[Issue 14674] Importing std.stdio causes another module to become undefined

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14674

Vladimir Panteleev  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
   Hardware|x86_64  |All
 Resolution|--- |INVALID
 OS|Mac OS X|All

--- Comment #5 from Vladimir Panteleev  ---
Closing per Kenji's wonderful explanation above.

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[Issue 14674] Importing std.stdio causes another module to become undefined

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14674

--- Comment #4 from Kenji Hara k.hara...@gmail.com ---
(In reply to sigsve from comment #2)
 Undefined symbols for architecture x86_64:
   _D5Stack12__ModuleInfoZ, referenced from:
   _D4Main12__ModuleInfoZ in Main.o
 ld: symbol(s) not found for architecture x86_64
 clang: error: linker command failed with exit code 1 (use -v to see
 invocation)

It says a ModuleInfo symbol of Stack module is missing.

(In reply to sigsve from comment #3)
 Sorry, I though DMD compiled and linked Stack.d automagically(Which it seems
 to have done, when I do not import std.stdio)

If you don't list a module file in dmd command line, the symbols in it are
compiled (== semantic analysis done) but those code won't be output to any
object files.

When you don't add `import std.stdio;` in Stack.d, today's dmd fortunately
determines the ModuleInfo object of Stack module is unnecessary, so the build
will succeed. However it's just undocumented behavior, and might be changed in
the future.

So I'd recommend to compile and link Stack.d always when you import it from
other modules.

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[Issue 14674] Importing std.stdio causes another module to become undefined

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14674

--- Comment #2 from sigsve sigurdbergsv...@gmail.com ---
My apologies for being vague, I was hoping you'd have a Mac available.

It is definitely a linking error(This is the error I get):

Undefined symbols for architecture x86_64:
  _D5Stack12__ModuleInfoZ, referenced from:
  _D4Main12__ModuleInfoZ in Main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

But, as said, this error only shows if I include std.stdio in the Stack.d file

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[Issue 14674] Importing std.stdio causes another module to become undefined

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14674

--- Comment #3 from sigsve sigurdbergsv...@gmail.com ---
Although, you are right.
Sorry, I though DMD compiled and linked Stack.d automagically(Which it seems to
have done, when I do not import std.stdio)

But when I compile each file separately to .o files, and link them, it works.

--

[Issue 14674] Importing std.stdio causes another module to become undefined

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14674

--- Comment #1 from Kenji Hara k.hara...@gmail.com ---
(In reply to sigsve from comment #0)
 When importing std.stdio in a specific context, causes an undefined symbols
 for architecture

I'm on Windows so I need to guess what undefined symbols for architecture is.
Maybe it's a linker error? As I can see the Rakefile, it does not compile and
link the file src/collector/Stack.d. It would be the reason of linker error.

D's import is not same with the #include in C. If you import a module, you also
need to compile and link it normally.

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