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>"The compiler tool chain was translated from C to Go, removing the last vestiges of C code from the Go code base." This is really cool. Writing a compiler in

• mrdrozdov 11y ago
  Perhaps this is a dumb question, but what language was used to compile the compiler? Was it compiled in C? Surely it must have had to of been compiled in a different language somewhere down the chain.
  • crawshaw 11y ago
    It is built with Go 1.4. Details: https://golang.org/s/go15bootstrap https://golang.org/s/go15bootstrap
  • whacker 11y ago
    The 1.5 build requires you to have a go1.4.2 build which is used as the bootstrapping compiler.
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  • rgbrenner 11y ago
    yes.. golang's compiler was originally in C. The process is called bootstrapping: https://en.wikipedia.org/wiki/Bootstrapping_(compilers) https://en.wikipedia.org/wiki/Bootstrapping_(compilers)
  • turtles99999 11y ago
    well, it's actually turtles all the way down.
• frou_dh 11y ago
  There is a good presentation from Pike talking all about the what/why/how of the C -> Go transition: http://youtu.be/cF1zJYkBW4A http://youtu.be/cF1zJYkBW4A http://talks.golang.org/2015/gogo.slide http://talks.golang.org/2015/gogo.slide
• jlees 11y ago
  Although you can end up with fun situations like the C compiler backdoor: http://scienceblogs.com/goodmath/2007/04/15/strange-loops-dennis-ritchie-a/ http://scienceblogs.com/goodmath/2007/04/15/strange-loops-de...
  • billjings 11y ago
    Haven't read the article you linked to, but the Brian Kernighan talk it discusses is fantastic, one of my favorite reads in the field: https://www.ece.cmu.edu/~ganger/712.fall02/papers/p761-thompson.pdf https://www.ece.cmu.edu/~ganger/712.fall02/papers/p761-thomp...
    • vezzy-fnord 11y ago
      That's ken, not bwk.
      • billjings 11y ago
        D'oh. Thanks.
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  • rsc 11y ago
    You can start from the C version and move forward and check that you get the same result as starting with released Go binaries. Unless you think Ken somehow backdoored the original C compilers to backdoor every C compiler in the world to backdoor the Go compilers that came about decades later. :-)
    • bmir-alum-007 11y ago
      Seems simpler to just backdoor the linker/library archiver, that way almost all toolchains are backdoored. ;)
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• gnuvince 11y ago
  How has this affected compile speeds? Go proponents often tout the speed at which it compiles code as an important feature, so I wonder if there's been a noticeable regression.
  • dmaz 11y ago
    > Builds in Go 1.5 will be slower by a factor of about two. https://golang.org/doc/go1.5#performance https://golang.org/doc/go1.5#performance
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  • chadaustin 11y ago
    Perhaps things have improved since then, but this thread indicates build times will regress a little: https://groups.google.com/forum/#!msg/golang-dev/6obxRcm-rqc/5k6016u41oEJ https://groups.google.com/forum/#!msg/golang-dev/6obxRcm-rqc...
  • sudhirj 11y ago
    Slower in the short term while the code remains transpiled from C. Will get faster as the team goes over it a couple times.
    • rsc 11y ago
      Yes, this is a good summary.
  • semiquaver 11y ago
    The small increase in build times doesn't bother me at all when I'm generating a binary, but unfortunately it's very noticeable and irritating when using tools like vim-go or syntastic which type-check/lint/gofmt your code. Using these now causes vim to be unresponsive for up to a second every time I save, whereas the delay used to be insignificant.
    • mseepgood 11y ago
• vram22 11y ago
  >This is really cool. Writing a compiler in the language that you're compiling seems kind of meta. It's been done before, for more than one language, IIRC. The technique by which they make an executable of a compiler for language L on platform B, using an existing executable of the same compiler for L on platform A, together with the source code of the compiler for L on A, is also cool. I forget the full details right now. Maybe someone else will pitch in and explain. It's called bootstrapping. It's also related to cross-compiling. Update: Looked it up in Google: https://en.wikipedia.org/wiki/Bootstrapping_(compilers) https://en.wikipedia.org/wiki/Bootstrapping_(compilers) https://en.wikipedia.org/wiki/Cross_compiler https://en.wikipedia.org/wiki/Cross_compiler Also see Canadian Cross under above article - this is like the cool technique I talked about above, but more complex.
  • smithkl42 11y ago
    TypeScript does the same thing - its compiler is written in TypeScript. See https://github.com/Microsoft/TypeScript/tree/master/src/compiler https://github.com/Microsoft/TypeScript/tree/master/src/comp.... But yeah, darned cool, and very meta.
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• andrepd 11y ago
  The term is self-hosting compiler, when a compiler can compile itself. https://en.wikipedia.org/wiki/Self-hosting https://en.wikipedia.org/wiki/Self-hosting
  • tankenmate 11y ago
    As the old hacker snark says 'Any language that can't compile itself is a toy language'.
• berfarah 11y ago
  This might be a dumb question: What happens if you find a bug in the language? Let's say something that you had written in C was being misinterpreted, and now the go compiler still uses that byte-code to compile new versions of the compiler. Or is that something that isn't really possible?
  • jlouis 11y ago
    I think Russ showed the translated code produces the same binaries as the Go 1.4 C variant. So this isn't very likely given he has the option to pipe roughly any Open Source Go project through the compiler.
  • emmab 11y ago
    You should read Reflections on Trusting Trust, it expands on this idea in the most beautiful way: https://www.ece.cmu.edu/~ganger/712.fall02/papers/p761-thompson.pdf https://www.ece.cmu.edu/~ganger/712.fall02/papers/p761-thomp...