| /* |
| * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_CODE_RELOCINFO_HPP |
| #define SHARE_VM_CODE_RELOCINFO_HPP |
| |
| #include "memory/allocation.hpp" |
| #include "runtime/os.hpp" |
| #include "utilities/macros.hpp" |
| |
| class nmethod; |
| class CompiledMethod; |
| class Metadata; |
| class NativeMovConstReg; |
| |
| // Types in this file: |
| // relocInfo |
| // One element of an array of halfwords encoding compressed relocations. |
| // Also, the source of relocation types (relocInfo::oop_type, ...). |
| // Relocation |
| // A flyweight object representing a single relocation. |
| // It is fully unpacked from the compressed relocation array. |
| // metadata_Relocation, ... (subclasses of Relocation) |
| // The location of some type-specific operations (metadata_addr, ...). |
| // Also, the source of relocation specs (metadata_Relocation::spec, ...). |
| // oop_Relocation, ... (subclasses of Relocation) |
| // oops in the code stream (strings, class loaders) |
| // Also, the source of relocation specs (oop_Relocation::spec, ...). |
| // RelocationHolder |
| // A ValueObj type which acts as a union holding a Relocation object. |
| // Represents a relocation spec passed into a CodeBuffer during assembly. |
| // RelocIterator |
| // A StackObj which iterates over the relocations associated with |
| // a range of code addresses. Can be used to operate a copy of code. |
| // BoundRelocation |
| // An _internal_ type shared by packers and unpackers of relocations. |
| // It pastes together a RelocationHolder with some pointers into |
| // code and relocInfo streams. |
| |
| |
| // Notes on relocType: |
| // |
| // These hold enough information to read or write a value embedded in |
| // the instructions of an CodeBlob. They're used to update: |
| // |
| // 1) embedded oops (isOop() == true) |
| // 2) inline caches (isIC() == true) |
| // 3) runtime calls (isRuntimeCall() == true) |
| // 4) internal word ref (isInternalWord() == true) |
| // 5) external word ref (isExternalWord() == true) |
| // |
| // when objects move (GC) or if code moves (compacting the code heap). |
| // They are also used to patch the code (if a call site must change) |
| // |
| // A relocInfo is represented in 16 bits: |
| // 4 bits indicating the relocation type |
| // 12 bits indicating the offset from the previous relocInfo address |
| // |
| // The offsets accumulate along the relocInfo stream to encode the |
| // address within the CodeBlob, which is named RelocIterator::addr(). |
| // The address of a particular relocInfo always points to the first |
| // byte of the relevant instruction (and not to any of its subfields |
| // or embedded immediate constants). |
| // |
| // The offset value is scaled appropriately for the target machine. |
| // (See relocInfo_<arch>.hpp for the offset scaling.) |
| // |
| // On some machines, there may also be a "format" field which may provide |
| // additional information about the format of the instruction stream |
| // at the corresponding code address. The format value is usually zero. |
| // Any machine (such as Intel) whose instructions can sometimes contain |
| // more than one relocatable constant needs format codes to distinguish |
| // which operand goes with a given relocation. |
| // |
| // If the target machine needs N format bits, the offset has 12-N bits, |
| // the format is encoded between the offset and the type, and the |
| // relocInfo_<arch>.hpp file has manifest constants for the format codes. |
| // |
| // If the type is "data_prefix_tag" then the offset bits are further encoded, |
| // and in fact represent not a code-stream offset but some inline data. |
| // The data takes the form of a counted sequence of halfwords, which |
| // precedes the actual relocation record. (Clients never see it directly.) |
| // The interpetation of this extra data depends on the relocation type. |
| // |
| // On machines that have 32-bit immediate fields, there is usually |
| // little need for relocation "prefix" data, because the instruction stream |
| // is a perfectly reasonable place to store the value. On machines in |
| // which 32-bit values must be "split" across instructions, the relocation |
| // data is the "true" specification of the value, which is then applied |
| // to some field of the instruction (22 or 13 bits, on SPARC). |
| // |
| // Whenever the location of the CodeBlob changes, any PC-relative |
| // relocations, and any internal_word_type relocations, must be reapplied. |
| // After the GC runs, oop_type relocations must be reapplied. |
| // |
| // |
| // Here are meanings of the types: |
| // |
| // relocInfo::none -- a filler record |
| // Value: none |
| // Instruction: The corresponding code address is ignored |
| // Data: Any data prefix and format code are ignored |
| // (This means that any relocInfo can be disabled by setting |
| // its type to none. See relocInfo::remove.) |
| // |
| // relocInfo::oop_type, relocInfo::metadata_type -- a reference to an oop or meta data |
| // Value: an oop, or else the address (handle) of an oop |
| // Instruction types: memory (load), set (load address) |
| // Data: [] an oop stored in 4 bytes of instruction |
| // [n] n is the index of an oop in the CodeBlob's oop pool |
| // [[N]n l] and l is a byte offset to be applied to the oop |
| // [Nn Ll] both index and offset may be 32 bits if necessary |
| // Here is a special hack, used only by the old compiler: |
| // [[N]n 00] the value is the __address__ of the nth oop in the pool |
| // (Note that the offset allows optimal references to class variables.) |
| // |
| // relocInfo::internal_word_type -- an address within the same CodeBlob |
| // relocInfo::section_word_type -- same, but can refer to another section |
| // Value: an address in the CodeBlob's code or constants section |
| // Instruction types: memory (load), set (load address) |
| // Data: [] stored in 4 bytes of instruction |
| // [[L]l] a relative offset (see [About Offsets] below) |
| // In the case of section_word_type, the offset is relative to a section |
| // base address, and the section number (e.g., SECT_INSTS) is encoded |
| // into the low two bits of the offset L. |
| // |
| // relocInfo::external_word_type -- a fixed address in the runtime system |
| // Value: an address |
| // Instruction types: memory (load), set (load address) |
