Use the 'count' attribute to calculate the upper bound of an array.

The count attribute is more accurate with regards to the size of an array. It
also obviates the upper bound attribute in the subrange. We can also better
handle an unbound array by setting the count to -1 instead of the lower bound to
1 and upper bound to 0.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169311 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index a4182afd1e467d3090e2f4bf0062abf121998438..f3468f29c1b370afe32f7961f4620434ccdecfac 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1473,25 +1473,19 @@ llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
 
 llvm::DIType CGDebugInfo::CreateType(const VectorType *Ty, llvm::DIFile Unit) {
   llvm::DIType ElementTy = getOrCreateType(Ty->getElementType(), Unit);
-  int64_t NumElems = Ty->getNumElements();
-  int64_t LowerBound = 0;
-  int64_t Count = NumElems;
-  if (NumElems == 0)
+  int64_t Count = Ty->getNumElements();
+  if (Count == 0)
     // If number of elements are not known then this is an unbounded array.
-    // Use Low = 1, Hi = 0 to express such arrays.
-    LowerBound = 1;
-  else
-    --NumElems;
+    // Use Count == -1 to express such arrays.
+    Count = -1;
 
-  llvm::Value *Subscript = DBuilder.getOrCreateSubrange(LowerBound, NumElems,
-                                                        Count);
+  llvm::Value *Subscript = DBuilder.getOrCreateSubrange(0, Count);
   llvm::DIArray SubscriptArray = DBuilder.getOrCreateArray(Subscript);
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
   uint64_t Align = CGM.getContext().getTypeAlign(Ty);
 
-  return
-    DBuilder.createVectorType(Size, Align, ElementTy, SubscriptArray);
+  return DBuilder.createVectorType(Size, Align, ElementTy, SubscriptArray);
 }
 
 llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
@@ -1532,23 +1526,12 @@ llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
     //   struct foo {
     //     int x[0];
     //   };
-    int64_t UpperBound = 0;
-    int64_t LowerBound = 0;
-    int64_t Count = -1;
-    if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Ty)) {
+    int64_t Count = -1;         // Count == -1 is an unbounded array.
+    if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Ty))
       Count = CAT->getSize().getZExtValue();
-      if (Count)
-        UpperBound = Count - 1;
-    } else {
-      // This is an unbounded array. Use Low = 1, Hi = 0 to express such 
-      // arrays.
-      LowerBound = 1;
-    }
     
     // FIXME: Verify this is right for VLAs.
-    Subscripts.push_back(DBuilder.getOrCreateSubrange(LowerBound,
-                                                      UpperBound,
-                                                      Count));
+    Subscripts.push_back(DBuilder.getOrCreateSubrange(0, Count));
     EltTy = Ty->getElementType();
   }
 

diff --git a/test/CodeGenCXX/debug-info-flex-member.cpp b/test/CodeGenCXX/debug-info-flex-member.cpp
index d38634cacf0937753bf1a3ea637a7808fb0e97ab..11329aa1e2b95a95cb2b4d91a712c6f2f1e4223d 100644 (file)
--- a/test/CodeGenCXX/debug-info-flex-member.cpp
+++ b/test/CodeGenCXX/debug-info-flex-member.cpp
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -emit-llvm -g -triple x86_64-apple-darwin %s -o - | FileCheck %s
 
-// CHECK: metadata !{i32 {{.*}}, i64 1, i64 0, i64 -1}        ; [ DW_TAG_subrange_type ]
+// CHECK: metadata !{i32 {{.*}}, i64 0, i64 -1}        ; [ DW_TAG_subrange_type ]
 
 struct StructName {
   int member[];

diff --git a/test/CodeGenCXX/debug-info-zero-length-arrays.cpp b/test/CodeGenCXX/debug-info-zero-length-arrays.cpp
index a7944c09c62b708a4fc5a3ef889b90734346bdf7..37e50cbe128efcb0d294bf4389f3e1782530bbfb 100644 (file)
--- a/test/CodeGenCXX/debug-info-zero-length-arrays.cpp
+++ b/test/CodeGenCXX/debug-info-zero-length-arrays.cpp
@@ -10,4 +10,4 @@ A a;
 // CHECK: [[ARRAY_TYPE]] = metadata !{i32 {{.*}}, null, metadata !"", null, i32 0, i64 0, i64 32, i32 0, i32 0, metadata [[BASE_TYPE:.*]], metadata [[ELEM_TYPE:.*]], i32 0, i32 0} ; [ DW_TAG_array_type ]
 // CHECK: [[BASE_TYPE]] = metadata !{i32 {{.*}}, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
 // CHECK: [[ELEM_TYPE]] = metadata !{metadata [[SUBRANGE:.*]]}
-// CHECK: [[SUBRANGE]] = metadata !{i32 786465, i64 1, i64 0, i64 -1} ; [ DW_TAG_subrange_type ] [1, 0]
+// CHECK: [[SUBRANGE]] = metadata !{i32 786465, i64 0, i64 -1} ; [ DW_TAG_subrange_type ] [unbound]