[Bug lto/44894] bogus warning: Use of type ‘struct nsNodeInfoManager’ with two mismatching declarations at field ‘mDocument’ [enabled by default]

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2010-07-10 11:21 -------
Somewhere down in type 

0x7ffff57497e0 struct nsRefreshDriver
0x7ffff5964348 struct nsRefreshDriver
(gdb) call debug_type_differences (0x7ffff57497e0, 0x7ffff5964348)
Hashes differ.
Field types not compatible.
type 0x7ffff59fb690 struct nsPresContext *
type 0x7ffff5af9d20 struct nsPresContext *
field 0x7ffff574b688 mPresContext
field 0x7ffff5941ab0 mPresContext
Field types not compatible.
type 0x7ffff574c150 struct nsTObserverArray[3]
type 0x7ffff5964dc8 struct nsTObserverArray[3]
field 0x7ffff574b7b8 mObservers
field 0x7ffff5941be0 mObservers
(gdb) call debug_type_differences (0x7ffff574c150, 0x7ffff5964dc8)
Hashes differ.

Because the array types have different size:

<array_type 0x7ffff574c150
    type <record_type 0x7ffff574c0a8 nsTObserverArray addressable
needs-constructing BLK
        size <integer_cst 0x7ffff7ed3938 constant 128>
        unit size <integer_cst 0x7ffff7ed3960 constant 16>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff574c0a8
        fields <field_decl 0x7ffff574b850 D.11101 type <record_type
0x7ffff5749e70 nsAutoTObserverArray>
            ignored BLK file tc/nsCopySupport.3.ii line 2745 col 25 size
<integer_cst 0x7ffff7ed3938 128> unit size <integer_cst 0x7ffff7ed3960 16>
            align 64 offset_align 128
            offset <integer_cst 0x7ffff7ed3410 constant 0>
            bit offset <integer_cst 0x7ffff7ed3b18 constant 0> context
<record_type 0x7ffff574c0a8 nsTObserverArray>>>
    needs-constructing BLK
    size <integer_cst 0x7ffff5b0e000 type <integer_type 0x7ffff7ee50a8
bit_size_type> constant 384>
    unit size <integer_cst 0x7ffff5af80f0 type <integer_type 0x7ffff7ee5000>
constant 48>
    align 64 symtab 0 alias set -1 canonical type 0x7ffff574c150
    domain <integer_type 0x7ffff59f1930
        type <integer_type 0x7ffff7ee5000 public unsigned sizetype DI
            size <integer_cst 0x7ffff7ed37a8 constant 64>
            unit size <integer_cst 0x7ffff7ed37d0 constant 8>
            align 64 symtab 0 alias set -1 canonical type 0x7ffff7ee5000
precision 64 min <integer_cst 0x7ffff7ed37f8 0> max <integer_cst 0x7ffff7ed39b0
-1>>
        DI size <integer_cst 0x7ffff7ed37a8 64> unit size <integer_cst
0x7ffff7ed37d0 8>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff59f1930 precision
64 min <integer_cst 0x7ffff7ed3410 0> max <integer_cst 0x7ffff7ed3618 2>>>


 <array_type 0x7ffff5964dc8
    type <record_type 0x7ffff5b283f0 nsTObserverArray addressable
needs-constructing BLK
        size <integer_cst 0x7ffff7ed3f28 constant 192>
        unit size <integer_cst 0x7ffff7ed3ed8 constant 24>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff5b283f0
        fields <field_decl 0x7ffff5b1cd10 D.2705 type <record_type
0x7ffff5b28498 nsAutoTObserverArray>
            ignored BLK file tc/nsContentUtils.3.3.ii line 3624 col 25 size
<integer_cst 0x7ffff7ed3f28 192> unit size <integer_cst 0x7ffff7ed3ed8 24>
            align 64 offset_align 128
            offset <integer_cst 0x7ffff7ed3410 constant 0>
            bit offset <integer_cst 0x7ffff7ed3b18 constant 0> context
<record_type 0x7ffff5b283f0 nsTObserverArray>>>
    needs-constructing BLK
    size <integer_cst 0x7ffff5b0cf78 type <integer_type 0x7ffff7ee50a8
bit_size_type> constant 576>
    unit size <integer_cst 0x7ffff5b0e028 type <integer_type 0x7ffff7ee5000>
constant 72>
    align 64 symtab 0 alias set -1 canonical type 0x7ffff5964dc8
    domain <integer_type 0x7ffff59f1930
        type <integer_type 0x7ffff7ee5000 public unsigned sizetype DI
            size <integer_cst 0x7ffff7ed37a8 constant 64>
            unit size <integer_cst 0x7ffff7ed37d0 constant 8>
            align 64 symtab 0 alias set -1 canonical type 0x7ffff7ee5000
precision 64 min <integer_cst 0x7ffff7ed37f8 0> max <integer_cst 0x7ffff7ed39b0
-1>>
        DI size <integer_cst 0x7ffff7ed37a8 64> unit size <integer_cst
0x7ffff7ed37d0 8>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff59f1930 precision
64 min <integer_cst 0x7ffff7ed3410 0> max <integer_cst 0x7ffff7ed3618 2>>>

because the array element types differ:

