//===- DWARFFormValue.h -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H
#define LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/Support/DataExtractor.h"
#include <cstdint>
namespace llvm {
class DWARFContext;
class DWARFObject;
class DWARFDataExtractor;
class DWARFUnit;
class raw_ostream;
class DWARFFormValue {
public:
enum FormClass {
FC_Unknown,
FC_Address,
FC_Block,
FC_Constant,
FC_String,
FC_Flag,
FC_Reference,
FC_Indirect,
FC_SectionOffset,
FC_Exprloc
};
private:
struct ValueType {
ValueType() { uval = 0; }
ValueType(int64_t V) : sval(V) {}
ValueType(uint64_t V) : uval(V) {}
ValueType(const char *V) : cstr(V) {}
union {
uint64_t uval;
int64_t sval;
const char *cstr;
};
const uint8_t *data = nullptr;
uint64_t SectionIndex; /// Section index for reference forms.
};
dwarf::Form Form; /// Form for this value.
dwarf::DwarfFormat Format =
dwarf::DWARF32; /// Remember the DWARF format at extract time.
ValueType Value; /// Contains all data for the form.
const DWARFUnit *U = nullptr; /// Remember the DWARFUnit at extract time.
const DWARFContext *C = nullptr; /// Context for extract time.
DWARFFormValue(dwarf::Form F, ValueType V) : Form(F), Value(V) {}
public:
DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F) {}
static DWARFFormValue createFromSValue(dwarf::Form F, int64_t V);
static DWARFFormValue createFromUValue(dwarf::Form F, uint64_t V);
static DWARFFormValue createFromPValue(dwarf::Form F, const char *V);
static DWARFFormValue createFromBlockValue(dwarf::Form F,
ArrayRef<uint8_t> D);
static DWARFFormValue createFromUnit(dwarf::Form F, const DWARFUnit *Unit,
uint64_t *OffsetPtr);
dwarf::Form getForm() const { return Form; }
uint64_t getRawUValue() const { return Value.uval; }
bool isFormClass(FormClass FC) const;
const DWARFUnit *getUnit() const { return U; }
void dump(raw_ostream &OS, DIDumpOptions DumpOpts = DIDumpOptions()) const;
void dumpSectionedAddress(raw_ostream &OS, DIDumpOptions DumpOpts,
object::SectionedAddress SA) const;
void dumpAddress(raw_ostream &OS, uint64_t Address) const;
static void dumpAddress(raw_ostream &OS, uint8_t AddressSize,
uint64_t Address);
static void dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS,
DIDumpOptions DumpOpts, uint64_t SectionIndex);
/// Extracts a value in \p Data at offset \p *OffsetPtr. The information
/// in \p FormParams is needed to interpret some forms. The optional
/// \p Context and \p Unit allows extracting information if the form refers
/// to other sections (e.g., .debug_str).
bool extractValue(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
dwarf::FormParams FormParams,
const DWARFContext *Context = nullptr,
const DWARFUnit *Unit = nullptr);
bool extractValue(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
dwarf::FormParams FormParams, const DWARFUnit *U) {
return extractValue(Data, OffsetPtr, FormParams, nullptr, U);
}
/// getAsFoo functions below return the extracted value as Foo if only
/// DWARFFormValue has form class is suitable for representing Foo.
std::optional<uint64_t> getAsReference() const;
struct UnitOffset {
DWARFUnit *Unit;
uint64_t Offset;
};
std::optional<UnitOffset> getAsRelativeReference() const;
std::optional<uint64_t> getAsUnsignedConstant() const;
std::optional<int64_t> getAsSignedConstant() const;
Expected<const char *> getAsCString() const;
std::optional<uint64_t> getAsAddress() const;
std::optional<object::SectionedAddress> getAsSectionedAddress() const;
std::optional<uint64_t> getAsSectionOffset() const;
std::optional<ArrayRef<uint8_t>> getAsBlock() const;
std::optional<uint64_t> getAsCStringOffset() const;
std::optional<uint64_t> getAsReferenceUVal() const;
/// Correctly extract any file paths from a form value.
///
/// These attributes can be in the from DW_AT_decl_file or DW_AT_call_file
/// attributes. We need to use the file index in the correct DWARFUnit's line
/// table prologue, and each DWARFFormValue has the DWARFUnit the form value
/// was extracted from.
///
/// \param Kind The kind of path to extract.
///
/// \returns A valid string value on success, or std::nullopt if the form
/// class is not FC_Constant, or if the file index is not valid.
std::optional<std::string>
getAsFile(DILineInfoSpecifier::FileLineInfoKind Kind) const;
/// Skip a form's value in \p DebugInfoData at the offset specified by
/// \p OffsetPtr.
///
/// Skips the bytes for the current form and updates the offset.
///
/// \param DebugInfoData The data where we want to skip the value.
/// \param OffsetPtr A reference to the offset that will be updated.
/// \param Params DWARF parameters to help interpret forms.
