I was going to ping this patch:
https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00875.html
but it has bit-rotted somewhat, so here's a refreshed version of it.
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
OK for trunk?
Thanks
Dave
Blurb from v1:
This patch is based on grepping the C++ frontend for %P
i.e. diagnostics that refer to a parameter number. It fixes up
these diagnostics to highlight the pertinent param where appropriate
(and possible), along with various other tweaks, as described in the
ChangeLog.
gcc/cp/ChangeLog:
PR c++/85110
* call.c (conversion_null_warnings): Try to use the location of
the expression for the warnings. Add notes showing the parameter
of the function decl, where available.
(get_fndecl_argument_location): Gracefully reject
non-FUNCTION_DECLs. For implicitly-declared functions, use the
fndecl location rather than that of the param.
(maybe_inform_about_fndecl_for_bogus_argument_init): New function.
(convert_like_real): Use it in various places to avoid repetition.
* cp-tree.h (maybe_inform_about_fndecl_for_bogus_argument_init):
New declaration.
* decl2.c: Include "gcc-rich-location.h".
(check_default_args): Use the location of the parameter when
complaining about parameters with missing default arguments in
preference to that of the fndecl.
Attempt to record the location of first parameter with a default
argument and add it as a secondary range to such errors.
* typeck.c (convert_arguments): When complaining about parameters
with incomplete types, attempt to use the location of the
argument. Where available, add a note showing the pertinent
parameter in the fndecl.
(convert_for_assignment): When complaining about bad conversions
at function calls, use the location of the unstripped argument.
(convert_for_initialization): When checking for bogus references,
add an auto_diagnostic_group, and update the note to use the
location of the pertinent parameter, rather than just the callee.
gcc/testsuite/ChangeLog:
PR c++/85110
* g++.dg/diagnostic/missing-default-args.C: New test.
* g++.dg/diagnostic/param-type-mismatch-3.C: New test.
* g++.dg/diagnostic/param-type-mismatch.C: Add tests for invalid
references and incomplete types.
* g++.dg/warn/Wconversion-null-4.C: New test.
---
gcc/cp/call.c | 88 ++++++++++++++--------
gcc/cp/cp-tree.h | 1 +
gcc/cp/decl2.c | 16 +++-
gcc/cp/typeck.c | 22 ++++--
.../g++.dg/diagnostic/missing-default-args.C | 53 +++++++++++++
.../g++.dg/diagnostic/param-type-mismatch-3.C | 26 +++++++
.../g++.dg/diagnostic/param-type-mismatch.C | 41 ++++++++++
gcc/testsuite/g++.dg/warn/Wconversion-null-4.C | 43 +++++++++++
8 files changed, 251 insertions(+), 39 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/diagnostic/missing-default-args.C
create mode 100644 gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-3.C
create mode 100644 gcc/testsuite/g++.dg/warn/Wconversion-null-4.C
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index ee099cc..cfc5641 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -6681,16 +6681,24 @@ conversion_null_warnings (tree totype, tree expr, tree
fn, int argnum)
if (null_node_p (expr) && TREE_CODE (totype) != BOOLEAN_TYPE
&& ARITHMETIC_TYPE_P (totype))
{
- location_t loc =
- expansion_point_location_if_in_system_header (input_location);
-
if (fn)
- warning_at (loc, OPT_Wconversion_null,
- "passing NULL to non-pointer argument %P of %qD",
- argnum, fn);
+ {
+ location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
+ loc = expansion_point_location_if_in_system_header (loc);
+ auto_diagnostic_group d;
+ if (warning_at (loc, OPT_Wconversion_null,
