[llvm] ca05601 - [DebugInfo] Don't error for zero-length arange entries
James Henderson via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 10 06:58:08 PDT 2020
Author: James Henderson
Date: 2020-08-10T14:57:52+01:00
New Revision: ca05601cd2a1b75050538ef2e78de205f1300692
URL: https://github.com/llvm/llvm-project/commit/ca05601cd2a1b75050538ef2e78de205f1300692
DIFF: https://github.com/llvm/llvm-project/commit/ca05601cd2a1b75050538ef2e78de205f1300692.diff
LOG: [DebugInfo] Don't error for zero-length arange entries
Although the DWARF specification states that .debug_aranges entries
can't have length zero, these can occur in the wild. There's no
particular reason to enforce this part of the spec, since functionally
they have no impact. The patch removes the error and introduces a new
warning for premature terminator entries which does not stop parsing.
This is a relanding of cb3a598c87db, adding the missing obj2yaml part
that was needed.
Fixes https://bugs.llvm.org/show_bug.cgi?id=46805. See also
https://reviews.llvm.org/D71932 which originally introduced the error.
Reviewed by: ikudrin, dblaikie, Higuoxing
Differential Revision: https://reviews.llvm.org/D85313
Added:
Modified:
llvm/include/llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h
llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
llvm/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
llvm/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
llvm/test/tools/obj2yaml/ELF/DWARF/debug-aranges.yaml
llvm/tools/obj2yaml/dwarf2yaml.cpp
llvm/unittests/DebugInfo/DWARF/DWARFDebugArangeSetTest.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h
index 0681a2e33a50..3d5852ee1518 100644
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h
@@ -60,7 +60,8 @@ class DWARFDebugArangeSet {
DWARFDebugArangeSet() { clear(); }
void clear();
- Error extract(DWARFDataExtractor data, uint64_t *offset_ptr);
+ Error extract(DWARFDataExtractor data, uint64_t *offset_ptr,
+ function_ref<void(Error)> WarningHandler);
void dump(raw_ostream &OS) const;
uint64_t getCompileUnitDIEOffset() const { return HeaderData.CuOffset; }
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index bf6219497770..3bcde8fafb1f 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -502,7 +502,8 @@ void DWARFContext::dump(
0);
DWARFDebugArangeSet set;
while (arangesData.isValidOffset(offset)) {
- if (Error E = set.extract(arangesData, &offset)) {
+ if (Error E =
+ set.extract(arangesData, &offset, DumpOpts.WarningHandler)) {
RecoverableErrorHandler(std::move(E));
break;
}
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
index 608fc0388af0..381dd476cd58 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
@@ -32,7 +32,8 @@ void DWARFDebugArangeSet::clear() {
}
Error DWARFDebugArangeSet::extract(DWARFDataExtractor data,
- uint64_t *offset_ptr) {
+ uint64_t *offset_ptr,
+ function_ref<void(Error)> WarningHandler) {
assert(data.isValidOffset(*offset_ptr));
ArangeDescriptors.clear();
Offset = *offset_ptr;
@@ -132,19 +133,20 @@ Error DWARFDebugArangeSet::extract(DWARFDataExtractor data,
uint64_t end_offset = Offset + full_length;
while (*offset_ptr < end_offset) {
+ uint64_t EntryOffset = *offset_ptr;
arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
- if (arangeDescriptor.Length == 0) {
- // Each set of tuples is terminated by a 0 for the address and 0
- // for the length.
- if (arangeDescriptor.Address == 0 && *offset_ptr == end_offset)
+ // Each set of tuples is terminated by a 0 for the address and 0
+ // for the length.
