+ int32: byte3 byte2 byte1 byte0 | byte0 byte1 byte2 byte3
+ int64: int32:low int32:high
+ string: int32:0 | int32:length char* char:0 padding
+ padding: | char:0 | char:0 char:0 | char:0 char:0 char:0
+ item: int32 | int64 | string
+
+ The basic format of the files is
+
+ file : int32:magic int32:version int32:stamp record*
+
+ The magic ident is different for the notes and the data files. The
+ magic ident is used to determine the endianness of the file, when
+ reading. The version is the same for both files and is derived
+ from gcc's version number. The stamp value is used to synchronize
+ note and data files and to synchronize merging within a data
+ file. It need not be an absolute time stamp, merely a ticker that
+ increments fast enough and cycles slow enough to distinguish
+ different compile/run/compile cycles.
+
+ Although the ident and version are formally 32 bit numbers, they
+ are derived from 4 character ASCII strings. The version number
+ consists of the single character major version number, a two
+ character minor version number (leading zero for versions less than
+ 10), and a single character indicating the status of the release.
+ That will be 'e' experimental, 'p' prerelease and 'r' for release.
+ Because, by good fortune, these are in alphabetical order, string
+ collating can be used to compare version strings. Be aware that
+ the 'e' designation will (naturally) be unstable and might be
+ incompatible with itself. For gcc 3.4 experimental, it would be
+ '304e' (0x33303465). When the major version reaches 10, the
+ letters A-Z will be used. Assuming minor increments releases every
+ 6 months, we have to make a major increment every 50 years.
+ Assuming major increments releases every 5 years, we're ok for the
+ next 155 years -- good enough for me.
+
+ A record has a tag, length and variable amount of data.
+
+ record: header data
+ header: int32:tag int32:length
+ data: item*
+
+ Records are not nested, but there is a record hierarchy. Tag
+ numbers reflect this hierarchy. Tags are unique across note and
+ data files. Some record types have a varying amount of data. The
+ LENGTH is the number of 4bytes that follow and is usually used to
+ determine how much data. The tag value is split into 4 8-bit
+ fields, one for each of four possible levels. The most significant
+ is allocated first. Unused levels are zero. Active levels are
+ odd-valued, so that the LSB of the level is one. A sub-level
+ incorporates the values of its superlevels. This formatting allows
+ you to determine the tag hierarchy, without understanding the tags
+ themselves, and is similar to the standard section numbering used
+ in technical documents. Level values [1..3f] are used for common
+ tags, values [41..9f] for the notes file and [a1..ff] for the data
+ file.
+
+ The basic block graph file contains the following records
+ note: unit function-graph*
+ unit: header int32:checksum string:source
+ function-graph: announce_function basic_blocks {arcs | lines}*
+ announce_function: header int32:ident int32:checksum
+ string:name string:source int32:lineno
+ basic_block: header int32:flags*
+ arcs: header int32:block_no arc*
+ arc: int32:dest_block int32:flags
+ lines: header int32:block_no line*
+ int32:0 string:NULL
+ line: int32:line_no | int32:0 string:filename
+
+ The BASIC_BLOCK record holds per-bb flags. The number of blocks
+ can be inferred from its data length. There is one ARCS record per
+ basic block. The number of arcs from a bb is implicit from the
+ data length. It enumerates the destination bb and per-arc flags.
+ There is one LINES record per basic block, it enumerates the source
+ lines which belong to that basic block. Source file names are
+ introduced by a line number of 0, following lines are from the new
+ source file. The initial source file for the function is NULL, but
+ the current source file should be remembered from one LINES record
+ to the next. The end of a block is indicated by an empty filename
+ - this does not reset the current source file. Note there is no
+ ordering of the ARCS and LINES records: they may be in any order,
+ interleaved in any manner. The current filename follows the order
+ the LINES records are stored in the file, *not* the ordering of the
+ blocks they are for.
+
+ The data file contains the following records.
+ data: {unit function-data* summary:object summary:program*}*
+ unit: header int32:checksum
+ function-data: announce_function arc_counts
+ announce_function: header int32:ident int32:checksum
+ arc_counts: header int64:count*
+ summary: int32:checksum {count-summary}GCOV_COUNTERS
+ count-summary: int32:num int32:runs int64:sum
+ int64:max int64:sum_max
+
+ The ANNOUNCE_FUNCTION record is the same as that in the note file,
+ but without the source location. The ARC_COUNTS gives the counter
+ values for those arcs that are instrumented. The SUMMARY records
+ give information about the whole object file and about the whole
+ program. The checksum is used for whole program summaries, and
+ disambiguates different programs which include the same
+ instrumented object file. There may be several program summaries,
+ each with a unique checksum. The object summary's checksum is zero.
+ Note that the data file might contain information from several runs
+ concatenated, or the data might be merged.
