[llvm-commits] [llvm] r129156 - in /llvm/trunk: docs/SourceLevelDebugging.html lib/CodeGen/AsmPrinter/DwarfDebug.cpp test/DebugInfo/array.ll

[Devang Patel]

Author: dpatel
Date: Fri Apr  8 16:55:10 2011
New Revision: 129156

URL: http://llvm.org/viewvc/llvm-project?rev=129156&view=rev
Log:
Do not emit DW_AT_upper_bound and DW_AT_lower_bound for unbouded array.
If lower bound is more then upper bound then consider it is an unbounded array.
An array is unbounded if non-zero lower bound is same as upper bound.
If lower bound and upper bound are zero than array has one element.

Added:
    llvm/trunk/test/DebugInfo/array.ll
Modified:
    llvm/trunk/docs/SourceLevelDebugging.html
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

Modified: llvm/trunk/docs/SourceLevelDebugging.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/SourceLevelDebugging.html?rev=129156&r1=129155&r2=129156&view=diff
==============================================================================
--- llvm/trunk/docs/SourceLevelDebugging.html (original)
+++ llvm/trunk/docs/SourceLevelDebugging.html Fri Apr  8 16:55:10 2011
@@ -708,7 +708,7 @@
    <a href="#format_composite_type">composite type</a>.  The low value defines
    the lower bounds typically zero for C/C++.  The high value is the upper
    bounds.  Values are 64 bit.  High - low + 1 is the size of the array.  If low
-   == high the array will be unbounded.</p>
+   > high the array will be unbounded.</p>
 
 </div>
 

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=129156&r1=129155&r2=129156&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Fri Apr  8 16:55:10 2011
@@ -1237,15 +1237,27 @@
 
 /// constructSubrangeDIE - Construct subrange DIE from DISubrange.
 void DwarfDebug::constructSubrangeDIE(DIE &Buffer, DISubrange SR, DIE *IndexTy){
+  DIE *DW_Subrange = new DIE(dwarf::DW_TAG_subrange_type);
+  addDIEEntry(DW_Subrange, dwarf::DW_AT_type, dwarf::DW_FORM_ref4, IndexTy);
   int64_t L = SR.getLo();
   int64_t H = SR.getHi();
-  DIE *DW_Subrange = new DIE(dwarf::DW_TAG_subrange_type);
 
-  addDIEEntry(DW_Subrange, dwarf::DW_AT_type, dwarf::DW_FORM_ref4, IndexTy);
+  // The L value defines the lower bounds typically zero for C/C++.  The H
+  // value is the upper bounds.  Values are 64 bit.  H - L + 1 is the size
+  // of the array. If L > H the array will be unbounded. If the L is 
+  // non zero and same is H then also the array will be unbounded. If L is
+  // zero and H is zero then the array has one element and in such case do
+  // not emit lower bound.
+
+  if (L > H || (L == H && L != 0)) {
+    // This is an unbounded subrange.
+    Buffer.addChild(DW_Subrange);
+    return;
+  }
+
   if (L)
     addSInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, L);
   addSInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, H);
-
   Buffer.addChild(DW_Subrange);
 }
 

Added: llvm/trunk/test/DebugInfo/array.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/array.ll?rev=129156&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/array.ll (added)
+++ llvm/trunk/test/DebugInfo/array.ll Fri Apr  8 16:55:10 2011
@@ -0,0 +1,34 @@
+; RUN: llc -O0 < %s | FileCheck %s
+; Do not emit AT_upper_bound for an unbounded array.
+
+define i32 @main() nounwind ssp {
+entry:
+  %retval = alloca i32, align 4
+  %a = alloca [0 x i32], align 4
+  store i32 0, i32* %retval
+  call void @llvm.dbg.declare(metadata !{[0 x i32]* %a}, metadata !6), !dbg !11
+  ret i32 0, !dbg !12
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+!llvm.dbg.sp = !{!0}
+
+!0 = metadata !{i32 589870, i32 0, metadata !1, metadata !"main", metadata !"main", metadata !"", metadata !1, i32 3, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 0, i1 false, i32 ()* @main, null} ; [ DW_TAG_subprogram ]
+!1 = metadata !{i32 589865, metadata !"array.c", metadata !"/private/tmp", metadata !2} ; [ DW_TAG_file_type ]
+!2 = metadata !{i32 589841, i32 0, i32 12, metadata !"array.c", metadata !"/private/tmp", metadata !"clang version 3.0 (trunk 129138)", i1 true, i1 false, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!3 = metadata !{i32 589845, metadata !1, metadata !"", metadata !1, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 589860, metadata !2, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!6 = metadata !{i32 590080, metadata !7, metadata !"a", metadata !1, i32 4, metadata !8, i32 0} ; [ DW_TAG_auto_variable ]
+!7 = metadata !{i32 589835, metadata !0, i32 3, i32 12, metadata !1, i32 0} ; [ DW_TAG_lexical_block ]
+!8 = metadata !{i32 589825, metadata !2, metadata !"", metadata !2, i32 0, i64 0, i64 32, i32 0, i32 0, metadata !5, metadata !9, i32 0, i32 0} ; [ DW_TAG_array_type ]
+!9 = metadata !{metadata !10}
+;CHECK: DW_TAG_subrange_type
+;CHECK-NEXT: DW_AT_type
+;CHECK-NOT: DW_AT_lower_bound
+;CHECK-NOT: DW_AT_upper_bound
+;CHECK-NEXT: End Of Children Mark
+!10 = metadata !{i32 589857, i64 1, i64 0}        ; [ DW_TAG_subrange_type ]
+!11 = metadata !{i32 4, i32 7, metadata !7, null}
+!12 = metadata !{i32 5, i32 3, metadata !7, null}