1. 18 Oct, 2016 1 commit
  2. 30 Aug, 2016 1 commit
    • mniip's avatar
      Tag pointers in interpreted constructors · a25bf267
      mniip authored and Ben Gamari's avatar Ben Gamari committed
      Instead of stg_interp_constr_entry there are now 7 functions (one for
      each value of the tag bits) that tag the constructor pointer before
      returning. This is consistent with compiled constructors' entry code,
      and expectations that compiled code places on compiled constructors. The
      iserv protocol is extended with an extra field that explains what
      pointer tag the constructor should use.
      
      Test Plan: Added tests for #12523
      
      Reviewers: erikd, bgamari, hvr, austin, simonmar
      
      Reviewed By: simonmar
      
      Subscribers: osa1, thomie, rwbarton
      
      Differential Revision: https://phabricator.haskell.org/D2473
      
      GHC Trac Issues: #12523
      a25bf267
  3. 24 Jun, 2016 1 commit
  4. 02 Feb, 2016 2 commits
    • Simon Marlow's avatar
      Remote GHCi: parallelise BCO serialization · c996db5b
      Simon Marlow authored
      Summary:
      Serialization of BCOs is slow, but we can parallelise it when using
      ghci -j<n>.  It parallelises nicely, saving multiple seconds off the
      link time in a large example I have.
      
      Test Plan:
      * validate
      * `ghci -fexternal-interpreter` in `nofib/real/anna`
      
      Reviewers: niteria, bgamari, ezyang, austin, hvr, erikd
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1877
      
      GHC Trac Issues: #11100
      c996db5b
    • Simon Marlow's avatar
      Remote GHCi: batch the creation of strings · 7cb1fae2
      Simon Marlow authored
      Summary:
      This makes a big performance difference especially when loading a
      large number of modules and using parallel compilation (ghci -jN).
      
      Test Plan:
      * validate
      * `ghci -fexternal-interpreter` in `nofib/real/anna`
      
      Reviewers: niteria, bgamari, ezyang, austin, hvr, erikd
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1876
      
      GHC Trac Issues: #11100
      7cb1fae2
  5. 27 Jan, 2016 1 commit
  6. 13 Jan, 2016 1 commit
  7. 08 Jan, 2016 1 commit
    • Simon Marlow's avatar
      Enable stack traces with ghci -fexternal-interpreter -prof · 6be09e88
      Simon Marlow authored
      Summary:
      The main goal here is enable stack traces in GHCi.  After this change,
      if you start GHCi like this:
      
        ghci -fexternal-interpreter -prof
      
      (which requires packages to be built for profiling, but not GHC
      itself) then the interpreter manages cost-centre stacks during
      execution and can produce a stack trace on request.  Call locations
      are available for all interpreted code, and any compiled code that was
      built with the `-fprof-auto` familiy of flags.
      
      There are a couple of ways to get a stack trace:
      
      * `error`/`undefined` automatically get one attached
      * `Debug.Trace.traceStack` can be used anywhere, and prints the current
        stack
      
      Because the interpreter is running in a separate process, only the
      interpreted code is running in profiled mode and the compiler itself
      isn't slowed down by profiling.
      
      The GHCi debugger still doesn't work with -fexternal-interpreter,
      although this patch gets it a step closer.  Most of the functionality
      of breakpoints is implemented, but the runtime value introspection is
      still not supported.
      
      Along the way I also did some refactoring and added type arguments to
      the various remote pointer types in `GHCi.RemotePtr`, so there's
      better type safety and documentation in the bridge code between GHC
      and ghc-iserv.
      
      Test Plan: validate
      
      Reviewers: bgamari, ezyang, austin, hvr, goldfire, erikd
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1747
      
      GHC Trac Issues: #11047, #11100
      6be09e88
  8. 21 Dec, 2015 1 commit
    • Simon Marlow's avatar
      Maintain cost-centre stacks in the interpreter · c8c44fd9
      Simon Marlow authored
      Summary:
      Breakpoints become SCCs, so we have detailed call-stack info for
      interpreted code.  Currently this only works when GHC is compiled with
      -prof, but D1562 (Remote GHCi) removes this constraint so that in the
      future call stacks will be available without building your own GHCi.
      
      How can you get a stack trace?
      
      * programmatically: GHC.Stack.currentCallStack
      * I've added an experimental :where command that shows the stack when
        stopped at a breakpoint
      * `error` attaches a call stack automatically, although since calls to
        `error` are often lifted out to the top level, this is less useful
        than it might be (ImplicitParams still works though).
      * Later we might attach call stacks to all exceptions
      
      Other related changes in this diff:
      
      * I reduced the number of places that get ticks attached for
        breakpoints.  In particular there was a breakpoint around the whole
        declaration, which was often redundant because it bound no variables.
        This reduces clutter in the stack traces and speeds up compilation.
      
      * I tidied up some RealSrcSpan stuff in InteractiveUI, and made a few
        other small cleanups
      
      Test Plan: validate
      
      Reviewers: ezyang, bgamari, austin, hvr
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1595
      
      GHC Trac Issues: #11047
      c8c44fd9
  9. 18 Dec, 2015 1 commit
  10. 17 Dec, 2015 1 commit
    • Simon Marlow's avatar
      Remote GHCi, -fexternal-interpreter · 4905b83a
      Simon Marlow authored
      Summary:
      (Apologies for the size of this patch, I couldn't make a smaller one
      that was validate-clean and also made sense independently)
      
      (Some of this code is derived from GHCJS.)
      
      This commit adds support for running interpreted code (for GHCi and
      TemplateHaskell) in a separate process.  The functionality is
      experimental, so for now it is off by default and enabled by the flag
      -fexternal-interpreter.
      
      Reaosns we want this:
      
      * compiling Template Haskell code with -prof does not require
        building the code without -prof first
      
      * when GHC itself is profiled, it can interpret unprofiled code, and
        the same applies to dynamic linking.  We would no longer need to
        force -dynamic-too with TemplateHaskell, and we can load ordinary
        objects into a dynamically-linked GHCi (and vice versa).
      
      * An unprofiled GHCi can load and run profiled code, which means it
        can use the stack-trace functionality provided by profiling without
        taking the performance hit on the compiler that profiling would
        entail.
      
      Amongst other things; see
      https://ghc.haskell.org/trac/ghc/wiki/RemoteGHCi for more details.
      
      Notes on the implementation are in Note [Remote GHCi] in the new
      module compiler/ghci/GHCi.hs.  It probably needs more documenting,
      feel free to suggest things I could elaborate on.
      
      Things that are not currently implemented for -fexternal-interpreter:
      
      * The GHCi debugger
      * :set prog, :set args in GHCi
      * `recover` in Template Haskell
      * Redirecting stdin/stdout for the external process
      
      These are all doable, I just wanted to get to a working validate-clean
      patch first.
      
      I also haven't done any benchmarking yet.  I expect there to be slight hit
      to link times for byte code and some penalty due to having to
      serialize/deserialize TH syntax, but I don't expect it to be a serious
      problem.  There's also lots of low-hanging fruit in the byte code
      generator/linker that we could exploit to speed things up.
      
      Test Plan:
      * validate
      * I've run parts of the test suite with
      EXTRA_HC_OPTS=-fexternal-interpreter, notably tests/ghci and tests/th.
      There are a few failures due to the things not currently implemented
      (see above).
      
      Reviewers: simonpj, goldfire, ezyang, austin, alanz, hvr, niteria, bgamari, gibiansky, luite
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1562
      4905b83a