http://d.puremagic.com/issues/show_bug.cgi?id=348

           Summary: string concat in dynamically loaded dll code crashes
                    program
           Product: D
           Version: 0.165
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: default_357-line@yahoo.de


A string concat in a dynamically loaded C linkage function crashes the program
with a SIGSEGV in _d_new (wtf)
Files:
_dll.d_
extern (C) { void test(char[] str) { char[] e=str~"bla"; } }
_test.d_
import std.c.windows.windows;

void main() {
  auto func=cast(void function(char[])) GetProcAddress(LoadLibraryA("dll.dll"),
"test");
  func("Bla bla bla ");
}

On gdcwin 0.19, this crashes with a SIGSEGV trying to access 0x0.
The stack trace is:
#0  0x610c1adb in _d_new ()
#1  0x610c1289 in _d_arraycatn ()
#2  0x610c1214 in test (str={length = 12, ptr = 0x41d00d "Bla bla bla "})
    at dll.d:1
#3  0x00401321 in _Dmain () at quick.d:5
#4  0x004013df in _d_run_main2goFZv ()
#5  0x004014e4 in _d_run_main ()
#6  0x00401363 in main ()


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=348





------- Comment #1 from default_357-line@yahoo.de  2006-09-14 16:09 -------
(In reply to comment #0)
> Files:
> _dll.d_
> extern (C) { void test(char[] str) { char[] e=str~"bla"; } }
> _test.d_
I forgot to mention two things.
a) dmd generates an access error.
b) Compile the first file into a dll with -Wl,--dll and -shared, and the second
file into an executable normally.


-- 

d-bugmail@puremagic.com wrote:
> 
> A string concat in a dynamically loaded C linkage function crashes the program
> with a SIGSEGV in _d_new (wtf)
> Files:
> _dll.d_
> extern (C) { void test(char[] str) { char[] e=str~"bla"; } }
> _test.d_
> import std.c.windows.windows;
> 
> void main() {
>   auto func=cast(void function(char[])) GetProcAddress(LoadLibraryA("dll.dll"),
> "test");
>   func("Bla bla bla ");
> }

Given the above code, I think this is to be expected.  See this link for a description of what must be done to produce a dynamic library in D:

http://www.digitalmars.com/d/dll.html

Basically, you must initialize the D compiler runtime, the garbage collector, and call module ctors when the library is loaded.  The current method for doing this kind of stinks, but it wouldn't be terribly difficult to improve.

http://d.puremagic.com/issues/show_bug.cgi?id=348


bugzilla@digitalmars.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID




------- Comment #3 from bugzilla@digitalmars.com  2008-06-25 04:18 -------
Sean is correct. Also, dmd doesn't have flags -Wl,--dll and -shared.


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