require 'set'

LIBRUBY_SO = 'libruby.so'

PROBES_D = 'probes.d'

# These probes are excluded by VM_COLLECT_USAGE_DETAILS ifdef.

EXCLUDE_PROBES = Set.new %w(insn insn__operand)

## Detect SystemTap section headers presence

stap_headers = [

  '\.stapsdt\.base',

  '\.note\.stapsdt'

]

header_regexp = %r{ (#{stap_headers.join('|')}) }

section_headers = `readelf -S "#{LIBRUBY_SO}"`

detected_stap_headers = section_headers.scan(header_regexp).flatten

# Assume there are both headers until this is proven wrong ;)

unless detected_stap_headers.size == 2

  puts 'ERROR: SystemTap (DTrace) headers were not detected in resulting library.'

  exit false

end

## Find if every declared probe is propagated to resulting library

# Colect probes specified in probes.d file.

probes_declared = []

File.open(PROBES_D) do |file|

  file.each_line do |line|

    if probe = line[/probe (\S+)\(.*\);/, 1]

      probes_declared << probe

    end

  end

end

probes_declared = Set.new probes_declared

unless EXCLUDE_PROBES.subset? probes_declared

  puts 'ERROR: Change in SystemTap (DTrace) probes definition file detected.'

  exit false

end

probes_declared -= EXCLUDE_PROBES

# Detect probes in resulting library.

get_probes_detected = %r{

^\s*Provider:\s+ruby,\s+Name:\s+(\S+),\s+.*$

}

probes_detected = `eu-readelf -n "#{LIBRUBY_SO}"`

probes_detected = Set.new probes_detected.scan(get_probes_detected).flatten

# Both sets must be equal, otherwise something is wrong.

unless probes_declared == probes_detected

  puts 'ERROR: SystemTap (DTrace) probes were not correctly propagated into resulting library.'

  puts "       Undetected probes: #{(probes_declared - probes_detected).sort.join(', ')}\n",

       "       Additional detected probes: #{(probes_detected - probes_declared).sort.join(', ')}"

  exit false

end