Build fails with gcc14: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]

[barracuda156]

The first error is with an old MLton which is used for bootstrap, so we can only patch it locally. The second should be fixed here, perhaps:

          /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileRpMQu9.o \
          /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c
In file included from /opt/local/libexec/mlton-bootstrap/lib/mlton/include/c-chunk.h:216,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:110:
/opt/local/libexec/mlton-bootstrap/lib/mlton/include/basis/coerce.h: In function 'Real32_castToWord32':
/opt/local/libexec/mlton-bootstrap/lib/mlton/include/basis/coerce.h:42:5: error: implicit declaration of function 'memcpy' [-Wimplicit-function-declaration]
   42 |     memcpy(&y, &x, sizeof(t));                  \
      |     ^~~~~~
/opt/local/libexec/mlton-bootstrap/lib/mlton/include/basis/coerce.h:46:1: note: in expansion of macro 'cast'
   46 | cast(Real32, Word32)
      | ^~~~
/opt/local/libexec/mlton-bootstrap/lib/mlton/include/basis/coerce.h:1:1: note: include '<string.h>' or provide a declaration of 'memcpy'
  +++ |+#include <string.h>
    1 | 
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c: In function 'Chunk0':
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:27869:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
27869 |         O(Objptr, G(Objptr, 5277), 0) = 0x11;
      |                                       ^
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:27874:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
27874 |         O(Objptr, G(Objptr, 5278), 0) = 0x9;
      |                                       ^
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:27879:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
27879 |         O(Objptr, G(Objptr, 5279), 0) = 0x5;
      |                                       ^
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:31807:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
31807 |         O(Objptr, G(Objptr, 5990), 0) = 0x81;
      |                                       ^
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:31812:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
31812 |         O(Objptr, G(Objptr, 5991), 0) = 0x41;
      |                                       ^
/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_lang_mlton/mlton/work/.tmp/fileEQaoED.363.c:31817:39: error: assignment to 'Objptr' {aka 'unsigned char *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
31817 |         O(Objptr, G(Objptr, 5992), 0) = 0x21;
      |                                       ^
   Compile and Assemble raised in 3.62 + 0.00 (0% GC)
MLton raised in 365.82 + 149.95 (29% GC)

[MatthewFluet]

The former is certainly already fixed: 3edda85

I do not observe an error with a C codegen self-compile on Fedora 40 (gcc 14); looking at the generated C code, I see statements like:

O(Objptr, T(Q, 97), 0) = (Objptr)(Word64)(0x21ull);

so there seem to be sufficient casts. I'm not precisely sure when those casts were introduced; there was a fair amount of refactoring of the RSSA and Machine IRs prior to the 20210117 release (which also includes the commit linked above).

What version of MLton is being used for the bootstrap?

[barracuda156]

@MatthewFluet The last version for ppc was 20070826, which is what we use: https://github.com/macports/macports-ports/blob/master/lang/mlton-bootstrap/Portfile

If a newer version is required, perhaps the only non-painful way would be if you could host my bootstrap binary (I can build it against 10.5 or possibly 10.4 target). And then I can update the port to pick a new version for bootstrapping mlton.

[MatthewFluet]

@barracuda156 Sure, I suppose we could host a ppc build on sourceforge.

[barracuda156]

@MatthewFluet Thank you! I will handle it in 2–3 days and update here.