Merge from trunk revision 104c05c5284b7822d770ee51a7d91946c7e56d50.

1 files changed, 196 insertions, 0 deletions

diff --git a/gcc/diagnostic-spec.c b/gcc/diagnostic-spec.c
new file mode 100644
index 0000000..85ffb72
--- /dev/null
+++ b/gcc/diagnostic-spec.c
@@ -0,0 +1,196 @@
+/* Functions to enable and disable individual warnings on an expression
+   and statement basis.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Martin Sebor <msebor@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/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "bitmap.h"
+#include "tree.h"
+#include "cgraph.h"
+#include "hash-map.h"
+#include "diagnostic-spec.h"
+#include "pretty-print.h"
+#include "options.h"
+
+/* Initialize *THIS from warning option OPT.  */
+
+nowarn_spec_t::nowarn_spec_t (opt_code opt)
+{
+  /* Create a very simple mapping based on testing and experience.
+     It should become more refined with time. */
+  switch (opt)
+    {
+    case no_warning:
+      m_bits = 0;
+      break;
+
+    case all_warnings:
+      m_bits = -1;
+      break;
+
+      /* Flow-sensitive warnings about pointer problems issued by both
+	 front ends and the middle end.  */
+    case OPT_Waddress:
+    case OPT_Wnonnull:
+      m_bits = NW_NONNULL;
+      break;
+
+      /* Flow-sensitive warnings about arithmetic overflow issued by both
+	 front ends and the middle end.  */
+    case OPT_Woverflow:
+    case OPT_Wshift_count_negative:
+    case OPT_Wshift_count_overflow:
+    case OPT_Wstrict_overflow:
+      m_bits = NW_VFLOW;
+      break;
+
+      /* Lexical warnings issued by front ends.  */
+    case OPT_Wabi:
+    case OPT_Wlogical_op:
+    case OPT_Wparentheses:
+    case OPT_Wreturn_type:
+    case OPT_Wsizeof_array_div:
+    case OPT_Wstrict_aliasing:
+    case OPT_Wunused:
+    case OPT_Wunused_function:
+    case OPT_Wunused_but_set_variable:
+    case OPT_Wunused_variable:
+    case OPT_Wunused_but_set_parameter:
+      m_bits = NW_LEXICAL;
+      break;
+
+      /* Access warning group.  */
+    case OPT_Warray_bounds:
+    case OPT_Warray_bounds_:
+    case OPT_Wformat_overflow_:
+    case OPT_Wformat_truncation_:
+    case OPT_Wrestrict:
+    case OPT_Wsizeof_pointer_memaccess:
+    case OPT_Wstrict_aliasing_:
+    case OPT_Wstringop_overflow_:
+    case OPT_Wstringop_overread:
+    case OPT_Wstringop_truncation:
+      m_bits = NW_ACCESS;
+      break;
+
+      /* Initialization warning group.  */
+    case OPT_Winit_self:
+    case OPT_Wuninitialized:
+    case OPT_Wmaybe_uninitialized:
+	m_bits = NW_UNINIT;
+      break;
+
+    default:
+      /* A catchall group for everything else.  */
+      m_bits = NW_OTHER;
+    }
+}
+
+/* A mapping from a 'location_t' to the warning spec set for it.  */
+
+GTY(()) xint_hash_map_t *nowarn_map;
+
+/* Return the no-warning disposition for location LOC and option OPT
+   or for all/any otions by default.  */
+
+bool
+warning_suppressed_at (location_t loc, opt_code opt /* = all_warnings */)
+{
+  gcc_checking_assert (!RESERVED_LOCATION_P (loc));
+
+  if (!nowarn_map)
+    return false;
+
+  if (const nowarn_spec_t* const pspec = nowarn_map->get (loc))
+    {
+      const nowarn_spec_t optspec (opt);
+      return *pspec & optspec;
+    }
+
+  return false;
+}
+
+ /* Change the supression of warnings for location LOC.
+    OPT controls which warnings are affected.
+    The wildcard OPT of -1 controls all warnings.
+    If SUPP is true (the default), enable the suppression of the warnings.
+    If SUPP is false, disable the suppression of the warnings.  */
+
+bool
+suppress_warning_at (location_t loc, opt_code opt /* = all_warnings */,
+		     bool supp /* = true */)
+{
+  gcc_checking_assert (!RESERVED_LOCATION_P (loc));
+
+  const nowarn_spec_t optspec (supp ? opt : opt_code ());
+
+  if (nowarn_spec_t *pspec = nowarn_map ? nowarn_map->get (loc) : NULL)
+    {
+      if (supp)
+	{
+	  *pspec |= optspec;
+	  return true;
+	}
+
+      *pspec &= optspec;
+      if (*pspec)
+	return true;
+
+      nowarn_map->remove (loc);
+      return false;
+    }
+
+  if (!supp || opt == no_warning)
+    return false;
+
+  if (!nowarn_map)
+    nowarn_map = xint_hash_map_t::create_ggc (32);
+
+  nowarn_map->put (loc, optspec);
+  return true;
+}
+
+/* Copy the no-warning disposition from one location to another.  */
+
+void
+copy_warning (location_t to, location_t from)
+{
+  if (!nowarn_map)
+    return;
+
+  nowarn_spec_t *from_spec;
+  if (RESERVED_LOCATION_P (from))
+    from_spec = NULL;
+  else
+    from_spec = nowarn_map->get (from);
+  if (RESERVED_LOCATION_P (to))
+    /* We cannot set no-warning dispositions for 'to', so we have no chance but
+       lose those potentially set for 'from'.  */
+    ;
+  else
+    {
+      if (from_spec)
+	nowarn_map->put (to, *from_spec);
+      else
+	nowarn_map->remove (to);
+    }
+}