#+TITLE: Notes
#+DATE: <2017-02-20 Mon>
#+AUTHOR: Yann Herklotz
#+EMAIL: ymherklotz@gmail.com
#+DESCRIPTION: These are notes about the Compiler project.

* Lexer

** DONE Lab (calculate statistics over text)
   DEADLINE: <2017-01-31 Tue>

*** Task

    We had to calculate statistics over text. This was to learn about 
    flex and how to use it.


** DONE Coursework (c lexer)
   DEADLINE: <2017-02-07 Tue>

*** Task

    Design a C lexer that could lex C and output the important information 
    about the C code. This made us read the C spec for the first time.

* Parser

** DONE Lab (parse maths)
   DEADLINE: <2017-02-14 Tue>

*** Task

    We had to design a maths parser and then analyse the tree that was 
    created by parsing it. The additional parts where to differentiate 
    equations using the different rules for differentiating. We also had to 
    evaluate the expressions and do other operations on the tree. This taught 
    us how to use bison.


** TODO Coursework (c parser)
   DEADLINE: <2017-03-07 Tue>

*** Task

*** AST (Abstract Syntax Tree)
    
    Finsihed the AST for now, using polymorphism to achieve this. Right now i
    t achieves the goal of this coursework as it does print out the AST in xml 
    format and supports all the features that the parser should support. The 
    expressions branch of the AST is completely bare because they are not needed 
    for this parser. I will continue working on this AST in the compiler section 
    so that it supports all the other constructs that I need for the compiler.

*** Grammar

    The grammar is not completely done yet as I dont support all of the declartions 
    that are possible, and as I add more constructs in the AST I will also have to add 
    declarations in the bison file. This I will only continue in the Compiler section.
* Compiler
** DONE Lab (codegen)
   DEADLINE: <2017-02-28 Tue>

*** Task

    In this lab we used the setup provided to us to make a compiler for the language
    specified in the lab. The AST was already built for us and the language was already
    parsed using C++ instead of bison.

** TODO Coursework (c compiler)
   DEADLINE: <2017-03-28 Tue>

*** Task    
*** Mips Assembly

    - %hi(id) :: loads the upper address of the global variable id
    - %lo(id) :: loads the lower address of the global variable id
    - addiu :: Add Immediate Unsigned
    - jr :: Jump Register
    - li :: Pseudo instruction interpreted as (	lui $rd, LabelAddr[31:16]
                                                ori $rd,$rd, LabelAddr[15:0] )
    - lui :: loads uppper immediate.
    - lw :: Load Word
    - move :: Pseudo instruction interpreted as (add $rt, $rs, $zero)
    - nop :: No Operation
    - sw :: Store Word
*** TODOs

**** DONE VariableStackBindings class

     The class will contain map of strings containing the variable name as the _key_ and the stack 
     position as the stack position and type as the attributes, which will be combined using a struct.

**** DONE Work on statements and declaration

     Implement the adding to the bindings part that has to be added in the statements and declarations.

**** DONE Store expression results on the stack

     To do this I created a function in my VariableStackBindings that will store the 
     position of the stack that will be used for the next expression.
**** DONE Reformat code
**** DONE Work on expression
     CLOCK: [2017-03-15 Wed 21:00]--[2017-03-16 Thu 00:39] =>  3:39

      Add more expression.

**** DONE Make functions work
***** DONE Make function calls work from expressions
***** DONE Make functions receive arguments
      - Work on bison file to get the parameters correctly
      - Work on storing them correctly in the binding
**** TODO Comment code

     comment code to know where I am at and what I still have to do.
**** DONE Definition class 

     - need function that will print the code for declaration. Basic code should be:
       
       li    $2, 6
       sw    $2, 4($fp)

     - Before that is executed it should evaluate the expression.

     - The expression should be the thing doing: li    $2, 6
       That is if we want a 6 stored in the variable.

     - The declaration class should only be in charge of storing it in the right location in
       the stack and adding that to the bindings.
**** DONE Add more expressions
     CLOCK: [2017-03-17 Fri 17:08]--[2017-03-17 Fri 20:59] =>  3:51
     CLOCK: [2017-03-17 Fri 13:21]--[2017-03-17 Fri 15:43] =>  2:22
     
     Expressions like > or < or == etc..

**** DONE Add more statements
***** DONE If statement
      CLOCK: [2017-03-18 Sat 08:42]--[2017-03-18 Sat 09:57] =>  1:15
***** DONE For statement
***** DONE While statement
***** TODO Do While statement
**** DONE Fixing Seg fault 1
     CLOCK: [2017-03-17 Fri 15:44]--[2017-03-17 Fri 16:00] =>  0:16

     Have to fix type assigment for declaration lists, need to make new pointers of the right type.
**** DONE Load more that 4 bytes into a variable.
**** DONE Fix expressions and temporary variables

     I have to store the temporary expression in normal registers.

**** DONE Convert cout to printf

     convert all cout to printf
     
**** DONE Add global variables

     Change code so that it also prints global variables. This should be done with 
     the globalAsm function.

     I might have to change the print Asm and the global Asm function in the declarations.
**** DONE Add post and pre increment
     CLOCK: [2017-03-20 Mon 15:12]

     For post increment I will have a special class that handles that, 
     for pre increment I will rewrite in terms of addition, which should be possible.
**** DONE Arrays
     Finished arrays

**** DONE Pointers
     Finished pointers
**** TODO Add initializer list count of expression depth