+ "passing NULL to non-pointer argument %P of %qD",
+ argnum, fn))
+ inform (get_fndecl_argument_location (fn, argnum),
+ " declared here");
+ }
else
- warning_at (loc, OPT_Wconversion_null,
- "converting to non-pointer type %qT from NULL", totype);
+ {
+ location_t loc
+ = expansion_point_location_if_in_system_header (input_location);
+ warning_at (loc, OPT_Wconversion_null,
+ "converting to non-pointer type %qT from NULL", totype);
+ }
}
/* Issue warnings if "false" is converted to a NULL pointer */
@@ -6698,9 +6706,15 @@ conversion_null_warnings (tree totype, tree expr, tree
fn, int argnum)
&& TYPE_PTR_P (totype))
{
if (fn)
- warning_at (input_location, OPT_Wconversion_null,
- "converting %<false%> to pointer type for argument %P "
- "of %qD", argnum, fn);
+ {
+ location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
+ auto_diagnostic_group d;
+ if (warning_at (loc, OPT_Wconversion_null,
+ "converting %<false%> to pointer type for argument "
+ "%P of %qD", argnum, fn))
+ inform (get_fndecl_argument_location (fn, argnum),
+ " declared here");
+ }
else
warning_at (input_location, OPT_Wconversion_null,
"converting %<false%> to pointer type %qT", totype);
@@ -6740,6 +6754,15 @@ maybe_print_user_conv_context (conversion *convs)
location_t
get_fndecl_argument_location (tree fndecl, int argnum)
{
+ /* Gracefully fail for e.g. TEMPLATE_DECL. */
+ if (TREE_CODE (fndecl) != FUNCTION_DECL)
+ return DECL_SOURCE_LOCATION (fndecl);
+
+ /* The locations of implicitly-declared functions are likely to be
+ more meaningful than those of their parameters. */
+ if (DECL_ARTIFICIAL (fndecl))
+ return DECL_SOURCE_LOCATION (fndecl);
+
int i;
tree param;
@@ -6757,6 +6780,18 @@ get_fndecl_argument_location (tree fndecl, int argnum)
return DECL_SOURCE_LOCATION (param);
}
+/* If FNDECL is non-NULL, issue a note highlighting ARGNUM
+ within its declaration (or the fndecl itself if something went
+ wrong). */
+
+void
+maybe_inform_about_fndecl_for_bogus_argument_init (tree fn, int argnum)
+{
+ if (fn)
+ inform (get_fndecl_argument_location (fn, argnum),
+ " initializing argument %P of %qD", argnum, fn);
+}
+
/* Perform the conversions in CONVS on the expression EXPR. FN and
ARGNUM are used for diagnostics. ARGNUM is zero based, -1
indicates the `this' argument of a method. INNER is nonzero when
@@ -6834,9 +6869,8 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
complain);
else
expr = cp_convert (totype, expr, complain);
- if (complained && fn)
- inform (DECL_SOURCE_LOCATION (fn),
- " initializing argument %P of %qD", argnum, fn);
+ if (complained)
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
return expr;
}
else if (t->kind == ck_user || !t->bad_p)
@@ -6863,9 +6897,8 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
"invalid conversion from %qH to %qI",
TREE_TYPE (expr), totype);
}
- if (complained && fn)
- inform (get_fndecl_argument_location (fn, argnum),
- " initializing argument %P of %qD", argnum, fn);
+ if (complained)
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
return cp_convert (totype, expr, complain);
}
@@ -6987,9 +7020,7 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
? LOOKUP_IMPLICIT : LOOKUP_NORMAL);
build_user_type_conversion (totype, convs->u.expr, flags, complain);
gcc_assert (seen_error ());
- if (fn)
- inform (DECL_SOURCE_LOCATION (fn),
- " initializing argument %P of %qD", argnum, fn);
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
}
return error_mark_node;
@@ -7083,9 +7114,7 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
{
auto_diagnostic_group d;
maybe_print_user_conv_context (convs);
- if (fn)
