Skip to content

Commit

Permalink
Modify DWARFFormValue to remember the DWARFUnit that it was decoded w…
Browse files Browse the repository at this point in the history 
…ith.

Modifying DWARFFormValue to remember the DWARFUnit that it was encoded with can simplify the usage of instances of this class. Previously users would have to try and pass in the same DWARFUnit that was used to decode the form value and there was a possibility that a different DWARFUnit might be supplied to the functions that extract values (strings, CU relative references, addresses) and cause problems. This fixes this potential issue by storing the DWARFUnit inside the DWARFFormValue so that this mistake can't be made. Instances of DWARFFormValue are not stored permanently and are used as temporary values, so the increase in size of an instance of DWARFFormValue isn't a big deal. This makes decoding form values more bullet proof and is a change that will be used by future modifications.

https://reviews.llvm.org/D26052



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285594 91177308-0d34-0410-b5e6-96231b3b80d8
  • Loading branch information
Greg Clayton committed Oct 31, 2016
1 parent d3f04d3 commit 1a30f4b
Show file tree
Hide file tree
Showing 7 changed files with 59 additions and 56 deletions.
23 changes: 12 additions & 11 deletions include/llvm/DebugInfo/DWARF/DWARFFormValue.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,40 +49,41 @@ class DWARFFormValue {
const uint8_t* data;
};

dwarf::Form Form; // Form for this value.
dwarf::Form Form; // Form for this value.
ValueType Value; // Contains all data for the form.
const DWARFUnit *U; // Remember the DWARFUnit at extract time.

public:
DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F) {}
DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F), U(nullptr) {}
dwarf::Form getForm() const { return Form; }
bool isFormClass(FormClass FC) const;

void dump(raw_ostream &OS, const DWARFUnit *U) const;
const DWARFUnit *getUnit() const { return U; }
void dump(raw_ostream &OS) const;

/// \brief extracts a value in data at offset *offset_ptr.
///
/// The passed DWARFUnit is allowed to be nullptr, in which
/// case no relocation processing will be performed and some
/// kind of forms that depend on Unit information are disallowed.
/// \returns whether the extraction succeeded.
bool extractValue(DataExtractor data, uint32_t *offset_ptr,
const DWARFUnit *u);
bool extractValue(const DataExtractor &Data, uint32_t *OffsetPtr,
const DWARFUnit *U);
bool isInlinedCStr() const {
return Value.data != nullptr && Value.data == (const uint8_t*)Value.cstr;
}

/// getAsFoo functions below return the extracted value as Foo if only
/// DWARFFormValue has form class is suitable for representing Foo.
Optional<uint64_t> getAsReference(const DWARFUnit *U) const;
Optional<uint64_t> getAsReference() const;
Optional<uint64_t> getAsUnsignedConstant() const;
Optional<int64_t> getAsSignedConstant() const;
Optional<const char *> getAsCString(const DWARFUnit *U) const;
Optional<uint64_t> getAsAddress(const DWARFUnit *U) const;
Optional<const char *> getAsCString() const;
Optional<uint64_t> getAsAddress() const;
Optional<uint64_t> getAsSectionOffset() const;
Optional<ArrayRef<uint8_t>> getAsBlock() const;

bool skipValue(DataExtractor debug_info_data, uint32_t *offset_ptr,
const DWARFUnit *u) const;
const DWARFUnit *U) const;
static bool skipValue(dwarf::Form form, DataExtractor debug_info_data,
uint32_t *offset_ptr, const DWARFUnit *u);
static bool skipValue(dwarf::Form form, DataExtractor debug_info_data,
Expand All @@ -92,7 +93,7 @@ class DWARFFormValue {
static ArrayRef<uint8_t> getFixedFormSizes(uint8_t AddrSize,
uint16_t Version);
private:
void dumpString(raw_ostream &OS, const DWARFUnit *U) const;
void dumpString(raw_ostream &OS) const;
};