+ if (arangeDescriptor.Length == 0 && arangeDescriptor.Address == 0) {
+ if (*offset_ptr == end_offset)
return ErrorSuccess();
- return createStringError(
+ WarningHandler(createStringError(
errc::invalid_argument,
"address range table at offset 0x%" PRIx64
- " has an invalid tuple (length = 0) at offset 0x%" PRIx64,
- Offset, *offset_ptr - tuple_size);
+ " has a premature terminator entry at offset 0x%" PRIx64,
+ Offset, EntryOffset));
}
ArangeDescriptors.push_back(arangeDescriptor);
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
index e8ed63075055..e0db469752cd 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
@@ -28,7 +28,8 @@ void DWARFDebugAranges::extract(
DWARFDebugArangeSet Set;
while (DebugArangesData.isValidOffset(Offset)) {
- if (Error E = Set.extract(DebugArangesData, &Offset)) {
+ if (Error E =
+ Set.extract(DebugArangesData, &Offset, RecoverableErrorHandler)) {
RecoverableErrorHandler(std::move(E));
return;
}
diff --git a/llvm/test/tools/obj2yaml/ELF/DWARF/debug-aranges.yaml b/llvm/test/tools/obj2yaml/ELF/DWARF/debug-aranges.yaml
index 95abc4e03d33..92d3514aee9a 100644
--- a/llvm/test/tools/obj2yaml/ELF/DWARF/debug-aranges.yaml
+++ b/llvm/test/tools/obj2yaml/ELF/DWARF/debug-aranges.yaml
@@ -4,16 +4,24 @@
## The .debug_aranges should be written to the 'DWARF' entry and the 'Sections' entry should remain empty.
# RUN: yaml2obj --docnum=1 -DBITS=32 -DENDIAN=LSB %s | obj2yaml | \
-# RUN: FileCheck -DLENGTH1=24 -DLENGTH2=24 -DADDRSIZE=0x04 %s --check-prefix=BASIC --implicit-check-not=Sections
+# RUN: FileCheck %s --check-prefix=BASIC --implicit-check-not=Sections \
+# RUN: -DLENGTH1=24 -DLENGTH2=24 -DADDRSIZE=0x04 \
+# RUN: -DVARADDR=0x0000000000001234 -DVARLEN=0x0000000000005678
# RUN: yaml2obj --docnum=1 -DBITS=32 -DENDIAN=MSB %s | obj2yaml | \
-# RUN: FileCheck -DLENGTH1=24 -DLENGTH2=24 -DADDRSIZE=0x04 %s --check-prefix=BASIC --implicit-check-not=Sections
+# RUN: FileCheck %s --check-prefix=BASIC --implicit-check-not=Sections \
+# RUN: -DLENGTH1=24 -DLENGTH2=24 -DADDRSIZE=0x04 \
+# RUN: -DVARADDR=0x0000000000001234 -DVARLEN=0x0000000000005678
# RUN: yaml2obj --docnum=1 -DBITS=64 -DENDIAN=LSB %s | obj2yaml | \
-# RUN: FileCheck -DLENGTH1=3C -DLENGTH2=44 -DADDRSIZE=0x08 %s --check-prefix=BASIC --implicit-check-not=Sections
+# RUN: FileCheck %s --check-prefix=BASIC --implicit-check-not=Sections \
+# RUN: -DLENGTH1=3C -DLENGTH2=44 -DADDRSIZE=0x08 \
+# RUN: -DVARADDR=0x0000000000001234 -DVARLEN=0x0000000000005678
# RUN: yaml2obj --docnum=1 -DBITS=64 -DENDIAN=MSB %s | obj2yaml | \
-# RUN: FileCheck -DLENGTH1=3C -DLENGTH2=44 -DADDRSIZE=0x08 %s --check-prefix=BASIC --implicit-check-not=Sections
+# RUN: FileCheck %s --check-prefix=BASIC --implicit-check-not=Sections \
+# RUN: -DLENGTH1=3C -DLENGTH2=44 -DADDRSIZE=0x08 \
+# RUN: -DVARADDR=0x0000000000001234 -DVARLEN=0x0000000000005678
# BASIC: DWARF:
# BASIC-NEXT: debug_aranges:
@@ -32,8 +40,8 @@
# BASIC-NEXT: CuOffset: 0x1234567890ABCDEF
# BASIC-NEXT: AddressSize: [[ADDRSIZE]]
# BASIC-NEXT: Descriptors:
-# BASIC-NEXT: - Address: 0x0000000000001234
-# BASIC-NEXT: Length: 0x0000000000005678
+# BASIC-NEXT: - Address: [[VARADDR]]
+# BASIC-NEXT: Length: [[VARLEN]]
# BASIC-NEXT: - Address: 0x0000000000001234
# BASIC-NEXT: Length: 0x0000000000005678
# BASIC-NEXT: ...
@@ -57,8 +65,8 @@ DWARF:
Version: 2
CuOffset: 0x1234567890abcdef
Descriptors:
- - Address: 0x1234
- Length: 0x5678
+ - Address: [[ADDR=0x1234]]
+ Length: [[LENGTH=0x5678]]
- Address: 0x1234
Length: 0x5678
@@ -187,3 +195,11 @@ FileHeader:
Machine: EM_X86_64
DWARF:
debug_aranges: []
+
+## f) Show that dumping a table with a premature terminator entry still uses the
+## DWARF tag.
