Dwarfdump complains about invalid file info

[llvmbot]

Bugzilla Link	9268
Version	trunk
OS	Linux
Reporter	LLVM Bugzilla Contributor

Extended Description

With the following attachment ("Hello2.ll"), compile using the following commands:

llc -O0 -disable-fp-elim -filetype=obj Hello2.ll
/usr/bin/c++ -g -o Hello2 Hello2.o

Now run dwarfdump -ka on the resulting executable:

dwarfdump -ka Hello2

Drawdump prints out a bunch of messages of the following form:

*** DWARF CHECK: DW_AT_decl_file: does not point to valid file info ***

Note that this issue occurs using both the old DIFactory and the new DIBuilder.

[llvmbot]

Looking through the dwarfdump output further, I noticed another strange thing, which is that the DIEs for subranges are also getting errors.

Here's a sample of the dwarfdump output:

<1>< 2607> DW_TAG_array_type
DW_AT_sibling <2623>
DW_AT_type <299>
<2>< 2616> DW_TAG_subrange_type
*** DWARF CHECK: DW_AT_type offset does not point to type info ***
DW_AT_type <1347>
DW_AT_upper_bound 0
<1>< 2623> DW_TAG_structure_type
DW_AT_sibling <2760>
DW_AT_name tart.core.TypeInfoBlock
DW_AT_byte_size 32

As far as I can tell, every occurrence of DW_TAG_subrange_type has this same error.

(I assume that the reason why the lower bound is not there is that it defaults to zero.)

[llvmbot]

This is still happening, btw.

[llvmbot]

I've confirmed that the problem does not happen on OS X, but does happen on Linux. (I only have a 32-bit OS X system and a 64-bit Linux system, so there may be other variables involved.)

[llvmbot]

Is this still an issue with mainline sources ?

[llvmbot]

See also bug 9995.

There is no attachment Hello2.ll AFAICT.

I presume the report is on 2.9 or earlier. I was told that 9995 was fixed
in 3.0 (and I know it is fixed in HEAD as of Jan 3, 2012).

The problem (bug 9995) is that DW_AT_stmt_list attribute (in DWARF) had a bad
FORM which meant dwarfdump could not find a file-number table.
Leading to the DW_AT_decl_file integers seeming wrong. Hence I
strongly suspect that this amounts to a duplicate of 9995.

Someone who has some idea what Hello2.ll is should retry this
with 3.0 or HEAD.

PS: I'm maintainer of dwarfdump and libdwarf, feel free to contact me
with dwarfdump/libdwarf issues