calgo

So far, the purpose of this project is to facilitate my own learning.

Environment

• Machine: x86-64
• OS: ubuntu 20.04
• Go version: 1.18

Install Step

1. git clone
2. cd calgo
3. go build
4. ./calgo

An example

The file 'intercode.demo' in directory 'demo' showcases what this language can achieve. If you just run ./calgo, the default output diretory is 'out' and the default output files include 'code.asm' which is the output of compiler and 'elf_reloc.o' which is the output of assembler. The file 'tmp_code_seg_out' is the data segment of 'elf_reloc.o'. You can view detailed information for 'elf_reloc.o' using 'readelf' and 'objdump'.

And you can view function's intercode generated by compiler by using command line argument '--print_intercode=func_name1,func_name2'. The following picture illustrates an example.

About language

Type

Basic Type

• void
• char
• int

Derived Type

• pointer
• array

Declaration and Definition

Global Scope

int var;
int var = 3;
int var1, var2;
int *ptr, arr[7];
void func();
char* func(int x, char *s) { ... }
int func() { ... }

/* Not currently supported */
int arr[] = {1, 2, 3}; //array initilization is not supported

Local Scope

Same as "Global Scope"

Expression

• =
• ||, &&
• >, <, >=, <=, ==, !=
• +, -, *, /, %
• !,-,&,*,
• ++,--: prefix increment/decrement
• ++,--: postfix increment/decrement
• (): Bracket expression
• []: array index expression
• (): function call expression

Statement

• expression statement
• while statement
• if statement
• break statement
• continue statement
• return statement