CYGPKG_LIBC_STDLIB
Dummy
Options associated with the standard utility functions in <stdlib.h>
CYGIMP_LIBC_STDLIB_INLINES
Boolean
This option chooses whether some of the particularly simple standard utility functions from <stdlib.h> are available as inline functions. This may improve performance, and as the functions are small, may even improve code size.
CYGPKG_LIBC_RAND
Boolean
This option chooses whether the pseudo-random number generator functions rand() and srand() are available. Some space may saved if not.
CYGNUM_LIBC_RAND_SEED
Count
This selects the initial random number seed for rand()'s pseudo-random number generator. For strict ISO standard compliance, this should be 1, as per section 7.10.2.2 of the standard.
CYGPKG_LIBC_MALLOC
Boolean
This enables support for dynamic memory allocation as supplied by the functions malloc(), free(), calloc() and realloc(). As these functions are often used, but can have quite an overhead, disabling them here can ensure they cannot even be used accidentally when static allocation is preferred.
CYGNUM_LIBC_MALLOC_MEMPOOL_SIZE
Count
At this stage, dynamic memory allocation by malloc() and calloc() must be from a fixed-size, contiguous memory pool. This option is the size of that pool, in bytes. Note that not all of this is available for programs to use - some is needed for internal information about memory regions, and some may be lost to ensure that memory allocation only returns memory aligned on word (or double word) boundaries - a very common architecture constraint.
CYGIMP_LIBC_MALLOC_CXX_DELETE_CALLS_FREE
Boolean
C++ new and delete operators can call the C library's malloc() and free() implicitly. If this is what is required, enable this option. However, if enabled, the dynamic memory allocation code is always linked in to the application, even if it is not explicitly called and new/delete are not used. This increases code and data size needlessly.
CYGFUN_LIBC_strtod
Boolean
This option allows use of the utility function strtod() (and consequently atof()) to convert from string to double precision floating point numbers. Disabling this option removes the dependency on the math library package.