| // Data: [] stored in 4 bytes of instruction |
| // [n] the index of a "well-known" stub (usual case on RISC) |
| // [Ll] a 32-bit address |
| // |
| // relocInfo::runtime_call_type -- a fixed subroutine in the runtime system |
| // Value: an address |
| // Instruction types: PC-relative call (or a PC-relative branch) |
| // Data: [] stored in 4 bytes of instruction |
| // |
| // relocInfo::static_call_type -- a static call |
| // Value: an CodeBlob, a stub, or a fixup routine |
| // Instruction types: a call |
| // Data: [] |
| // The identity of the callee is extracted from debugging information. |
| // //%note reloc_3 |
| // |
| // relocInfo::virtual_call_type -- a virtual call site (which includes an inline |
| // cache) |
| // Value: an CodeBlob, a stub, the interpreter, or a fixup routine |
| // Instruction types: a call, plus some associated set-oop instructions |
| // Data: [] the associated set-oops are adjacent to the call |
| // [n] n is a relative offset to the first set-oop |
| // [[N]n l] and l is a limit within which the set-oops occur |
| // [Nn Ll] both n and l may be 32 bits if necessary |
| // The identity of the callee is extracted from debugging information. |
| // |
| // relocInfo::opt_virtual_call_type -- a virtual call site that is statically bound |
| // |
| // Same info as a static_call_type. We use a special type, so the handling of |
| // virtuals and statics are separated. |
| // |
| // |
| // The offset n points to the first set-oop. (See [About Offsets] below.) |
| // In turn, the set-oop instruction specifies or contains an oop cell devoted |
| // exclusively to the IC call, which can be patched along with the call. |
| // |
| // The locations of any other set-oops are found by searching the relocation |
| // information starting at the first set-oop, and continuing until all |
| // relocations up through l have been inspected. The value l is another |
| // relative offset. (Both n and l are relative to the call's first byte.) |
| // |
| // The limit l of the search is exclusive. However, if it points within |
| // the call (e.g., offset zero), it is adjusted to point after the call and |
| // any associated machine-specific delay slot. |
| // |
| // Since the offsets could be as wide as 32-bits, these conventions |
| // put no restrictions whatever upon code reorganization. |
| // |
| // The compiler is responsible for ensuring that transition from a clean |
| // state to a monomorphic compiled state is MP-safe. This implies that |
| // the system must respond well to intermediate states where a random |
| // subset of the set-oops has been correctly from the clean state |
| // upon entry to the VEP of the compiled method. In the case of a |
| // machine (Intel) with a single set-oop instruction, the 32-bit |
| // immediate field must not straddle a unit of memory coherence. |
| // //%note reloc_3 |
| // |
| // relocInfo::static_stub_type -- an extra stub for each static_call_type |
| // Value: none |
| // Instruction types: a virtual call: { set_oop; jump; } |
| // Data: [[N]n] the offset of the associated static_call reloc |
| // This stub becomes the target of a static call which must be upgraded |
| // to a virtual call (because the callee is interpreted). |
| // See [About Offsets] below. |
| // //%note reloc_2 |
| // |
| // relocInfo::poll_[return_]type -- a safepoint poll |
| // Value: none |
| // Instruction types: memory load or test |
| // Data: none |
| // |
| // For example: |
| // |
| // INSTRUCTIONS RELOC: TYPE PREFIX DATA |
| // ------------ ---- ----------- |
| // sethi %hi(myObject), R oop_type [n(myObject)] |
| // ld [R+%lo(myObject)+fldOffset], R2 oop_type [n(myObject) fldOffset] |
| // add R2, 1, R2 |
| // st R2, [R+%lo(myObject)+fldOffset] oop_type [n(myObject) fldOffset] |
| //%note reloc_1 |
| // |
| // This uses 4 instruction words, 8 relocation halfwords, |
| // and an entry (which is sharable) in the CodeBlob's oop pool, |
| // for a total of 36 bytes. |
| // |
| // Note that the compiler is responsible for ensuring the "fldOffset" when |
| // added to "%lo(myObject)" does not overflow the immediate fields of the |
| // memory instructions. |
| // |
| // |
| // [About Offsets] Relative offsets are supplied to this module as |
| // positive byte offsets, but they may be internally stored scaled |
| // and/or negated, depending on what is most compact for the target |
| // system. Since the object pointed to by the offset typically |
| // precedes the relocation address, it is profitable to store |
| // these negative offsets as positive numbers, but this decision |
| // is internal to the relocation information abstractions. |
| // |
| |
| class Relocation; |
| class CodeBuffer; |
| class CodeSection; |
| class RelocIterator; |
| |
| class relocInfo VALUE_OBJ_CLASS_SPEC { |
| friend class RelocIterator; |
| public: |
| enum relocType { |
| none = 0, // Used when no relocation should be generated |
| oop_type = 1, // embedded oop |
| virtual_call_type = 2, // a standard inline cache call for a virtual send |
| opt_virtual_call_type = 3, // a virtual call that has been statically bound (i.e., no IC cache) |
| static_call_type = 4, // a static send |
| static_stub_type = 5, // stub-entry for static send (takes care of interpreter case) |
| runtime_call_type = 6, // call to fixed external routine |
| external_word_type = 7, // reference to fixed external address |
| internal_word_type = 8, // reference within the current code blob |
| section_word_type = 9, // internal, but a cross-section reference |
| poll_type = 10, // polling instruction for safepoints |
| poll_return_type = 11, // polling instruction for safepoints at return |
| metadata_type = 12, // metadata that used to be oops |
| trampoline_stub_type = 13, // stub-entry for trampoline |
| runtime_call_w_cp_type = 14, // Runtime call which may load its target from the constant pool |
| data_prefix_tag = 15, // tag for a prefix (carries data arguments) |
| type_mask = 15 // A mask which selects only the above values |
| }; |
| |
| protected: |
| unsigned short _value; |
| |
| enum RawBitsToken { RAW_BITS }; |
| relocInfo(relocType type, RawBitsToken ignore, int bits) |
| : _value((type << nontype_width) + bits) { } |
| |
| relocInfo(relocType type, RawBitsToken ignore, int off, int f) |
| : _value((type << nontype_width) + (off / (unsigned)offset_unit) + (f << offset_width)) { } |
