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diff --git a/tools/profiler/tests/gtest/LulTestInfrastructure.h b/tools/profiler/tests/gtest/LulTestInfrastructure.h new file mode 100644 index 0000000000..a48353071f --- /dev/null +++ b/tools/profiler/tests/gtest/LulTestInfrastructure.h @@ -0,0 +1,735 @@ +// -*- mode: C++ -*- + +// Copyright (c) 2010, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> + +// Derived from: +// cfi_assembler.h: Define CFISection, a class for creating properly +// (and improperly) formatted DWARF CFI data for unit tests. + +// Derived from: +// test-assembler.h: interface to class for building complex binary streams. + +// To test the Breakpad symbol dumper and processor thoroughly, for +// all combinations of host system and minidump processor +// architecture, we need to be able to easily generate complex test +// data like debugging information and minidump files. +// +// For example, if we want our unit tests to provide full code +// coverage for stack walking, it may be difficult to persuade the +// compiler to generate every possible sort of stack walking +// information that we want to support; there are probably DWARF CFI +// opcodes that GCC never emits. Similarly, if we want to test our +// error handling, we will need to generate damaged minidumps or +// debugging information that (we hope) the client or compiler will +// never produce on its own. +// +// google_breakpad::TestAssembler provides a predictable and +// (relatively) simple way to generate complex formatted data streams +// like minidumps and CFI. Furthermore, because TestAssembler is +// portable, developers without access to (say) Visual Studio or a +// SPARC assembler can still work on test data for those targets. + +#ifndef LUL_TEST_INFRASTRUCTURE_H +#define LUL_TEST_INFRASTRUCTURE_H + +#include "LulDwarfExt.h" + +#include <string> +#include <vector> + +using std::string; +using std::vector; + +namespace lul_test { +namespace test_assembler { + +// A Label represents a value not yet known that we need to store in a +// section. As long as all the labels a section refers to are defined +// by the time we retrieve its contents as bytes, we can use undefined +// labels freely in that section's construction. +// +// A label can be in one of three states: +// - undefined, +// - defined as the sum of some other label and a constant, or +// - a constant. +// +// A label's value never changes, but it can accumulate constraints. +// Adding labels and integers is permitted, and yields a label. +// Subtracting a constant from a label is permitted, and also yields a +// label. Subtracting two labels that have some relationship to each +// other is permitted, and yields a constant. +// +// For example: +// +// Label a; // a's value is undefined +// Label b; // b's value is undefined +// { +// Label c = a + 4; // okay, even though a's value is unknown +// b = c + 4; // also okay; b is now a+8 +// } +// Label d = b - 2; // okay; d == a+6, even though c is gone +// d.Value(); // error: d's value is not yet known +// d - a; // is 6, even though their values are not known +// a = 12; // now b == 20, and d == 18 +// d.Value(); // 18: no longer an error +// b.Value(); // 20 +// d = 10; // error: d is already defined. +// +// Label objects' lifetimes are unconstrained: notice that, in the +// above example, even though a and b are only related through c, and +// c goes out of scope, the assignment to a sets b's value as well. In +// particular, it's not necessary to ensure that a Label lives beyond +// Sections that refer to it. +class Label { + public: + Label(); // An undefined label. + explicit Label(uint64_t value); // A label with a fixed value + Label(const Label& value); // A label equal to another. + ~Label(); + + Label& operator=(uint64_t value); + Label& operator=(const Label& value); + Label operator+(uint64_t addend) const; + Label operator-(uint64_t subtrahend) const; + uint64_t operator-(const Label& subtrahend) const; + + // We could also provide == and != that work on undefined, but + // related, labels. + + // Return true if this label's value is known. If VALUE_P is given, + // set *VALUE_P to the known value if returning true. + bool IsKnownConstant(uint64_t* value_p = NULL) const; + + // Return true if the offset from LABEL to this label is known. If + // OFFSET_P is given, set *OFFSET_P to the offset when returning true. + // + // You can think of l.KnownOffsetFrom(m, &d) as being like 'd = l-m', + // except that