path: root/libraries/pack200/src/unpack.h

/*
 * Copyright (c) 2002, 2008, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 */

// Global Structures
struct jar;
struct gunzip;
struct band;
struct constant_pool;
struct entry;
struct cpindex;
struct inner_class;
struct value_stream;

struct cpindex
{
	uint32_t len;
	entry *base1;  // base of primary index
	entry **base2; // base of secondary index
	byte ixTag;	// type of entries (!= CONSTANT_None), plus 64 if sub-index
	enum
	{
		SUB_TAG = 64
	};

	entry *get(uint32_t i);

	void init(int len_, entry *base1_, int ixTag_)
	{
		len = len_;
		base1 = base1_;
		base2 = nullptr;
		ixTag = ixTag_;
	}
	void init(int len_, entry **base2_, int ixTag_)
	{
		len = len_;
		base1 = nullptr;
		base2 = base2_;
		ixTag = ixTag_;
	}
};

struct constant_pool
{
	uint32_t nentries;
	entry *entries;
	entry *first_extra_entry;
	uint32_t maxentries; // total allocated size of entries

	// Position and size of each homogeneous subrange:
	int tag_count[CONSTANT_Limit];
	int tag_base[CONSTANT_Limit];
	cpindex tag_index[CONSTANT_Limit];
	ptrlist tag_extras[CONSTANT_Limit];

	cpindex *member_indexes; // indexed by 2*CONSTANT_Class.inord
	cpindex *getFieldIndex(entry *classRef);
	cpindex *getMethodIndex(entry *classRef);

	inner_class **ic_index;
	inner_class **ic_child_index;
	inner_class *getIC(entry *inner);
	inner_class *getFirstChildIC(entry *outer);
	inner_class *getNextChildIC(inner_class *child);

	int outputIndexLimit;  // index limit after renumbering
	ptrlist outputEntries; // list of entry* needing output idx assigned

	entry **hashTab;
	uint32_t hashTabLength;
	entry *&hashTabRef(byte tag, bytes &b);
	entry *ensureUtf8(bytes &b);
	entry *ensureClass(bytes &b);

	// Well-known Utf8 symbols.
	enum
	{
#define SNAME(n, s) s_##s,
		ALL_ATTR_DO(SNAME)
#undef SNAME
		s_lt_init_gt, // <init>
		s_LIMIT
	};
	entry *sym[s_LIMIT];

	// read counts from hdr, allocate main arrays
	enum
	{
		NUM_COUNTS = 12
	};
	void init(unpacker *u, int counts[NUM_COUNTS]);

	// pointer to outer unpacker, for error checks etc.
	unpacker *u;

	int getCount(byte tag)
	{
		assert((uint32_t)tag < CONSTANT_Limit);
		return tag_count[tag];
	}
	cpindex *getIndex(byte tag)
	{
		assert((uint32_t)tag < CONSTANT_Limit);
		return &tag_index[tag];
	}
	cpindex *getKQIndex(); // uses cur_descr

	void expandSignatures();
	void initMemberIndexes();

	void computeOutputOrder();
	void computeOutputIndexes();
	void resetOutputIndexes();
};

/*
 * The unpacker provides the entry points to the unpack engine,
 * as well as maintains the state of the engine.
 */
struct unpacker
{
	// One element of the resulting JAR.
	struct file
	{
		const char *name;
		uint64_t size;
		int modtime;
		int options;
		bytes data[2];
		// Note:  If Sum(data[*].len) < size,
		// remaining bytes must be read directly from the input stream.
		bool deflate_hint()
		{
			return ((options & FO_DEFLATE_HINT) != 0);
		}
	};

	// if running Unix-style, here are the inputs and outputs
	FILE *infileptr; // buffered
	bytes inbytes;   // direct
	gunzip *gzin;	// gunzip filter, if any
	jar *jarout;	 // output JAR file

	// pointer to self, for U_NEW macro
	unpacker *u;

	ptrlist mallocs;	 // list of guys to free when we are all done
	ptrlist tmallocs;	// list of guys to free on next client request
	fillbytes smallbuf;  // supplies small alloc requests
	fillbytes tsmallbuf; // supplies temporary small alloc requests