}
Expand Down
4 changes: 4 additions & 0 deletions include/llvm/DebugInfo/DWARF/DWARFUnit.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -195,6 +195,10 @@ class DWARFUnit {
return Abbrevs;
}
uint8_t getAddressByteSize() const { return AddrSize; }
uint8_t getRefAddrByteSize() const {
// FIXME: Support DWARF64.
return (Version == 2) ? AddrSize : 4;
}
uint64_t getBaseAddress() const { return BaseAddr; }

void setBaseAddress(uint64_t base_addr) {
Expand Down
2 changes: 1 addition & 1 deletion lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -120,7 +120,7 @@ void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
for (auto &Atom : AtomForms) {
OS << format("{Atom[%d]: ", i++);
if (Atom.extractValue(AccelSection, &DataOffset, nullptr))
Atom.dump(OS, nullptr);
Atom.dump(OS);
else
OS << "Error extracting the value";
OS << "} ";
Expand Down
10 changes: 5 additions & 5 deletions lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -158,13 +158,13 @@ void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
else if (attr == DW_AT_decl_line || attr == DW_AT_call_line)
OS << *formValue.getAsUnsignedConstant();
else
formValue.dump(OS, u);
formValue.dump(OS);

// We have dumped the attribute raw value. For some attributes
// having both the raw value and the pretty-printed value is
// interesting. These attributes are handled below.
if (attr == DW_AT_specification || attr == DW_AT_abstract_origin) {
Optional<uint64_t> Ref = formValue.getAsReference(u);
Optional<uint64_t> Ref = formValue.getAsReference();
if (Ref.hasValue()) {
uint32_t RefOffset = Ref.getValue();
DWARFDebugInfoEntryMinimal DIE;
Expand Down Expand Up @@ -264,7 +264,7 @@ const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
DWARFFormValue FormValue;
if (!getAttributeValue(U, Attr, FormValue))
return FailValue;
Optional<const char *> Result = FormValue.getAsCString(U);
Optional<const char *> Result = FormValue.getAsCString();
return Result.hasValue() ? Result.getValue() : FailValue;
}

Expand All @@ -274,7 +274,7 @@ uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsAddress(
DWARFFormValue FormValue;
if (!getAttributeValue(U, Attr, FormValue))
return FailValue;
Optional<uint64_t> Result = FormValue.getAsAddress(U);
Optional<uint64_t> Result = FormValue.getAsAddress();
return Result.hasValue() ? Result.getValue() : FailValue;
}

Expand All @@ -294,7 +294,7 @@ uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
DWARFFormValue FormValue;
if (!getAttributeValue(U, Attr, FormValue))
return FailValue;
Optional<uint64_t> Result = FormValue.getAsReference(U);
Optional<uint64_t> Result = FormValue.getAsReference();
return Result.hasValue() ? Result.getValue() : FailValue;
}

Expand Down
54 changes: 29 additions & 25 deletions lib/DebugInfo/DWARF/DWARFFormValue.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -133,8 +133,10 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
FC == FC_SectionOffset;
}

bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
bool DWARFFormValue::extractValue(const DataExtractor &data,
uint32_t *offset_ptr,
const DWARFUnit *cu) {
U = cu;
bool indirect = false;
bool is_block = false;
Value.data = nullptr;
Expand All @@ -145,14 +147,14 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
switch (Form) {
case DW_FORM_addr:
case DW_FORM_ref_addr: {
if (!cu)
if (!U)
return false;
uint16_t AddrSize =
(Form == DW_FORM_addr)
? cu->getAddressByteSize()
: getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
if (AI != cu->getRelocMap()->end()) {
? U->getAddressByteSize()
: U->getRefAddrByteSize();
RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
if (AI != U->getRelocMap()->end()) {
const std::pair<uint8_t, int64_t> &R = AI->second;
Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
} else
Expand Down Expand Up @@ -188,10 +190,10 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
case DW_FORM_data4:
case DW_FORM_ref4: {
Value.uval = data.getU32(offset_ptr);
if (!cu)
if (!U)
break;
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
if (AI != cu->getRelocMap()->end())
RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr-4);
if (AI != U->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
Expand Down Expand Up @@ -219,11 +221,11 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
case DW_FORM_GNU_strp_alt: {
// FIXME: This is 64-bit for DWARF64.
Value.uval = data.getU32(offset_ptr);
if (!cu)
if (!U)
break;
RelocAddrMap::const_iterator AI =
cu->getRelocMap()->find(*offset_ptr - 4);
if (AI != cu->getRelocMap()->end())
U->getRelocMap()->find(*offset_ptr - 4);
if (AI != U->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
Expand Down Expand Up @@ -256,8 +258,8 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,