/// \returns true on success, false if the form was not skipped.
bool skipValue(DataExtractor DebugInfoData, uint64_t *OffsetPtr,
const dwarf::FormParams Params) const {
return DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, Params);
}
/// Skip a form's value in \p DebugInfoData at the offset specified by
/// \p OffsetPtr.
///
/// Skips the bytes for the specified form and updates the offset.
///
/// \param Form The DW_FORM enumeration that indicates the form to skip.
/// \param DebugInfoData The data where we want to skip the value.
/// \param OffsetPtr A reference to the offset that will be updated.
/// \param FormParams DWARF parameters to help interpret forms.
/// \returns true on success, false if the form was not skipped.
static bool skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
uint64_t *OffsetPtr,
const dwarf::FormParams FormParams);
private:
void dumpString(raw_ostream &OS) const;
};
namespace dwarf {
/// Take an optional DWARFFormValue and try to extract a string value from it.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and was a string.
inline std::optional<const char *>
toString(const std::optional<DWARFFormValue> &V) {
if (!V)
return std::nullopt;
Expected<const char*> E = V->getAsCString();
if (!E) {
consumeError(E.takeError());
return std::nullopt;
}
return *E;
}
/// Take an optional DWARFFormValue and try to extract a string value from it.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and was a string.
inline StringRef toStringRef(const std::optional<DWARFFormValue> &V,
StringRef Default = {}) {
if (!V)
return Default;
auto S = V->getAsCString();
if (!S) {
consumeError(S.takeError());
return Default;
}
if (!*S)
return Default;
return *S;
}
/// Take an optional DWARFFormValue and extract a string value from it.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the string value or Default if the V doesn't have a value or the
/// form value's encoding wasn't a string.
inline const char *toString(const std::optional<DWARFFormValue> &V,
const char *Default) {
if (auto E = toString(V))
return *E;
return Default;
}
/// Take an optional DWARFFormValue and try to extract an unsigned constant.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a unsigned constant form.
inline std::optional<uint64_t>
toUnsigned(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsUnsignedConstant();
return std::nullopt;
}
/// Take an optional DWARFFormValue and extract a unsigned constant.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the extracted unsigned value or Default if the V doesn't have a
/// value or the form value's encoding wasn't an unsigned constant form.
inline uint64_t toUnsigned(const std::optional<DWARFFormValue> &V,
uint64_t Default) {
return toUnsigned(V).value_or(Default);
}
/// Take an optional DWARFFormValue and try to extract an reference.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a reference form.
inline std::optional<uint64_t>
toReference(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsReference();
return std::nullopt;
}
/// Take an optional DWARFFormValue and extract a reference.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the extracted reference value or Default if the V doesn't have a
/// value or the form value's encoding wasn't a reference form.
inline uint64_t toReference(const std::optional<DWARFFormValue> &V,
uint64_t Default) {
return toReference(V).value_or(Default);
}
/// Take an optional DWARFFormValue and try to extract an signed constant.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a signed constant form.
inline std::optional<int64_t> toSigned(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsSignedConstant();
return std::nullopt;
}
/// Take an optional DWARFFormValue and extract a signed integer.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the extracted signed integer value or Default if the V doesn't
/// have a value or the form value's encoding wasn't a signed integer form.
inline int64_t toSigned(const std::optional<DWARFFormValue> &V,
int64_t Default) {
return toSigned(V).value_or(Default);
}
/// Take an optional DWARFFormValue and try to extract an address.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a address form.
inline std::optional<uint64_t>
toAddress(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsAddress();
return std::nullopt;
}
inline std::optional<object::SectionedAddress>
toSectionedAddress(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsSectionedAddress();
return std::nullopt;
}
/// Take an optional DWARFFormValue and extract a address.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the extracted address value or Default if the V doesn't have a
/// value or the form value's encoding wasn't an address form.
inline uint64_t toAddress(const std::optional<DWARFFormValue> &V,
uint64_t Default) {
return toAddress(V).value_or(Default);
}
/// Take an optional DWARFFormValue and try to extract an section offset.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a section offset form.
inline std::optional<uint64_t>
toSectionOffset(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsSectionOffset();
return std::nullopt;
}
/// Take an optional DWARFFormValue and extract a section offset.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \param Default the default value to return in case of failure.
/// \returns the extracted section offset value or Default if the V doesn't
/// have a value or the form value's encoding wasn't a section offset form.
inline uint64_t toSectionOffset(const std::optional<DWARFFormValue> &V,
uint64_t Default) {
return toSectionOffset(V).value_or(Default);
}
/// Take an optional DWARFFormValue and try to extract block data.
///
/// \param V and optional DWARFFormValue to attempt to extract the value from.
/// \returns an optional value that contains a value if the form value
/// was valid and has a block form.
inline std::optional<ArrayRef<uint8_t>>
toBlock(const std::optional<DWARFFormValue> &V) {
if (V)
return V->getAsBlock();
return std::nullopt;
}
} // end namespace dwarf
} // end namespace llvm
#endif // LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H