Compiling with a C++ compiler ?

[sletz]

I get errors when compiling the "source" folder with a C++ compiler, here on macOS 10.13. Any plan to allow that?

[vshymanskyy]

Work has been done to allow compiling with C++, but this is not used for some time already.
It should be a matter of a few fixes, howewer we do not plan to officially support it.

BTW, why do you need that?

[sletz]

I can live without, but it always simplify the build process.

[vshymanskyy]

Could you please elaborate on your scenario and the exact errors you get? Maybe we're talking about different things.. Most compilers will switch to C for files with `.c` extension. It's actually harder to "build as C++".

…

On Sun, 19 Jan 2020, 13:05 Stéphane Letz, ***@***.***> wrote: I can live without, but it always simplify the build process. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#61?email_source=notifications&email_token=AALP3FALLIEDQ4UUDGRHNILQ6QXYVA5CNFSM4KIXVUA2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEJKPLKI#issuecomment-575993257>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALP3FHPY3VQSMKD2C2FQ6LQ6QXYVANCNFSM4KIXVUAQ> .

[sletz]

c++ -Ofast -march=native ../source/*.c -Dd_m3LogOutput=0 -c 
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
../source/m3_bind.c:148:12: error: no matching function for call to
      'FindAndLinkFunction'
    return FindAndLinkFunction (io_module, i_moduleName, i_functionName...
           ^~~~~~~~~~~~~~~~~~~
../source/m3_bind.c:85:11: note: candidate function not viable: no known
      conversion from 'M3RawCall' (aka 'const void *(*)(M3Runtime *, unsigned
      long long *, void *)') to 'voidptr_t' (aka 'const void *') for 5th
      argument; take the address of the argument with &
M3Result  FindAndLinkFunction      (IM3Module       io_module,
          ^
1 error generated.
../source/m3_compile.c:868:1: error: cannot jump from this goto statement to its
      label
_   (ReadLEB_u32 (& localIndex, & o->wasm, o->wasmEnd));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:870:8: note: jump bypasses variable initialization
    u8 type = o->typeStack [localIndex];
       ^
../source/m3_compile.c:1049:1: error: cannot jump from this goto statement to
      its label
_      (MoveStackTopToRegister (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1051:9: note: jump bypasses variable initialization
    u32 numCodeLines = targetCount + 4; // 3 => IM3Operation + slot + ta...
        ^
../source/m3_compile.c:1043:1: error: cannot jump from this goto statement to
      its label
_   (Pop (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1051:9: note: jump bypasses variable initialization
    u32 numCodeLines = targetCount + 4; // 3 => IM3Operation + slot + ta...
        ^
../source/m3_compile.c:1041:1: error: cannot jump from this goto statement to
      its label
_   (PreserveRegisterIfOccupied (o, c_m3Type_i64));         // move bran...
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1051:9: note: jump bypasses variable initialization
    u32 numCodeLines = targetCount + 4; // 3 => IM3Operation + slot + ta...
        ^
../source/m3_compile.c:1042:9: note: jump bypasses variable initialization
    u16 slot = GetStackTopSlotIndex (o);
        ^
../source/m3_compile.c:1039:1: error: cannot jump from this goto statement to
      its label
_   (ReadLEB_u32 (& targetCount, & o->wasm, o->wasmEnd));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1051:9: note: jump bypasses variable initialization
    u32 numCodeLines = targetCount + 4; // 3 => IM3Operation + slot + ta...
        ^
../source/m3_compile.c:1042:9: note: jump bypasses variable initialization
    u16 slot = GetStackTopSlotIndex (o);
        ^
../source/m3_compile.c:1126:1: error: cannot jump from this goto statement to
      its label
_       (Pop (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1129:9: note: jump bypasses variable initialization
    i32 numReturns = i_type->returnType ? 1 : 0;
        ^
../source/m3_compile.c:1125:1: error: cannot jump from this goto statement to
      its label
_       (CopyTopSlot (o, --argTop));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1129:9: note: jump bypasses variable initialization
    i32 numReturns = i_type->returnType ? 1 : 0;
        ^
