55 lines
1.8 KiB
Markdown
55 lines
1.8 KiB
Markdown
# C++ support for RT-Thread #
|
|
|
|
This is the C++ component in RT-Thread RTOS. In order to support C++ language, this component
|
|
implement a basic environment, such as new/delete operators.
|
|
|
|
Because RT-Thread RTOS is used in embedded system mostly, there are some rules for C++ applications:
|
|
|
|
1. DOES NOT use exception.
|
|
2. DOES NOT use Run-Time Type Information (RTTI).
|
|
3. Template is discouraged and it easily causes code text large.
|
|
4. Static class variables are discouraged. The time and place to call their constructor function could not be precisely controlled and make multi-threaded programming a nightmare.
|
|
5. Multiple inheritance is strongly discouraged, as it can cause intolerable confusion.
|
|
|
|
*NOTE*: The libc (RT_USING_LIBC in rtconfig.h) must be enable.
|
|
|
|
About GNU GCC compiler
|
|
|
|
please add following string in your ld link script:
|
|
|
|
// in your .text section
|
|
PROVIDE(__ctors_start__ = .);
|
|
/* old GCC version uses .ctors */
|
|
KEEP(*(SORT(.ctors.*)))
|
|
KEEP(*(.ctors))
|
|
/* new GCC version uses .init_array */
|
|
KEEP (*(SORT(.init_array.*)))
|
|
KEEP (*(.init_array))
|
|
PROVIDE(__ctors_end__ = .);
|
|
|
|
. = ALIGN(4);
|
|
|
|
// as a standalone section if you use ARM target.
|
|
|
|
/* The .ARM.exidx section is used for C++ exception handling. */
|
|
/* .ARM.exidx is sorted, so has to go in its own output section. */
|
|
__exidx_start = .;
|
|
ARM.exidx :
|
|
{
|
|
*(.ARM.exidx* .gnu.linkonce.armexidx.*)
|
|
|
|
/* This is used by the startup in order to initialize the .data secion */
|
|
_sidata = .;
|
|
} > CODE
|
|
__exidx_end = .;
|
|
|
|
/* .data section which is used for initialized data */
|
|
|
|
// in your .data section
|
|
PROVIDE(__dtors_start__ = .);
|
|
KEEP(*(SORT(.dtors.*)))
|
|
KEEP(*(.dtors))
|
|
PROVIDE(__dtors_end__ = .);
|
|
|
|
. = ALIGN(4);
|