pragma unused

[inteluser]

I am looking for a way to suppress warning #177: "variable was declared but never referenced" for certain variables throughout my code. The GCC compiler has __attribute__((unused)) for this.

According to the documentation Composer XE 12.1 should allow me to use "#pragma unused". However, using this approach the compiler issues the warning: "warning #161: unrecognized #pragma unused".

[Judith_W_Intel]

Does attribute unused not work with our compiler? If so can you provide an example and tell us which version of the compiler you are using?

I tried a simpleexample with version 12.1 and it seems towork for me:

sptxl8-446> cat att.c

#ifdef OK
static void foo() __attribute__((unused));
#endif

static void foo()
{
#ifdef OK
int j __attribute__((unused));
#else
int j;
#endif
}
sptxl8-447> icpc -Wremarks -c att.c
att.c(13): remark #177: variable "j" was declared but never referenced
int j;
^

att.c(8): remark #177: function "foo" was declared but never referenced
static void foo()
^

sptxl8-448> icpc -Wremarks -DOK -c att.c
sptxl8-449>

thanks
Judy

[inteluser]

I use the following version together with Visual Studio 2010 on Windows 7 64bit.

c:\\Program Files (x86)\\Intel\\Composer XE 2011 SP1\\bin\\intel64\\icl

Intel C++ Intel 64 Compiler XE for applications running on Intel 64, Version 12.1.3.300 Build 20120130

I've tried your simple example:

3> main.cpp

3>main.cpp(5): error : expected a "{"

3> static void foo() __attribute__((unused));

3> ^

3>

3>main.cpp(8): warning #12: parsing restarts here after previous syntax error

3> {

3> ^

3>

3>main.cpp(9): error : expected a ";"

3> int j __attribute__((unused));

3> ^

[TimP]

Unfortunately, gcc extensions such as __attribute__ don't work with the Microsoft-compatible Windows compiler. You may find the mingw 64-bit gcc compiler useful.

[jimdempseyatthecove]

#define _UNUSED_(x) (void)x;
void foo(int a, int b)
{
++a;
_UNUSED_(b)
}

Jim Dempsey

[inteluser]

#pragma unused does also not work because of Microsoft compatiblity?

http://software.intel.com/sites/products/documentation/hpc/composerxe/en-us/2011Update/cpp/win/cref_cls/common/cppref_pragma_unused.htm#cppref_pragma_unused