Extended Description

Reproducing the issue:

• Compile the followoing code snippet with "clang++ -g var.cpp":
  int main() {
  for (int i = 0; i < 10; ++i) {
  int x[i + 1];
  x[0]++;
  }
  }
• Inspect the debug info for variable 'x'

The relevant parts of the debug info:
<4><6b>: Abbrev Number: 5 (DW_TAG_variable)
<6c> DW_AT_location : 0x0 (location list)
<70> DW_AT_name : (indirect string, offset: 0x71): x
<74> DW_AT_decl_file : 1
<75> DW_AT_decl_line : 3
<76> DW_AT_type : <0x84>

<1><84>: Abbrev Number: 7 (DW_TAG_array_type)
<85> DW_AT_type : <0x7d>
<2><89>: Abbrev Number: 8 (DW_TAG_subrange_type)
<8a> DW_AT_type : <0x8f>
<2><8e>: Abbrev Number: 0
<1><8f>: Abbrev Number: 9 (DW_TAG_base_type)
<90> DW_AT_name : (indirect string, offset: 0x73): sizetype
<94> DW_AT_byte_size : 8
<95> DW_AT_encoding : 7 (unsigned)
<1><96>: Abbrev Number: 0

The problem is that clang specifies a DW_TAG_subrange_type under DW_TAG_array_type but is fails to fill it in with some information specifying the number of elements in the array (DW_AT_count or DW_AT_upper_bound).

The issue is reproduced with clang 3.5.0 and with 3.8.0 (trunk 256170). Gcc 4.8.4 generates correct debug info with producing a DW_AT_upper_bound containing a dwarf expression to a memory location containing the current array size.