This patch is intended to help Martin's new middle-end sprintf format
warning.
It moves most of the on-demand locations-within-strings
code in c-family into gcc, into a new substring-locations.c file to
go with substring-locations.h: class substring_loc, representing
a source caret and source range within a STRING_CST, along with
format_warning for handling emitting a warning relating to it.
The actual work of reconstructing the source locations within
a string seems inherently frontend-specific, so the patch introduces a
langhook to do this, implementing it for C using the existing code
(and thus hiding the details of string-concatenation as being
specific to the c-family). Attempts to get substring location
from other frontends will fail, and the format_warning_* calls
handle such failures gracefully by simply using the location of
the string as a whole for the warning.
I've tested it with Martin's gimple-ssa-sprintf patch, and I'm able to
emit carets and underlines in the correct places in C code from the
middle end with this approach (patch to follow).
Successfully bootstrapped®rtested on x86_64-pc-linux-gnu.
OK for trunk?
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: Include <cpplib.h>.
(class substring_loc): Move class here from c-family/c-common.h.
Add 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".
---
gcc/Makefile.in | 1 +
gcc/c-family/c-common.c | 23 +--
gcc/c-family/c-common.h | 32 +---
gcc/c-family/c-format.c | 157 +----------------
gcc/c/c-lang.c | 3 +
gcc/langhooks-def.h | 8 +-
gcc/langhooks.c | 8 +
gcc/langhooks.h | 9 +
gcc/substring-locations.c | 195 +++++++++++++++++++++
gcc/substring-locations.h | 67 +++++++
.../diagnostic_plugin_test_string_literals.c | 1 +
11 files changed, 308 insertions(+), 196 deletions(-)
create mode 100644 gcc/substring-locations.c
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 1b7464b..769efcf 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1444,6 +1444,7 @@ OBJS = \
store-motion.o \
streamer-hooks.o \
stringpool.o \
+ substring-locations.o \
target-globals.o \
targhooks.o \
timevar.o \
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 3feb910..f3e44c2 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -1122,6 +1122,9 @@ static enum cpp_ttype
get_cpp_ttype_from_string_type (tree string_type)
{
gcc_assert (string_type);
+ if (TREE_CODE (string_type) == POINTER_TYPE)
+ string_type = TREE_TYPE (string_type);
+
if (TREE_CODE (string_type) != ARRAY_TYPE)
return CPP_OTHER;
@@ -1148,23 +1151,23 @@ get_cpp_ttype_from_string_type (tree string_type)
GTY(()) string_concat_db *g_string_concat_db;
-/* 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. */
+/* Implementation of LANG_HOOKS_GET_SUBSTRING_LOCATION. */
const char *
-substring_loc::get_location (location_t *out_loc) const
+c_get_substring_location (const substring_loc &substr_loc,
+ location_t *out_loc)
{
- gcc_assert (out_loc);
-
- enum cpp_ttype tok_type = get_cpp_ttype_from_string_type (m_string_type);
+ enum cpp_ttype tok_type
+ = get_cpp_ttype_from_string_type (substr_loc.get_string_type ());
if (tok_type == CPP_OTHER)
return "unrecognized string type";
return get_source_location_for_substring (parse_in, g_string_concat_db,
- m_fmt_string_loc, tok_type,
- m_caret_idx, m_start_idx, m_end_idx,
+ substr_loc.get_fmt_string_loc (),
+ tok_type,
+ substr_loc.get_caret_idx (),
+ substr_loc.get_start_idx (),
+ substr_loc.get_end_idx (),
out_loc);
}
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index bc22baa..4470b4f 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1131,35 +1131,9 @@ extern const char *cb_get_suggestion (cpp_reader *,
const char *,
extern GTY(()) string_concat_db *g_string_concat_db;
-/* libcpp can calculate location information about a range of characters
- within a string literal, but doing so is non-trivial.
-
- This class encapsulates such a source location, so that it can be
- passed around (e.g. within c-format.c). It is effectively a deferred
- call into libcpp. If needed by a diagnostic, the actual source_range
- can be calculated by calling the get_range method. */
-
-class substring_loc
-{
- public:
- 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; }
-
- private:
- location_t m_fmt_string_loc;
- tree m_string_type;
- int m_caret_idx;
- int m_start_idx;
- int m_end_idx;
-};
+class substring_loc;
+extern const char *c_get_substring_location (const substring_loc &substr_loc,
+ location_t *out_loc);
/* In c-gimplify.c */
extern void c_genericize (tree);
diff --git a/gcc/c-family/c-format.c b/gcc/c-family/c-format.c
index d373819..ac40ac3 100644
--- a/gcc/c-family/c-format.c
+++ b/gcc/c-family/c-format.c
@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3. If not see
#include "langhooks.h"
#include "c-format.h"
#include "diagnostic.h"
+#include "substring-locations.h"
#include "selftest.h"
/* Handle attributes associated with format checking. */
@@ -67,162 +68,6 @@ static int first_target_format_type;
static const char *format_name (int format_num);
static int format_flags (int format_num);
-/* 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)
-static bool