| |
| public: |
| // constructor |
| relocInfo(relocType type, int offset, int format = 0) |
| #ifndef ASSERT |
| { |
| (*this) = relocInfo(type, RAW_BITS, offset, format); |
| } |
| #else |
| // Put a bunch of assertions out-of-line. |
| ; |
| #endif |
| |
| #define APPLY_TO_RELOCATIONS(visitor) \ |
| visitor(oop) \ |
| visitor(metadata) \ |
| visitor(virtual_call) \ |
| visitor(opt_virtual_call) \ |
| visitor(static_call) \ |
| visitor(static_stub) \ |
| visitor(runtime_call) \ |
| visitor(runtime_call_w_cp) \ |
| visitor(external_word) \ |
| visitor(internal_word) \ |
| visitor(poll) \ |
| visitor(poll_return) \ |
| visitor(section_word) \ |
| visitor(trampoline_stub) \ |
| |
| |
| public: |
| enum { |
| value_width = sizeof(unsigned short) * BitsPerByte, |
| type_width = 4, // == log2(type_mask+1) |
| nontype_width = value_width - type_width, |
| datalen_width = nontype_width-1, |
| datalen_tag = 1 << datalen_width, // or-ed into _value |
| datalen_limit = 1 << datalen_width, |
| datalen_mask = (1 << datalen_width)-1 |
| }; |
| |
| // accessors |
| public: |
| relocType type() const { return (relocType)((unsigned)_value >> nontype_width); } |
| int format() const { return format_mask==0? 0: format_mask & |
| ((unsigned)_value >> offset_width); } |
| int addr_offset() const { assert(!is_prefix(), "must have offset"); |
| return (_value & offset_mask)*offset_unit; } |
| |
| protected: |
| const short* data() const { assert(is_datalen(), "must have data"); |
| return (const short*)(this + 1); } |
| int datalen() const { assert(is_datalen(), "must have data"); |
| return (_value & datalen_mask); } |
| int immediate() const { assert(is_immediate(), "must have immed"); |
| return (_value & datalen_mask); } |
| public: |
| static int addr_unit() { return offset_unit; } |
| static int offset_limit() { return (1 << offset_width) * offset_unit; } |
| |
| void set_type(relocType type); |
| void set_format(int format); |
| |
| void remove() { set_type(none); } |
| |
| protected: |
| bool is_none() const { return type() == none; } |
| bool is_prefix() const { return type() == data_prefix_tag; } |
| bool is_datalen() const { assert(is_prefix(), "must be prefix"); |
| return (_value & datalen_tag) != 0; } |
| bool is_immediate() const { assert(is_prefix(), "must be prefix"); |
| return (_value & datalen_tag) == 0; } |
| |
| public: |
| // Occasionally records of type relocInfo::none will appear in the stream. |
| // We do not bother to filter these out, but clients should ignore them. |
| // These records serve as "filler" in three ways: |
| // - to skip large spans of unrelocated code (this is rare) |
| // - to pad out the relocInfo array to the required oop alignment |
| // - to disable old relocation information which is no longer applicable |
| |
| inline friend relocInfo filler_relocInfo(); |
| |
| // Every non-prefix relocation may be preceded by at most one prefix, |
| // which supplies 1 or more halfwords of associated data. Conventionally, |
| // an int is represented by 0, 1, or 2 halfwords, depending on how |
| // many bits are required to represent the value. (In addition, |
| // if the sole halfword is a 10-bit unsigned number, it is made |
| // "immediate" in the prefix header word itself. This optimization |
| // is invisible outside this module.) |
| |
| inline friend relocInfo prefix_relocInfo(int datalen); |
| |
| protected: |
| // an immediate relocInfo optimizes a prefix with one 10-bit unsigned value |
| static relocInfo immediate_relocInfo(int data0) { |
| assert(fits_into_immediate(data0), "data0 in limits"); |
| return relocInfo(relocInfo::data_prefix_tag, RAW_BITS, data0); |
| } |
| static bool fits_into_immediate(int data0) { |
| return (data0 >= 0 && data0 < datalen_limit); |
| } |
| |
| public: |
| // Support routines for compilers. |
| |
| // This routine takes an infant relocInfo (unprefixed) and |
| // edits in its prefix, if any. It also updates dest.locs_end. |
| void initialize(CodeSection* dest, Relocation* reloc); |
| |
| // This routine updates a prefix and returns the limit pointer. |
| // It tries to compress the prefix from 32 to 16 bits, and if |
| // successful returns a reduced "prefix_limit" pointer. |
| relocInfo* finish_prefix(short* prefix_limit); |
| |
| // bit-packers for the data array: |
| |
| // As it happens, the bytes within the shorts are ordered natively, |
| // but the shorts within the word are ordered big-endian. |
| // This is an arbitrary choice, made this way mainly to ease debugging. |
| static int data0_from_int(jint x) { return x >> value_width; } |
| static int data1_from_int(jint x) { return (short)x; } |
| static jint jint_from_data(short* data) { |
| return (data[0] << value_width) + (unsigned short)data[1]; |
| } |
| |
| static jint short_data_at(int n, short* data, int datalen) { |
| return datalen > n ? data[n] : 0; |
| } |
| |
| static jint jint_data_at(int n, short* data, int datalen) { |
| return datalen > n+1 ? jint_from_data(&data[n]) : short_data_at(n, data, datalen); |
| } |
| |
| // Update methods for relocation information |
| // (since code is dynamically patched, we also need to dynamically update the relocation info) |
| // Both methods takes old_type, so it is able to performe sanity checks on the information removed. |
| static void change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type); |
| static void remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type); |
| |
| // Machine dependent stuff |
| #include CPU_HEADER(relocInfo) |
| |
| protected: |
| // Derived constant, based on format_width which is PD: |
| enum { |
| offset_width = nontype_width - format_width, |
| offset_mask = (1<<offset_width) - 1, |
| format_mask = (1<<format_width) - 1 |
| }; |
| public: |
| enum { |
| #ifdef _LP64 |
| // for use in format |
| // format_width must be at least 1 on _LP64 |
| narrow_oop_in_const = 1, |
| #endif |
| // Conservatively large estimate of maximum length (in shorts) |
| // of any relocation record. |
| // Extended format is length prefix, data words, and tag/offset suffix. |
| length_limit = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1, |
| have_format = format_width > 0 |
| }; |
| }; |
| |
| #define FORWARD_DECLARE_EACH_CLASS(name) \ |
| class name##_Relocation; |
| APPLY_TO_RELOCATIONS(FORWARD_DECLARE_EACH_CLASS) |
| #undef FORWARD_DECLARE_EACH_CLASS |
