#11784: panic "hscCmmFile: no_mod" with `-v2 and above -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * priority: normal => high Comment: This is a regression from 7.10.3. To reproduce, create an empty file called `Test.cmm`. Then run: {{{ $ ghc-8.0.1 -c -dcmm-lint Test.cmm -v2 ... ghc: panic! (the 'impossible' happened) (GHC version 8.0.0.20160511 for x86_64-unknown-linux): hscCmmFile: no_mod }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11784#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11784: panic "hscCmmFile: no_mod" with `-v2 and above -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): The problem here is that `hscCompileCmmFile` needs a `Module` to give to `CodeOutput.codeOutput`. The downstream uses of this `Module` are, * `outputForeignStubs`: needs a string to form the stem of the stub filename * `PIC.howToAccessLabel`: calls `CLabel.labelDynamic`, which, * then wants to compare it against another `Module` taken from a `HpcTicksLabel` * and uses it to call `Packages.isDllName` Given that `PIC.howToAccessLabel` hasn't blowing up due to the bottoming `Module`s we give it for C-- files, I suppose it should be safe for `hscCompileCmmFile` to simply make up a module name to give to the backend. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11784#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11784: panic "hscCmmFile: no_mod" with `-v2 and above -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: patch Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2864 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"222e99d9e6b24c17a67c07d24d05999701b83e96/ghc" 222e99d9/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="222e99d9e6b24c17a67c07d24d05999701b83e96" Make up a module name for c-- files Summary: We used to pass a bottoming Module to the NCG, which resulted in panics when `-v` was used due to debug output (see #11784). Instead we make up a module name. This is a bit scary since `PIC.howToAccessLabel` might actually use the Module, but if it wasn't crashing before I suppose it's fine. Test Plan: `touch hi.cmm; ghc -v2 -c -dcmm-lint hi.cmm` Reviewers: austin, simonmar Reviewed By: simonmar Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2864 GHC Trac Issues: #11784 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11784#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler