RealView Compilation Tools - ARM Information Center

Compiler-specific Features
• __attribute__((noinline)) constant variable attribute on page 4-51
• __declspec(noinline) on page 4-27
• __attribute__((noinline)) on page 4-34.
4.6.15 #pragma no_pch
This pragma suppresses PCH processing for a given source file.
See also
• --pch on page 2-101
• Precompiled header files on page 2-17 in the Compiler User Guide.
4.6.16 #pragma Onum
This pragma changes the optimization level.
Syntax
#pragma Onum
Where:
num
is the new optimization level.
The value of num is 0, 1, 2 or 3.
See also
• -Onum on page 2-96.
4.6.17 #pragma once
This pragma enables the compiler to skips subsequent includes of that header file.
#pragma once is accepted for compatibility with other compilers, and enables you to use
other forms of header guard coding. However, it is preferable to use #ifndef and #define
coding because this is more portable.
Example
The following example shows the placement of a #ifndef guard around the body of the
file, with a #define of the guard variable after the #ifndef.
ARM DUI 0348C Copyright © 2007-2010 ARM. All rights reserved. 4-67
ID101213
Non-Confidential,