Bug 10058 – Inconsistent mangling between C++ and extern(C++).

Noticed this when looking at bug 7024. test.cc: void foo1(void*) {} void foo2(void (*)(void*)) {} void foo3(void* (*)(void*)) {} void foo4(void (*)(void*), void*) {} void foo5(void* (*)(void*), void*) {} void foo6(void (*)(void*), void*, void*) {} void foo6(void* (*)(void*), void*, void*) {} test.d: extern(C++) void foo1(void*) {} extern(C++) void foo2(void function(void*)) {} extern(C++) void foo3(void* function(void*)) {} extern(C++) void foo4(void function(void*), void*) {} extern(C++) void foo5(void* function(void*), void*) {} extern(C++) void foo6(void function(void*), void*, void*) {} extern(C++) void foo6(void* function(void*), void*, void*) {} g++ produces following mangling: --- _Z4foo1Pv _Z4foo2PFvPvE _Z4foo3PFPvS_E _Z4foo4PFvPvES_ _Z4foo5PFPvS_ES_ _Z4foo6PFvPvES_S_ _Z4foo6PFPvS_ES_S_ --- dmd produces following mangling: --- _Z4foo1Pv _Z4foo2PFvPvE _Z4foo3PFPvS0_E _Z4foo4PFvPvES0_ _Z4foo5PFPvS0_ES0_ _Z4foo6PFvPvES0_S0_ _Z4foo6PFPvS0_ES0_S0_ --- The code in cppmangle.c is: --- /* Sequence is S_, S0_, .., S9_, SA_, ..., SZ_, S10_, ... */ buf->writeByte('S'); if (i) writeBase36(buf, i - 1); --- So something is wrong with the logic before this point...

A better example: test.cc: void foo1(void* (*)(void*)) {} void foo2(void* (*)(void*), void*) {} void foo3(void* (*)(void*), void* (*)(void*)) {} void foo4(void* (*)(void*), void*, void*) {} void foo5(void* (*)(void*), void* (*)(void*), void*) {} void foo6(void* (*)(void*), void* (*)(void*), void* (*)(void*)) {} test.d: extern(C++) void foo1(void* function(void*)) {} extern(C++) void foo2(void* function(void*), void*) {} extern(C++) void foo3(void* function(void*), void* function(void*)) {} extern(C++) void foo4(void* function(void*), void*, void*) {} extern(C++) void foo5(void* function(void*), void* function(void*), void*) {} extern(C++) void foo6(void* function(void*), void* function(void*), void* function(void*)) {} testcc.o --- _Z4foo1PFPvS_E _Z4foo2PFPvS_ES_ _Z4foo3PFPvS_ES1_ _Z4foo4PFPvS_ES_S_ _Z4foo5PFPvS_ES1_S_ _Z4foo6PFPvS_ES1_S1_ testd.o --- _Z4foo1PFPvS0_E _Z4foo2PFPvS0_ES0_ _Z4foo3PFPvS0_ES1_ _Z4foo4PFPvS0_ES0_S0_ _Z4foo5PFPvS0_ES1_S0_ _Z4foo6PFPvS0_ES1_S1_

Hmm... tested with patch (using gdc) there is still a discrepancy. testcc.o --- _Z4foo1PFPvS_E _Z4foo2PFPvS_ES_ _Z4foo3PFPvS_ES1_ _Z4foo4PFPvS_ES_S_ _Z4foo5PFPvS_ES1_S_ _Z4foo6PFPvS_ES1_S1_ testd.o --- _Z4foo1PFPvS_E _Z4foo2PFPvS_ES_ _Z4foo3PFPvS_ES0_ _Z4foo4PFPvS_ES_S_ _Z4foo5PFPvS_ES0_S_ _Z4foo6PFPvS_ES0_S0_ Looks like the sequence goes: S_, S1_, .., S9_, SA_, ..., SZ_, S10_, ... Will need to check this to make sure...

That is, if I can find a way to trigger it. =)

With current pull: test.cc: void foo1(void* (*)(void*)) {} void foo2(void* (*)(void*), void* (*)(void*)) {} void foo3(void* (*)(void*), void* (*)(const void*)) {} void foo4(void* (*)(void*), void* (*)(const void*), const void* (*)(void*)) {} test.d: extern(C++) void foo1(void* function(void*)) {} extern(C++) void foo2(void* function(void*), void* function(void*)) {} extern(C++) void foo3(void* function(void*), void* function(const (void)*)) {} extern(C++) void foo4(void* function(void*), void* function(const (void)*), const(void)* function(void*)) {} testcc.o --- _Z4foo1PFPvS_E _Z4foo2PFPvS_ES1_ _Z4foo3PFPvS_EPFS_PKvE _Z4foo4PFPvS_EPFS_PKvEPFS3_S_E testd.o --- _Z4foo1PFPvS_E _Z4foo2PFPvS_ES1_ _Z4foo3PFPvS_EPFS_PKvE _Z4foo4PFPvS_EPFS_PKvEPFS3_S_E Looks good so far. Can anyone think of any other ways to break it? Regards Iain

Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/2e5d2ded0522abca587091b2ce7e84102decee58 Fix Issue 10058. https://github.com/D-Programming-Language/dmd/commit/60dee0bde7db72c84a99b18a911ad14e5bf88db9 Merge pull request #2007 from ibuclaw/cppmangle Fix Issue 10058 - Inconsistent mangling between C++ and extern(C++).