bool
DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
const DWARFUnit *cu) const {
return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
const DWARFUnit *U) const {
return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, U);
}

bool
Expand Down Expand Up @@ -371,7 +373,7 @@ DWARFFormValue::skipValue(dwarf::Form form, DataExtractor debug_info_data,
}

void
DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
DWARFFormValue::dump(raw_ostream &OS) const {
uint64_t uvalue = Value.uval;
bool cu_relative_offset = false;

Expand All @@ -380,7 +382,9 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
case DW_FORM_GNU_addr_index: {
OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
uint64_t Address;
if (cu->getAddrOffsetSectionItem(uvalue, Address))
if (U == nullptr)
OS << "<invalid dwarf unit>";
else if (U->getAddrOffsetSectionItem(uvalue, Address))
OS << format("0x%016" PRIx64, Address);
else
OS << "<no .debug_addr section>";
Expand Down Expand Up @@ -431,17 +435,17 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
case DW_FORM_udata: OS << Value.uval; break;
case DW_FORM_strp: {
OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
dumpString(OS, cu);
dumpString(OS);
break;
}
case DW_FORM_GNU_str_index: {
OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
dumpString(OS, cu);
dumpString(OS);
break;
}
case DW_FORM_GNU_strp_alt: {
OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue);
dumpString(OS, cu);
dumpString(OS);
break;
}
case DW_FORM_ref_addr:
Expand Down Expand Up @@ -490,13 +494,13 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
if (cu_relative_offset) {
OS << " => {";
WithColor(OS, syntax::Address).get()
<< format("0x%8.8" PRIx64, uvalue + (cu ? cu->getOffset() : 0));
<< format("0x%8.8" PRIx64, uvalue + (U ? U->getOffset() : 0));
OS << "}";
}
}

void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
Optional<const char *> DbgStr = getAsCString(U);
void DWARFFormValue::dumpString(raw_ostream &OS) const {
Optional<const char *> DbgStr = getAsCString();
if (DbgStr.hasValue()) {
raw_ostream &COS = WithColor(OS, syntax::String);
COS << '"';
Expand All @@ -505,7 +509,7 @@ void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
}
}

Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
Optional<const char *> DWARFFormValue::getAsCString() const {
if (!isFormClass(FC_String))
return None;
if (Form == DW_FORM_string)
Expand All @@ -526,7 +530,7 @@ Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
return None;
}

Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
Optional<uint64_t> DWARFFormValue::getAsAddress() const {
if (!isFormClass(FC_Address))
return None;
if (Form == DW_FORM_GNU_addr_index) {
Expand All @@ -539,7 +543,7 @@ Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
return Value.uval;
}

Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
Optional<uint64_t> DWARFFormValue::getAsReference() const {
if (!isFormClass(FC_Reference))
return None;
switch (Form) {
Expand Down
2 changes: 1 addition & 1 deletion lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ void DWARFTypeUnit::dump(raw_ostream &OS, bool SummarizeTypes) {
DWARFFormValue NameVal;
const char *Name = "";
if (TD->getAttributeValue(this, llvm::dwarf::DW_AT_name, NameVal))
if (auto ON = NameVal.getAsCString(this))
if (auto ON = NameVal.getAsCString())
Name = *ON;