(gdb) call debug_type_differences (0x7ffff574c0a8, 0x7ffff5b283f0)
Hashes differ.
Field types not compatible.
type 0x7ffff5749e70 struct nsAutoTObserverArray
type 0x7ffff5b28498 struct nsAutoTObserverArray
field 0x7ffff574b850 D.11101
field 0x7ffff5b1cd10 D.2705
(gdb) call debug_type_differences (0x7ffff5749e70, 0x7ffff5b28498)
Hashes differ.
Field types not compatible.
type 0x7ffff5749f18 struct nsAutoTArray
type 0x7ffff5b28930 struct nsAutoTArray
field 0x7ffff574b980 mArray
field 0x7ffff5b2a098 mArray
(gdb) call debug_type_differences (0x7ffff5749f18, 0x7ffff5b28930)
Hashes differ.
Different number of fields.

Type decls:

<type_decl 0x7ffff5933e60 nsAutoTArray
    type <record_type 0x7ffff5749f18 nsAutoTArray addressable
needs-constructing BLK
        size <integer_cst 0x7ffff7ed37a8 constant 64>
        unit size <integer_cst 0x7ffff7ed37d0 constant 8>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff5749f18
        fields <field_decl 0x7ffff574ba18 D.11104 type <record_type
0x7ffff5bc03f0 nsTArray>
            ignored BLK file tc/nsCopySupport.3.ii line 2126 col 25 size
<integer_cst 0x7ffff7ed37a8 64> unit size <integer_cst 0x7ffff7ed37d0 8>
            align 64 offset_align 128
            offset <integer_cst 0x7ffff7ed3410 constant 0>
            bit offset <integer_cst 0x7ffff7ed3b18 constant 0> context
<record_type 0x7ffff5749f18 nsAutoTArray>>>
    public BLK file tc/nsCopySupport.3.ii line 2106 col 37
    align 8>

and

 <type_decl 0x7ffff5b257e8 nsAutoTArray
    type <record_type 0x7ffff5b28930 nsAutoTArray addressable
needs-constructing BLK
        size <integer_cst 0x7ffff7ed3938 constant 128>
        unit size <integer_cst 0x7ffff7ed3960 constant 16>
        align 64 symtab 0 alias set -1 canonical type 0x7ffff5b28930
        fields <field_decl 0x7ffff5b2a130 D.2715 type <record_type
0x7ffff5bc03f0 nsTArray>
            ignored BLK file tc/nsContentUtils.3.3.ii line 1757 col 37
            size <integer_cst 0x7ffff7ed37a8 constant 64>
            unit size <integer_cst 0x7ffff7ed37d0 constant 8>
            align 64 offset_align 128
            offset <integer_cst 0x7ffff7ed3410 constant 0>
            bit offset <integer_cst 0x7ffff7ed3b18 constant 0> context
<record_type 0x7ffff5b28930 nsAutoTArray> chain <field_decl 0x7ffff5b2a4c0
D.2725>>>
    public BLK file tc/nsContentUtils.3.3.ii line 1757 col 37
    align 8>

One type misses the protected union member (both sources are identical
though):

template<class E, PRUint32 N> class nsAutoTArray : public nsTArray<E> {
public:
    typedef nsTArray<E> base_type;
    typedef typename base_type::Header Header;
    typedef typename base_type::elem_type elem_type;
    nsAutoTArray() {
        base_type::mHdr = reinterpret_cast<Header*>(&mAutoBuf);
        base_type::mHdr->mLength = 0;
        base_type::mHdr->mCapacity = N;
        base_type::mHdr->mIsAutoArray = 1;
        do {
        }
        while (0)                                                           ;
    }
protected:
    union {
        char mAutoBuf[sizeof(Header) + N * sizeof(elem_type)];
        PRUint64 dummy;
    };
};

One source misses the specialization for N == 0 (maybe an error of my
reduction though).

template<class E> class nsAutoTArray<E, 0> : public nsTArray<E> {
   public:
     nsAutoTArray() {
}
 };

most definitely.  :/


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44894