Handle non-default array bounds.

Some languages, e.g. Ada and Pascal, allow you to specify that the array bounds
are different from the default (1 in these cases). If we have a lower bound
that's non-default, then we emit the lower bound. We also calculate the correct
upper bound in those cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169484 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/DebugInfo.h b/include/llvm/DebugInfo.h
index 8601f5532b3adbc77b1c8ec2e6af7c9fd029ba7b..43af6ed080bf9f97f92400e92de05ff67a54b34f 100644 (file)
--- a/include/llvm/DebugInfo.h
+++ b/include/llvm/DebugInfo.h
@@ -142,7 +142,7 @@ namespace llvm {
   public:
     explicit DISubrange(const MDNode *N = 0) : DIDescriptor(N) {}
 
-    uint64_t getLo() const { return getUInt64Field(1); }
+    int64_t getLo() const { return getInt64Field(1); }
     int64_t  getCount() const { return getInt64Field(2); }
   };
 

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index c88070794918fe391f95489cd72185f7cecb85ac..255ae1ec500c013fbf8692683c5d495381c7bce1 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -51,6 +51,50 @@ DIEEntry *CompileUnit::createDIEEntry(DIE *Entry) {
   return Value;
 }
 
+/// getLowerBoundDefault - Return the default lower bound for an array. If the
+/// DWARF version doesn't handle the language, return -1.
+int64_t CompileUnit::getLowerBoundDefault() const {
+  switch (Language) {
+  default:
+    break;
+
+  case dwarf::DW_LANG_C89:
+  case dwarf::DW_LANG_C99:
+  case dwarf::DW_LANG_C:
+  case dwarf::DW_LANG_C_plus_plus:
+  case dwarf::DW_LANG_ObjC:
+  case dwarf::DW_LANG_ObjC_plus_plus:
+    return 0;
+
+  case dwarf::DW_LANG_Fortran77:
+  case dwarf::DW_LANG_Fortran90:
+  case dwarf::DW_LANG_Fortran95:
+    return 1;
+
+  // The languages below have valid values only if the DWARF version >= 4.
+  case dwarf::DW_LANG_Java:
+  case dwarf::DW_LANG_Python:
+  case dwarf::DW_LANG_UPC:
+  case dwarf::DW_LANG_D:
+    if (dwarf::DWARF_VERSION >= 4)
+      return 0;
+    break;
+
+  case dwarf::DW_LANG_Ada83:
+  case dwarf::DW_LANG_Ada95:
+  case dwarf::DW_LANG_Cobol74:
+  case dwarf::DW_LANG_Cobol85:
+  case dwarf::DW_LANG_Modula2:
+  case dwarf::DW_LANG_Pascal83:
+  case dwarf::DW_LANG_PLI:
+    if (dwarf::DWARF_VERSION >= 4)
+      return 1;
+    break;
+  }
+
+  return -1;
+}
+
 /// addFlag - Add a flag that is true.
 void CompileUnit::addFlag(DIE *Die, unsigned Attribute) {
   if (!DD->useDarwinGDBCompat())
@@ -1251,23 +1295,23 @@ void CompileUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR,
   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 which is typically zero for C/C++. The
-  // Count value is the number of elements.  Values are 64 bit. If Count == -1
-  // then the array is unbounded and we do not emit DW_AT_lower_bound and
-  // DW_AT_upper_bound attributes. If L == 0 and Count == 0, then the array has
-  // zero elements in which case we do not emit an upper bound.
-  uint64_t L = SR.getLo();
+  // The LowerBound value defines the lower bounds which is typically zero for
+  // C/C++. The Count value is the number of elements.  Values are 64 bit. If
+  // Count == -1 then the array is unbounded and we do not emit
+  // DW_AT_lower_bound and DW_AT_upper_bound attributes. If LowerBound == 0 and
+  // Count == 0, then the array has zero elements in which case we do not emit
+  // an upper bound.
+  int64_t LowerBound = SR.getLo();
+  int64_t DefaultLowerBound = getLowerBoundDefault();
   int64_t Count = SR.getCount();
 
-  if (Count != -1) {
+  if (LowerBound != DefaultLowerBound || DefaultLowerBound == -1)
+    addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, LowerBound);
+
+  if (Count != -1 && Count != 0)
     // FIXME: An unbounded array should reference the expression that defines
     // the array.
-    if (L)
-      addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, L);
-
-    if (Count != 0)
-      addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, Count - 1);
-  }
+    addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, LowerBound + Count - 1);
 
   Buffer.addChild(DW_Subrange);
 }

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index 136e1578f4ce6383a237a649ff0a29fc8008b99b..340e470979822321ce3194119b02786303a9b5dc 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -79,6 +79,8 @@ class CompileUnit {
   /// corresponds to the MDNode mapped with the subprogram DIE.
   DenseMap<DIE *, const MDNode *> ContainingTypeMap;
 