| |
| |
| |
| inline relocInfo filler_relocInfo() { |
| return relocInfo(relocInfo::none, relocInfo::offset_limit() - relocInfo::offset_unit); |
| } |
| |
| inline relocInfo prefix_relocInfo(int datalen = 0) { |
| assert(relocInfo::fits_into_immediate(datalen), "datalen in limits"); |
| return relocInfo(relocInfo::data_prefix_tag, relocInfo::RAW_BITS, relocInfo::datalen_tag | datalen); |
| } |
| |
| |
| // Holder for flyweight relocation objects. |
| // Although the flyweight subclasses are of varying sizes, |
| // the holder is "one size fits all". |
| class RelocationHolder VALUE_OBJ_CLASS_SPEC { |
| friend class Relocation; |
| friend class CodeSection; |
| |
| private: |
| // this preallocated memory must accommodate all subclasses of Relocation |
| // (this number is assertion-checked in Relocation::operator new) |
| enum { _relocbuf_size = 5 }; |
| void* _relocbuf[ _relocbuf_size ]; |
| |
| public: |
| Relocation* reloc() const { return (Relocation*) &_relocbuf[0]; } |
| inline relocInfo::relocType type() const; |
| |
| // Add a constant offset to a relocation. Helper for class Address. |
| RelocationHolder plus(int offset) const; |
| |
| inline RelocationHolder(); // initializes type to none |
| |
| inline RelocationHolder(Relocation* r); // make a copy |
| |
| static const RelocationHolder none; |
| }; |
| |
| // A RelocIterator iterates through the relocation information of a CodeBlob. |
| // It is a variable BoundRelocation which is able to take on successive |
| // values as it is advanced through a code stream. |
| // Usage: |
| // RelocIterator iter(nm); |
| // while (iter.next()) { |
| // iter.reloc()->some_operation(); |
| // } |
| // or: |
| // RelocIterator iter(nm); |
| // while (iter.next()) { |
| // switch (iter.type()) { |
| // case relocInfo::oop_type : |
| // case relocInfo::ic_type : |
| // case relocInfo::prim_type : |
| // case relocInfo::uncommon_type : |
| // case relocInfo::runtime_call_type : |
| // case relocInfo::internal_word_type: |
| // case relocInfo::external_word_type: |
| // ... |
| // } |
| // } |
| |
| class RelocIterator : public StackObj { |
| enum { SECT_LIMIT = 3 }; // must be equal to CodeBuffer::SECT_LIMIT, checked in ctor |
| friend class Relocation; |
| friend class relocInfo; // for change_reloc_info_for_address only |
| typedef relocInfo::relocType relocType; |
| |
| private: |
| address _limit; // stop producing relocations after this _addr |
| relocInfo* _current; // the current relocation information |
| relocInfo* _end; // end marker; we're done iterating when _current == _end |
| CompiledMethod* _code; // compiled method containing _addr |
| address _addr; // instruction to which the relocation applies |
| short _databuf; // spare buffer for compressed data |
| short* _data; // pointer to the relocation's data |
| short _datalen; // number of halfwords in _data |
| char _format; // position within the instruction |
| |
| // Base addresses needed to compute targets of section_word_type relocs. |
| address _section_start[SECT_LIMIT]; |
| address _section_end [SECT_LIMIT]; |
| |
| void set_has_current(bool b) { |
| _datalen = !b ? -1 : 0; |
| debug_only(_data = NULL); |
| } |
| void set_current(relocInfo& ri) { |
| _current = &ri; |
| set_has_current(true); |
| } |
| |
| RelocationHolder _rh; // where the current relocation is allocated |
| |
| relocInfo* current() const { assert(has_current(), "must have current"); |
| return _current; } |
| |
| void set_limits(address begin, address limit); |
| |
| void advance_over_prefix(); // helper method |
| |
| void initialize_misc(); |
| |
| void initialize(CompiledMethod* nm, address begin, address limit); |
| |
| RelocIterator() { initialize_misc(); } |
| |
| public: |
| // constructor |
| RelocIterator(CompiledMethod* nm, address begin = NULL, address limit = NULL); |
| RelocIterator(CodeSection* cb, address begin = NULL, address limit = NULL); |
| |
| // get next reloc info, return !eos |
| bool next() { |
| _current++; |
| assert(_current <= _end, "must not overrun relocInfo"); |
| if (_current == _end) { |
| set_has_current(false); |
| return false; |
| } |
| set_has_current(true); |
| |
| if (_current->is_prefix()) { |
| advance_over_prefix(); |
| assert(!current()->is_prefix(), "only one prefix at a time"); |
| } |
| |
| _addr += _current->addr_offset(); |
| |
| if (_limit != NULL && _addr >= _limit) { |
| set_has_current(false); |
| return false; |
| } |
| |
| if (relocInfo::have_format) _format = current()->format(); |
| return true; |
| } |
| |
| // accessors |
| address limit() const { return _limit; } |
| void set_limit(address x); |
| relocType type() const { return current()->type(); } |
| int format() const { return (relocInfo::have_format) ? current()->format() : 0; } |
| address addr() const { return _addr; } |
| CompiledMethod* code() const { return _code; } |
| nmethod* code_as_nmethod() const; |
| short* data() const { return _data; } |
| int datalen() const { return _datalen; } |
| bool has_current() const { return _datalen >= 0; } |
| |
| void set_addr(address addr) { _addr = addr; } |
| bool addr_in_const() const; |
| |
| address section_start(int n) const { |
| assert(_section_start[n], "must be initialized"); |
| return _section_start[n]; |
| } |
| address section_end(int n) const { |
| assert(_section_end[n], "must be initialized"); |
| return _section_end[n]; |
| } |
| |
| // The address points to the affected displacement part of the instruction. |
| // For RISC, this is just the whole instruction. |
| // For Intel, this is an unaligned 32-bit word. |
| |
| // type-specific relocation accessors: oop_Relocation* oop_reloc(), etc. |
| #define EACH_TYPE(name) \ |
| inline name##_Relocation* name##_reloc(); |
| APPLY_TO_RELOCATIONS(EACH_TYPE) |
| #undef EACH_TYPE |
| // generic relocation accessor; switches on type to call the above |
| Relocation* reloc(); |
| |
| #ifndef PRODUCT |
| public: |
| void print(); |
| void print_current(); |
| #endif |
| }; |
| |
| |
| // A Relocation is a flyweight object allocated within a RelocationHolder. |
| // It represents the relocation data of relocation record. |
| // So, the RelocIterator unpacks relocInfos into Relocations. |
| |
| class Relocation VALUE_OBJ_CLASS_SPEC { |
| friend class RelocationHolder; |
| friend class RelocIterator; |
| |
| private: |
| static void guarantee_size(); |
| |