+
+ This file is included by both the compiler, gcov tools and the
+ runtime support library libgcov. IN_LIBGCOV and IN_GCOV are used to
+ distinguish which case is which. If IN_LIBGCOV is nonzero,
+ libgcov is being built. If IN_GCOV is nonzero, the gcov tools are
+ being built. Otherwise the compiler is being built. IN_GCOV may be
+ positive or negative. If positive, we are compiling a tool that
+ requires additional functions (see the code for knowledge of what
+ those functions are). */
+
+#ifndef GCC_GCOV_IO_H
+#define GCC_GCOV_IO_H
+
+#if IN_LIBGCOV
+/* About the target */
+
+#if BITS_PER_UNIT == 8
+typedef unsigned gcov_unsigned_t __attribute__ ((mode (SI)));
+typedef unsigned gcov_position_t __attribute__ ((mode (SI)));
+#if LONG_LONG_TYPE_SIZE > 32
+typedef signed gcov_type __attribute__ ((mode (DI)));
+#else
+typedef signed gcov_type __attribute__ ((mode (SI)));
+#endif
+#else
+#if BITS_PER_UNIT == 16
+typedef unsigned gcov_unsigned_t __attribute__ ((mode (HI)));
+typedef unsigned gcov_position_t __attribute__ ((mode (HI)));
+#if LONG_LONG_TYPE_SIZE > 32
+typedef signed gcov_type __attribute__ ((mode (SI)));
+#else
+typedef signed gcov_type __attribute__ ((mode (HI)));
+#endif
+#else
+typedef unsigned gcov_unsigned_t __attribute__ ((mode (QI)));
+typedef unsigned gcov_position_t __attribute__ ((mode (QI)));
+#if LONG_LONG_TYPE_SIZE > 32
+typedef signed gcov_type __attribute__ ((mode (HI)));
+#else
+typedef signed gcov_type __attribute__ ((mode (QI)));
+#endif
+#endif
+#endif
+
+
+#if defined (TARGET_HAS_F_SETLKW)
+#define GCOV_LOCKED 1
+#else
+#define GCOV_LOCKED 0
+#endif
+
+#else /* !IN_LIBGCOV */
+/* About the host */
+
+typedef unsigned gcov_unsigned_t;
+typedef unsigned gcov_position_t;
+/* gcov_type is typedef'd elsewhere for the compiler */
+#if IN_GCOV
+#define GCOV_LINKAGE static
+typedef HOST_WIDEST_INT gcov_type;
+#if IN_GCOV > 0
+#include <sys/types.h>
+#endif
+#else /*!IN_GCOV */
+#if LONG_LONG_TYPE_SIZE > 32
+#define GCOV_TYPE_NODE intDI_type_node
+#else
+#define GCOV_TYPE_NODE intSI_type_node
+#endif
+#endif
+
+#if defined (HOST_HAS_F_SETLKW)
+#define GCOV_LOCKED 1
+#else
+#define GCOV_LOCKED 0
+#endif
+
+#endif /* !IN_LIBGCOV */
+
+/* In gcov we want function linkage to be static. In libgcov we need
+ these functions to be extern, so prefix them with __gcov. In the
+ compiler we want it extern, so that they can be accessed from
+ elsewhere. */
+#if IN_LIBGCOV
+#define gcov_var __gcov_var
+#define gcov_open __gcov_open
+#define gcov_close __gcov_close
+#define gcov_write_tag_length __gcov_write_tag_length
+#define gcov_position __gcov_position
+#define gcov_seek __gcov_seek
+#define gcov_rewrite __gcov_rewrite
+#define gcov_is_error __gcov_is_error
+#define gcov_write_unsigned __gcov_write_unsigned
+#define gcov_write_counter __gcov_write_counter
+#define gcov_write_summary __gcov_write_summary
+#define gcov_read_unsigned __gcov_read_unsigned
+#define gcov_read_counter __gcov_read_counter
+#define gcov_read_summary __gcov_read_summary
+
+/* Poison these, so they don't accidentally slip in. */
+#pragma GCC poison gcov_write_string gcov_write_tag gcov_write_length
+#pragma GCC poison gcov_read_string gcov_sync gcov_time gcov_magic
+
+#endif
+
+#ifndef GCOV_LINKAGE
+#define GCOV_LINKAGE extern
+#endif
+
+/* File suffixes. */
+#define GCOV_DATA_SUFFIX ".gcda"
+#define GCOV_NOTE_SUFFIX ".gcno"
+
+/* File magic. Must not be palindromes. */
+#define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
+#define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
+
+/* gcov-iov.h is automatically generated by the makefile from
+ version.c, it looks like
+ #define GCOV_VERSION ((gcov_unsigned_t)0x89abcdef)
+*/
+#include "gcov-iov.h"
+
+/* Convert a magic or version number to a 4 character string. */
+#define GCOV_UNSIGNED2STRING(ARRAY,VALUE) \