+
+# RUN: yaml2obj --docnum=1 %s -DADDR=0 -DLENGTH=0 -DBITS=64 -DENDIAN=LSB | obj2yaml | \
+# RUN: FileCheck %s --check-prefix=BASIC --implicit-check-not=Sections \
+# RUN: -DLENGTH1=3C -DLENGTH2=44 -DADDRSIZE=0x08 \
+# RUN: -DVARADDR=0x0000000000000000 -DVARLEN=0x0000000000000000
diff --git a/llvm/tools/obj2yaml/dwarf2yaml.cpp b/llvm/tools/obj2yaml/dwarf2yaml.cpp
index d4e48927d06b..4e8677184648 100644
--- a/llvm/tools/obj2yaml/dwarf2yaml.cpp
+++ b/llvm/tools/obj2yaml/dwarf2yaml.cpp
@@ -65,8 +65,14 @@ Error dumpDebugARanges(DWARFContext &DCtx, DWARFYAML::Data &Y) {
uint64_t Offset = 0;
DWARFDebugArangeSet Set;
std::vector<DWARFYAML::ARange> DebugAranges;
+
+ // We ignore any errors that don't prevent parsing the section, since we can
+ // still represent such sections. These errors are recorded via the
+ // WarningHandler parameter of Set.extract().
+ auto DiscardError = [](Error Err) { consumeError(std::move(Err)); };
+
while (ArangesData.isValidOffset(Offset)) {
- if (Error E = Set.extract(ArangesData, &Offset))
+ if (Error E = Set.extract(ArangesData, &Offset, DiscardError))
return E;
DWARFYAML::ARange Range;
Range.Format = Set.getHeader().Format;
diff --git a/llvm/unittests/DebugInfo/DWARF/DWARFDebugArangeSetTest.cpp b/llvm/unittests/DebugInfo/DWARF/DWARFDebugArangeSetTest.cpp
index 4ec9c5d1c0be..face8ec024fa 100644
--- a/llvm/unittests/DebugInfo/DWARF/DWARFDebugArangeSetTest.cpp
+++ b/llvm/unittests/DebugInfo/DWARF/DWARFDebugArangeSetTest.cpp
@@ -7,12 +7,23 @@
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
+#include "llvm/Testing/Support/Error.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
+struct WarningHandler {
+ ~WarningHandler() { EXPECT_THAT_ERROR(std::move(Err), Succeeded()); }
+
+ void operator()(Error E) { Err = joinErrors(std::move(Err), std::move(E)); }
+
+ Error getWarning() { return std::move(Err); }
+
+ Error Err = Error::success();
+};
+
template <size_t SecSize>
void ExpectExtractError(const char (&SecDataRaw)[SecSize],
const char *ErrorMessage) {
@@ -21,7 +32,8 @@ void ExpectExtractError(const char (&SecDataRaw)[SecSize],
/* AddressSize = */ 4);
DWARFDebugArangeSet Set;
uint64_t Offset = 0;
- Error E = Set.extract(Extractor, &Offset);
+ WarningHandler Warnings;
+ Error E = Set.extract(Extractor, &Offset, Warnings);
ASSERT_TRUE(E.operator bool());
EXPECT_STREQ(ErrorMessage, toString(std::move(E)).c_str());
}
@@ -166,9 +178,9 @@ TEST(DWARFDebugArangeSet, UnevenLength) {
"of the tuple size");
}
-TEST(DWARFDebugArangeSet, ZeroLengthEntry) {
+TEST(DWARFDebugArangeSet, ZeroAddressEntry) {
static const char DebugArangesSecRaw[] =
- "\x24\x00\x00\x00" // Length
+ "\x1c\x00\x00\x00" // Length
"\x02\x00" // Version
"\x00\x00\x00\x00" // Debug Info Offset
"\x04" // Address Size
@@ -176,14 +188,84 @@ TEST(DWARFDebugArangeSet, ZeroLengthEntry) {
"\x00\x00\x00\x00" // Padding
"\x00\x00\x00\x00" // Entry1: Address