| // When a relocation has been created by a RelocIterator, |
| // this field is non-null. It allows the relocation to know |
| // its context, such as the address to which it applies. |
| RelocIterator* _binding; |
| |
| protected: |
| RelocIterator* binding() const { |
| assert(_binding != NULL, "must be bound"); |
| return _binding; |
| } |
| void set_binding(RelocIterator* b) { |
| assert(_binding == NULL, "must be unbound"); |
| _binding = b; |
| assert(_binding != NULL, "must now be bound"); |
| } |
| |
| Relocation() { |
| _binding = NULL; |
| } |
| |
| static RelocationHolder newHolder() { |
| return RelocationHolder(); |
| } |
| |
| public: |
| void* operator new(size_t size, const RelocationHolder& holder) throw() { |
| if (size > sizeof(holder._relocbuf)) guarantee_size(); |
| assert((void* const *)holder.reloc() == &holder._relocbuf[0], "ptrs must agree"); |
| return holder.reloc(); |
| } |
| |
| // make a generic relocation for a given type (if possible) |
| static RelocationHolder spec_simple(relocInfo::relocType rtype); |
| |
| // here is the type-specific hook which writes relocation data: |
| virtual void pack_data_to(CodeSection* dest) { } |
| |
| // here is the type-specific hook which reads (unpacks) relocation data: |
| virtual void unpack_data() { |
| assert(datalen()==0 || type()==relocInfo::none, "no data here"); |
| } |
| |
| protected: |
| // Helper functions for pack_data_to() and unpack_data(). |
| |
| // Most of the compression logic is confined here. |
| // (The "immediate data" mechanism of relocInfo works independently |
| // of this stuff, and acts to further compress most 1-word data prefixes.) |
| |
| // A variable-width int is encoded as a short if it will fit in 16 bits. |
| // The decoder looks at datalen to decide whether to unpack short or jint. |
| // Most relocation records are quite simple, containing at most two ints. |
| |
| static bool is_short(jint x) { return x == (short)x; } |
| static short* add_short(short* p, int x) { *p++ = x; return p; } |
| static short* add_jint (short* p, jint x) { |
| *p++ = relocInfo::data0_from_int(x); *p++ = relocInfo::data1_from_int(x); |
| return p; |
| } |
| static short* add_var_int(short* p, jint x) { // add a variable-width int |
| if (is_short(x)) p = add_short(p, x); |
| else p = add_jint (p, x); |
| return p; |
| } |
| |
| static short* pack_1_int_to(short* p, jint x0) { |
| // Format is one of: [] [x] [Xx] |
| if (x0 != 0) p = add_var_int(p, x0); |
| return p; |
| } |
| int unpack_1_int() { |
| assert(datalen() <= 2, "too much data"); |
| return relocInfo::jint_data_at(0, data(), datalen()); |
| } |
| |
| // With two ints, the short form is used only if both ints are short. |
| short* pack_2_ints_to(short* p, jint x0, jint x1) { |
| // Format is one of: [] [x y?] [Xx Y?y] |
| if (x0 == 0 && x1 == 0) { |
| // no halfwords needed to store zeroes |
| } else if (is_short(x0) && is_short(x1)) { |
| // 1-2 halfwords needed to store shorts |
| p = add_short(p, x0); if (x1!=0) p = add_short(p, x1); |
| } else { |
| // 3-4 halfwords needed to store jints |
| p = add_jint(p, x0); p = add_var_int(p, x1); |
| } |
| return p; |
| } |
| void unpack_2_ints(jint& x0, jint& x1) { |
| int dlen = datalen(); |
| short* dp = data(); |
| if (dlen <= 2) { |
| x0 = relocInfo::short_data_at(0, dp, dlen); |
| x1 = relocInfo::short_data_at(1, dp, dlen); |
| } else { |
| assert(dlen <= 4, "too much data"); |
| x0 = relocInfo::jint_data_at(0, dp, dlen); |
| x1 = relocInfo::jint_data_at(2, dp, dlen); |
| } |
| } |
| |
| protected: |
| // platform-independent utility for patching constant section |
| void const_set_data_value (address x); |
| void const_verify_data_value (address x); |
| // platform-dependent utilities for decoding and patching instructions |
| void pd_set_data_value (address x, intptr_t off, bool verify_only = false); // a set or mem-ref |
| void pd_verify_data_value (address x, intptr_t off) { pd_set_data_value(x, off, true); } |
| address pd_call_destination (address orig_addr = NULL); |
| void pd_set_call_destination (address x); |
| |
| // this extracts the address of an address in the code stream instead of the reloc data |
| address* pd_address_in_code (); |
| |
| // this extracts an address from the code stream instead of the reloc data |
| address pd_get_address_from_code (); |
| |
| // these convert from byte offsets, to scaled offsets, to addresses |
| static jint scaled_offset(address x, address base) { |
| int byte_offset = x - base; |
| int offset = -byte_offset / relocInfo::addr_unit(); |
| assert(address_from_scaled_offset(offset, base) == x, "just checkin'"); |
| return offset; |
| } |
| static jint scaled_offset_null_special(address x, address base) { |
| // Some relocations treat offset=0 as meaning NULL. |
| // Handle this extra convention carefully. |
| if (x == NULL) return 0; |
| assert(x != base, "offset must not be zero"); |
| return scaled_offset(x, base); |
| } |
| static address address_from_scaled_offset(jint offset, address base) { |
| int byte_offset = -( offset * relocInfo::addr_unit() ); |
| return base + byte_offset; |
| } |
| |
| // helpers for mapping between old and new addresses after a move or resize |
| address old_addr_for(address newa, const CodeBuffer* src, CodeBuffer* dest); |
| address new_addr_for(address olda, const CodeBuffer* src, CodeBuffer* dest); |
| void normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections = false); |
| |
| public: |
| // accessors which only make sense for a bound Relocation |
| address addr() const { return binding()->addr(); } |
| CompiledMethod* code() const { return binding()->code(); } |
| nmethod* code_as_nmethod() const { return binding()->code_as_nmethod(); } |
| bool addr_in_const() const { return binding()->addr_in_const(); } |
| protected: |
| short* data() const { return binding()->data(); } |
| int datalen() const { return binding()->datalen(); } |
| int format() const { return binding()->format(); } |
| |
| public: |
| virtual relocInfo::relocType type() { return relocInfo::none; } |
| |
| // is it a call instruction? |
| virtual bool is_call() { return false; } |
| |
| // is it a data movement instruction? |
| virtual bool is_data() { return false; } |
| |
| // some relocations can compute their own values |
| virtual address value(); |
| |
| // all relocations are able to reassert their values |
