From 38385630adb072c65882f1a18a4e634dcba9ff46 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel@labath.sk>
Date: Fri, 28 Feb 2020 10:03:00 +0100
Subject: [PATCH] Use DWARFDataExtractor::getInitialLength in DWARFDebugAddr

Reviewers: ikudrin, jhenderson, probinson

Subscribers: hiraditya, dblaikie, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75532
---
 llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp        | 34 +++++-----------------
 .../X86/debug_addr_reserved_length.s               |  2 +-
 ...ebug_addr_too_small_for_extended_length_field.s |  2 +-
 .../X86/debug_addr_too_small_for_length_field.s    |  2 +-
 4 files changed, 10 insertions(+), 30 deletions(-)

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
index 273d316..e0f4a3b 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
@@ -44,34 +44,14 @@ Error DWARFDebugAddrTable::extractV5(const DWARFDataExtractor &Data,
                                      uint64_t *OffsetPtr, uint8_t CUAddrSize,
                                      std::function<void(Error)> WarnCallback) {
   Offset = *OffsetPtr;
-  // Check that we can read the unit length field.
-  if (!Data.isValidOffsetForDataOfSize(Offset, 4))
-    return createStringError(errc::invalid_argument,
-                             "section is not large enough to contain an "
-                             "address table length at offset 0x%" PRIx64,
-                             Offset);
-  Format = dwarf::DwarfFormat::DWARF32;
-  Length = Data.getU32(OffsetPtr);
-  if (Length == dwarf::DW_LENGTH_DWARF64) {
-    // Check that we can read the extended unit length field.
-    if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, 8)) {
-      invalidateLength();
-      return createStringError(
-          errc::invalid_argument,
-          "section is not large enough to contain an extended length field "
-          "of the address table at offset 0x%" PRIx64,
-          Offset);
-    }
-    Format = dwarf::DwarfFormat::DWARF64;
-    Length = Data.getU64(OffsetPtr);
-  } else if (Length >= dwarf::DW_LENGTH_lo_reserved) {
-    uint64_t DiagnosticLength = Length;
+  llvm::Error Err = Error::success();
+  std::tie(Length, Format) = Data.getInitialLength(OffsetPtr, &Err);
+  if (Err) {
     invalidateLength();
-    return createStringError(
-        errc::not_supported,
-        "address table at offset 0x%" PRIx64
-        " has unsupported reserved unit length of value 0x%" PRIx64,
-        Offset, DiagnosticLength);
+    return createStringError(errc::invalid_argument,
+                             "parsing address table at offset 0x%" PRIx64
+                             ": %s",
+                             Offset, toString(std::move(Err)).c_str());
   }
 
   if (!Data.isValidOffsetForDataOfSize(*OffsetPtr, Length)) {
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_reserved_length.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_reserved_length.s
index 5885780..125be83 100644
--- a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_reserved_length.s
+++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_reserved_length.s
@@ -2,7 +2,7 @@
 # RUN:   llvm-dwarfdump --debug-addr - 2>&1 | \
 # RUN:   FileCheck %s --implicit-check-not=error
 
-# CHECK: error: address table at offset 0x0 has unsupported reserved unit length of value 0xfffffff0
+# CHECK: error: parsing address table at offset 0x0: unsupported reserved unit length of value 0xfffffff0
 
 .section .debug_addr,"",@progbits
 .long 0xfffffff0
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_extended_length_field.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_extended_length_field.s
index 8c2cc11..8ac3cc5 100644
--- a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_extended_length_field.s
+++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_extended_length_field.s
@@ -4,7 +4,7 @@
 
 # CHECK: .debug_addr contents:
 # CHECK-NOT: {{.}}
-# ERR: section is not large enough to contain an extended length field of the address table at offset 0x0
+# ERR: parsing address table at offset 0x0: unexpected end of data at offset 0x4
 # ERR-NOT: {{.}}
 
 # too small section to contain an extended length field of a DWARF64 address table.
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_length_field.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_length_field.s
index dcec7da..1a51541 100644
--- a/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_length_field.s
+++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_addr_too_small_for_length_field.s
@@ -4,7 +4,7 @@
 
 # CHECK: .debug_addr contents:
 # CHECK-NOT: {{.}}
-# ERR: section is not large enough to contain an address table length at offset 0x0
+# ERR: parsing address table at offset 0x0: unexpected end of data at offset 0x0
 # ERR-NOT: {{.}}
 
 # too small section to contain length field
-- 
2.7.4