Module: Truffle::Debug

Defined in:
truffle/src/main/ruby/core/truffle/debug.rb

Overview

Debug utilities specific to Truffle.

Class Method Summary (collapse)

Class Method Details

+ (nil) break(file = nil, line = nil, condition = nil)

Break and enter an interactive shell, or set a line breakpoint to enter the shell.

Examples

Truffle::Debug.break

Enter the shell immediately.

Truffle::Debug.break 'foo.rb', 59

Enter the shell every time the program reaches line 59 in foo.rb (see #clear).

Shell Usage

In the shell you can type normal Ruby expressions and have them evaluated in the current frame. Results will be printed via #inspect, like in IRB.

Extra commands available are:

  • continue leave the interactive shell and continue execution

  • exit exit the VM

  • backtrace print a backtrace, with numbered frames

  • frame n make the nth frame active for expressions that you type into the shell (see backtrace to find the frame you want)

Example

In your ruby code call Truffle::Debug.break where you want to break. When that method is called you will see the shell:

> backtrace
  ▶    at Truffle::Primitive#simple_shell
  1    at core:/core/truffle/debug.rb:14:in 'break'
  2    at test.rb:4:in 'foo'
  3    at test.rb:9:in 'bar'
  4    at test.rb:12:in '<main>'
> frame 2
> x + y
110
> frame 3
> a
99
> continue

Returns:

  • (nil) 


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# File 'truffle/src/main/ruby/core/truffle/debug.rb', line 66

def self.break(file = nil, line = nil, condition = nil)
  if line.nil?
    raise 'must specify both a file and a line, or neither' unless file.nil?
    Truffle::Primitive.simple_shell
  elsif not condition.nil?
    Truffle::Primitive.attach file, line do |binding|
      if binding.eval(condition)
        Truffle::Primitive.simple_shell
      end
    end
  elsif block_given?
    Truffle::Primitive.attach file, line do |binding|
      if yield binding
        Truffle::Primitive.simple_shell
      end
    end
  else
    Truffle::Primitive.attach file, line do |binding|
      Truffle::Primitive.simple_shell
    end
  end
end

+ (Object) clear(file, line)

Remove a breakpoint set in #break.



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# File 'truffle/src/main/ruby/core/truffle/debug.rb', line 90

def self.clear(file, line)
  Truffle::Primitive.detach file, line
end