https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95831
Bug ID: 95831
Summary: Wrong line number in " -Wconversion" warning message
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: haoxintu at gmail dot com
CC: mpolacek at gcc dot gnu.org
Target Milestone: ---
This code, bug.cc, GCC might emit the wrong line number of the "-Wconversion"
warning.
$cat bug.cc
unsigned a = 0;
void foo (
short param1 = a,
short param2 = a,
char param3 = a)
{ }
$g++ -Wconversion -c bug.cc
bug.cc:6:20: warning: conversion from 'unsigned int' to 'short int' may change
value [-Wconversion]
6 | char param3 = a)
| ^
bug.cc:6:20: warning: conversion from 'unsigned int' to 'short int' may change
value [-Wconversion]
bug.cc:6:20: warning: conversion from 'unsigned int' to 'char' may change value
[-Wconversion]
Compiler returned: 0
While in Clang:
$clang++ -Wconversion -c bug.cc
bug.cc:3:21: warning: implicit conversion loses integer precision: 'unsigned
int' to 'short' [-Wimplicit-int-conversion]
short param1 = a,
~ ^
bug.cc:4:21: warning: implicit conversion loses integer precision: 'unsigned
int' to 'short' [-Wimplicit-int-conversion]
short param2 = a,
~ ^
bug.cc:5:19: warning: implicit conversion loses integer precision: 'unsigned
int' to 'char' [-Wimplicit-int-conversion]
char param3 = a)
~ ^
3 warnings generated.
Reproduced in godblot: https://godbolt.org/z/AoGkVQ
Noted that I have tested it in almost all GCC versions, they all have this
issue. I guess maybe someone have reported this already, but I can't find one.
