Support Compiler of IAR extensions

Type: Feature Request

Hello! I‘m a vscode user.

Sorry to submit a new issue be similar to existing issues. I use GNU Arm Embedded toolchain before, It works very well on vscode with C++ Intellisense("intelliSenseMode": "gcc-arm", "compilerPath": "xxx/gcc-arm-none-eabi.exe"). Recently, I use vscode as the editor of IAR to develop arm program. And I found that vscode does not support some keywords of ICC(IAR-CC ARM).

define symbol

There are some symbols that can cheat the compiler by defines, such as bit in MCS51:

xxx.c:

bit a = 0;

c_cpp_properties.json:

"defines": [
   "bit=bool"
],

other keyword

But there are some keyword that still report errors, such as interrupt in MCS51 or @ in IAR :

static rt_device_t xxx_dev @ ".ccmram";
void Timer_isr(void) interrupt 1
{
   //...
}

This code means to define the variable in ".ccmram" area, and define a function for timer interrupt.

user code

I can define a macro #define NVIC(n) interrupt n if __VSCODE__ is not defined. But this only applies to user code, I shouldn't have to modify the firmware library code.

Of course, this doesn't affect programming, and I don't know how does compiler support work. So it's just a suggestion.

Start with the IAR examples in the issue, including the interrupt keyword and @ placement syntax, and review how compiler extensions are handled by the extension. Done means IAR firmware code can be parsed without diagnostics for these constructs, without requiring changes to the firmware library.