- inform (DECL_SOURCE_LOCATION (fn),
- " initializing argument %P of %qD", argnum, fn);
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
}
return error_mark_node;
}
@@ -7136,9 +7165,7 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
{
auto_diagnostic_group d;
maybe_print_user_conv_context (convs);
- if (fn)
- inform (DECL_SOURCE_LOCATION (fn),
- " initializing argument %P of %qD", argnum, fn);
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
}
return build_cplus_new (totype, expr, complain);
@@ -7165,9 +7192,8 @@ convert_like_real (conversion *convs, tree expr, tree fn,
int argnum,
else
gcc_unreachable ();
maybe_print_user_conv_context (convs);
- if (fn)
- inform (DECL_SOURCE_LOCATION (fn),
- " initializing argument %P of %qD", argnum, fn);
+ maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
+
return error_mark_node;
}
@@ -9299,8 +9325,8 @@ complain_about_bad_argument (location_t arg_loc,
error_at (&richloc,
"cannot convert %qH to %qI",
from_type, to_type);
- inform (get_fndecl_argument_location (fndecl, parmnum),
- " initializing argument %P of %qD", parmnum, fndecl);
+ maybe_inform_about_fndecl_for_bogus_argument_init (fndecl,
+ parmnum);
}
/* Subroutine of build_new_method_call_1, for where there are no viable
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 111a123..c1f9931 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6145,6 +6145,7 @@ extern location_t get_fndecl_argument_location (tree,
int);
extern void complain_about_bad_argument (location_t arg_loc,
tree from_type, tree to_type,
tree fndecl, int parmnum);
+extern void maybe_inform_about_fndecl_for_bogus_argument_init (tree, int);
/* A class for recording information about access failures (e.g. private
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index ffc0d0d..265826a 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -48,6 +48,7 @@ along with GCC; see the file COPYING3. If not see
#include "intl.h"
#include "c-family/c-ada-spec.h"
#include "asan.h"
+#include "gcc-rich-location.h"
/* Id for dumping the raw trees. */
int raw_dump_id;
@@ -5179,14 +5180,25 @@ check_default_args (tree x)
{
tree arg = TYPE_ARG_TYPES (TREE_TYPE (x));
bool saw_def = false;
+ location_t loc_of_first_default_arg = UNKNOWN_LOCATION;
int i = 0 - (TREE_CODE (TREE_TYPE (x)) == METHOD_TYPE);
for (; arg && arg != void_list_node; arg = TREE_CHAIN (arg), ++i)
{
if (TREE_PURPOSE (arg))
- saw_def = true;
+ {
+ saw_def = true;
+ location_t loc = get_fndecl_argument_location (x, i);
+ if (loc != DECL_SOURCE_LOCATION (x))
+ loc_of_first_default_arg = loc;
+ }
else if (saw_def && !PACK_EXPANSION_P (TREE_VALUE (arg)))
{
- error ("default argument missing for parameter %P of %q+#D", i, x);
+ location_t loc = get_fndecl_argument_location (x, i);
+ gcc_rich_location richloc (loc);
+ if (loc_of_first_default_arg != UNKNOWN_LOCATION)
+ richloc.add_range (loc_of_first_default_arg);
+ error_at (&richloc,
+ "default argument missing for parameter %P of %q#D", i, x);
TREE_PURPOSE (arg) = error_mark_node;
}
}
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index f45c06e..c3807de 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -4007,11 +4007,19 @@ convert_arguments (tree typelist, vec<tree, va_gc>
**values, tree fndecl,
{
if (complain & tf_error)
{
+ location_t loc = EXPR_LOC_OR_LOC (val, input_location);
if (fndecl)
- error ("parameter %P of %qD has incomplete type %qT",
- i, fndecl, type);
+ {
+ auto_diagnostic_group d;
+ error_at (loc,
+ "parameter %P of %qD has incomplete type %qT",
+ i, fndecl, type);
+ inform (get_fndecl_argument_location (fndecl, i),
+ " declared here");
+ }
else