it also returns a value indicating whether the + // subtraction is possible given what we currently know of l and m. + // It can be possible even if we don't know l and m's values. For + // example: + // + // Label l, m; + // m = l + 10; + // l.IsKnownConstant(); // false + // m.IsKnownConstant(); // false + // uint64_t d; + // l.IsKnownOffsetFrom(m, &d); // true, and sets d to -10. + // l-m // -10 + // m-l // 10 + // m.Value() // error: m's value is not known + bool IsKnownOffsetFrom(const Label& label, uint64_t* offset_p = NULL) const; + + private: + // A label's value, or if that is not yet known, how the value is + // related to other labels' values. A binding may be: + // - a known constant, + // - constrained to be equal to some other binding plus a constant, or + // - unconstrained, and free to take on any value. + // + // Many labels may point to a single binding, and each binding may + // refer to another, so bindings and labels form trees whose leaves + // are labels, whose interior nodes (and roots) are bindings, and + // where links point from children to parents. Bindings are + // reference counted, allowing labels to be lightweight, copyable, + // assignable, placed in containers, and so on. + class Binding { + public: + Binding(); + explicit Binding(uint64_t addend); + ~Binding(); + + // Increment our reference count. + void Acquire() { reference_count_++; }; + // Decrement our reference count, and return true if it is zero. + bool Release() { return --reference_count_ == 0; } + + // Set this binding to be equal to BINDING + ADDEND. If BINDING is + // NULL, then set this binding to the known constant ADDEND. + // Update every binding on this binding's chain to point directly + // to BINDING, or to be a constant, with addends adjusted + // appropriately. + void Set(Binding* binding, uint64_t value); + + // Return what we know about the value of this binding. + // - If this binding's value is a known constant, set BASE to + // NULL, and set ADDEND to its value. + // - If this binding is not a known constant but related to other + // bindings, set BASE to the binding at the end of the relation + // chain (which will always be unconstrained), and set ADDEND to the + // value to add to that binding's value to get this binding's + // value. + // - If this binding is unconstrained, set BASE to this, and leave + // ADDEND unchanged. + void Get(Binding** base, uint64_t* addend); + + private: + // There are three cases: + // + // - A binding representing a known constant value has base_ NULL, + // and addend_ equal to the value. + // + // - A binding representing a completely unconstrained value has + // base_ pointing to this; addend_ is unused. + // + // - A binding whose value is related to some other binding's + // value has base_ pointing to that other binding, and addend_ + // set to the amount to add to that binding's value to get this + // binding's value. We only represent relationships of the form + // x = y+c. + // + // Thus, the bind_ links form a chain terminating in either a + // known constant value or a completely unconstrained value. Most + // operations on bindings do path compression: they change every + // binding on the chain to point directly to the final value, + // adjusting addends as appropriate. + Binding* base_; + uint64_t addend_; + + // The number of Labels and Bindings pointing to this binding. + // (When a binding points to itself, indicating a completely + // unconstrained binding, that doesn't count as a reference.) + int reference_count_; + }; + + // This label's value. + Binding* value_; +}; + +// Conventions for representing larger numbers as sequences of bytes. +enum Endianness { + kBigEndian, // Big-endian: the most significant byte comes first. + kLittleEndian, // Little-endian: the least significant byte comes first. + kUnsetEndian, // used internally +}; + +// A section is a sequence of bytes, constructed by appending bytes +// to the end. Sections have a convenient and flexible set of member +// functions for appending data in various formats: big-endian and +// little-endian signed and unsigned values of different sizes; +// LEB128 and ULEB128 values (see below), and raw blocks of bytes. +// +// If you need to append a value to a section that is not convenient +// to compute immediately, you can create a label, append the +// label's value to the section, and then set the label's value +// later, when it's convenient to do so. Once a label's value is +// known, the section