Move class substring_loc from c-family into gcc

gcc/ChangeLog:
	* Makefile.in (OBJS): Add substring-locations.o.
	* langhooks-def.h (class substring_loc): New forward decl.
	(lhd_get_substring_location): New decl.
	(LANG_HOOKS_GET_SUBSTRING_LOCATION): New macro.
	(LANG_HOOKS_INITIALIZER): Add LANG_HOOKS_GET_SUBSTRING_LOCATION.
	* langhooks.c (lhd_get_substring_location): New function.
	* langhooks.h (class substring_loc): New forward decl.
	(struct lang_hooks): Add field get_substring_location.
	* substring-locations.c: New file, taking definition of
	format_warning_va and format_warning_at_substring from
	c-family/c-format.c, making them non-static.
	* substring-locations.h (class substring_loc): Move class here
	from c-family/c-common.h.  Add and rewrite comments.
	(format_warning_va): New decl.
	(format_warning_at_substring): New decl.
	(get_source_location_for_substring): Add comment.

gcc/c-family/ChangeLog:
	* c-common.c (get_cpp_ttype_from_string_type): Handle being passed
	a POINTER_TYPE.
	(substring_loc::get_location): Move to substring-locations.c,
	keeping implementation as...
	(c_get_substring_location): New function, from the above, reworked
	to use accessors rather than member lookup.
	* c-common.h (class substring_loc): Move to substring-locations.h,
	replacing with a forward decl.
	(c_get_substring_location): New decl.
	* c-format.c: Include "substring-locations.h".
	(format_warning_va): Move to substring-locations.c.
	(format_warning_at_substring): Likewise.

gcc/c/ChangeLog:
	* c-lang.c (LANG_HOOKS_GET_SUBSTRING_LOCATION): Use
	c_get_substring_location for this new langhook.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/diagnostic_plugin_test_string_literals.c: Include
	"substring-locations.h".