- error ("parameter %P has incomplete type %qT", i, type);
+ error_at (loc, "parameter %P has incomplete type %qT", i,
+ type);
}
parmval = error_mark_node;
}
@@ -8795,6 +8803,8 @@ convert_for_assignment (tree type, tree rhs,
tree rhstype;
enum tree_code coder;
+ location_t rhs_loc = EXPR_LOC_OR_LOC (rhs, input_location);
+
/* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
rhs = TREE_OPERAND (rhs, 0);
@@ -8901,7 +8911,7 @@ convert_for_assignment (tree type, tree rhs,
parmnum, complain, flags);
}
else if (fndecl)
- complain_about_bad_argument (cp_expr_location (rhs),
+ complain_about_bad_argument (rhs_loc,
rhstype, type,
fndecl, parmnum);
else
@@ -9068,6 +9078,7 @@ convert_for_initialization (tree exp, tree type, tree
rhs, int flags,
if (codel == REFERENCE_TYPE)
{
+ auto_diagnostic_group d;
/* This should eventually happen in convert_arguments. */
int savew = 0, savee = 0;
@@ -9077,9 +9088,8 @@ convert_for_initialization (tree exp, tree type, tree
rhs, int flags,
if (fndecl
&& (warningcount + werrorcount > savew || errorcount > savee))
- inform (DECL_SOURCE_LOCATION (fndecl),
+ inform (get_fndecl_argument_location (fndecl, parmnum),
"in passing argument %P of %qD", parmnum, fndecl);
-
return rhs;
}
diff --git a/gcc/testsuite/g++.dg/diagnostic/missing-default-args.C
b/gcc/testsuite/g++.dg/diagnostic/missing-default-args.C
new file mode 100644
index 0000000..f681842
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/missing-default-args.C
@@ -0,0 +1,53 @@
+// { dg-options "-fdiagnostics-show-caret" }
+
+/* Function. */
+
+void test_1 (int a, int b = 42, int c, int d); // { dg-line test_1 }
+
+// { dg-error "default argument missing for parameter 3 of " "" { target *-*-*
} test_1 }
+/* { dg-begin-multiline-output "" }
+ void test_1 (int a, int b = 42, int c, int d);
+ ~~~~~~~~~~ ~~~~^
+ { dg-end-multiline-output "" } */
+
+// { dg-error "default argument missing for parameter 4 of " "" { target *-*-*
} test_1 }
+/* { dg-begin-multiline-output "" }
+ void test_1 (int a, int b = 42, int c, int d);
+ ~~~~~~~~~~ ~~~~^
+ { dg-end-multiline-output "" } */
+
+
+/* Non-static member fn. */
+
+struct test_2
+{
+ void member_2 (int a, int b = 42, int c); // { dg-error "default argument
missing for parameter 3 of " }
+};
+
+
+/* { dg-begin-multiline-output "" }
+ void member_2 (int a, int b = 42, int c);
+ ~~~~~~~~~~ ~~~~^
+ { dg-end-multiline-output "" } */
+
+
+/* Static member fn. */
+
+struct test_3
+{
+ static void member_3 (int a, int b = 42, int c); // { dg-error "default
argument missing for parameter 3 of " }
+};
+/* { dg-begin-multiline-output "" }
+ static void member_3 (int a, int b = 42, int c);
+ ~~~~~~~~~~ ~~~~^
+ { dg-end-multiline-output "" } */
+
+
+/* Template. */
+
+template <typename Type>
+void test_4 (int a, int b = 42, int c); // { dg-error "default argument
missing for parameter 3 of " }
+/* { dg-begin-multiline-output "" }
+ void test_4 (int a, int b = 42, int c);
+ ~~~~~~~~~~ ~~~~^
+ { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-3.C
b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-3.C
new file mode 100644
index 0000000..3ffbbd8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-3.C
@@ -0,0 +1,26 @@
+// { dg-do compile { target c++14 } }
+// { dg-options "-fdiagnostics-show-caret" }
+
+void f2(int, char (*)(int), int) { } // { dg-line f2 }
+
+void test_1 ()
+{
+ auto glambda = [](auto a) { return a; }; // { dg-line candidate }
+ int (*fp)(int) = glambda;
+ f2(1, glambda, 3); // { dg-error "invalid user-defined conversion" }
+ /* { dg-begin-multiline-output "" }
+ f2(1, glambda, 3);
+ ^~~~~~~
+ { dg-end-multiline-output "" } */