+  int64_t getLowerBoundDefault() const;
+
 public:
   CompileUnit(unsigned UID, unsigned L, DIE *D, AsmPrinter *A, DwarfDebug *DW);
   ~CompileUnit();
@@ -174,7 +176,6 @@ public:
   void setIndexTyDie(DIE *D) {
     IndexTyDie = D;
   }
-public:
 
   /// addFlag - Add a flag that is true to the DIE.
   void addFlag(DIE *Die, unsigned Attribute);

diff --git a/test/DebugInfo/X86/nondefault-subrange-array.ll b/test/DebugInfo/X86/nondefault-subrange-array.ll
new file mode 100644 (file)
index 0000000..5845f3e
--- /dev/null
+++ b/test/DebugInfo/X86/nondefault-subrange-array.ll
@@ -0,0 +1,48 @@
+; RUN: llc -mtriple=x86_64-apple-darwin -O0 -filetype=obj -o %t < %s
+; RUN: llvm-dwarfdump %t | FileCheck %s
+
+%class.A = type { [42 x i32] }
+
+@a = global %class.A zeroinitializer, align 4
+
+; Check that we can handle non-default array bounds. In this case, the array
+; goes from [-3, 38].
+
+; CHECK:      0x0000002d:   DW_TAG_base_type [3]  
+; CHECK-NEXT: 0x0000002e:     DW_AT_byte_size [DW_FORM_data1]  (0x04)
+; CHECK-NEXT: 0x0000002f:     DW_AT_encoding [DW_FORM_data1]   (0x05)
+
+; CHECK:      0x00000030:   DW_TAG_array_type [4] *
+; CHECK-NEXT: 0x00000031:     DW_AT_type [DW_FORM_ref4]    (cu + 0x0026 => {0x00000026})
+
+; CHECK:      0x00000035:     DW_TAG_subrange_type [5]
+; CHECK-NEXT: 0x00000036:       DW_AT_type [DW_FORM_ref4]  (cu + 0x002d => {0x0000002d})
+; CHECK-NEXT: 0x0000003a:       DW_AT_lower_bound [DW_FORM_data8]      (0xfffffffffffffffd)
+; CHECK-NEXT: 0x00000042:       DW_AT_upper_bound [DW_FORM_data1]      (0x26)
+
+; CHECK:      0x00000051:     DW_TAG_member [8]  
+; CHECK-NEXT: 0x00000052:       DW_AT_name [DW_FORM_strp]      ( .debug_str[0x0000003f] = "x")
+; CHECK-NEXT: 0x00000056:       DW_AT_type [DW_FORM_ref4]      (cu + 0x0030 => {0x00000030})
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 4, metadata !"t.cpp", metadata !"/Volumes/Sandbox/llvm", metadata !"clang version 3.3 (trunk 169136)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !1, metadata !3} ; [ DW_TAG_compile_unit ] [/Volumes/Sandbox/llvm/t.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786484, i32 0, null, metadata !"a", metadata !"a", metadata !"", metadata !6, i32 1, metadata !7, i32 0, i32 1, %class.A* @a} ; [ DW_TAG_variable ] [a] [line 1] [def]
+!6 = metadata !{i32 786473, metadata !"t.cpp", metadata !"/Volumes/Sandbox/llvm", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786434, null, metadata !"A", metadata !6, i32 1, i64 0, i64 32, i32 0, i32 0, null, metadata !8, i32 0, null, null} ; [ DW_TAG_class_type ] [A] [line 1, size 0, align 32, offset 0] [from ]
+!8 = metadata !{metadata !9, metadata !14}
+!9 = metadata !{i32 786445, metadata !7, metadata !"x", metadata !6, i32 1, i64 0, i64 0, i64 0, i32 1, metadata !10} ; [ DW_TAG_member ] [x] [line 1, size 0, align 0, offset 0] [private] [from ]
+!10 = metadata !{i32 786433, null, metadata !"", null, i32 0, i64 0, i64 32, i32 0, i32 0, metadata !11, metadata !12, i32 0, i32 0} ; [ DW_TAG_array_type ] [line 0, size 0, align 32, offset 0] [from int]
+!11 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!12 = metadata !{metadata !13}
+!13 = metadata !{i32 786465, i64 -3, i64 42} ; [ DW_TAG_subrange_type ] [-3, 39]
+!14 = metadata !{i32 786478, i32 0, metadata !7, metadata !"A", metadata !"A", metadata !"", metadata !6, i32 1, metadata !15, i1 false, i1 false, i32 0, i32 0, null, i32 320, i1 false, null, null, i32 0, metadata !18, i32 1} ; [ DW_TAG_subprogram ] [line 1] [A]
+!15 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !16, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!16 = metadata !{null, metadata !17}
+!17 = metadata !{i32 786447, i32 0, metadata !"", i32 0, i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !7} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from A]
+!18 = metadata !{metadata !19}
+!19 = metadata !{i32 786468}                      ; [ DW_TAG_base_type ] [line 0, size 0, align 0, offset 0]