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digitalmars.D.bugs - [Issue 4212] New: DWARF: void arrays cause gdb errors

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=4212

           Summary: DWARF: void arrays cause gdb errors
           Product: D
           Version: 1.057
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: nfxjfg gmail.com


--- Comment #0 from nfxjfg gmail.com 2010-05-20 12:04:46 PDT ---
(This bug report is for dmd 1.061)

This code:

extern (C) void abort();

struct X {
 union {
   void[] a;
   void[a.sizeof] b;
 }
}

void foo(X b) {
    abort();
}

void main() {
    foo(X.init);
}

Makes gdb output "Dwarf Error: Cannot find DIE at 0x0 referenced from DIE at
0x68 [in module /tmp/test/dr]" when the abort() jumps back into the debugger,
and you request a stacktrace with "bt".

I suspect something is wrong with static void[] arrays.

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next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=4212


Robert Clipsham <robert octarineparrot.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |robert octarineparrot.com


--- Comment #1 from Robert Clipsham <robert octarineparrot.com> 2010-05-20
20:21:57 BST ---
Test case is for D1, with D2 it fails with an error that has no line number
information. Reduced test case for D2:
----
void[8] foo = void;
void main(){}
----

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prev sibling next sibling parent d-bugmail puremagic.com writes:
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Robert Clipsham <robert octarineparrot.com> changed:

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


--- Comment #2 from Robert Clipsham <robert octarineparrot.com> 2010-05-20
20:45:35 BST ---
The patch below fixes both test cases:
Index: backend/dwarf.c
===================================================================
--- backend/dwarf.c     (revisión: 494)
+++ backend/dwarf.c     (copia de trabajo)
   -1558,6 +1558,13   
                 DW_AT_type,             DW_FORM_ref4,
                 0,                      0,
             };
+            static unsigned char abbrevTypeArrayVoid[] =
+            {
+                DW_TAG_array_type,
+                1,                      // child (the subrange type)
+                DW_AT_sibling,          DW_FORM_ref4,
+                0,                      0,
+            };
             static unsigned char abbrevTypeSubrange[] =
             {
                 DW_TAG_subrange_type,
   -1573,7 +1580,6   
                 DW_AT_type,             DW_FORM_ref4,
                 0,                      0,
             };
-            unsigned code1 = dwarf_abbrev_code(abbrevTypeArray,
sizeof(abbrevTypeArray));
             unsigned code2 = (t->Tflags & TFsizeunknown)
                 ? dwarf_abbrev_code(abbrevTypeSubrange2,
sizeof(abbrevTypeSubrange2))
                 : dwarf_abbrev_code(abbrevTypeSubrange,
sizeof(abbrevTypeSubrange));
   -1581,12 +1587,15   
             unsigned idxsibling = 0;
             unsigned siblingoffset;
             nextidx = dwarf_typidx(t->Tnext);
+            unsigned code1 = nextidx ? dwarf_abbrev_code(abbrevTypeArray,
sizeof(abbrevTypeArray))
+                                     : dwarf_abbrev_code(abbrevTypeArrayVoid,
sizeof(abbrevTypeArrayVoid));
             idx = infobuf->size();

             infobuf->writeuLEB128(code1);       // DW_TAG_array_type
             siblingoffset = infobuf->size();
             infobuf->write32(idxsibling);       // DW_AT_sibling
-            infobuf->write32(nextidx);          // DW_AT_type
+            if (nextidx)
+                infobuf->write32(nextidx);      // DW_AT_type

             infobuf->writeuLEB128(code2);       // DW_TAG_subrange_type
             infobuf->write32(idxbase);          // DW_AT_type

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prev sibling parent d-bugmail puremagic.com writes:
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Walter Bright <bugzilla digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |bugzilla digitalmars.com
         Resolution|                            |FIXED


--- Comment #3 from Walter Bright <bugzilla digitalmars.com> 2010-05-20
22:07:14 PDT ---
changeset 495 (dwarf.c changes)

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