"\x01\x00\x00\x00" // Length
+ "\x00\x00\x00\x00" // Termination tuple
+ "\x00\x00\x00\x00";
+ DWARFDataExtractor Extractor(
+ StringRef(DebugArangesSecRaw, sizeof(DebugArangesSecRaw) - 1),
+ /*IsLittleEndian=*/true,
+ /*AddressSize=*/4);
+ DWARFDebugArangeSet Set;
+ uint64_t Offset = 0;
+ ASSERT_THAT_ERROR(Set.extract(Extractor, &Offset, WarningHandler()),
+ Succeeded());
+ auto Range = Set.descriptors();
+ auto Iter = Range.begin();
+ ASSERT_EQ(std::distance(Iter, Range.end()), 1u);
+ EXPECT_EQ(Iter->Address, 0u);
+ EXPECT_EQ(Iter->Length, 1u);
+}
+
+TEST(DWARFDebugArangeSet, ZeroLengthEntry) {
+ static const char DebugArangesSecRaw[] =
+ "\x1c\x00\x00\x00" // Length
+ "\x02\x00" // Version
+ "\x00\x00\x00\x00" // Debug Info Offset
+ "\x04" // Address Size
+ "\x00" // Segment Selector Size
+ "\x00\x00\x00\x00" // Padding
+ "\x01\x00\x00\x00" // Entry1: Address
+ "\x00\x00\x00\x00" // Length
+ "\x00\x00\x00\x00" // Termination tuple
+ "\x00\x00\x00\x00";
+ DWARFDataExtractor Extractor(
+ StringRef(DebugArangesSecRaw, sizeof(DebugArangesSecRaw) - 1),
+ /*IsLittleEndian=*/true,
+ /*AddressSize=*/4);
+ DWARFDebugArangeSet Set;
+ uint64_t Offset = 0;
+ ASSERT_THAT_ERROR(Set.extract(Extractor, &Offset, WarningHandler()),
+ Succeeded());
+ auto Range = Set.descriptors();
+ auto Iter = Range.begin();
+ ASSERT_EQ(std::distance(Iter, Range.end()), 1u);
+ EXPECT_EQ(Iter->Address, 1u);
+ EXPECT_EQ(Iter->Length, 0u);
+}
+
+TEST(DWARFDebugArangesSet, PrematureTerminator) {
+ static const char DebugArangesSecRaw[] =
+ "\x24\x00\x00\x00" // Length
+ "\x02\x00" // Version
+ "\x00\x00\x00\x00" // Debug Info Offset
+ "\x04" // Address Size
+ "\x00" // Segment Selector Size
+ "\x00\x00\x00\x00" // Padding
+ "\x00\x00\x00\x00" // Entry1: Premature
+ "\x00\x00\x00\x00" // terminator
"\x01\x00\x00\x00" // Entry2: Address
- "\x00\x00\x00\x00" // Length (invalid)
+ "\x01\x00\x00\x00" // Length
"\x00\x00\x00\x00" // Termination tuple
"\x00\x00\x00\x00";
- ExpectExtractError(
- DebugArangesSecRaw,
- "address range table at offset 0x0 has an invalid tuple (length = 0) "
- "at offset 0x18");
+ DWARFDataExtractor Extractor(
+ StringRef(DebugArangesSecRaw, sizeof(DebugArangesSecRaw) - 1),
+ /*IsLittleEndian=*/true,
+ /*AddressSize=*/4);
+ DWARFDebugArangeSet Set;
+ uint64_t Offset = 0;
+ WarningHandler Warnings;
+ ASSERT_THAT_ERROR(Set.extract(Extractor, &Offset, Warnings), Succeeded());
+ auto Range = Set.descriptors();
+ auto Iter = Range.begin();
+ ASSERT_EQ(std::distance(Iter, Range.end()), 2u);
+ EXPECT_EQ(Iter->Address, 0u);
+ EXPECT_EQ(Iter->Length, 0u);
+ ++Iter;
+ EXPECT_EQ(Iter->Address, 1u);
+ EXPECT_EQ(Iter->Length, 1u);
+ EXPECT_THAT_ERROR(
+ Warnings.getWarning(),
+ FailedWithMessage("address range table at offset 0x0 has a premature "
+ "terminator entry at offset 0x10"));
}
} // end anonymous namespace
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