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