http://d.puremagic.com/issues/show_bug.cgi?id=1678

           Summary: ref with varargs generates invalid code
           Product: D
           Version: 1.023
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: ary@esperanto.org.ar


Given this code:

***
module main;

import std.stdio;
import std.stdarg;

void foo(int x, ...) {
    writefln("%d arguments", _arguments.length);
    for (int i = 0; i < _arguments.length; i++) {
            _arguments[i].print();
        int j = va_arg!(int)(_argptr);
            writefln("\t%d", j);
    }
}

void fooRef(ref int x, ...) {
    writefln("%d arguments", _arguments.length);
    for (int i = 0; i < _arguments.length; i++) {
            _arguments[i].print();
        int j = va_arg!(int)(_argptr);
            writefln("\t%d", j);
    }
}

void main() {
        foo(1, 2, 3, 4, 5);

        writefln("---");

        int x = 1;
        fooRef(x, 2, 3, 4, 5);
}
***

the output is:

***
4 arguments
int
        2
int
        3
int
        4
int
        5
---
4 arguments
int
        1245056
int
        4203171
int
        1
int
        1245004
***

Note that both functions are identical, except the last one has a ref parameter. Without it, the function works as expected.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=1678


smjg@iname.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |smjg@iname.com
           Keywords|                            |wrong-code




------- Comment #1 from smjg@iname.com  2007-11-19 09:16 -------
Please remember to assign keywords to bug reports.  To everybody reading this: Please look through issues you've reported and check for missing keywords.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=1678





------- Comment #2 from ary@esperanto.org.ar  2007-11-19 09:29 -------
Is there a standard keyword list? I always see "accepts-invalid", and now that I know it, I'll use it. For this one, it's "wrong-code", but I was going to write "invalid-code" but I was afraid that wasn't the "standard" keyword. Also, I was going to write "ref varargs"...


-- 

d-bugmail@puremagic.com wrote:
> http://d.puremagic.com/issues/show_bug.cgi?id=1678
> 
> 
> 
> 
> 
> ------- Comment #2 from ary@esperanto.org.ar  2007-11-19 09:29 -------
> Is there a standard keyword list? I always see "accepts-invalid", and now that
> I know it, I'll use it. For this one, it's "wrong-code", but I was going to
> write "invalid-code" but I was afraid that wasn't the "standard" keyword. Also,
> I was going to write "ref varargs"...

If you click on the word "Keywords" in the report it will take you to a page listing the keywords.

It's a bad interface though.  If there were some kind of clicky list probably more people would add keywords.  Me included.

--bb

http://d.puremagic.com/issues/show_bug.cgi?id=1678





------- Comment #3 from smjg@iname.com  2007-11-19 09:44 -------
Keywords in Bugzilla aren't quite like the keywords you use on web pages to guide search engines.  They're more like flags.  And if you'd bothered to follow the link that is the word "Keywords", you would have found a list of them.


-- 

Bill Baxter wrote:
> d-bugmail@puremagic.com wrote:
>> http://d.puremagic.com/issues/show_bug.cgi?id=1678
>>
>>
>>
>>
>>
>> ------- Comment #2 from ary@esperanto.org.ar  2007-11-19 09:29 -------
>> Is there a standard keyword list? I always see "accepts-invalid", and now that
>> I know it, I'll use it. For this one, it's "wrong-code", but I was going to
>> write "invalid-code" but I was afraid that wasn't the "standard" keyword. Also,
>> I was going to write "ref varargs"...
> 
> If you click on the word "Keywords" in the report it will take you to a page listing the keywords.
> 
> It's a bad interface though.  If there were some kind of clicky list probably more people would add keywords.  Me included.
> 
> --bb

Thanks, I didn't see that link.

<d-bugmail@puremagic.com> wrote in message news:fhsb1m$2bek$1@digitalmars.com...
> http://d.puremagic.com/issues/show_bug.cgi?id=1678

> And if you'd bothered to
> follow the link that is the word "Keywords", you would have found a list
> of
> them.

You know, you don't always have to be nasty to everyone.

http://d.puremagic.com/issues/show_bug.cgi?id=1678


Markus Dangl <sky@q1cc.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sky@q1cc.net


--- Comment #5 from Markus Dangl <sky@q1cc.net> 2010-06-16 17:18:23 PDT ---
*** Issue 4336 has been marked as a duplicate of this issue. ***

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Don <clugdbug@yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |clugdbug@yahoo.com.au


--- Comment #6 from Don <clugdbug@yahoo.com.au> 2010-07-24 22:30:56 PDT ---
This also applies to 'out' parameters, as well as 'ref'.

The problem is in func.c, FuncDeclaration::semantic3(), around line 1380, where __argptr is created. It's set equal to (&p + offset), where p is the last non-variadic parameter. This fails if p is a reference -- it gives the address of the thing p is pointing to.

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Don <clugdbug@yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


--- Comment #7 from Don <clugdbug@yahoo.com.au> 2010-07-26 13:03:13 PDT ---
There's probably a simpler way to patch this. What I've done is find the first non-ref parameter, and set __argptr off it.

Index: func.c ===================================================================
--- func.c    (revision 588)
+++ func.c    (working copy)
@@ -1367,18 +1367,32 @@
 #else
                 Type *t = argptr->type;
                 VarDeclaration *p;
-                unsigned offset;
-
+                unsigned offset = 0;
                 Expression *e1 = new VarExp(0, argptr);
+                // Find the last non-ref parameter
                 if (parameters && parameters->dim)
-                    p = (VarDeclaration *)parameters->data[parameters->dim -
1];
+                {
+                    int lastNonref = parameters->dim -1;
+                    p = (VarDeclaration *)parameters->data[lastNonref];
+                    while (p->storage_class & (STCout | STCref))
+                    {
+                        --lastNonref;
+                        offset += PTRSIZE;
+                        if (lastNonref < 0)
+                        {
+                            p = v_arguments;
+                            break;
+                        }
+                        p = (VarDeclaration *)parameters->data[lastNonref];
+                    }
+                }
                 else
-                    p = v_arguments;            // last parameter is
_arguments[]
+                    p = v_arguments;
                 if (p->storage_class & STClazy)
                     // If the last parameter is lazy, it's the size of a
delegate
-                    offset = PTRSIZE * 2;
+                    offset += PTRSIZE * 2;
                 else
-                    offset = p->type->size();
+                    offset += p->type->size();
                 offset = (offset + 3) & ~3;     // assume stack aligns on 4
                 Expression *e = new SymOffExp(0, p, offset);
                 e->type = Type::tvoidptr;

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