picoC Compiler

Disclaimer: This project is a learning project and useless for almost everyone who visits this repository. :)

picoC is a very small and low-level language based on C which only contains minimal language features such as functions and variables. Its only target platform is my FlexRTE platform.

The goal of this language is to provide an easy way to write FlexRTE applications without the need of writing only low-level FlexASM code. It should also be kept as simple as possible as a I'd like to write a more complex compiler in the future.

Most picoC code will not be compatible with the C standard.

Planned features

• Global & Local Variables:
  • const, pointers/references
  • unsigned, signed
  • char, short, int
  • bool
  • Arrays / Strings
• Functions
  • Arguments
  • Return value
• Structs
  • Defining structs containing variables
• Inline-Assembler
  • With support of picoC variables
• Compiler directives
  • #include
  • #pragma once
  • #define
  • #ifdef #ifndef #else #endif

Examples

Hello World

int32_t main()
{
  uint8_t * helloWorldStr = "Hello World";
  println(helloWorldStr);
  
  return 0;
}

void println(uint8_t * str)
{
  asm
  {
    mov eax, 3    ; print until 0
    mov ebx, $str ; inline-assembler supports picoC variables
    int 0x40      ; console system call
  }
}

Current progress

• Tokenizer ✔️ Done
• Abstrac Syntax Tree Current task

The AST parser is able to parse following picoC code int an AST:

picoC

unsigned int main(int arg1 = 5, int* arg2)
{
  char a = (32+(10*8)-13);
  unsigned int& b;
  short* c;
  bool d = a >= 50;
  
  if (d && a > 66)
  {
    bool e = a + (d - 420);
  }
}
char*** e;

Abstract Syntax Tree

+ ASTProgram
  > Children:
    + ASTFunctionDeclaration
      > Arguments:
        + ASTVariableDeclaration
          > Type:
            + ASTTypeExpression
              > Signed: True
              > Data Type: int
          > Identifier:
            + ASTIdentifierExpression
              > Name: arg1
          > Initialization:
            + ASTNumericLiteralExperssion
              > Number: 5
        + ASTVariableDeclaration
          > Type:
            + ASTTypePointerExpression
              > Signed: Pointer
              > Element:
                + ASTTypeExpression
                  > Signed: True
                  > Data Type: int
          > Identifier:
            + ASTIdentifierExpression
              > Name: arg2
      > Type:
        + ASTTypeExpression
          > Signed: False
          > Data Type: int
      > Identifier:
        + ASTIdentifierExpression
          > Name: main
      > Body:
        + ASTBlockElement
            + ASTVariableDeclaration
              > Type:
                + ASTTypeExpression
                  > Signed: True
                  > Data Type: char
              > Identifier:
                + ASTIdentifierExpression
                  > Name: a
              > Initialization:
                + ASTParenthesizedExpression
                    + ASTBinaryExpression
                      > Operator: +
                      > Left:
                        + ASTNumericLiteralExperssion
                          > Number: 32
                      > Right:
                        + ASTBinaryExpression
                          > Operator: -
                          > Left:
                            + ASTParenthesizedExpression
                                + ASTBinaryExpression
                                  > Operator: *
                                  > Left:
                                    + ASTNumericLiteralExperssion
                                      > Number: 10
                                  > Right:
                                    + ASTNumericLiteralExperssion
                                      > Number: 8
                          > Right:
                            + ASTNumericLiteralExperssion
                              > Number: 13
            + ASTVariableDeclaration
              > Type:
                + ASTTypePointerExpression
                  > Signed: Reference
                  > Element:
                    + ASTTypeExpression
                      > Signed: False
                      > Data Type: int
              > Identifier:
                + ASTIdentifierExpression
                  > Name: b
            + ASTVariableDeclaration
              > Type:
                + ASTTypePointerExpression
                  > Signed: Pointer
                  > Element:
                    + ASTTypeExpression
                      > Signed: True
                      > Data Type: short
              > Identifier:
                + ASTIdentifierExpression
                  > Name: c
            + ASTVariableDeclaration
              > Type:
                + ASTTypeExpression
                  > Signed: True
                  > Data Type: bool
              > Identifier:
                + ASTIdentifierExpression
                  > Name: d
              > Initialization:
                + ASTBinaryExpression
                  > Operator: >=
                  > Left:
                    + ASTIdentifierExpression
                      > Name: a
                  > Right:
                    + ASTNumericLiteralExperssion
                      > Number: 50
            + ASTIfStatement
              > Condition:
                + ASTBinaryExpression
                  > Operator: &&
                  > Left:
                    + ASTIdentifierExpression
                      > Name: d
                  > Right:
                    + ASTBinaryExpression
                      > Operator: >
                      > Left:
                        + ASTIdentifierExpression
                          > Name: a
                      > Right:
                        + ASTNumericLiteralExperssion
                          > Number: 66
              > Children:
                + ASTVariableDeclaration
                  > Type:
                    + ASTTypeExpression
                      > Signed: True
                      > Data Type: bool
                  > Identifier:
                    + ASTIdentifierExpression
                      > Name: e
                  > Initialization:
                    + ASTBinaryExpression
                      > Operator: +
                      > Left:
                        + ASTIdentifierExpression
                          > Name: a
                      > Right:
                        + ASTParenthesizedExpression
                            + ASTBinaryExpression
                              > Operator: -
                              > Left:
                                + ASTIdentifierExpression
                                  > Name: d
                              > Right:
                                + ASTNumericLiteralExperssion
                                  > Number: 420
    + ASTVariableDeclaration
      > Type:
        + ASTTypePointerExpression
          > Signed: Pointer
          > Element:
            + ASTTypePointerExpression
              > Signed: Pointer
              > Element:
                + ASTTypePointerExpression
                  > Signed: Pointer
                  > Element:
                    + ASTTypeExpression
                      > Signed: True
                      > Data Type: char
      > Identifier:
        + ASTIdentifierExpression
          > Name: e