analyzer: add function-set.cc/h

This patch adds a simple mechanism for tracking sets of functions
for which a particular property holds, as a pragmatic way to build
knowledge about important APIs into the analyzer without requiring
markup of the user's libc.

gcc/ChangeLog:
	* Makefile.in (ANALYZER_OBJS): Add analyzer/function-set.o.

gcc/analyzer/ChangeLog:
	* analyzer-selftests.cc (selftest::run_analyzer_selftests): Call
	selftest::analyzer_function_set_cc_tests.
	* analyzer-selftests.h (selftest::analyzer_function_set_cc_tests):
	New decl.
	* function-set.cc: New file.
	* function-set.h: New file.

1 files changed, 46 insertions, 0 deletions

diff --git a/gcc/analyzer/function-set.h b/gcc/analyzer/function-set.h
new file mode 100644
index 0000000..9c73bf5
--- /dev/null
+++ b/gcc/analyzer/function-set.h
@@ -0,0 +1,46 @@
+/* Sets of function names.
+   Copyright (C) 2019-2020 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_ANALYZER_FUNCTION_SET_H
+#define GCC_ANALYZER_FUNCTION_SET_H
+
+/* A set of names.  */
+
+class function_set
+{
+public:
+  /* Construct from a sorted array NAMES of size COUNT.  */
+  function_set (const char * const *names, size_t count)
+  : m_names (names), m_count (count)
+  {
+  }
+
+  bool contains_name_p (const char *name) const;
+  bool contains_decl_p (tree fndecl) const;
+
+  void assert_sorted () const;
+  void assert_sane () const;
+
+private:
+  const char * const *m_names; // must be sorted
+  size_t m_count;
+};
+
+#endif /* GCC_ANALYZER_FUNCTION_SET_H */