| virtual void set_value(address x); |
| |
| virtual void clear_inline_cache() { } |
| |
| // This method assumes that all virtual/static (inline) caches are cleared (since for static_call_type and |
| // ic_call_type is not always posisition dependent (depending on the state of the cache)). However, this is |
| // probably a reasonable assumption, since empty caches simplifies code reloacation. |
| virtual void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { } |
| }; |
| |
| |
| // certain inlines must be deferred until class Relocation is defined: |
| |
| inline RelocationHolder::RelocationHolder() { |
| // initialize the vtbl, just to keep things type-safe |
| new(*this) Relocation(); |
| } |
| |
| |
| inline RelocationHolder::RelocationHolder(Relocation* r) { |
| // wordwise copy from r (ok if it copies garbage after r) |
| for (int i = 0; i < _relocbuf_size; i++) { |
| _relocbuf[i] = ((void**)r)[i]; |
| } |
| } |
| |
| |
| relocInfo::relocType RelocationHolder::type() const { |
| return reloc()->type(); |
| } |
| |
| // A DataRelocation always points at a memory or load-constant instruction.. |
| // It is absolute on most machines, and the constant is split on RISCs. |
| // The specific subtypes are oop, external_word, and internal_word. |
| // By convention, the "value" does not include a separately reckoned "offset". |
| class DataRelocation : public Relocation { |
| public: |
| bool is_data() { return true; } |
| |
| // both target and offset must be computed somehow from relocation data |
| virtual int offset() { return 0; } |
| address value() = 0; |
| void set_value(address x) { set_value(x, offset()); } |
| void set_value(address x, intptr_t o) { |
| if (addr_in_const()) |
| const_set_data_value(x); |
| else |
| pd_set_data_value(x, o); |
| } |
| void verify_value(address x) { |
| if (addr_in_const()) |
| const_verify_data_value(x); |
| else |
| pd_verify_data_value(x, offset()); |
| } |
| |
| // The "o" (displacement) argument is relevant only to split relocations |
| // on RISC machines. In some CPUs (SPARC), the set-hi and set-lo ins'ns |
| // can encode more than 32 bits between them. This allows compilers to |
| // share set-hi instructions between addresses that differ by a small |
| // offset (e.g., different static variables in the same class). |
| // On such machines, the "x" argument to set_value on all set-lo |
| // instructions must be the same as the "x" argument for the |
| // corresponding set-hi instructions. The "o" arguments for the |
| // set-hi instructions are ignored, and must not affect the high-half |
| // immediate constant. The "o" arguments for the set-lo instructions are |
| // added into the low-half immediate constant, and must not overflow it. |
| }; |
| |
| // A CallRelocation always points at a call instruction. |
| // It is PC-relative on most machines. |
| class CallRelocation : public Relocation { |
| public: |
| bool is_call() { return true; } |
| |
| address destination() { return pd_call_destination(); } |
| void set_destination(address x); // pd_set_call_destination |
| |
| void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| address value() { return destination(); } |
| void set_value(address x) { set_destination(x); } |
| }; |
| |
| class oop_Relocation : public DataRelocation { |
| relocInfo::relocType type() { return relocInfo::oop_type; } |
| |
| public: |
| // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll] |
| // an oop in the CodeBlob's oop pool |
| static RelocationHolder spec(int oop_index, int offset = 0) { |
| assert(oop_index > 0, "must be a pool-resident oop"); |
| RelocationHolder rh = newHolder(); |
| new(rh) oop_Relocation(oop_index, offset); |
| return rh; |
| } |
| // an oop in the instruction stream |
| static RelocationHolder spec_for_immediate() { |
| const int oop_index = 0; |
| const int offset = 0; // if you want an offset, use the oop pool |
| RelocationHolder rh = newHolder(); |
| new(rh) oop_Relocation(oop_index, offset); |
| return rh; |
| } |
| |
| private: |
| jint _oop_index; // if > 0, index into CodeBlob::oop_at |
| jint _offset; // byte offset to apply to the oop itself |
| |
| oop_Relocation(int oop_index, int offset) { |
| _oop_index = oop_index; _offset = offset; |
| } |
| |
| friend class RelocIterator; |
| oop_Relocation() { } |
| |
| public: |
| int oop_index() { return _oop_index; } |
| int offset() { return _offset; } |
| |
| // data is packed in "2_ints" format: [i o] or [Ii Oo] |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void fix_oop_relocation(); // reasserts oop value |
| |
| void verify_oop_relocation(); |
| |
| address value() { return (address) *oop_addr(); } |
| |
| bool oop_is_immediate() { return oop_index() == 0; } |
| |
| oop* oop_addr(); // addr or &pool[jint_data] |
| oop oop_value(); // *oop_addr |
| // Note: oop_value transparently converts Universe::non_oop_word to NULL. |
| }; |
| |
| |
| // copy of oop_Relocation for now but may delete stuff in both/either |
| class metadata_Relocation : public DataRelocation { |
| relocInfo::relocType type() { return relocInfo::metadata_type; } |
| |
| public: |
| // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll] |
| // an metadata in the CodeBlob's metadata pool |
| static RelocationHolder spec(int metadata_index, int offset = 0) { |
| assert(metadata_index > 0, "must be a pool-resident metadata"); |
| RelocationHolder rh = newHolder(); |
| new(rh) metadata_Relocation(metadata_index, offset); |
| return rh; |
| } |
| // an metadata in the instruction stream |
| static RelocationHolder spec_for_immediate() { |
| const int metadata_index = 0; |
| const int offset = 0; // if you want an offset, use the metadata pool |
| RelocationHolder rh = newHolder(); |
| new(rh) metadata_Relocation(metadata_index, offset); |
| return rh; |
| } |
| |
| private: |
| jint _metadata_index; // if > 0, index into nmethod::metadata_at |
| jint _offset; // byte offset to apply to the metadata itself |
| |
| metadata_Relocation(int metadata_index, int offset) { |
| _metadata_index = metadata_index; _offset = offset; |
| } |
| |
| friend class RelocIterator; |
| metadata_Relocation() { } |
| |
| // Fixes a Metadata pointer in the code. Most platforms embeds the |
| // Metadata pointer in the code at compile time so this is empty |
| // for them. |
| void pd_fix_value(address x); |
| |
| public: |
