done readme and adde licesnse

LICENSCE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 EthanSK QFSW
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

readme.md

@@ -1,13 +1,87 @@
-# C90 (ANSI) to MIPS Compiler
+# C90 (ANSI) to MIPS 1 Compiler
 
 ### Introduction
 
-This is a (non fully featured) compiler written in C++ for ANSI C89/C90.
-It conforms to this specification: https://github.com/LangProc/langproc-2018-cw   
+- This is a (non fully featured) compiler written in C++ for ANSI C89/C90 to MIPS 1 (ABI Compliant)
+- It uses Flex for lexical analysis, and Bison (3.3.2) for parsing to an AST.
+- The target environment is Ubuntu 16, however a lot of the features may work on Unix based systems such as MacOS (exempt features are mentioned below).
+- The compiler conforms to this specification: http://port70.net/~nsz/c/c89/c89-draft.html
+- The projcet conforms to this specification: https://github.com/LangProc/langproc-2018-cw  
+- It assumes the input C is perfectly valid, well-formed, pre-processed C90. It performs some minimal optimization and error checking but do not rely on it for anything useful.
+- Also includes a basic C to Python translator
 
+### Usage
+
+Make the project:  
+```make clean``` 
+```make bin/c_compiler```
+
+To compile a C file into MIPS, simply run   
+```bin/c_compiler -S <source-file.c> -o <dest-file.s>```   
+
+To translate from C to Python (limitations described below), simply run   
+```bin/c_compiler --translate <source-file.c> -o <dest-file.py>```
+
+
+
+### Features
+
+You will see these things printed to the console when running the compiler:  
+- The input C code printed in canonical form. This is to ensure the parser correctly read and converted the C code into an AST. It can be found in ```bin/printC.c```
+- The 3 address code intermediate language. It can be found in ```bin/intermediateLanguage.txt```
+- The MIPS code generated
+- The translated Python (if running with the ```--translate``` flag)
+
+##### Compiler:  
+
+The compiler does not support the full range of C90 features due to time constraints we had with the project, however we encourage anyone to improve/finish the compiler (hence the MIT License).
+
+Some things the compiler fully supports:   
+- Functions with unlimited arguments
+- Variables of ```int``` type
+- Arithmetic and logical expressions
+- If else and switch statements
+- Operators
+- For, while, and do while loops
+- Arrays
+- Char literals
+- Sizeof (kind of)
+- Pointers, addressing and dereferencing
+
+Some things the compiler does not support:
+- Structs and Unions
+- Enums (started, never finished)
+- Strings
+- Multithreading
+- Goto
+- Macros and other preprocessing directives
+- Comma operator (for sequencing within expressions)
+- The old K&R style of declaring functions
+- Variable-length arrays
+- Const
+- Pointer arithmetic
+- Non int primitives
+- Typedef
+
+##### C to Python translator:   
+
+Some things the translator supports:   
+- Local and global integer variables (non nested scopes)
+- Functions (definition and invocation) with integer arguments and void/integer return type
+- Explicit support for main special functionality
+- If, else, while, return, and sequences
+- Decimal integer constants
+- Integer arithmetic
+- &&, ||, <, and ==
+- Assignment as a direct expression statement
+
+
+Some things the translator does not support:   
+- Variable shadowing
+- Most other things not listed in support section above
 
 ### Testbench
-The testbench runs unit tests to test the C to Python translator and the compiler itself.  The compiler unit tests only run on ubuntu, with ```mips-linux-gnu-gcc``` and ```qemu-mips``` installed.
+The testbench runs unit tests to test the C to Python translator and the compiler itself.  The compiler-specific unit tests only (have been confirmed to) run on Linux, with ```mips-linux-gnu-gcc``` and ```qemu-mips``` installed.
 
 The compiler tests can be run using: 
 
@@ -18,4 +92,21 @@ and the C to Python translator tests can be run using:
 ```test/pythonTranslator/src/runTests.sh```
 
 
-You will see a ```pythonTranslator``` folder in ```test/compiler/tests```. These were generated by a tool, ```devtools/translatorToCompilerTests.sh```, that converts C to Python translator tests into compiler tests.
+You will see a ```pythonTranslator``` folder in ```test/compiler/tests```. These were generated by a tool, ```devtools/translatorToCompilerTests.sh```, that converts C to Python translator tests into compiler tests.   
+
+You can see the results in the ```log``` folder in ```test/compiler``` and ```test/pythonTranslator/log``` folders.   
+
+The compiler currently passes 172/177 tests
+
+
+### Extras
+
+We added some cool features:   
+- View diagram of AST with Graphviz (or an online dot file viewer, like https://dreampuf.github.io/GraphvizOnline)(dot file can be found in ```bin/ast.dot``` once compiler has been run as described in Usage section) 
+- View the AST that the Clang compiler generates on any C file you give it using ```playground/ast/generateAST.sh <program_name.c>```
+
+### Credits
+
+The creators of this project are:
+EthanSK https://github.com/EthanSK
+QFSW https://github.com/QFSW