Module Loader Stability

[Samy-33]

Compilation Cache

jank now compiles the modules to multiple targets i.e. cpp, object file and llvm ir. The current behaviour of the module loader is to skip compilation if compiled object file already exists for that module.

This becomes a problem when the user wants to compile a module to cpp target or llvm ir target and object file already exists. Module loader currectly skips the compilation resulting into a no-op.

Recompilation into an executable fails

;; core.jank
(ns core (:require [lib] [lib-cpp]))

(defn -main [] (lib/hello))

;; lib.jank
(ns lib)

(defn foo [] "Hello from foo")

// lib_cpp.cpp
#include<iostream>

extern "C" void jank_module_set_loaded(char const *);

extern "C" void jank_load_lib_cpp()
{
  jank_module_set_loaded("lib-cpp");
  std::cout<<"Hello from lib-cpp\n";
}

Now, if we AoT compile core twice. Module loader, fails to find the lib ns

> jank compile core
> jank compile core

Stack trace (most recent call first):
#0  in jank::error::internal_failure at error.cpp:495
#1  in jank::error::throw_internal_failure at error.cpp:501
#2
#3
#4
#5
#6  in jank::runtime::module::loader::load_o at loader.cpp:995
#7  in jank::runtime::module::loader::load at loader.cpp:935
#8  in jank::runtime::context::load_module at context.cpp:363
#9  in jank::runtime::context::compile_module at context.cpp:386
#10 in jank::compile at main.cpp:362
#11 in main::$_0::operator at main.cpp:428
#12 in main::$_0::__invoke at main.cpp:378
#13 in jank_init_with_pch at c_api.cpp:1077
#14 in jank_init at c_api.cpp:1026
#15 in main at main.cpp:378
#16 at libc.so.6
#17 in __libc_start_main at libc.so.6

Testing

• AoT recompilation works
• Compilation to all the targets (cpp, object, llvm ir) works with proper caching

[jeaye]

This is a dupe of #668 (which was also created by you, at the same time). Please close one of them.