| int metadata_index() { return _metadata_index; } |
| int offset() { return _offset; } |
| |
| // data is packed in "2_ints" format: [i o] or [Ii Oo] |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void fix_metadata_relocation(); // reasserts metadata value |
| |
| void verify_metadata_relocation(); |
| |
| address value() { return (address) *metadata_addr(); } |
| |
| bool metadata_is_immediate() { return metadata_index() == 0; } |
| |
| Metadata** metadata_addr(); // addr or &pool[jint_data] |
| Metadata* metadata_value(); // *metadata_addr |
| // Note: metadata_value transparently converts Universe::non_metadata_word to NULL. |
| }; |
| |
| |
| class virtual_call_Relocation : public CallRelocation { |
| relocInfo::relocType type() { return relocInfo::virtual_call_type; } |
| |
| public: |
| // "cached_value" points to the first associated set-oop. |
| // The oop_limit helps find the last associated set-oop. |
| // (See comments at the top of this file.) |
| static RelocationHolder spec(address cached_value, jint method_index = 0) { |
| RelocationHolder rh = newHolder(); |
| new(rh) virtual_call_Relocation(cached_value, method_index); |
| return rh; |
| } |
| |
| private: |
| address _cached_value; // location of set-value instruction |
| jint _method_index; // resolved method for a Java call |
| |
| virtual_call_Relocation(address cached_value, int method_index) { |
| _cached_value = cached_value; |
| _method_index = method_index; |
| assert(cached_value != NULL, "first oop address must be specified"); |
| } |
| |
| friend class RelocIterator; |
| virtual_call_Relocation() { } |
| |
| public: |
| address cached_value(); |
| |
| int method_index() { return _method_index; } |
| Method* method_value(); |
| |
| // data is packed as scaled offsets in "2_ints" format: [f l] or [Ff Ll] |
| // oop_limit is set to 0 if the limit falls somewhere within the call. |
| // When unpacking, a zero oop_limit is taken to refer to the end of the call. |
| // (This has the effect of bringing in the call's delay slot on SPARC.) |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void clear_inline_cache(); |
| }; |
| |
| |
| class opt_virtual_call_Relocation : public CallRelocation { |
| relocInfo::relocType type() { return relocInfo::opt_virtual_call_type; } |
| |
| public: |
| static RelocationHolder spec(int method_index = 0) { |
| RelocationHolder rh = newHolder(); |
| new(rh) opt_virtual_call_Relocation(method_index); |
| return rh; |
| } |
| |
| private: |
| jint _method_index; // resolved method for a Java call |
| |
| opt_virtual_call_Relocation(int method_index) { |
| _method_index = method_index; |
| } |
| |
| friend class RelocIterator; |
| opt_virtual_call_Relocation() {} |
| |
| public: |
| int method_index() { return _method_index; } |
| Method* method_value(); |
| |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void clear_inline_cache(); |
| |
| // find the matching static_stub |
| address static_stub(bool is_aot); |
| }; |
| |
| |
| class static_call_Relocation : public CallRelocation { |
| relocInfo::relocType type() { return relocInfo::static_call_type; } |
| |
| public: |
| static RelocationHolder spec(int method_index = 0) { |
| RelocationHolder rh = newHolder(); |
| new(rh) static_call_Relocation(method_index); |
| return rh; |
| } |
| |
| private: |
| jint _method_index; // resolved method for a Java call |
| |
| static_call_Relocation(int method_index) { |
| _method_index = method_index; |
| } |
| |
| friend class RelocIterator; |
| static_call_Relocation() {} |
| |
| public: |
| int method_index() { return _method_index; } |
| Method* method_value(); |
| |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void clear_inline_cache(); |
| |
| // find the matching static_stub |
| address static_stub(bool is_aot); |
| }; |
| |
| class static_stub_Relocation : public Relocation { |
| relocInfo::relocType type() { return relocInfo::static_stub_type; } |
| |
| public: |
| static RelocationHolder spec(address static_call, bool is_aot = false) { |
| RelocationHolder rh = newHolder(); |
| new(rh) static_stub_Relocation(static_call, is_aot); |
| return rh; |
| } |
| |
| private: |
| address _static_call; // location of corresponding static_call |
| bool _is_aot; // trampoline to aot code |
| |
| static_stub_Relocation(address static_call, bool is_aot) { |
| _static_call = static_call; |
| _is_aot = is_aot; |
| } |
| |
| friend class RelocIterator; |
| static_stub_Relocation() { } |
| |
| public: |
| void clear_inline_cache(); |
| |
| address static_call() { return _static_call; } |
| bool is_aot() { return _is_aot; } |
| |
| // data is packed as a scaled offset in "1_int" format: [c] or [Cc] |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| }; |
| |
| class runtime_call_Relocation : public CallRelocation { |
| relocInfo::relocType type() { return relocInfo::runtime_call_type; } |
| |
| public: |
| static RelocationHolder spec() { |
| RelocationHolder rh = newHolder(); |
| new(rh) runtime_call_Relocation(); |
| return rh; |
| } |
| |
| private: |
| friend class RelocIterator; |
| runtime_call_Relocation() { } |
| |
| public: |
| }; |
| |
| |
| class runtime_call_w_cp_Relocation : public CallRelocation { |
| relocInfo::relocType type() { return relocInfo::runtime_call_w_cp_type; } |
| |
| public: |
| static RelocationHolder spec() { |
| RelocationHolder rh = newHolder(); |
| new(rh) runtime_call_w_cp_Relocation(); |
| return rh; |
| } |
| |
| private: |
| friend class RelocIterator; |
| runtime_call_w_cp_Relocation() { _offset = -4; /* <0 = invalid */ } |
| // On z/Architecture, runtime calls are either a sequence |
| // of two instructions (load destination of call from constant pool + do call) |
| // or a pc-relative call. The pc-relative call is faster, but it can only |
| // be used if the destination of the call is not too far away. |
| // In order to be able to patch a pc-relative call back into one using |
| // the constant pool, we have to remember the location of the call's destination |
| // in the constant pool. |
| int _offset; |
| |
| public: |
| void set_constant_pool_offset(int offset) { _offset = offset; } |
| int get_constant_pool_offset() { return _offset; } |
| void pack_data_to(CodeSection * dest); |
| void unpack_data(); |
| }; |
| |
| // Trampoline Relocations. |
| // A trampoline allows to encode a small branch in the code, even if there |
