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, 71 insertions, 0 deletions

diff --git a/gcc/substring-locations.h b/gcc/substring-locations.h
index f839c74..f8788c9 100644
--- a/gcc/substring-locations.h
+++ b/gcc/substring-locations.h
@@ -20,6 +20,77 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_SUBSTRING_LOCATIONS_H
 #define GCC_SUBSTRING_LOCATIONS_H
 
+/* The substring_loc class encapsulates information on the source location
+   of a range of characters within a STRING_CST.
+
+   If needed by a diagnostic, the actual location_t of the substring_loc
+   can be calculated by calling its get_location method.  This calls a
+   langhook, since this is inherently frontend-specific.  For the C family
+   of frontends, it calls back into libcpp to reparse the strings.  This
+   gets the location information "on demand", rather than storing the
+   location information in the initial lex for every string.  Thus the
+   substring_loc can also be thought of as a deferred call into libcpp,
+   to allow the non-trivial work of reparsing the string to be delayed
+   until we actually need it (to emit a diagnostic for a particular range
+   of characters).
+
+   substring_loc::get_location returns NULL if it succeeds, or an
+   error message if it fails.  Error messages are intended for GCC
+   developers (to help debugging) rather than for end-users.
+
+   The easiest way to use a substring_loc is via the format_warning_* APIs,
+   which gracefully handle failure of substring_loc::get_location by using
+   the location of the string as a whole if substring-information is
+   unavailable.  */
+
+class substring_loc
+{
+ public:
+  /* Constructor.  FMT_STRING_LOC is the location of the string as
+     a whole.  STRING_TYPE is the type of the string.  It should be an
+     ARRAY_TYPE of INTEGER_TYPE, or a POINTER_TYPE to such an ARRAY_TYPE.
+     CARET_IDX, START_IDX, and END_IDX are offsets from the start
+     of the string data.  */
+  substring_loc (location_t fmt_string_loc, tree string_type,
+		 int caret_idx, int start_idx, int end_idx)
+  : m_fmt_string_loc (fmt_string_loc), m_string_type (string_type),
+    m_caret_idx (caret_idx), m_start_idx (start_idx), m_end_idx (end_idx) {}
+
+  void set_caret_index (int caret_idx) { m_caret_idx = caret_idx; }
+
+  const char *get_location (location_t *out_loc) const;
+
+  location_t get_fmt_string_loc () const { return m_fmt_string_loc; }
+  tree get_string_type () const { return m_string_type; }
+  int get_caret_idx () const { return m_caret_idx; }
+  int get_start_idx () const { return m_start_idx; }
+  int get_end_idx () const { return m_end_idx; }
+
+ private:
+  location_t m_fmt_string_loc;
+  tree m_string_type;
+  int m_caret_idx;
+  int m_start_idx;
+  int m_end_idx;
+};
+
+/* Functions for emitting a warning about a format string.  */
+
+extern 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)
+  ATTRIBUTE_GCC_DIAG (5,0);
+
+extern bool format_warning_at_substring (const substring_loc &fmt_loc,
+					 const source_range *param_range,
+					 const char *corrected_substring,
+					 int opt, const char *gmsgid, ...)
+  ATTRIBUTE_GCC_DIAG (5,0);
+
+/* Implementation detail, for use when implementing
+   LANG_HOOKS_GET_SUBSTRING_LOCATION.  */
+
 extern const char *get_source_location_for_substring (cpp_reader *pfile,
 						      string_concat_db *concats,
 						      location_t strloc,