class takes care of updating all previously +// appended references to it. +// +// Once all the labels to which a section refers have had their +// values determined, you can get a copy of the section's contents +// as a string. +// +// Note that there is no specified "start of section" label. This is +// because there are typically several different meanings for "the +// start of a section": the offset of the section within an object +// file, the address in memory at which the section's content appear, +// and so on. It's up to the code that uses the Section class to +// keep track of these explicitly, as they depend on the application. +class Section { + public: + explicit Section(Endianness endianness = kUnsetEndian) + : endianness_(endianness){}; + + // A base class destructor should be either public and virtual, + // or protected and nonvirtual. + virtual ~Section(){}; + + // Return the default endianness of this section. + Endianness endianness() const { return endianness_; } + + // Append the SIZE bytes at DATA to the end of this section. Return + // a reference to this section. + Section& Append(const string& data) { + contents_.append(data); + return *this; + }; + + // Append data from SLICE to the end of this section. Return + // a reference to this section. + Section& Append(const lul::ImageSlice& slice) { + for (size_t i = 0; i < slice.length_; i++) { + contents_.append(1, slice.start_[i]); + } + return *this; + } + + // Append data from CSTRING to the end of this section. The terminating + // zero is not included. Return a reference to this section. + Section& Append(const char* cstring) { + for (size_t i = 0; cstring[i] != '\0'; i++) { + contents_.append(1, cstring[i]); + } + return *this; + } + + // Append SIZE copies of BYTE to the end of this section. Return a + // reference to this section. + Section& Append(size_t size, uint8_t byte) { + contents_.append(size, (char)byte); + return *this; + } + + // Append NUMBER to this section. ENDIANNESS is the endianness to + // use to write the number. SIZE is the length of the number in + // bytes. Return a reference to this section. + Section& Append(Endianness endianness, size_t size, uint64_t number); + Section& Append(Endianness endianness, size_t size, const Label& label); + + // Append SECTION to the end of this section. The labels SECTION + // refers to need not be defined yet. + // + // Note that this has no effect on any Labels' values, or on + // SECTION. If placing SECTION within 'this' provides new + // constraints on existing labels' values, then it's up to the + // caller to fiddle with those labels as needed. + Section& Append(const Section& section); + + // Append the contents of DATA as a series of bytes terminated by + // a NULL character. + Section& AppendCString(const string& data) { + Append(data); + contents_ += '\0'; + return *this; + } + + // Append VALUE or LABEL to this section, with the given bit width and + // endianness. Return a reference to this section. + // + // The names of these functions have the form <ENDIANNESS><BITWIDTH>: + // <ENDIANNESS> is either 'L' (little-endian, least significant byte first), + // 'B' (big-endian, most significant byte first), or + // 'D' (default, the section's default endianness) + // <BITWIDTH> is 8, 16, 32, or 64. + // + // Since endianness doesn't matter for a single byte, all the + // <BITWIDTH>=8 functions are equivalent. + // + // These can be used to write both signed and unsigned values, as + // the compiler will properly sign-extend a signed value before + // passing it to the function, at which point the function's + // behavior is the same either way. + Section& L8(uint8_t value) { + contents_ += value; + return *this; + } + Section& B8(uint8_t value) { + contents_ += value; + return *this; + } + Section& D8(uint8_t value) { + contents_ += value; + return *this; + } + Section &L16(uint16_t), &L32(uint32_t), &L64(uint64_t), &B16(uint16_t), + &B32(uint32_t), &B64(uint64_t), &D16(uint16_t), &D32(uint32_t), + &D64(uint64_t); + Section &L8(const Label&label), &L16(const Label&label), + &L32(const Label&label), &L64(const Label&label), &B8(const Label&label), + &B16(const Label&label), &B32(const Label&label), &B64(const Label&label), + &D8(const Label&label), &D16(const Label&label), &D32(const Label&label), + &D64(const Label&label); + + // Append VALUE in a signed LEB128 (Little-Endian Base 128) form. + // + // The signed LEB128 representation of an integer N is a variable + // number of bytes: + // + // - If N is between -0x40 and 0x3f, then its signed LEB128 + // representation is a single byte whose value is N. + // + // - Otherwise, its signed LEB128 representation is (N & 0x7f) | + // 0x80, followed by the signed LEB128 representation of N / 128, + // rounded towards negative infinity. + // + // In other words, we break VALUE into groups of seven bits, put + // them in little-endian order, and then write them as eight-bit + // bytes with the high bit on all but the last. + // + // Note that VALUE cannot be a Label (we would have to implement + // relaxation). + Section& LEB128(long long value); + + // Append VALUE in unsigned LEB128 (Little-Endian Base 128) form. + // + // The unsigned LEB128 representation of an integer N is a variable + // number of bytes: + // + // - If N is between 0 and 0x7f, then its unsigned LEB128 + // representation is a single byte whose value is N. + // + // - Otherwise, its unsigned LEB128 representation is (N & 0x7f) | + // 0x80, followed by the unsigned LEB128 representation of N / + // 128, rounded towards negative infinity. + // + // Note that VALUE cannot be a Label (we would have to implement + // relaxation). + Section& ULEB128(uint64_t value); + + // Jump to the next location aligned on an ALIGNMENT-byte boundary, + // relative to the start of the section. Fill the gap with PAD_BYTE. + // ALIGNMENT must be a power of two. Return a reference to this + // section. + Section& Align(size_t alignment, uint8_t pad_byte = 0); + + // Return the current size of the section. + size_t Size() const { return contents_.size(); } + + // Return a label representing the start of the section. + // + // It is up to the user whether this label represents the section's + // position in an object file, the section's address in memory, or + // what have you; some applications may need both, in which case + // this simple-minded interface won't be enough. This class only + // provides a single start label, for use with the Here and Mark + // member functions. + // + // Ideally, we'd provide this in a subclass that actually knows more + // about the application at hand and can provide an appropriate + // collection of start labels. But then the appending member + // functions like Append and D32 would return a reference to the + // base class, not the derived class, and the chaining won't work. + // Since the only value here is in pretty notation, that's a fatal + // flaw. + Label start() const { return start_; } + + // Return a label representing the point at which the next Appended + // item will appear in the section, relative to start(). + Label Here() const { return start_ + Size(); } + + // Set *LABEL to Here, and return a reference to this section. + Section& Mark(Label* label) { + *label = Here(); + return *this; + } + + // If there are no undefined label references left in this + // section, set CONTENTS to the contents of this section, as a + // string, and clear this section. Return true on success, or false + // if there were still undefined labels. + bool GetContents(string* contents); + + private: + // Used internally. A reference to a label's value. + struct Reference { + Reference(size_t set_offset, Endianness set_endianness, size_t set_size, + const Label& set_label) + : offset(set_offset), + endianness(set_endianness), + size(set_size), + label(set_label) {} + + // The offset of the reference within the section. + size_t offset; + + // The endianness of the reference. + Endianness endianness; + + // The size of the reference. + size_t size; + + // The label to which this is a reference. + Label label; + }; + + // The default endianness of this section. + Endianness endianness_; + + // The contents of the section. + string contents_; + + // References to labels within those contents. + vector<Reference> references_; + + // A label referring to the beginning of the section. + Label start_; +}; + +} // namespace test_assembler +} // namespace lul_test + +namespace lul_test { + +using lul::DwarfPointerEncoding; +using lul_test::test_assembler::Endianness; +using lul_test::test_assembler::Label; +using lul_test::test_assembler::Section; + +class CFISection : public Section { + public: + // CFI augmentation strings beginning with 'z', defined by the + // Linux/IA-64 C++ ABI, can specify interesting encodings for + // addresses appearing in FDE headers and call frame instructions (and + // for additional fields whose presence the augmentation string + // specifies). In particular, pointers