-format_warning_va (const substring_loc &fmt_loc, 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. */
-
-ATTRIBUTE_GCC_DIAG (5,0)
-static bool
-format_warning_at_substring (const substring_loc &fmt_loc,
- 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;
-}
-
/* Emit a warning as per format_warning_va, but construct the substring_loc
for the character at offset (CHAR_IDX - 1) within a string constant
FORMAT_STRING_CST at FMT_STRING_LOC. */
diff --git a/gcc/c/c-lang.c b/gcc/c/c-lang.c
index b26be6a..b4096d0 100644
--- a/gcc/c/c-lang.c
+++ b/gcc/c/c-lang.c
@@ -43,6 +43,9 @@ enum c_language_kind c_language = clk_c;
#define LANG_HOOKS_RUN_LANG_SELFTESTS selftest::run_c_tests
#endif /* #if CHECKING_P */
+#undef LANG_HOOKS_GET_SUBSTRING_LOCATION
+#define LANG_HOOKS_GET_SUBSTRING_LOCATION c_get_substring_location
+
/* Each front end provides its own lang hook initializer. */
struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
diff --git a/gcc/langhooks-def.h b/gcc/langhooks-def.h
index 10d910c..cf5f91d 100644
--- a/gcc/langhooks-def.h
+++ b/gcc/langhooks-def.h
@@ -24,6 +24,7 @@ along with GCC; see the file COPYING3. If not see
#include "hooks.h"
struct diagnostic_info;
+class substring_loc;
/* Note to creators of new hooks:
@@ -81,6 +82,9 @@ extern void lhd_omp_firstprivatize_type_sizes (struct
gimplify_omp_ctx *,
tree);
extern bool lhd_omp_mappable_type (tree);
+extern const char *lhd_get_substring_location (const substring_loc &,
+ location_t *out_loc);
+
#define LANG_HOOKS_NAME "GNU unknown"
#define LANG_HOOKS_IDENTIFIER_SIZE sizeof (struct lang_identifier)
#define LANG_HOOKS_INIT hook_bool_void_false
@@ -121,6 +125,7 @@ extern bool lhd_omp_mappable_type (tree);
#define LANG_HOOKS_EH_USE_CXA_END_CLEANUP false
#define LANG_HOOKS_DEEP_UNSHARING false
#define LANG_HOOKS_RUN_LANG_SELFTESTS lhd_do_nothing
+#define LANG_HOOKS_GET_SUBSTRING_LOCATION lhd_get_substring_location
/* Attribute hooks. */
#define LANG_HOOKS_ATTRIBUTE_TABLE NULL
@@ -323,7 +328,8 @@ extern void lhd_end_section (void);
LANG_HOOKS_BLOCK_MAY_FALLTHRU, \
LANG_HOOKS_EH_USE_CXA_END_CLEANUP, \
LANG_HOOKS_DEEP_UNSHARING, \
- LANG_HOOKS_RUN_LANG_SELFTESTS \
+ LANG_HOOKS_RUN_LANG_SELFTESTS, \
+ LANG_HOOKS_GET_SUBSTRING_LOCATION \
}
#endif /* GCC_LANG_HOOKS_DEF_H */
diff --git a/gcc/langhooks.c b/gcc/langhooks.c
index 3256a9d..538d9f9 100644
--- a/gcc/langhooks.c
+++ b/gcc/langhooks.c
@@ -693,6 +693,14 @@ lhd_enum_underlying_base_type (const_tree enum_type)
TYPE_UNSIGNED (enum_type));
}
+/* Default implementation of LANG_HOOKS_GET_SUBSTRING_LOCATION. */
+
+const char *
+lhd_get_substring_location (const substring_loc &, location_t *)
+{
+ return "unimplemented";
+}
+
/* Returns true if the current lang_hooks represents the GNU C frontend. */
bool
diff --git a/gcc/langhooks.h b/gcc/langhooks.h
index 44c258e..c109c8c 100644
--- a/gcc/langhooks.h
+++ b/gcc/langhooks.h
@@ -34,6 +34,8 @@ typedef void (*lang_print_tree_hook) (FILE *, tree, int
indent);
enum classify_record
{ RECORD_IS_STRUCT, RECORD_IS_CLASS, RECORD_IS_INTERFACE };
+class substring_loc;
+
/* The following hooks are documented in langhooks.c. Must not be
NULL. */
@@ -513,6 +515,13 @@ struct lang_hooks
/* Run all lang-specific selftests. */
void (*run_lang_selftests) (void);
+ /* 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 *(*get_substring_location) (const substring_loc &,
+ location_t *out_loc);
+
/* Whenever you add entries here, make sure you adjust langhooks-def.h
and langhooks.c accordingly. */
};
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);
+}
diff --git a/gcc/substring-locations.h b/gcc/substring-locations.h
index f839c74..bb0de4f 100644
--- a/gcc/substring-locations.h
+++ b/gcc/substring-locations.h
@@ -20,6 +20,73 @@ along with GCC; see the file COPYING3. If not see
#ifndef GCC_SUBSTRING_LOCATIONS_H
#define GCC_SUBSTRING_LOCATIONS_H
+#include <cpplib.h>
+
+/* libcpp can calculate location information about a range of characters
+ within a string literal, but doing so is non-trivial.
+
+ This class encapsulates such a source location, so that it can be
+ passed around (e.g. within c-format.c). It is effectively a deferred
+ call into libcpp.
+
+ If needed by a diagnostic, the actual location can be calculated by
+ calling the get_location method. This calls a langhook, since
+ this is inherently frontend-specific (it reparses the strings to
+ get the location information on-demand, rather than storing the
+ location information in the initial lex for every string).
+
+ 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. */
+
+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,
diff --git
a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_string_literals.c
b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_string_literals.c
index dff999c..99a504d 100644
--- a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_string_literals.c
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_string_literals.c
@@ -33,6 +33,7 @@
#include "print-tree.h"
#include "cpplib.h"
#include "c-family/c-pragma.h"
+#include "substring-locations.h"
int plugin_is_GPL_compatible;
