Developer Guide and Reference

Contents

ftrapuv
, Qtrapuv

Initializes stack local variables to an unusual value to aid error detection.

Syntax

Linux:
-ftrapuv
Windows:
/Qtrapuv
(C++ only)
Windows:
None
(DPC++ only)
Arguments
None
Default
OFF
The compiler does not initialize local variables.
Description
This option initializes stack local variables to an unusual value to aid error detection. Normally, these local variables should be initialized in the application. It also unmasks the floating-point invalid exception.
The option sets any uninitialized local variables that are allocated on the stack to a value that is typically interpreted as a very large integer or an invalid address. References to these variables are then likely to cause run-time errors that can help you detect coding errors.
This option sets option
-g
(Linux*) and
/Zi
or
/Z7
(Windows*), which changes the default optimization level from
O2
to
-O0
(Linux) or
/Od
(Windows). You can override this effect by explicitly specifying an
O
option setting.
For more details on using options
-ftrapuv
and
/Qtrapuv
(C++)
with compiler option
O
, see the article in Intel® Developer Zone titled
Don't optimize when using -ftrapuv for uninitialized variable detection
, which is located in https://software.intel.com/content/www/us/en/develop/articles/dont-optimize-when-using-ftrapuv-for-uninitialized-variable-detection.html.
Another way to detect uninitialized local scalar variables is by specifying keyword
uninit
for option
check
.
IDE Equivalent
Visual Studio:
None
Eclipse:
Run-Time > Initialize Stack Variables to an Unusual Value
Alternate Options
None

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.