Datasheet
C and C++ Compilers
ARM DUI 0067D Copyright © 1999-2001 ARM Limited. All rights reserved. 2-33
C2621W: double constant automatically converted to float
These warnings are given when the default type of unqualified
floating-point constants is changed by the
-auto_float_constants
option.
This warning is switched on by default.
-Wl
This option turns off the warning:
C2951W: lower precision in wider context
when code like the following is found:
long x; int y, z; x = y*z
where the multiplication yields an
int
result that is then widened to
long
.
This warning indicates a potential problem when either the destination is
long long
or where the code has been ported to a system that uses 16-bit
integers or 64-bit longs. This option is off by default. It can be enabled
with
-W+l
.
-Wm
This option suppresses warnings about multiple-character
char
constants.
-Wn
This option suppresses the warning message:
C2921W: implicit narrowing cast
This warning is issued when the compiler detects the implicit narrowing
of a long expression in an
int
or
char
context, or detects the implicit
narrowing of a floating-point expression in an integer or narrower
floating-point context.
Such implicit narrowing casts are almost always a source of problems
when moving code that has been developed on a 32-bit system to a
system where
int
occupies 16 bits and
long
occupies 32 bits. This option
is off by default.
-Wo
This option suppresses warnings for implicit conversion to signed
long
long
constants.
-Wp
This option suppresses the warning message:
C2812W: Non-ANSI #include <…>
The ANSI C standard requires that you use
#include <…>
for ANSI C
headers only. However, it is useful to disable this warning when
compiling code not conforming to this aspect of the standard. This
warning is suppressed by default unless you specify the
-strict
option.
-Wq
This option suppresses warnings in C++ constructor initialization order.
-Wr
This option suppresses the implicit virtual warning (C++ only) issued
when a non-virtual member function of a derived class hides a virtual
member of a parent class. For example: