Importing the module that was compiled as main module causes link error

[demotomohiro]

mytests/mymodule.nim:

# Any code compiles without errors

mytests/test.nim:

import mymodule

At first compile mytests/mymodule.nim, then compile mytests/test.nim:

$ ./bin/nimony c -r mytests/mymodule.nim
bin/nimsem  --isSystem m nimcache/sysvq0asl.1.nif nimcache/sysvq0asl.2.nif nimcache/sysvq0asl.2.idx.nif
bin/nimsem  m nimcache/mym1dun561.1.nif nimcache/mym1dun561.2.nif nimcache/mym1dun561.2.idx.nif
cc -c   -Ivendor/mimalloc/include vendor/mimalloc/src/static.c -o nimcache/static.o
bin/hexer --bits:64 nimcache/mym1dun561.2.nif
bin/nifc c --compileOnly --isMain  nimcache/mym1dun561.c.nif
cc -c  -Imytests  nimcache/mym1dun561.c -o nimcache/mym1dun561.o
bin/hexer --bits:64 nimcache/sysvq0asl.2.nif
bin/nifc c --compileOnly  nimcache/sysvq0asl.c.nif
cc -c  -Imytests  nimcache/sysvq0asl.c -o nimcache/sysvq0asl.o
cc -o nimcache/mym1dun561 nimcache/static.o nimcache/mym1dun561.o nimcache/sysvq0asl.o
$ ./bin/nimony c -r mytests/test.nim
bin/nimsem  m nimcache/tes9hvujc.1.nif nimcache/tes9hvujc.2.nif nimcache/tes9hvujc.2.idx.nif
bin/hexer --bits:64 nimcache/tes9hvujc.2.nif
bin/nifc c --compileOnly --isMain  nimcache/tes9hvujc.c.nif
cc -c  -Imytests  nimcache/tes9hvujc.c -o nimcache/tes9hvujc.o
cc -o nimcache/tes9hvujc nimcache/static.o nimcache/tes9hvujc.o nimcache/mym1dun561.o nimcache/sysvq0asl.o
/usr/lib/gcc/x86_64-pc-linux-gnu/14/../../../../x86_64-pc-linux-gnu/bin/ld: nimcache/mym1dun561.o:(.tbss+0x0): multiple definition of `NIFC_E
RR_'; nimcache/tes9hvujc.o:(.tbss+0x0): first defined here
/usr/lib/gcc/x86_64-pc-linux-gnu/14/../../../../x86_64-pc-linux-gnu/bin/ld: nimcache/mym1dun561.o:(.bss+0x0): multiple definition of `cmdCoun
t'; nimcache/tes9hvujc.o:(.bss+0x0): first defined here
/usr/lib/gcc/x86_64-pc-linux-gnu/14/../../../../x86_64-pc-linux-gnu/bin/ld: nimcache/mym1dun561.o:(.bss+0x8): multiple definition of `cmdLine
'; nimcache/tes9hvujc.o:(.bss+0x8): first defined here
/usr/lib/gcc/x86_64-pc-linux-gnu/14/../../../../x86_64-pc-linux-gnu/bin/ld: nimcache/mym1dun561.o: in function `main':
mym1dun561.c:(.text+0x0): multiple definition of `main'; nimcache/tes9hvujc.o:tes9hvujc.c:(.text+0x0): first defined here
collect2: error: ld returned 1 exit status

mytests/test.nim compiles without error if I delete the cache before compiling it.
When I compile mytests/mymodule.nim, it is compiled to nimcache/mym1dun561.c as main module and it has main function.
And when I compile mytests/test.nim, nimcache/mym1dun561.c is not updated and nimcache/mym1dun561.o is reused.
So there are two object files tes9hvujc.o and mym1dun561.o contains main function and linker generates multiple definition error.

[Araq]

Interesting, maybe we have to encode "mainness" in the filename somehow.