if (SummarizeTypes) {
Expand Down
20 changes: 7 additions & 13 deletions tools/dsymutil/DwarfLinker.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1487,7 +1487,7 @@ static const DWARFDebugInfoEntryMinimal *resolveDIEReference(
const DWARFFormValue &RefValue, const DWARFUnit &Unit,
const DWARFDebugInfoEntryMinimal &DIE, CompileUnit *&RefCU) {
assert(RefValue.isFormClass(DWARFFormValue::FC_Reference));
uint64_t RefOffset = *RefValue.getAsReference(&Unit);
uint64_t RefOffset = *RefValue.getAsReference();

if ((RefCU = getUnitForOffset(Units, RefOffset)))
if (const auto *RefDie = RefCU->getOrigUnit().getDIEForOffset(RefOffset))
Expand Down Expand Up @@ -1838,12 +1838,6 @@ static bool dieNeedsChildrenToBeMeaningful(uint32_t Tag) {
llvm_unreachable("Invalid Tag");
}

static unsigned getRefAddrSize(const DWARFUnit &U) {
if (U.getVersion() == 2)
return U.getAddressByteSize();
return 4;
}

void DwarfLinker::startDebugObject(DWARFContext &Dwarf, DebugMapObject &Obj) {
Units.reserve(Dwarf.getNumCompileUnits());
// Iterate over the debug map entries and put all the ones that are
Expand Down Expand Up @@ -2159,7 +2153,7 @@ unsigned DwarfLinker::shouldKeepSubprogramDIE(

uint64_t HighPc;
if (HighPcValue.isFormClass(DWARFFormValue::FC_Address)) {
HighPc = *HighPcValue.getAsAddress(&OrigUnit);
HighPc = *HighPcValue.getAsAddress();
} else {
assert(HighPcValue.isFormClass(DWARFFormValue::FC_Constant));
HighPc = LowPc + *HighPcValue.getAsUnsignedConstant();
Expand Down Expand Up @@ -2357,7 +2351,7 @@ unsigned DwarfLinker::DIECloner::cloneStringAttribute(DIE &Die,
const DWARFFormValue &Val,
const DWARFUnit &U) {
// Switch everything to out of line strings.
const char *String = *Val.getAsCString(&U);
const char *String = *Val.getAsCString();
unsigned Offset = Linker.StringPool.getStringOffset(String);
Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_strp,
DIEInteger(Offset));
Expand All @@ -2369,7 +2363,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
AttributeSpec AttrSpec, unsigned AttrSize, const DWARFFormValue &Val,
CompileUnit &Unit) {
const DWARFUnit &U = Unit.getOrigUnit();
uint32_t Ref = *Val.getAsReference(&U);
uint32_t Ref = *Val.getAsReference();
DIE *NewRefDie = nullptr;
CompileUnit *RefUnit = nullptr;
DeclContext *Ctxt = nullptr;
Expand All @@ -2392,7 +2386,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
DIEInteger Attr(Ctxt->getCanonicalDIEOffset());
Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
dwarf::DW_FORM_ref_addr, Attr);
return getRefAddrSize(U);
return U.getRefAddrByteSize();
}
}

Expand Down Expand Up @@ -2427,7 +2421,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
dwarf::DW_FORM_ref_addr, DIEInteger(Attr)));
}
return getRefAddrSize(U);
return U.getRefAddrByteSize();
}

Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
Expand Down Expand Up @@ -2481,7 +2475,7 @@ unsigned DwarfLinker::DIECloner::cloneBlockAttribute(DIE &Die,
unsigned DwarfLinker::DIECloner::cloneAddressAttribute(
DIE &Die, AttributeSpec AttrSpec, const DWARFFormValue &Val,
const CompileUnit &Unit, AttributesInfo &Info) {
uint64_t Addr = *Val.getAsAddress(&Unit.getOrigUnit());
uint64_t Addr = *Val.getAsAddress();
if (AttrSpec.Attr == dwarf::DW_AT_low_pc) {
if (Die.getTag() == dwarf::DW_TAG_inlined_subroutine ||
Die.getTag() == dwarf::DW_TAG_lexical_block)
Expand Down

0 comments on commit 1a30f4b

Please sign in to comment.