can be specified to be relative + // to various base address: the start of the .text section, the + // location holding the address itself, and so on. These allow the + // frame data to be position-independent even when they live in + // write-protected pages. These variants are specified at the + // following two URLs: + // + // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/dwarfext.html + // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html + // + // CFISection leaves the production of well-formed 'z'-augmented CIEs and + // FDEs to the user, but does provide EncodedPointer, to emit + // properly-encoded addresses for a given pointer encoding. + // EncodedPointer uses an instance of this structure to find the base + // addresses it should use; you can establish a default for all encoded + // pointers appended to this section with SetEncodedPointerBases. + struct EncodedPointerBases { + EncodedPointerBases() : cfi(), text(), data() {} + + // The starting address of this CFI section in memory, for + // DW_EH_PE_pcrel. DW_EH_PE_pcrel pointers may only be used in data + // that has is loaded into the program's address space. + uint64_t cfi; + + // The starting address of this file's .text section, for DW_EH_PE_textrel. + uint64_t text; + + // The starting address of this file's .got or .eh_frame_hdr section, + // for DW_EH_PE_datarel. + uint64_t data; + }; + + // Create a CFISection whose endianness is ENDIANNESS, and where + // machine addresses are ADDRESS_SIZE bytes long. If EH_FRAME is + // true, use the .eh_frame format, as described by the Linux + // Standards Base Core Specification, instead of the DWARF CFI + // format. + CFISection(Endianness endianness, size_t address_size, bool eh_frame = false) + : Section(endianness), + address_size_(address_size), + eh_frame_(eh_frame), + pointer_encoding_(lul::DW_EH_PE_absptr), + encoded_pointer_bases_(), + entry_length_(NULL), + in_fde_(false) { + // The 'start', 'Here', and 'Mark' members of a CFISection all refer + // to section offsets. + start() = 0; + } + + // Return this CFISection's address size. + size_t AddressSize() const { return address_size_; } + + // Return true if this CFISection uses the .eh_frame format, or + // false if it contains ordinary DWARF CFI data. + bool ContainsEHFrame() const { return eh_frame_; } + + // Use ENCODING for pointers in calls to FDEHeader and EncodedPointer. + void SetPointerEncoding(DwarfPointerEncoding encoding) { + pointer_encoding_ = encoding; + } + + // Use the addresses in BASES as the base addresses for encoded + // pointers in subsequent calls to FDEHeader or EncodedPointer. + // This function makes a copy of BASES. + void SetEncodedPointerBases(const EncodedPointerBases& bases) { + encoded_pointer_bases_ = bases; + } + + // Append a Common Information Entry header to this section with the + // given values. If dwarf64 is true, use the 64-bit DWARF initial + // length format for the CIE's initial length. Return a reference to + // this section. You should call FinishEntry after writing the last + // instruction for the CIE. + // + // Before calling this function, you will typically want to use Mark + // or Here to make a label to pass to FDEHeader that refers to this + // CIE's position in the section. + CFISection& CIEHeader(uint64_t code_alignment_factor, + int data_alignment_factor, + unsigned return_address_register, uint8_t version = 3, + const string& augmentation = "", bool dwarf64 = false); + + // Append a Frame Description Entry header to this section with the + // given values. If dwarf64 is true, use the 64-bit DWARF initial + // length format for the CIE's initial length. Return a reference to + // this section. You should call FinishEntry after writing the last + // instruction for the CIE. + // + // This function doesn't support entries that are longer than + // 0xffffff00 bytes. (The "initial length" is always a 32-bit + // value.) Nor does it support .debug_frame sections longer than + // 0xffffff00 bytes. + CFISection& FDEHeader(Label cie_pointer, uint64_t initial_location, + uint64_t address_range, bool dwarf64 = false); + + // Note the current position as the end of the last CIE or FDE we + // started, after padding with DW_CFA_nops for alignment. This + // defines the label representing the entry's length, cited in the + // entry's header. Return a reference to this section. + CFISection& FinishEntry(); + + // Append the contents of BLOCK as a DW_FORM_block value: an + // unsigned LEB128 