[llvm] 61671e2 - [DebugInfo] Fix faulty DIExpression::appendToStack assert (#85255)

[via llvm-commits]

Author: David Stenberg
Date: 2024-03-15T12:51:06+01:00
New Revision: 61671e2500771dfbf502acd86e2ef70cba847a39

URL: https://github.com/llvm/llvm-project/commit/61671e2500771dfbf502acd86e2ef70cba847a39
DIFF: https://github.com/llvm/llvm-project/commit/61671e2500771dfbf502acd86e2ef70cba847a39.diff

LOG: [DebugInfo] Fix faulty DIExpression::appendToStack assert (#85255)

The appendToStack() function asserts that no DW_OP_stack_value or
DW_OP_LLVM_fragment operations are present in the operations to be
appended. The function did that by iterating over all elements in the
array rather than just the operations, leading it to falsely asserting
on the following input produced by getExt(), since 159 (0x9f) is the
DWARF code for DW_OP_stack_value:

  {dwarf::DW_OP_LLVM_convert, 159, dwarf::DW_ATE_signed}

Fix this by using expr_op iterators.

Added: 
    

Modified: 
    llvm/lib/IR/DebugInfoMetadata.cpp
    llvm/unittests/IR/MetadataTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index 28f96653d815b5..f37add2120f13b 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -1880,11 +1880,12 @@ DIExpression *DIExpression::append(const DIExpression *Expr,
 DIExpression *DIExpression::appendToStack(const DIExpression *Expr,
                                           ArrayRef<uint64_t> Ops) {
   assert(Expr && !Ops.empty() && "Can't append ops to this expression");
-  assert(none_of(Ops,
-                 [](uint64_t Op) {
-                   return Op == dwarf::DW_OP_stack_value ||
-                          Op == dwarf::DW_OP_LLVM_fragment;
-                 }) &&
+  assert(std::none_of(expr_op_iterator(Ops.begin()),
+                      expr_op_iterator(Ops.end()),
+                      [](auto Op) {
+                        return Op.getOp() == dwarf::DW_OP_stack_value ||
+                               Op.getOp() == dwarf::DW_OP_LLVM_fragment;
+                      }) &&
          "Can't append this op");
 
   // Append a DW_OP_deref after Expr's current op list if it's non-empty and

diff  --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 767dd1a59d2b9e..ac27869b8c21ed 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -3560,6 +3560,27 @@ TEST_F(DIExpressionTest, foldConstant) {
 #undef EXPECT_FOLD_CONST
 }
 
+TEST_F(DIExpressionTest, appendToStackAssert) {
+  DIExpression *Expr = DIExpression::get(Context, {});
+
+  // Verify that the DW_OP_LLVM_convert operands, which have the same values as
+  // DW_OP_stack_value and DW_OP_LLVM_fragment, do not get interpreted as such
+  // operations. This previously triggered an assert.
+  uint64_t FromSize = dwarf::DW_OP_stack_value;
+  uint64_t ToSize = dwarf::DW_OP_LLVM_fragment;
+  uint64_t Ops[] = {
+      dwarf::DW_OP_LLVM_convert, FromSize, dwarf::DW_ATE_signed,
+      dwarf::DW_OP_LLVM_convert, ToSize,   dwarf::DW_ATE_signed,
+  };
+  Expr = DIExpression::appendToStack(Expr, Ops);
+
+  uint64_t Expected[] = {
+      dwarf::DW_OP_LLVM_convert, FromSize, dwarf::DW_ATE_signed,
+      dwarf::DW_OP_LLVM_convert, ToSize,   dwarf::DW_ATE_signed,
+      dwarf::DW_OP_stack_value};
+  EXPECT_EQ(Expr->getElements(), ArrayRef<uint64_t>(Expected));
+}
+
 typedef MetadataTest DIObjCPropertyTest;
 
 TEST_F(DIObjCPropertyTest, get) {