gnnng/pascal

A naive pascal compiler written in C++, using flex/bison as front-end and llvm as the back-end

Pascal

a pascal compiler implemented by LLVM 3.5.1.

This is the final project of the course Compiler Course Design in ZJU. Sorry for bugs and lacking of documents

Current Status: in Updating docs

Authors

• Li Yiting (@lyt9304)
• Zhang Yuhao (@denil1111)
• Gong Deli (@Gnnng)

Build

• llvm 3.5.1 (must be)
• -std=stdc++11 (see more in makefile)
• Mac OSX (recommended)

Pascal Grammar Support

Details about grammar support can be found in yacc source file pascal.y

Type

• Integer
• Real
• Char
• Bool
• Record (imperfectly)
• Array (imperfectly)

Control flow

• if statement
• for statement
• repeat statement
• while statement
• case statement
• goto statement (imperfectly)

Others

• function/procedure declaration/execution
• binary operators
• system functions
  • read/readln
  • write/writeln

References

• LLVM官网教程

http://llvm.org/docs/tutorial/index.html

• 使用 LLVM 框架创建一个工作编译器，这里有IR的教程

http://www.ibm.com/developerworks/cn/opensource/os-createcompilerllvm1/

• 一个完整的flex+bison+llvm的例子

http://www.cppblog.com/woaidongmao/archive/2009/11/11/100693.aspx

• 例子源代码

https://github.com/lsegal/my_toy_compiler

• 另外一个例子

http://my.oschina.net/linlifeng/blog/97457

pascal's Issues

More Types: Step 2 user-defined types

check multiple declaration

program llvm;
var a, b, c: integer; a, b, c: integer;
...

Codes like this will pass the check, a,b,c should not be allowed to declared again.
Need to reimplement the function getValue of CodeGenBlock, and check if a symbol has not been declared

Error in Make/Build!

$ make

g++ -c `/usr/local/opt/llvm35/bin/llvm-config-3.5 --cppflags` -std=c++11 -Wno-return-type -Wno-c++11-compat-deprecated-writable-strings -Wno-deprecated-register -Wno-switch  -g -o parser.o parser.cpp 
/bin/sh: 1: /usr/local/opt/llvm35/bin/llvm-config-3.5: not found
In file included from pascal.y:7:0:
ast.h:4:27: fatal error: llvm/IR/Value.h: No such file or directory
 #include "llvm/IR/Value.h"
                           ^
compilation terminated.
makefile:27: recipe for target 'parser.o' failed
make: *** [parser.o] Error 1

How fix?

Add read and readln

Currently only support integer type

Friendly Error Prompt and Recovery

Two sets of error:

1. compile error
2. running error

More subtypes in each set. E.g. syntax error and invalid type error are both compile errors

More Types: Step 1 SYS_TYPE

1. const_value (real, char, boolean)
2. array_type_decl
3. record_type_decl