[GHC] #11829: C++ does not catch exceptions when used with Haskell-main and linked by ghc

13 Apr 2016

      #11829: C++ does not catch exceptions when used with Haskell-main and linked by ghc
-------------------------------------+-------------------------------------
           Reporter:  pl             |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Runtime        |           Version:  7.10.3
  System                             |
           Keywords:  c++            |  Operating System:  Unknown/Multiple
  exceptions                         |
       Architecture:                 |   Type of failure:  Runtime crash
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 Consider the C++ program
 {{{
 // Main_cc.cc
 #include <iostream>
 #include <exception>
 extern "C" {
 int func() {
   try {
     throw std::runtime_error("THIS FAILS!");
   } catch(const std::runtime_error &c) {
     std::cerr << c.what();
   }
   return 0;
 }
 }
 }}}
 and the Haskell program
 {{{#!hs
 -- Main.hs
 module Main where
 import Foreign.C.Types
 foreign import ccall func :: IO CInt
 main :: IO ()
 main = print =<< func
 }}}
 When compiled with
 {{{
 ghc --make Main.hs Main_cc.cc -lstdc++
 }}}
 and being run on mac os x 10.11.3 the result is
 {{{
 libc++abi.dylib: terminating with uncaught exception of type
 std::runtime_error: THIS FAILS!
 Abort trap: 6
 }}}
 and not (as it should be):
 {{{
 THIS FAILS!0
 }}}
 When compiled in a similar way under windows some c++ exceptions of a
 larger project are not caught as well. However, these were hard to track
 down and I was unable to construct a simple example like the one above.

 As a workaround one can
   * write a main() function in c++ and call from there into Haskell,
   * compile the Haskell-Module with the options  "-c -no-hs-main", and
   * link the application using g++ (not ghc!).
 When being compiled / linked this way, all c++ exceptions are being caught
 in mac os x as well as under windows.

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11829
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