http://d.puremagic.com/issues/show_bug.cgi?id=3975

           Summary: Misnamed main causes linker errors
           Product: D
           Version: 1.057
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody@puremagic.com
        ReportedBy: baseball.mjp@gmail.com


--- Comment #0 from Michael P <baseball.mjp@gmail.com> 2010-03-16 08:15:49 PDT ---
typo.d:
void mann() { }

michael@michael-laptop:~/d/projects$ dmd typo.d
/home/michael/dmd/linux/bin/../lib/libphobos.a(dmain2_7a_1a5.o): In function
`main':
internal/dmain2.d:(.text.main+0x74): undefined reference to `_Dmain'
internal/dmain2.d:(.text.main+0xc5): undefined reference to `_Dmain'
/home/michael/dmd/linux/bin/../lib/libphobos.a(deh2_171_525.o): In function
`_D4deh213__eh_finddataFPvZPS4deh213DHandlerTable':
internal/deh2.d:(.text._D4deh213__eh_finddataFPvZPS4deh213DHandlerTable+0x4):
undefined reference to `_deh_beg'
internal/deh2.d:(.text._D4deh213__eh_finddataFPvZPS4deh213DHandlerTable+0xc):
undefined reference to `_deh_beg'
internal/deh2.d:(.text._D4deh213__eh_finddataFPvZPS4deh213DHandlerTable+0x13):
undefined reference to `_deh_end'
internal/deh2.d:(.text._D4deh213__eh_finddataFPvZPS4deh213DHandlerTable+0x37):
undefined reference to `_deh_end'
collect2: ld returned 1 exit status
--- errorlevel 1

Should this be happening?
Compiling with -c is fine, and produces no output.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=3975


Bernard Helyer <blood.of.life@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |blood.of.life@gmail.com
         Resolution|                            |INVALID


--- Comment #1 from Bernard Helyer <blood.of.life@gmail.com> 2011-02-07 02:33:12 PST ---
Yes, that is working as intended. When you compile without '-c' you are telling DMD to build you an executable -- one whose entry point is 'main'; so the linker looks for the function, and can't find it, and tells you so. This behaviour is the same as in C or C++.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=3975


bearophile_hugs@eml.cc changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bearophile_hugs@eml.cc


--- Comment #2 from bearophile_hugs@eml.cc 2011-02-07 03:49:26 PST ---
Yet, I'd like the front-end to catch (and show an error message) this common bug before it reaches the linker, if possible.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=3975



--- Comment #3 from Bernard Helyer <blood.of.life@gmail.com> 2011-02-11 19:53:50 PST ---
Agreed, but it's not quite as simple as checking the existence of a 'main' function when compiling without -c. If object files, libraries, or anything of the sort are being used -- all those must be searched for a main function. On Linux, where linking is handled by GCC, this would lead to duplication of code and work -- all for a fairly minor issue.

Another option is to merely issue a warning if we don't see one -- this would lead to spurious warnings, and as DMD has no granularity options when it comes to warnings, is not really an option.

So I think the only viable option is to handle the simple case, where the only thing passed to DMD is source files (as we know Phobos doesn't have a main). Not ideal, but should catch cases where the user is genuinely confused by the linker output.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------