The least optimized compiler you'll ever see.
- functions and function calls (Sysv ABI)
- variables and global variables
- forward declarations (functions and global variables)
- loops
- break, continue
- conditionals
- binary operations
- unary operations (++, --, !, ~, -)
- postfix operations (++, --)
- add good error messages
- add octal char, hex char, unicode code point escape codes in lexer
- add power of two optimization for mul, div, mod
- support lvalues not just being identifiers (pointers)
- add comma operator (have to make it lower precedence than =)
- honestly almost never used
- move function redefinition & param count error checking out of parser
- missing features
- void, float
- pointers (arrays, strings)
- https://en.cppreference.com/w/c/language/pointer
- pointer type
- take pointer to (&)
- for now don't support taking pointer to func args, but later on mark variable as having been moved to stack and move
- lea -4(%rbp)
- lea foo(%rip)
- dereference (*)
- load ptr into register, use register as mem addr
- test break after nested for loop
- keep track of pointer depth (char **arr)
char + char = char no widening int + char = int widen rhs char + int = int widen lhs int + int = int no widening
char a = char b no widening int a = char b widen rhs char a = int b truncate lhs int a = int b no widening
https://norasandler.com/2017/11/29/Write-a-Compiler.html https://github.com/DoctorWkt/acwj
http://www.quut.com/c/ANSI-C-grammar-y-1999.html http://www.quut.com/c/ANSI-C-grammar-l-1999.html