#14970: GHC.Err.errorWithoutStackTrace produces stack trace when profiling enabled -------------------------------------+------------------------------------- Reporter: rotaerk | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by osa1): * cc: simonmar (added) Comment: Why do you think this is a bug? We're talking about two kinds of stacks here 1. Stack trace constructed by user-provided `HasCallStack` constraints 2. Stack trace constructed by the RTS and generated code via (sometimes auto-generated) `SCC` annotations (aka. "cost-centre stack") and it's quite possible that these two stack traces show different things, they have different purposes. `errorWithoutStackTrace` overrides (1) but it can't override (2), (2) is a lower-level thing. Paging simonmar as he made `error` include the CCS stack in profiling mode in Phab:D1426. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14970#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14970: GHC.Err.errorWithoutStackTrace produces stack trace when profiling enabled -------------------------------------+------------------------------------- Reporter: rotaerk | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Indeed I think this is expected. The point (as I understand it) of `errorWithoutStackTrace` is to avoid the (potential) runtime cost of `HasCallStack`. In the case of the CCS stack there is no additional cost to providing the stack-trace. We probably ought to document this, however. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14970#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14970: GHC.Err.errorWithoutStackTrace produces stack trace when profiling enabled -------------------------------------+------------------------------------- Reporter: rotaerk | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: libraries/base | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 8.4.2 => 8.6.1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14970#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14970: GHC.Err.errorWithoutStackTrace produces stack trace when profiling enabled -------------------------------------+------------------------------------- Reporter: rotaerk | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: libraries/base | Version: 8.2.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4648 Wiki Page: | -------------------------------------+------------------------------------- Changes (by dfeuer): * cc: dfeuer (added) Comment: bgamari, that's a bit tricky. It's only possible to avoid building the call stack if the demand analyzer can see that it won't be used. I think the only reliable way to avoid building one is to be careful with your constraints. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14970#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14970: GHC.Err.errorWithoutStackTrace produces stack trace when profiling enabled -------------------------------------+------------------------------------- Reporter: rotaerk | Owner: simonmar Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: libraries/base | Version: 8.2.2 Resolution: fixed | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4648 Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonmar): * status: new => closed * resolution: => fixed -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14970#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler