#!/usr/bin/env python

import os
import glob
import subprocess

LLVM_PATH = glob.glob('/usr/lib/llvm-3.8/lib/clang/3.8.[0-9]/lib/linux/')[0]
COVERAGE_OPTIONS = '-Ccodegen-units=1 -Clink-dead-code -Cpasses=insert-gcov-profiling -Zno-landing-pads -L%s -lclang_rt.profile-x86_64' % LLVM_PATH
LCOVOPTS = '--gcov-tool ./admin/llvm-gcov --rc lcov_branch_coverage=1 --rc lcov_excl_line=assert'.split()

def lcov_exe(*args):
    return ['lcov'] + LCOVOPTS + list(args)

def sh(cmd):
    subprocess.check_call(cmd, shell = True)

def cleanup():
    sh('cargo clean')
    sh("rm -rf *.gcda *.gcno")

def run(which):
    exe = filter(lambda x: '.d' not in x, glob.glob('target/debug/' + which + '-*'))[0]
    sh('./' + exe)

def cargo():
    # run stable cargo, because nightly is oft-broken
    out = subprocess.check_output(['rustup', 'run', 'stable', 'rustup', 'which', 'cargo'])
    return out.strip()

def rustc(*args):
    exe = [cargo(), 'rustc', '--all-features'] + list(args)
    env = dict(os.environ)
    env.update(RUSTC_WRAPPER = './admin/coverage-rustc',
               COVERAGE_OPTIONS = COVERAGE_OPTIONS,
               CARGO_INCREMENTAL = '0')
    subprocess.check_call(exe, env = env)

def lcov(outfile):
    exe = lcov_exe('--capture', '--directory', '.', '--base-directory', '.', '-o', outfile)
    subprocess.check_call(exe)
    return outfile

def merge(outfile, infiles):
    arg = []
    for i in infiles:
        arg.append('--add')
        arg.append(i)
    arg.append('-o')
    arg.append(outfile)
    subprocess.check_call(lcov_exe(*arg))

def extract(outfile, infile):
    subprocess.check_call(lcov_exe('--extract', infile, os.getcwd() + '/src/*', '-o', outfile))

def genhtml(outdir, infile):
    subprocess.check_call(['genhtml', '--branch-coverage', '--demangle-cpp', '--legend',
        infile, '-o', outdir, '--ignore-errors', 'source'])

all_infos = []

# unit tests
cleanup()
rustc('--profile', 'test', '--lib')
run('sct')
all_infos.append(lcov('sct.info'))

merge('coverage.info', all_infos)
extract('final.info', 'coverage.info')
genhtml('target/coverage/', 'final.info')