From-SVN: r240028

1 files changed, 195 insertions, 0 deletions

diff --git a/gcc/substring-locations.c b/gcc/substring-locations.c
new file mode 100644
index 0000000..60bf1b0
--- /dev/null
+++ b/gcc/substring-locations.c
@@ -0,0 +1,195 @@
+/* Source locations within string literals.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+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 "diagnostic.h"
+#include "cpplib.h"
+#include "tree.h"
+#include "langhooks.h"
+#include "substring-locations.h"
+
+/* Emit a warning governed by option OPT, using GMSGID as the format
+   string and AP as its arguments.
+
+   Attempt to obtain precise location information within a string
+   literal from FMT_LOC.
+
+   Case 1: if substring location is available, and is within the range of
+   the format string itself, the primary location of the
+   diagnostic is the substring range obtained from FMT_LOC, with the
+   caret at the *end* of the substring range.
+
+   For example:
+
+     test.c:90:10: warning: problem with '%i' here [-Wformat=]
+     printf ("hello %i", msg);
+                    ~^
+
+   Case 2: if the substring location is available, but is not within
+   the range of the format string, the primary location is that of the
+   format string, and an note is emitted showing the substring location.
+
+   For example:
+     test.c:90:10: warning: problem with '%i' here [-Wformat=]
+     printf("hello " INT_FMT " world", msg);
+            ^~~~~~~~~~~~~~~~~~~~~~~~~
+     test.c:19: note: format string is defined here
+     #define INT_FMT "%i"
+                      ~^
+
+   Case 3: if precise substring information is unavailable, the primary
+   location is that of the whole string passed to FMT_LOC's constructor.
+   For example:
+
+     test.c:90:10: warning: problem with '%i' here [-Wformat=]
+     printf(fmt, msg);
+            ^~~
+
+   For each of cases 1-3, if param_range is non-NULL, then it is used
+   as a secondary range within the warning.  For example, here it
+   is used with case 1:
+
+     test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
+     printf ("foo %s bar", long_i + long_j);
+                  ~^       ~~~~~~~~~~~~~~~
+
+   and here with case 2:
+
+     test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
+     printf ("foo " STR_FMT " bar", long_i + long_j);
+             ^~~~~~~~~~~~~~~~~~~~~  ~~~~~~~~~~~~~~~
+     test.c:89:16: note: format string is defined here
+     #define STR_FMT "%s"
+                      ~^
+
+   and with case 3:
+
+     test.c:90:10: warning: '%i' here, but arg 2 is "const char *' [-Wformat=]
+     printf(fmt, msg);
+            ^~~  ~~~
+
+   If CORRECTED_SUBSTRING is non-NULL, use it for cases 1 and 2 to provide
+   a fix-it hint, suggesting that it should replace the text within the
+   substring range.  For example:
+
+     test.c:90:10: warning: problem with '%i' here [-Wformat=]
+     printf ("hello %i", msg);
+                    ~^
+                    %s
+
+   Return true if a warning was emitted, false otherwise.  */
+
+ATTRIBUTE_GCC_DIAG (5,0)
+bool
+format_warning_va (const substring_loc &fmt_loc,
+		   const source_range *param_range,
+		   const char *corrected_substring,
+		   int opt, const char *gmsgid, va_list *ap)
+{
+  bool substring_within_range = false;
+  location_t primary_loc;
+  location_t fmt_substring_loc = UNKNOWN_LOCATION;
+  source_range fmt_loc_range
+    = get_range_from_loc (line_table, fmt_loc.get_fmt_string_loc ());
+  const char *err = fmt_loc.get_location (&fmt_substring_loc);
+  source_range fmt_substring_range
+    = get_range_from_loc (line_table, fmt_substring_loc);
+  if (err)
+    /* Case 3: unable to get substring location.  */
+    primary_loc = fmt_loc.get_fmt_string_loc ();
+  else
+    {
+      if (fmt_substring_range.m_start >= fmt_loc_range.m_start
+	  && fmt_substring_range.m_finish <= fmt_loc_range.m_finish)
+	/* Case 1.  */
+	{
+	  substring_within_range = true;
+	  primary_loc = fmt_substring_loc;
+	}
+      else
+	/* Case 2.  */
+	{
+	  substring_within_range = false;
+	  primary_loc = fmt_loc.get_fmt_string_loc ();
+	}
+    }
+
+  rich_location richloc (line_table, primary_loc);
+
+  if (param_range)
+    {
+      location_t param_loc = make_location (param_range->m_start,
+					    param_range->m_start,
+					    param_range->m_finish);
+      richloc.add_range (param_loc, false);
+    }
+
+  if (!err && corrected_substring && substring_within_range)
+    richloc.add_fixit_replace (fmt_substring_range, corrected_substring);
+
+  diagnostic_info diagnostic;
+  diagnostic_set_info (&diagnostic, gmsgid, ap, &richloc, DK_WARNING);
+  diagnostic.option_index = opt;
+  bool warned = report_diagnostic (&diagnostic);
+
+  if (!err && fmt_substring_loc && !substring_within_range)
+    /* Case 2.  */
+    if (warned)
+      {
+	rich_location substring_richloc (line_table, fmt_substring_loc);
+	if (corrected_substring)
+	  substring_richloc.add_fixit_replace (fmt_substring_range,
+					       corrected_substring);
+	inform_at_rich_loc (&substring_richloc,
+			    "format string is defined here");
+      }
+
+  return warned;
+}
+
+/* Variadic call to format_warning_va.  */
+
+bool
+format_warning_at_substring (const substring_loc &fmt_loc,
+			     const source_range *param_range,
+			     const char *corrected_substring,
+			     int opt, const char *gmsgid, ...)
+{
+  va_list ap;
+  va_start (ap, gmsgid);
+  bool warned = format_warning_va (fmt_loc, param_range, corrected_substring,
+				   opt, gmsgid, &ap);
+  va_end (ap);
+
+  return warned;
+}
+
+/* Attempt to determine the source location of the substring.
+   If successful, return NULL and write the source location to *OUT_LOC.
+   Otherwise return an error message.  Error messages are intended
+   for GCC developers (to help debugging) rather than for end-users.  */
+
+const char *
+substring_loc::get_location (location_t *out_loc) const
+{
+  gcc_assert (out_loc);
+  return lang_hooks.get_substring_location (*this, out_loc);
+}