https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85110
--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Author: dmalcolm Date: Thu Mar 29 14:43:01 2018 New Revision: 258957 URL: https://gcc.gnu.org/viewcvs?rev=258957&root=gcc&view=rev Log: More underlining of bad arguments (PR c++/85110) As of r256448, the C++ frontend underlines many bad arguments in its diagnostics; those where perform_overload_resolution returns a non-NULL candidate, but there's a failure in convert_like_real. However, for the case where perform_overload_resolution fails, but there's a single non-viable candidate, the error is diagnosed by cp_build_function_call_vec, and that currently doesn't underline the bad argument: $ cat test.cc void callee (int one, const char **two, int three); void caller (const char *fmt) { callee (1, fmt, 3); } We emit: $ g++ test.cc test.cc: In function 'void caller(const char*)': test.cc:6:20: error: cannot convert 'const char*' to 'const char**' for argument '2' to 'void callee(int, const char**, int)' callee (1, fmt, 3); ^ It's going through convert_for_assignment, and implicitly using input_location. This patch updates convert_for_assignment for this case, using an EXPR_LOCATION if there is one, or falling back to input_location otherwise, underlining the argument in question: test.cc: In function 'void caller(const char*)': test.cc:6:14: error: cannot convert 'const char*' to 'const char**' for argument '2' to 'void callee(int, const char**, int)' callee (1, fmt, 3); ^~~ gcc/cp/ChangeLog: PR c++/85110 * typeck.c (convert_for_assignment): When complaining due to conversions for an argument, attempt to use the location of the argument. gcc/testsuite/ChangeLog: PR c++/85110 * g++.dg/diagnostic/param-type-mismatch-2.C: New test. Added: trunk/gcc/testsuite/g++.dg/diagnostic/param-type-mismatch-2.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/typeck.c trunk/gcc/testsuite/ChangeLog