../source/m3_compile.c:1358:1: error: cannot jump from this goto statement to
      its label
_   (EmitTopSlotAndPop (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1362:12: note: jump bypasses variable initialization
    pc_t * pc = (pc_t *) ReservePointer (o);
           ^
../source/m3_compile.c:1360:9: note: jump bypasses variable initialization
    i32 stackIndex = o->stackIndex;
        ^
../source/m3_compile.c:1357:1: error: cannot jump from this goto statement to
      its label
_   (EmitOp (o, op));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1362:12: note: jump bypasses variable initialization
    pc_t * pc = (pc_t *) ReservePointer (o);
           ^
../source/m3_compile.c:1360:9: note: jump bypasses variable initialization
    i32 stackIndex = o->stackIndex;
        ^
../source/m3_compile.c:1353:1: error: cannot jump from this goto statement to
      its label
_   (PreserveArgsAndLocals (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1362:12: note: jump bypasses variable initialization
    pc_t * pc = (pc_t *) ReservePointer (o);
           ^
../source/m3_compile.c:1360:9: note: jump bypasses variable initialization
    i32 stackIndex = o->stackIndex;
        ^
../source/m3_compile.c:1355:18: note: jump bypasses variable initialization
    IM3Operation op = IsStackTopInRegister (o) ? op_If_r : op_If_s;
                 ^
../source/m3_compile.c:1352:1: error: cannot jump from this goto statement to
      its label
_   (PreserveNonTopRegisters (o));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1362:12: note: jump bypasses variable initialization
    pc_t * pc = (pc_t *) ReservePointer (o);
           ^
../source/m3_compile.c:1360:9: note: jump bypasses variable initialization
    i32 stackIndex = o->stackIndex;
        ^
../source/m3_compile.c:1355:18: note: jump bypasses variable initialization
    IM3Operation op = IsStackTopInRegister (o) ? op_If_r : op_If_s;
                 ^
../source/m3_compile.c:1602:1: error: cannot jump from this goto statement to
      its label
_   (ReadLEB_u32 (& memoryOffset, & o->wasm, o->wasmEnd));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1604:22: note: jump bypasses variable initialization
    const M3OpInfo * op = & c_operations [i_opcode];
                     ^
../source/m3_compile.c:1601:1: error: cannot jump from this goto statement to
      its label
_   (ReadLEB_u32 (& alignHint, & o->wasm, o->wasmEnd));
^
../source/m3_exception.h:17:72: note: expanded from macro '_'
  ...{ result = TRY; if (result) { EXCEPTION_PRINT; goto _catch; } }
                                                    ^
../source/m3_compile.c:1604:22: note: jump bypasses variable initialization
    const M3OpInfo * op = & c_operations [i_opcode];
                     ^
13 errors generated.
../source/m3_emit.c:90:9: warning: cast to 'void *' from smaller integer type
      'i32' (aka 'int') [-Wint-to-void-pointer-cast]
        EmitWord (o->page, i_offset);
        ^
../source/m3_code.h:40:49: note: expanded from macro 'EmitWord'
#define EmitWord(page, val) EmitWord_impl(page, (void*)(val))
                                                ^

[vshymanskyy]

Several comments here.

1. Compiling with -Ofast will make the engine even faster, however can break floating point calculations. Use with great care.

2. When compiling with C++, you can run into linking issues (due to different name mangling).

[sletz]

Yes, thanks, I know both of the issues.

I 'm trying wasm3 with Faust generated wasm code, see https://github.com/sletz/wasm3/tree/master/faust. It already works (slowly of course....), still working on adding math functions.

[vshymanskyy]

You should be able to build as C++ now

[sletz]

Working, thanks.

BTW to implement the following function that links a given math function in the WASM module when it is actually used, I wrote:

void wasm3_dsp_factory::addFunction(const char* name, const char* type, ModuleFun fun)
{
    if (v_FindFunction(fModule, name)) {
        M3Result result = m3_LinkRawFunction(fModule, "env", name, type, fun);
        if (result) FATAL("addFunction: %s", result);
    }
}

So I needed to define (to be officially added in m3.h header ?) :

typedef const void* (ModuleFun) (IM3Runtime runtime, uint64_t* _sp, void* _mem);