	// option management members
	int verbose;			  // verbose level, 0 means no output
	int deflate_hint_or_zero; // ==0 means not set, otherwise -1 or 1
	int modification_time_or_zero;

	// input stream
	fillbytes input; // the whole block (size is predicted, has slop too)
	bool live_input; // is the data in this block live?
	bool free_input; // must the input buffer be freed?
	byte *rp;		// read pointer (< rplimit <= input.limit())
	byte *rplimit;   // how much of the input block has been read?
	uint64_t bytes_read;
	int unsized_bytes_read;

	// callback to read at least one byte, up to available input
	typedef int64_t (*read_input_fn_t)(unpacker *self, void *buf, int64_t minlen,
									   int64_t maxlen);
	read_input_fn_t read_input_fn;

	// archive header fields
	int magic, minver, majver;
	size_t archive_size;
	int archive_next_count, archive_options, archive_modtime;
	int band_headers_size;
	int file_count, attr_definition_count, ic_count, class_count;
	int default_class_minver, default_class_majver;
	int default_file_options, suppress_file_options;   // not header fields
	int default_archive_modtime, default_file_modtime; // not header fields
	int code_count;									// not a header field
	int files_remaining;							   // not a header field

	// engine state
	band *all_bands;  // indexed by band_number
	byte *meta_rp;	// read-pointer into (copy of) band_headers
	constant_pool cp; // all constant pool information
	inner_class *ics; // InnerClasses

	// output stream
	bytes output;  // output block (either classfile head or tail)
	byte *wp;	  // write pointer (< wplimit == output.limit())
	byte *wpbase;  // write pointer starting address (<= wp)
	byte *wplimit; // how much of the output block has been written?

	// output state
	file cur_file;
	entry *cur_class;	// CONSTANT_Class entry
	entry *cur_super;	// CONSTANT_Class entry or nullptr
	entry *cur_descr;	// CONSTANT_NameandType entry
	int cur_descr_flags; // flags corresponding to cur_descr
	int cur_class_minver, cur_class_majver;
	bool cur_class_has_local_ics;
	fillbytes cur_classfile_head;
	fillbytes cur_classfile_tail;
	int files_written;   // also tells which file we're working on
	int classes_written; // also tells which class we're working on
	uint64_t bytes_written;
	intlist bcimap;
	fillbytes class_fixup_type;
	intlist class_fixup_offset;
	ptrlist class_fixup_ref;
	fillbytes code_fixup_type; // which format of branch operand?
	intlist code_fixup_offset; // location of operand needing fixup
	intlist code_fixup_source; // encoded ID of branch insn
	ptrlist requested_ics;	 // which ics need output?

	// stats pertaining to multiple segments (updated on reset)
	uint64_t bytes_read_before_reset;
	uint64_t bytes_written_before_reset;
	int files_written_before_reset;
	int classes_written_before_reset;
	int segments_read_before_reset;

	// attribute state
	struct layout_definition
	{
		uint32_t idx;	 // index (0..31...) which identifies this layout
		const char *name; // name of layout
		entry *nameEntry;
		const char *layout; // string of layout (not yet parsed)
		band **elems;	   // array of top-level layout elems (or callables)

		bool hasCallables()
		{
			return layout[0] == '[';
		}
		band **bands()
		{
			assert(elems != nullptr);
			return elems;
		}
	};
	struct attr_definitions
	{
		unpacker *u;		 // pointer to self, for U_NEW macro
		int xxx_flags_hi_bn; // locator for flags, count, indexes, calls bands
		int attrc;		   // ATTR_CONTEXT_CLASS, etc.
		uint32_t flag_limit; // 32 or 63, depending on archive_options bit
		uint64_t predef;	 // mask of built-in definitions
		uint64_t redef;	  // mask of local flag definitions or redefinitions
		ptrlist layouts;	 // local (compressor-defined) defs, in index order
		int flag_count[X_ATTR_LIMIT_FLAGS_HI];
		intlist overflow_count;
		ptrlist strip_names;   // what attribute names are being stripped?
		ptrlist band_stack;	// Temp., used during layout parsing.
		ptrlist calls_to_link; //  (ditto)
		int bands_made;		//  (ditto)

		void free()
		{
			layouts.free();
			overflow_count.free();
			strip_names.free();
			band_stack.free();
			calls_to_link.free();
		}