+ // { dg-message "candidate is: " "" { target *-*-* } candidate }
+ /* { dg-begin-multiline-output "" }
+ auto glambda = [](auto a) { return a; };
+ ^
+ { dg-end-multiline-output "" } */
+ // { dg-message "no known conversion from " "" { target *-*-* } candidate }
+ // { dg-message "initializing argument 2 of " "" { target *-*-* } f2 }
+ /* { dg-begin-multiline-output "" }
+ void f2(int, char (*)(int), int) { }
+ ^~~~~~~~~~~~~
+ { dg-end-multiline-output "" } */
+}
diff --git a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
index cb5c360..54ffb06 100644
--- a/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
+++ b/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch.C
@@ -224,4 +224,45 @@ int test_11 (int first, int second, float third)
{ dg-end-multiline-output "" } */
}
+/* Bad reference. */
+
+struct s12;
+
+extern int callee_12 (int one, s12 &second, float three); // { dg-line
callee_12 }
+
+int test_12 (int first, int second, float third)
+{
+ return callee_12 (first, second, third); // { dg-error "invalid
initialization of reference of " }
+ /* { dg-begin-multiline-output "" }
+ return callee_12 (first, second, third);
+ ^~~~~~
+ { dg-end-multiline-output "" } */
+ // { dg-message "in passing argument 2 of " "" { target *-*-* } callee_12 }
+ /* { dg-begin-multiline-output "" }
+ extern int callee_12 (int one, s12 &second, float three);
+ ~~~~~^~~~~~
+ { dg-end-multiline-output "" } */
+}
+
+/* Incomplete type. */
+
+struct s13;
+
+extern int callee_13 (int one, s13 second, float three); // { dg-line
callee_13 }
+
+int test_13 (int first, int second, float third)
+{
+ return callee_13 (first, second, third); // { dg-error "has incomplete type"
}
+ /* { dg-begin-multiline-output "" }
+ return callee_13 (first, second, third);
+ ^~~~~~
+ { dg-end-multiline-output "" } */
+ // { dg-message "declared here" "" { target *-*-* } callee_13 }
+ /* { dg-begin-multiline-output "" }
+ extern int callee_13 (int one, s13 second, float three);
+ ~~~~^~~~~~
+ { dg-end-multiline-output "" } */
+}
+
+
// TODO: template callsite
diff --git a/gcc/testsuite/g++.dg/warn/Wconversion-null-4.C
b/gcc/testsuite/g++.dg/warn/Wconversion-null-4.C
new file mode 100644
index 0000000..465dc5a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wconversion-null-4.C
@@ -0,0 +1,43 @@
+// { dg-do compile }
+// { dg-options "-Wconversion-null -fdiagnostics-show-caret" }
+
+#include <stddef.h>
+
+void callee_1 (int, int, int) {} // { dg-message "declared here" }
+
+void caller_1 (void)
+{
+ callee_1 (0, NULL, 2); // { dg-warning "passing NULL to non-pointer argument
2 of" }
+ /* { dg-begin-multiline-output "" }
+ callee_1 (0, NULL, 2);
+ ^~~~
+ { dg-end-multiline-output "" } */
+ /* { dg-begin-multiline-output "" }
+ void callee_1 (int, int, int) {}
+ ^~~
+ { dg-end-multiline-output "" } */
+}
+
+void callee_2 (int, void *, int) {} // { dg-message "declared here" "" {
target { ! c++11 } } }
+// { dg-message "initializing argument 2 of " "" { target c++11 } .-1 }
+
+void caller_2 (void)
+{
+ callee_2 (0, false, 2); // { dg-warning "converting 'false' to pointer type
for argument 2 of " "" { target { ! c++11 } } }
+ // { dg-error "cannot convert" "" { target c++11 } .-1 }
+
+ /* { dg-begin-multiline-output "" }
+ callee_2 (0, false, 2);
+ ^~~~~
+ { dg-end-multiline-output "" { target { ! c++11 } } } */
+ /* { dg-begin-multiline-output "" }
+ callee_2 (0, false, 2);
+ ^~~~~
+ |
+ bool
+ { dg-end-multiline-output "" { target c++11 } } */
+ /* { dg-begin-multiline-output "" }
+ void callee_2 (int, void *, int) {}
+ ^~~~~~
+ { dg-end-multiline-output "" } */
+}
--
1.8.5.3
