Typechecker & LLVM compiler

Prerequisites

• Haskell Stack
• LLVM
• BNFC
• Happy
• Alex

Make:

make

Run

Typechecker

./latc [-v] <file [files...]>

Compiler

./latc_llvm [-v] <file [files...]>

What has been done

• Basic Latte typechecker and LLVM compiler
• Using PHI nodes instead of alloca and store
• Copy Propagation and Constant Folding
• Dead Code Elimination
• Global Common Subexpression Elimination
• Extensions:
  • Classes with virtual methods

Important note: Even though the typechecker is able to validate arrays, the compiler does not support them. It informs the user with an error message.

Source structure

• src/
  • Latte.cf - Grammar
  • Forontend/
    • Desugaring.hs - Desugaring of the AST, mainly transforming for loops into while loops and incrementation and decrementation of variables into simple arithmetic.
    • Typechecker.hs - Typechecking of the AST.
  • Backend/
    • Milkremover.hs - Transforms Latte into Espresso IR
    • SingleShotAffogato.hs - Transform Espresso IR into SSA form and performs (CP, DCE, GCSE) loop until a fixpoint is reached.
    • ArabicaGenearator.hs - Generates LLVM IR from Espresso IR, assuming it is in SSA form. Here is where the main vritual methods are implemented.
    • ASTInterpreter.hs - An early version of Espresso IR interpreter, used for debugging.
• tests/ - Tests for the typechecker and the compiler (tests/extensions/arrays1 are irrelevant)
• lib/ - Latte standard library with addition of concatStrings, compareStrings and __calloc__

Verbose output

• .desugared - Latte program after desugaring
• .esp - Espresso IR
• .esp.ssa - Espresso IR in SSA form after optimizations
• .ll - LLVM IR
• .bc - LLVM Bitcode