[llvm] c6ed1fc - [DebugInfo] Dump raw data in a case of decoding error of an expression.

[Igor Kudrin via llvm-commits]

Author: Igor Kudrin
Date: 2020-05-09T10:04:22+07:00
New Revision: c6ed1fcf245b858731b242fcae253260b3e850a5

URL: https://github.com/llvm/llvm-project/commit/c6ed1fcf245b858731b242fcae253260b3e850a5
DIFF: https://github.com/llvm/llvm-project/commit/c6ed1fcf245b858731b242fcae253260b3e850a5.diff

LOG: [DebugInfo] Dump raw data in a case of decoding error of an expression.

It looks like that was an initial intention, but some code paths in
`DWARFExpression::Operation::extract()` did not initialize `EndOffset`
properly.

Differential Revision: https://reviews.llvm.org/D79622

Added: 
    

Modified: 
    llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
    llvm/test/DebugInfo/X86/DW_OP_call_ref_unexpected.s
    llvm/test/tools/llvm-dwarfdump/X86/verify_broken_exprloc.s

Removed: 
    


################################################################################
diff  --git a/llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp b/llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
index 605236bc1833..28b24b3baaab 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp
@@ -120,13 +120,12 @@ static DWARFExpression::Operation::Description getOpDesc(unsigned OpCode) {
 bool DWARFExpression::Operation::extract(DataExtractor Data,
                                          uint8_t AddressSize, uint64_t Offset,
                                          Optional<DwarfFormat> Format) {
+  EndOffset = Offset;
   Opcode = Data.getU8(&Offset);
 
   Desc = getOpDesc(Opcode);
-  if (Desc.Version == Operation::DwarfNA) {
-    EndOffset = Offset;
+  if (Desc.Version == Operation::DwarfNA)
     return false;
-  }
 
   for (unsigned Operand = 0; Operand < 2; ++Operand) {
     unsigned Size = Desc.Op[Operand];
@@ -135,7 +134,6 @@ bool DWARFExpression::Operation::extract(DataExtractor Data,
     if (Size == Operation::SizeNA)
       break;
 
-    EndOffset = Offset;
     switch (Size & ~Operation::SignBit) {
     case Operation::Size1:
       Operands[Operand] = Data.getU8(&Offset);

diff  --git a/llvm/test/DebugInfo/X86/DW_OP_call_ref_unexpected.s b/llvm/test/DebugInfo/X86/DW_OP_call_ref_unexpected.s
index 036e044270b6..4a3ac03f797b 100644
--- a/llvm/test/DebugInfo/X86/DW_OP_call_ref_unexpected.s
+++ b/llvm/test/DebugInfo/X86/DW_OP_call_ref_unexpected.s
@@ -6,7 +6,7 @@
 
 # CHECK: .debug_loc contents:
 # CHECK-NEXT: 0x00000000:
-# CHECK-NEXT:   (0x0000000000000000, 0x0000000000000015): <decoding error>
+# CHECK-NEXT:   (0x0000000000000000, 0x0000000000000015): <decoding error> 9a ff 00 00 00
 
     .section .debug_loc, "", @progbits
     .quad 0                         # Beginning address offset

diff  --git a/llvm/test/tools/llvm-dwarfdump/X86/verify_broken_exprloc.s b/llvm/test/tools/llvm-dwarfdump/X86/verify_broken_exprloc.s
index 33a9aedbbb4f..21a2ec530d7c 100644
--- a/llvm/test/tools/llvm-dwarfdump/X86/verify_broken_exprloc.s
+++ b/llvm/test/tools/llvm-dwarfdump/X86/verify_broken_exprloc.s
@@ -3,13 +3,13 @@
 ## Check we don't crash when parsing invalid expression opcode.
 # RUN: llvm-dwarfdump %t | FileCheck %s
 # CHECK:      DW_TAG_GNU_call_site_parameter
-# CHECK-NEXT:  DW_AT_location  (<decoding error>)
+# CHECK-NEXT:  DW_AT_location  (<decoding error> ff)
 
 ## Check verifier reports an error.
 # RUN: not llvm-dwarfdump -verify %t 2>&1 | FileCheck %s --check-prefix=VERIFY
 # VERIFY:      DIE contains invalid DWARF expression:
 # VERIFY:      DW_TAG_GNU_call_site_parameter
-# VERIFY-NEXT:   DW_AT_location    (<decoding error>)
+# VERIFY-NEXT:   DW_AT_location    (<decoding error> ff)
 
 .section  .debug_info,"", at progbits
   .long  0x12