Macho: Programming With Man Pages
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Transcript of Macho: Programming With Man Pages
Macho: Programming
With Man Pages
Anthony Cozzie, Murph Finnicum, Sam KingUniversity of Illinois at Urbana-Champaign
Programming is hard!
• Extreme Detail• Extreme Precision
Lots of Automated Tools
• Static Analysis– Coverity
• Code Snippet search engines– Prospector, SNIFF, Xsnippet, even Google
• Automated Debuggers– Genetic programming, Delta debugging
Automating Programming
• Computer makes decisions• But it will make mistakes too!• Programmer must go back and check the tool
– not easy• So, how can we do this efficiently?
Macho Architecture
NL parsing Database Stitching Debugger
RawText
RequestedComputation Code Snippets
CandidatePrograms
Runtime Feedback
Solutions
The Trick
NL parsing Database Stitching Debugger
Examples!
• Example is end-to-end: covers many decisions• Easy to understand compared to code
The Example (LS)
Print the names of files in a directory. Sort the names.
Extract Implied Computation
directory -> filesfiles -> namesprint(names)sort(names)
Print the names of files in a directory. Sort names.
Use Programmer’s Labels
public static void main(String[] args) {
....
//first (original) database files = directory.listFiles();
....}
Input to Synthesis: LS1public static void Ls1(java.lang.String p_directory) { java.io.File tmp = new File(p_directory); java.io.File[] files = tmp.listFiles(); int tmp_0 = files.length; java.lang.String[] tmp_1 = new java.lang.String[tmp_0]; for(int tmp_3 = 0; tmp_3 < files.length; ++tmp_3) { java.io.File tmp_2 = files[tmp_3]; java.lang.String names = tmp_2.getName(); tmp_1[tmp_3] = names; } Arrays.sort(tmp_1); for(int tmp_5 = 0; tmp_5 < tmp_1.length; ++tmp_5) { java.lang.String tmp_4 = tmp_1[tmp_5]; System.out.println(tmp_4); } }
Bugs!
• Prints hidden files• Crashes if the input is not a directory
Synthesized Version of LSpublic static void Ls3(String p_dir) { java.io.File tmp = new File(p_dir); java.io.File[] files = tmp.listFiles(); boolean tmp_3 = tmp.isDirectory(); if(tmp_3) { Arrays.sort(files); for(int tmp_1 = 0; tmp_1 < files.length; ++tmp_1) { java.io.File tmp_0 = files[tmp_1]; java.lang.String names = tmp_0.getName(); boolean tmp_2 = tmp_0.isHidden(); if(!tmp_2)
System.out.println(names); } } else System.out.println(tmp + ""); }
Pure NL Spec
Take the path "/home/zerocool/" If the path is a file, print it. Otherwise get the list of files in the directory. Sort the result alphabetically. Go over the result from the beginning to the end: If the current element's filename does not begin with ".", print it.
Macho
Print the names of files in a directory. Sort the names.
+ simple example
Input Synergy
• NL: moderate information over a large part of the state space
• Examples: very precise information over a tiny part of the state space
• Together: win