niuk

==8944== Memcheck, a memory error detector
==8944== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==8944== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==8944== Command: ./Generator
==8944== 
; ModuleID = 'myModule'
==8944== Invalid write of size 8
==8944==    at 0xB3BB8C: ??? (in /home/karl/Haskell/Hammer/Generator)
==8944==  Address 0x64ed560 is not stack'd, malloc'd or (recently) free'd
==8944== 

niuk

{-# LANGUAGE
    OverloadedStrings,
    FlexibleInstances #-}

module Main where

import Prelude

import System.IO

niuk

OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to localhost [::1] port 22.
debug1: Connection established.
debug1: identity file /home/test/.ssh/identity type -1
debug1: identity file /home/test/.ssh/id_rsa type 1
debug1: identity file /home/test/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*

niuk

main : IO ()
open : IO Handle
write : Handle -> String -> IO ()
close : Handle -> IO ()

main = do
  fd <- open "log.txt"
  write fd "Hello World!"
  close fd

niuk

/* The Hammer code for read_buf_from_file would look like this: */

void *read_buf_from_file(char *path) {
  int ret = -1;
  void *buf = malloc(512) <-
    lambda(buf) {
      if (ret < 0) free(buf);
    };
  int fd = open(path, O_RDONLY) <-
    lambda(fd) {

niuk

/* Say you want to read some stuff into a buffer.
 * To do so in C, a (very) naive programmer would write something like: */

void *read_buf_from_file(char *path) {
  void *buf = malloc(512);
  int fd = open(path, O_RDONLY);
  read(fd, buf, 512);
  return buf;
}

niuk

interface Eq require
  {type T; eq}

interface Eq provide
  type T : Type
  eq : (T, T) -> Bool

module EqInt : Eq where
  type T = Int
  eq = builtIn_eqInt