| // is the chance that this branch can not reach all possible code locations. |
| // If the relocation finds that a branch is too far for the instruction |
| // in the code, it can patch it to jump to the trampoline where is |
| // sufficient space for a far branch. Needed on PPC. |
| class trampoline_stub_Relocation : public Relocation { |
| relocInfo::relocType type() { return relocInfo::trampoline_stub_type; } |
| |
| public: |
| static RelocationHolder spec(address static_call) { |
| RelocationHolder rh = newHolder(); |
| return (new (rh) trampoline_stub_Relocation(static_call)); |
| } |
| |
| private: |
| address _owner; // Address of the NativeCall that owns the trampoline. |
| |
| trampoline_stub_Relocation(address owner) { |
| _owner = owner; |
| } |
| |
| friend class RelocIterator; |
| trampoline_stub_Relocation() { } |
| |
| public: |
| |
| // Return the address of the NativeCall that owns the trampoline. |
| address owner() { return _owner; } |
| |
| void pack_data_to(CodeSection * dest); |
| void unpack_data(); |
| |
| // Find the trampoline stub for a call. |
| static address get_trampoline_for(address call, nmethod* code); |
| }; |
| |
| class external_word_Relocation : public DataRelocation { |
| relocInfo::relocType type() { return relocInfo::external_word_type; } |
| |
| public: |
| static RelocationHolder spec(address target) { |
| assert(target != NULL, "must not be null"); |
| RelocationHolder rh = newHolder(); |
| new(rh) external_word_Relocation(target); |
| return rh; |
| } |
| |
| // Use this one where all 32/64 bits of the target live in the code stream. |
| // The target must be an intptr_t, and must be absolute (not relative). |
| static RelocationHolder spec_for_immediate() { |
| RelocationHolder rh = newHolder(); |
| new(rh) external_word_Relocation(NULL); |
| return rh; |
| } |
| |
| // Some address looking values aren't safe to treat as relocations |
| // and should just be treated as constants. |
| static bool can_be_relocated(address target) { |
| assert(target == NULL || (uintptr_t)target >= (uintptr_t)os::vm_page_size(), INTPTR_FORMAT, (intptr_t)target); |
| return target != NULL; |
| } |
| |
| private: |
| address _target; // address in runtime |
| |
| external_word_Relocation(address target) { |
| _target = target; |
| } |
| |
| friend class RelocIterator; |
| external_word_Relocation() { } |
| |
| public: |
| // data is packed as a well-known address in "1_int" format: [a] or [Aa] |
| // The function runtime_address_to_index is used to turn full addresses |
| // to short indexes, if they are pre-registered by the stub mechanism. |
| // If the "a" value is 0 (i.e., _target is NULL), the address is stored |
| // in the code stream. See external_word_Relocation::target(). |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| address target(); // if _target==NULL, fetch addr from code stream |
| address value() { return target(); } |
| }; |
| |
| class internal_word_Relocation : public DataRelocation { |
| relocInfo::relocType type() { return relocInfo::internal_word_type; } |
| |
| public: |
| static RelocationHolder spec(address target) { |
| assert(target != NULL, "must not be null"); |
| RelocationHolder rh = newHolder(); |
| new(rh) internal_word_Relocation(target); |
| return rh; |
| } |
| |
| // use this one where all the bits of the target can fit in the code stream: |
| static RelocationHolder spec_for_immediate() { |
| RelocationHolder rh = newHolder(); |
| new(rh) internal_word_Relocation(NULL); |
| return rh; |
| } |
| |
| internal_word_Relocation(address target) { |
| _target = target; |
| _section = -1; // self-relative |
| } |
| |
| protected: |
| address _target; // address in CodeBlob |
| int _section; // section providing base address, if any |
| |
| friend class RelocIterator; |
| internal_word_Relocation() { } |
| |
| // bit-width of LSB field in packed offset, if section >= 0 |
| enum { section_width = 2 }; // must equal CodeBuffer::sect_bits |
| |
| public: |
| // data is packed as a scaled offset in "1_int" format: [o] or [Oo] |
| // If the "o" value is 0 (i.e., _target is NULL), the offset is stored |
| // in the code stream. See internal_word_Relocation::target(). |
| // If _section is not -1, it is appended to the low bits of the offset. |
| void pack_data_to(CodeSection* dest); |
| void unpack_data(); |
| |
| void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| address target(); // if _target==NULL, fetch addr from code stream |
| int section() { return _section; } |
| address value() { return target(); } |
| }; |
| |
| class section_word_Relocation : public internal_word_Relocation { |
| relocInfo::relocType type() { return relocInfo::section_word_type; } |
| |
| public: |
| static RelocationHolder spec(address target, int section) { |
| RelocationHolder rh = newHolder(); |
| new(rh) section_word_Relocation(target, section); |
| return rh; |
| } |
| |
| section_word_Relocation(address target, int section) { |
| assert(target != NULL, "must not be null"); |
| assert(section >= 0, "must be a valid section"); |
| _target = target; |
| _section = section; |
| } |
| |
| //void pack_data_to -- inherited |
| void unpack_data(); |
| |
| private: |
| friend class RelocIterator; |
| section_word_Relocation() { } |
| }; |
| |
| |
| class poll_Relocation : public Relocation { |
| bool is_data() { return true; } |
| relocInfo::relocType type() { return relocInfo::poll_type; } |
| void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); |
| }; |
| |
| class poll_return_Relocation : public poll_Relocation { |
| relocInfo::relocType type() { return relocInfo::poll_return_type; } |
| }; |
| |
| // We know all the xxx_Relocation classes, so now we can define these: |
| #define EACH_CASE(name) \ |
| inline name##_Relocation* RelocIterator::name##_reloc() { \ |
| assert(type() == relocInfo::name##_type, "type must agree"); \ |
| /* The purpose of the placed "new" is to re-use the same */ \ |
| /* stack storage for each new iteration. */ \ |
| name##_Relocation* r = new(_rh) name##_Relocation(); \ |
| r->set_binding(this); \ |
| r->name##_Relocation::unpack_data(); \ |
| return r; \ |
| } |
| APPLY_TO_RELOCATIONS(EACH_CASE); |
| #undef EACH_CASE |
| |
| inline RelocIterator::RelocIterator(CompiledMethod* nm, address begin, address limit) { |
| initialize(nm, begin, limit); |
| } |
| |
| #endif // SHARE_VM_CODE_RELOCINFO_HPP |