length, followed by that many bytes of data. + CFISection& Block(const lul::ImageSlice& block) { + ULEB128(block.length_); + Append(block); + return *this; + } + + // Append data from CSTRING as a DW_FORM_block value: an unsigned LEB128 + // length, followed by that many bytes of data. The terminating zero is not + // included. + CFISection& Block(const char* cstring) { + ULEB128(strlen(cstring)); + Append(cstring); + return *this; + } + + // Append ADDRESS to this section, in the appropriate size and + // endianness. Return a reference to this section. + CFISection& Address(uint64_t address) { + Section::Append(endianness(), address_size_, address); + return *this; + } + + // Append ADDRESS to this section, using ENCODING and BASES. ENCODING + // defaults to this section's default encoding, established by + // SetPointerEncoding. BASES defaults to this section's bases, set by + // SetEncodedPointerBases. If the DW_EH_PE_indirect bit is set in the + // encoding, assume that ADDRESS is where the true address is stored. + // Return a reference to this section. + // + // (C++ doesn't let me use default arguments here, because I want to + // refer to members of *this in the default argument expression.) + CFISection& EncodedPointer(uint64_t address) { + return EncodedPointer(address, pointer_encoding_, encoded_pointer_bases_); + } + CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding) { + return EncodedPointer(address, encoding, encoded_pointer_bases_); + } + CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding, + const EncodedPointerBases& bases); + + // Restate some member functions, to keep chaining working nicely. + CFISection& Mark(Label* label) { + Section::Mark(label); + return *this; + } + CFISection& D8(uint8_t v) { + Section::D8(v); + return *this; + } + CFISection& D16(uint16_t v) { + Section::D16(v); + return *this; + } + CFISection& D16(Label v) { + Section::D16(v); + return *this; + } + CFISection& D32(uint32_t v) { + Section::D32(v); + return *this; + } + CFISection& D32(const Label& v) { + Section::D32(v); + return *this; + } + CFISection& D64(uint64_t v) { + Section::D64(v); + return *this; + } + CFISection& D64(const Label& v) { + Section::D64(v); + return *this; + } + CFISection& LEB128(long long v) { + Section::LEB128(v); + return *this; + } + CFISection& ULEB128(uint64_t v) { + Section::ULEB128(v); + return *this; + } + + private: + // A length value that we've appended to the section, but is not yet + // known. LENGTH is the appended value; START is a label referring + // to the start of the data whose length was cited. + struct PendingLength { + Label length; + Label start; + }; + + // Constants used in CFI/.eh_frame data: + + // If the first four bytes of an "initial length" are this constant, then + // the data uses the 64-bit DWARF format, and the length itself is the + // subsequent eight bytes. + static const uint32_t kDwarf64InitialLengthMarker = 0xffffffffU; + + // The CIE identifier for 32- and 64-bit DWARF CFI and .eh_frame data. + static const uint32_t kDwarf32CIEIdentifier = ~(uint32_t)0; + static const uint64_t kDwarf64CIEIdentifier = ~(uint64_t)0; + static const uint32_t kEHFrame32CIEIdentifier = 0; + static const uint64_t kEHFrame64CIEIdentifier = 0; + + // The size of a machine address for the data in this section. + size_t address_size_; + + // If true, we are generating a Linux .eh_frame section, instead of + // a standard DWARF .debug_frame section. + bool eh_frame_; + + // The encoding to use for FDE pointers. + DwarfPointerEncoding pointer_encoding_; + + // The base addresses to use when emitting encoded pointers. + EncodedPointerBases encoded_pointer_bases_; + + // The length value for the current entry. + // + // Oddly, this must be dynamically allocated. Labels never get new + // values; they only acquire constraints on the value they already + // have, or assert if you assign them something incompatible. So + // each header needs truly fresh Label objects to cite in their + // headers and track their positions. The alternative is explicit + // destructor invocation and a placement new. Ick. + PendingLength* entry_length_; + + // True if we are currently emitting an FDE --- that is, we have + // called FDEHeader but have not yet called FinishEntry. + bool in_fde_; + + // If in_fde_ is true, this is its starting address. We use this for + // emitting DW_EH_PE_funcrel pointers. + uint64_t fde_start_address_; +}; + +} // namespace lul_test + +#endif // LUL_TEST_INFRASTRUCTURE_H |