		// Locate the five fixed bands.
		band &xxx_flags_hi();
		band &xxx_flags_lo();
		band &xxx_attr_count();
		band &xxx_attr_indexes();
		band &xxx_attr_calls();
		band &fixed_band(int e_class_xxx);

		// Register a new layout, and make bands for it.
		layout_definition *defineLayout(int idx, const char *name, const char *layout);
		layout_definition *defineLayout(int idx, entry *nameEntry, const char *layout);
		band **buildBands(layout_definition *lo);

		// Parse a layout string or part of one, recursively if necessary.
		const char *parseLayout(const char *lp, band **&res, int curCble);
		const char *parseNumeral(const char *lp, int &res);
		const char *parseIntLayout(const char *lp, band *&res, byte le_kind,
								   bool can_be_signed = false);
		band **popBody(int band_stack_base); // pops a body off band_stack

		// Read data into the bands of the idx-th layout.
		void readBandData(int idx);					 // parse layout, make bands, read data
		void readBandData(band **body, uint32_t count); // recursive helper

		layout_definition *getLayout(uint32_t idx)
		{
			if (idx >= (uint32_t)layouts.length())
				return nullptr;
			return (layout_definition *)layouts.get(idx);
		}

		void setHaveLongFlags(bool z)
		{
			assert(flag_limit == 0); // not set up yet
			flag_limit = (z ? X_ATTR_LIMIT_FLAGS_HI : X_ATTR_LIMIT_NO_FLAGS_HI);
		}
		bool haveLongFlags()
		{
			assert(flag_limit == X_ATTR_LIMIT_NO_FLAGS_HI ||
				   flag_limit == X_ATTR_LIMIT_FLAGS_HI);
			return flag_limit == X_ATTR_LIMIT_FLAGS_HI;
		}

		// Return flag_count if idx is predef and not redef, else zero.
		int predefCount(uint32_t idx);

		bool isRedefined(uint32_t idx)
		{
			if (idx >= flag_limit)
				return false;
			return (bool)((redef >> idx) & 1);
		}
		bool isPredefined(uint32_t idx)
		{
			if (idx >= flag_limit)
				return false;
			return (bool)(((predef & ~redef) >> idx) & 1);
		}
		uint64_t flagIndexMask()
		{
			return (predef | redef);
		}
		bool isIndex(uint32_t idx)
		{
			assert(flag_limit != 0); // must be set up already
			if (idx < flag_limit)
				return (bool)(((predef | redef) >> idx) & 1);
			else
				return (idx - flag_limit < (uint32_t)overflow_count.length());
		}
		int &getCount(uint32_t idx)
		{
			assert(isIndex(idx));
			if (idx < flag_limit)
				return flag_count[idx];
			else
				return overflow_count.get(idx - flag_limit);
		}
	};

	attr_definitions attr_defs[ATTR_CONTEXT_LIMIT];

	// Initialization
	void init(read_input_fn_t input_fn = nullptr);
	// Resets to a known sane state
	void reset();
	// Deallocates all storage.
	void free();
	// Deallocates temporary storage (volatile after next client call).
	void free_temps()
	{
		tsmallbuf.init();
		tmallocs.freeAll();
	}

	// Option management methods
	bool set_option(const char *option, const char *value);
	const char *get_option(const char *option);

	// Fetching input.
	bool ensure_input(int64_t more);
	byte *input_scan()
	{
		return rp;
	}
	size_t input_remaining()
	{
		return rplimit - rp;
	}
	size_t input_consumed()
	{
		return rp - input.base();
	}

	// Entry points to the unpack engine
	static int run(int argc, char **argv); // Unix-style entry point.
	void check_options();
	void start(void *packptr = nullptr, size_t len = 0);
	void write_file_to_jar(file *f);
	void finish();

	// Public post unpack methods
	int get_files_remaining()
	{
		return files_remaining;
	}
	int get_segments_remaining()
	{
		return archive_next_count;
	}
	file *get_next_file(); // returns nullptr on last file