[demotomohiro]

There is similar problem when using -d option.

mytests/testdefine.nim

import std/syncio

proc foo*(): string =
  result = when defined(foo): "defined" else: "Not defined"

echo foo()

$ rm -rf nimcache/
$ ./bin/nimony c -r mytests/testdefine.nim 
bin/nimsem  --isSystem m nimcache/sysvq0asl.1.nif nimcache/sysvq0asl.2.nif nimcache/sysvq0asl.2.idx.nif
bin/nimsem  m nimcache/syn1lfpjv.1.nif nimcache/syn1lfpjv.2.nif nimcache/syn1lfpjv.2.idx.nif
bin/nimsem  m nimcache/tesqq7kqu1.1.nif nimcache/tesqq7kqu1.2.nif nimcache/tesqq7kqu1.2.idx.nif
cc -c   -Ivendor/mimalloc/include vendor/mimalloc/src/static.c -o nimcache/static.o
bin/hexer --bits:64 nimcache/tesqq7kqu1.2.nif
bin/nifc c --compileOnly --isMain  nimcache/tesqq7kqu1.c.nif
cc -c  -Imytests  nimcache/tesqq7kqu1.c -o nimcache/tesqq7kqu1.o
bin/hexer --bits:64 nimcache/syn1lfpjv.2.nif
bin/nifc c --compileOnly  nimcache/syn1lfpjv.c.nif
cc -c  -Imytests  nimcache/syn1lfpjv.c -o nimcache/syn1lfpjv.o
bin/hexer --bits:64 nimcache/sysvq0asl.2.nif
bin/nifc c --compileOnly  nimcache/sysvq0asl.c.nif
cc -c  -Imytests  nimcache/sysvq0asl.c -o nimcache/sysvq0asl.o
cc -o nimcache/tesqq7kqu1 nimcache/static.o nimcache/tesqq7kqu1.o nimcache/syn1lfpjv.o nimcache/sysvq0asl.o
Not defined
$ ./bin/nimony c -r -d:foo mytests/testdefine.nim 
make: 'nimcache/tesqq7kqu1.2.idx.nif' is up to date.
make: Nothing to be done for 'all'.
Not defined
$ rm -rf nimcache/
$ ./bin/nimony c -r -d:foo mytests/testdefine.nim 
bin/nimsem  --d:foo --isSystem m nimcache/sysvq0asl.1.nif nimcache/sysvq0asl.2.nif nimcache/sysvq0asl.2.idx.nif
bin/nimsem  --d:foo m nimcache/syn1lfpjv.1.nif nimcache/syn1lfpjv.2.nif nimcache/syn1lfpjv.2.idx.nif
bin/nimsem  --d:foo m nimcache/tesqq7kqu1.1.nif nimcache/tesqq7kqu1.2.nif nimcache/tesqq7kqu1.2.idx.nif
cc -c   -Ivendor/mimalloc/include vendor/mimalloc/src/static.c -o nimcache/static.o
bin/hexer --bits:64 nimcache/tesqq7kqu1.2.nif
bin/nifc c --compileOnly --isMain  nimcache/tesqq7kqu1.c.nif
cc -c  -Imytests  nimcache/tesqq7kqu1.c -o nimcache/tesqq7kqu1.o
bin/hexer --bits:64 nimcache/syn1lfpjv.2.nif
bin/nifc c --compileOnly  nimcache/syn1lfpjv.c.nif
cc -c  -Imytests  nimcache/syn1lfpjv.c -o nimcache/syn1lfpjv.o
bin/hexer --bits:64 nimcache/sysvq0asl.2.nif
bin/nifc c --compileOnly  nimcache/sysvq0asl.c.nif
cc -c  -Imytests  nimcache/sysvq0asl.c -o nimcache/sysvq0asl.o
cc -o nimcache/tesqq7kqu1 nimcache/static.o nimcache/tesqq7kqu1.o nimcache/syn1lfpjv.o nimcache/sysvq0asl.o
defined

I think caching logic need to care about all command line options that can change generated nif or c files.