error: redeclaration of 'initialize' cannot add 'dllexport' attribute

[zhmt]

I created a helloworld project,
https://github.com/grow-graphics/eg/blob/master/1d/helloworld/main.go
go.sum and go.mod are also copied.

I got errors below when buiding:
go build -buildmode=c-shared src/game.go

go build -buildmode=c-shared ./
# graphics.gd/startup
In file included from _cgo_export.c:4:
cgo-gcc-export-header-prolog:50:35: error: redeclaration of 'initialize' cannot add 'dllexport' attribute
startup_cgo.go:150:13: note: previous declaration is here
cgo-gcc-export-header-prolog:51:35: error: redeclaration of 'deinitialize' cannot add 'dllexport' attribute
startup_cgo.go:151:13: note: previous declaration is here
cgo-gcc-export-header-prolog:52:38: error: redeclaration of 'set_func' cannot add 'dllexport' attribute
startup_cgo.go:484:13: note: previous declaration is here
cgo-gcc-export-header-prolog:53:38: error: redeclaration of 'get_func' cannot add 'dllexport' attribute
startup_cgo.go:485:13: note: previous declaration is here
cgo-gcc-export-header-prolog:54:55: error: redeclaration of 'get_property_list_func' cannot add 'dllexport' attribute   
startup_cgo.go:486:33: note: previous declaration is here
cgo-gcc-export-header-prolog:55:35: error: redeclaration of 'free_property_list_func' cannot add 'dllexport' attribute  
startup_cgo.go:487:13: note: previous declaration is here
cgo-gcc-export-header-prolog:56:38: error: redeclaration of 'property_can_revert_func' cannot add 'dllexport' attribute 
startup_cgo.go:488:13: note: previous declaration is here
cgo-gcc-export-header-prolog:57:38: error: redeclaration of 'property_get_revert_func' cannot add 'dllexport' attribute 
startup_cgo.go:489:13: note: previous declaration is here
cgo-gcc-export-header-prolog:58:35: error: redeclaration of 'notification_func' cannot add 'dllexport' attribute        
startup_cgo.go:491:13: note: previous declaration is here
cgo-gcc-export-header-prolog:59:35: error: redeclaration of 'to_string_func' cannot add 'dllexport' attribute
startup_cgo.go:492:13: note: previous declaration is here
cgo-gcc-export-header-prolog:60:35: error: redeclaration of 'reference_func' cannot add 'dllexport' attribute
startup_cgo.go:493:13: note: previous declaration is here
cgo-gcc-export-header-prolog:61:35: error: redeclaration of 'unreference_func' cannot add 'dllexport' attribute
startup_cgo.go:494:13: note: previous declaration is here
cgo-gcc-export-header-prolog:62:40: error: redeclaration of 'create_instance_func' cannot add 'dllexport' attribute     
startup_cgo.go:495:16: note: previous declaration is here
cgo-gcc-export-header-prolog:63:35: error: redeclaration of 'free_instance_func' cannot add 'dllexport' attribute       
startup_cgo.go:496:13: note: previous declaration is here
cgo-gcc-export-header-prolog:64:40: error: redeclaration of 'get_virtual_call_data_func' cannot add 'dllexport' attribute
startup_cgo.go:497:16: note: previous declaration is here
cgo-gcc-export-header-prolog:65:35: error: redeclaration of 'call_virtual_with_data_func' cannot add 'dllexport' attribute
startup_cgo.go:498:13: note: previous declaration is here
cgo-gcc-export-header-prolog:66:39: error: redeclaration of 'get_rid_func' cannot add 'dllexport' attribute
startup_cgo.go:499:17: note: previous declaration is here
cgo-gcc-export-header-prolog:67:35: error: redeclaration of 'callable_call' cannot add 'dllexport' attribute
startup_cgo.go:477:13: note: previous declaration is here
cgo-gcc-export-header-prolog:68:35: error: redeclaration of 'method_call' cannot add 'dllexport' attribute
startup_cgo.go:522:13: note: previous declaration is here
fatal error: too many errors emitted, stopping now [-ferror-limit=]

How to fix this?

[Splizard]

You need to be building a package - not an individual file, if src is the main package, replace src/game.go with src/

go build -buildmode=c-shared src/

[zhmt]

I moved game.go to root dir:

goext
│  go.mod
│  go.sum
│  main.go

and build with:
(c comilpler is llvm-mingw-20250114-ucrt-x86_64)

cd goext
go build -buildmode=c-shared ./

got same errors .

[zhmt]

I have seen these *.c files created by cgo,
_cgo_export.c

CGO_NO_SANITIZE_THREAD
__declspec(dllexport) void initialize(void* _, GDExtensionInitializationLevel level)

_cgo_export.h

extern void initialize(void *userdata, GDExtensionInitializationLevel p_level);

it seems that conflicts.

[Splizard]

there shouldn't be any c files in your project, as cgo usually creates these in a different location, what version of Go are you on?

[zhmt]

They are in cache folder, I found them with -work option.

[zhmt]

C:\Users\zhmt>go version
go version go1.24.1 windows/amd64

[zhmt]

Sorry about this.
It works now when c compiler is changed from llvm-mingw-20250114-ucrt-x86_64 to "MSYS2 mingw64".

[zhmt]

Thanks for your help.