#11047: Provide call stacks in GHCi -------------------------------------+------------------------------------- Reporter: simonmar | Owner: simonmar Type: task | Status: new Priority: high | Milestone: 8.0.1 Component: GHCi | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #545, #4837, | Differential Rev(s): Phab:D1407 #11100 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Marlow <marlowsd@…>): In [changeset:"c8c44fd91b509b9eb644c826497ed5268e89363a/ghc" c8c44fd/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="c8c44fd91b509b9eb644c826497ed5268e89363a" Maintain cost-centre stacks in the interpreter 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 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11047#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler