llvm-6502/include/llvm/DebugInfo/DWARFFormValue.h
Frederic Riss 0275be3a97 Allow DWARFFormValue::extractValue to be called with a null CU.
Currently FormValues are only used for attributes of DIEs and thus
uers always have a CU lying around when calling into the FormValue
API.
Accelerator tables encode their information using the same Forms
as the attributes, thus it is natural to use DWARFFormValue to
extract/dump them. There is no CU in that case though. Allow the
API to be called with a null CU arguemnt by making the RelocMap
lookup conditional on the CU pointer validity. And document this
new behvior in the header. (Test coverage for this use of the API
comes in the DwarfAccelTable support patch)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:04 +00:00

94 lines
2.6 KiB
C++

//===-- DWARFFormValue.h ----------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_DEBUGINFO_DWARFFORMVALUE_H
#define LLVM_DEBUGINFO_DWARFFORMVALUE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/DataExtractor.h"
namespace llvm {
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() : data(nullptr) {
uval = 0;
}
union {
uint64_t uval;
int64_t sval;
const char* cstr;
};
const uint8_t* data;
};
uint16_t Form; // Form for this value.
ValueType Value; // Contains all data for the form.
public:
DWARFFormValue(uint16_t Form = 0) : Form(Form) {}
uint16_t getForm() const { return Form; }
bool isFormClass(FormClass FC) const;
void dump(raw_ostream &OS, const DWARFUnit *U) 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 wether the extraction succeeded.
bool extractValue(DataExtractor data, uint32_t *offset_ptr,
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> getAsUnsignedConstant() const;
Optional<const char *> getAsCString(const DWARFUnit *U) const;
Optional<uint64_t> getAsAddress(const DWARFUnit *U) 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;
static bool skipValue(uint16_t form, DataExtractor debug_info_data,
uint32_t *offset_ptr, const DWARFUnit *u);
static ArrayRef<uint8_t> getFixedFormSizes(uint8_t AddrSize,
uint16_t Version);
};
}
#endif