdb/symtab.h
index 8b429a8..cd6dbae 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1561,10 +1561,37 @@ extern symbol *find_function_alias_target (bound_minimal_symbol msymbol);
 /* Note: struct symbol_search, search_symbols, et.al. are declared here,
    instead of making them local to symtab.c, for gdbtk's sake.  */
 
-/* When using search_symbols, a list of the following structs is returned.
-   Callers must free the search list using free_search_symbols!  */
+/* When using search_symbols, a vector of the following structs is
+   returned.  */
 struct symbol_search
 {
+  symbol_search (int block_, struct symbol *symbol_)
+    : block (block_),
+      symbol (symbol_)
+  {
+    msymbol.minsym = nullptr;
+    msymbol.objfile = nullptr;
+  }
+
+  symbol_search (int block_, struct minimal_symbol *minsym,
+		 struct objfile *objfile)
+    : block (block_),
+      symbol (nullptr)
+  {
+    msymbol.minsym = minsym;
+    msymbol.objfile = objfile;
+  }
+
+  bool operator< (const symbol_search &other) const
+  {
+    return compare_search_syms (*this, other) < 0;
+  }
+
+  bool operator== (const symbol_search &other) const
+  {
+    return compare_search_syms (*this, other) == 0;
+  }
+
   /* The block in which the match was found.  Could be, for example,
      STATIC_BLOCK or GLOBAL_BLOCK.  */
   int block;
@@ -1578,15 +1605,15 @@ struct symbol_search
      which only minimal_symbols exist.  */
   struct bound_minimal_symbol msymbol;
 
-  /* A link to the next match, or NULL for the end.  */
-  struct symbol_search *next;
+private:
+
+  static int compare_search_syms (const symbol_search &sym_a,
+				  const symbol_search &sym_b);
 };
 
-extern void search_symbols (const char *, enum search_domain, int,
-			    const char **, struct symbol_search **);
-extern void free_search_symbols (struct symbol_search *);
-extern struct cleanup *make_cleanup_free_search_symbols (struct symbol_search
-							 **);
+extern std::vector<symbol_search> search_symbols (const char *,
+						  enum search_domain, int,
+						  const char **);
 
 /* The name of the ``main'' function.
    FIXME: cagney/2001-03-20: Can't make main_name() const since some