	// General purpose methods
	void *alloc(size_t size)
	{
		return alloc_heap(size, true);
	}
	void *temp_alloc(size_t size)
	{
		return alloc_heap(size, true, true);
	}
	void *alloc_heap(size_t size, bool smallOK = false, bool temp = false);
	void saveTo(bytes &b, const char *str)
	{
		saveTo(b, (byte *)str, strlen(str));
	}
	void saveTo(bytes &b, bytes &data)
	{
		saveTo(b, data.ptr, data.len);
	}
	void saveTo(bytes &b, byte *ptr, size_t len); //{ b.ptr = U_NEW...}
	const char *saveStr(const char *str)
	{
		bytes buf;
		saveTo(buf, str);
		return buf.strval();
	}
	const char *saveIntStr(int num)
	{
		char buf[30];
		sprintf(buf, "%d", num);
		return saveStr(buf);
	}
	static unpacker *current(); // find current instance

	// Output management
	void set_output(fillbytes *which)
	{
		assert(wp == nullptr);
		which->ensureSize(1 << 12); // covers the average classfile
		wpbase = which->base();
		wp = which->limit();
		wplimit = which->end();
	}
	fillbytes *close_output(fillbytes *which = nullptr); // inverse of set_output

	// These take an implicit parameter of wp/wplimit, and resize as necessary:
	byte *put_space(size_t len); // allocates space at wp, returns pointer
	size_t put_empty(size_t s)
	{
		byte *p = put_space(s);
		return p - wpbase;
	}
	void ensure_put_space(size_t len);
	void put_bytes(bytes &b)
	{
		b.writeTo(put_space(b.len));
	}
	void putu1(int n)
	{
		putu1_at(put_space(1), n);
	}
	void putu1_fast(int n)
	{
		putu1_at(wp++, n);
	}
	void putu2(int n);					// { putu2_at(put_space(2), n); }
	void putu4(int n);					// { putu4_at(put_space(4), n); }
	void putu8(int64_t n);				// { putu8_at(put_space(8), n); }
	void putref(entry *e);				// { putu2_at(put_space(2), putref_index(e, 2)); }
	void putu1ref(entry *e);			  // { putu1_at(put_space(1), putref_index(e, 1)); }
	int putref_index(entry *e, int size); // size in [1..2]
	void put_label(int curIP, int size);  // size in {2,4}
	void putlayout(band **body);
	void put_stackmap_type();

	size_t wpoffset()
	{
		return (size_t)(wp - wpbase);
	} // (unvariant across overflow)
	byte *wp_at(size_t offset)
	{
		return wpbase + offset;
	}
	uint32_t to_bci(uint32_t bii);
	void get_code_header(int &max_stack, int &max_na_locals, int &handler_count, int &cflags);
	band *ref_band_for_self_op(int bc, bool &isAloadVar, int &origBCVar);
	band *ref_band_for_op(int bc);

	// Definitions of standard classfile int formats:
	static void putu1_at(byte *wp, int n)
	{
		assert(n == (n & 0xFF));
		wp[0] = n;
	}
	static void putu2_at(byte *wp, int n);
	static void putu4_at(byte *wp, int n);
	static void putu8_at(byte *wp, int64_t n);

	// Private stuff
	void reset_cur_classfile();
	void write_classfile_tail();
	void write_classfile_head();
	void write_code();
	void write_bc_ops();
	void write_members(int num, int attrc); // attrc=ATTR_CONTEXT_FIELD/METHOD
	int write_attrs(int attrc, uint64_t indexBits);

	// The readers
	void read_bands();
	void read_file_header();
	void read_cp();
	void read_cp_counts(value_stream &hdr);
	void read_attr_defs();
	void read_ics();
	void read_attrs(int attrc, int obj_count);
	void read_classes();
	void read_code_headers();
	void read_bcs();
	void read_bc_ops();
	void read_files();
	void read_Utf8_values(entry *cpMap, int len);
	void read_single_words(band &cp_band, entry *cpMap, int len);
	void read_double_words(band &cp_bands, entry *cpMap, int len);
	void read_single_refs(band &cp_band, byte refTag, entry *cpMap, int len);
	void read_double_refs(band &cp_band, byte ref1Tag, byte ref2Tag, entry *cpMap, int len);
	void read_signature_values(entry *cpMap, int len);
};