+ ((ARRAY)[0] = (char)((VALUE) >> 24), \
+ (ARRAY)[1] = (char)((VALUE) >> 16), \
+ (ARRAY)[2] = (char)((VALUE) >> 8), \
+ (ARRAY)[3] = (char)((VALUE) >> 0))
+
+/* The record tags. Values [1..3f] are for tags which may be in either
+ file. Values [41..9f] for those in the note file and [a1..ff] for
+ the data file. The tag value zero is used as an explicit end of
+ file marker -- it is not required to be present. */
+
+#define GCOV_TAG_FUNCTION ((gcov_unsigned_t)0x01000000)
+#define GCOV_TAG_FUNCTION_LENGTH (2)
+#define GCOV_TAG_BLOCKS ((gcov_unsigned_t)0x01410000)
+#define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
+#define GCOV_TAG_BLOCKS_NUM(LENGTH) (LENGTH)
+#define GCOV_TAG_ARCS ((gcov_unsigned_t)0x01430000)
+#define GCOV_TAG_ARCS_LENGTH(NUM) (1 + (NUM) * 2)
+#define GCOV_TAG_ARCS_NUM(LENGTH) (((LENGTH) - 1) / 2)
+#define GCOV_TAG_LINES ((gcov_unsigned_t)0x01450000)
+#define GCOV_TAG_COUNTER_BASE ((gcov_unsigned_t)0x01a10000)
+#define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
+#define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
+#define GCOV_TAG_OBJECT_SUMMARY ((gcov_unsigned_t)0xa1000000)
+#define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000)
+#define GCOV_TAG_SUMMARY_LENGTH \
+ (1 + GCOV_COUNTERS_SUMMABLE * (2 + 3 * 2))
+
+/* Counters that are collected. */
+#define GCOV_COUNTER_ARCS 0 /* Arc transitions. */
+#define GCOV_COUNTERS_SUMMABLE 1 /* Counters which can be
+ summaried. */
+#define GCOV_FIRST_VALUE_COUNTER 1 /* The first of counters used for value
+ profiling. They must form a consecutive
+ interval and their order must match
+ the order of HIST_TYPEs in
+ value-prof.h. */
+#define GCOV_COUNTER_V_INTERVAL 1 /* Histogram of value inside an interval. */
+#define GCOV_COUNTER_V_POW2 2 /* Histogram of exact power2 logarithm
+ of a value. */
+#define GCOV_COUNTER_V_SINGLE 3 /* The most common value of expression. */
+#define GCOV_COUNTER_V_DELTA 4 /* The most common difference between
+ consecutive values of expression. */
+#define GCOV_LAST_VALUE_COUNTER 4 /* The last of counters used for value
+ profiling. */
+#define GCOV_COUNTERS 5
+
+/* Number of counters used for value profiling. */
+#define GCOV_N_VALUE_COUNTERS \
+ (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
+
+ /* A list of human readable names of the counters */
+#define GCOV_COUNTER_NAMES {"arcs", "interval", "pow2", "single", "delta"}
+
+ /* Names of merge functions for counters. */
+#define GCOV_MERGE_FUNCTIONS {"__gcov_merge_add", \
+ "__gcov_merge_add", \
+ "__gcov_merge_add", \
+ "__gcov_merge_single", \
+ "__gcov_merge_delta"}
+
+/* Convert a counter index to a tag. */
+#define GCOV_TAG_FOR_COUNTER(COUNT) \
+ (GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
+/* Convert a tag to a counter. */
+#define GCOV_COUNTER_FOR_TAG(TAG) \
+ ((unsigned)(((TAG) - GCOV_TAG_COUNTER_BASE) >> 17))
+/* Check whether a tag is a counter tag. */
+#define GCOV_TAG_IS_COUNTER(TAG) \
+ (!((TAG) & 0xFFFF) && GCOV_COUNTER_FOR_TAG (TAG) < GCOV_COUNTERS)
+
+/* The tag level mask has 1's in the position of the inner levels, &
+ the lsb of the current level, and zero on the current and outer
+ levels. */
+#define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
+
+/* Return nonzero if SUB is an immediate subtag of TAG. */
+#define GCOV_TAG_IS_SUBTAG(TAG,SUB) \
+ (GCOV_TAG_MASK (TAG) >> 8 == GCOV_TAG_MASK (SUB) \
+ && !(((SUB) ^ (TAG)) & ~GCOV_TAG_MASK(TAG)))
+
+/* Return nonzero if SUB is at a sublevel to TAG. */
+#define GCOV_TAG_IS_SUBLEVEL(TAG,SUB) \
+ (GCOV_TAG_MASK (TAG) > GCOV_TAG_MASK (SUB))
+
+/* Basic block flags. */
+#define GCOV_BLOCK_UNEXPECTED (1 << 1)
+
+/* Arc flags. */
+#define GCOV_ARC_ON_TREE (1 << 0)
+#define GCOV_ARC_FAKE (1 << 1)
+#define GCOV_ARC_FALLTHROUGH (1 << 2)
+
+/* Structured records. */
+
+/* Cumulative counter data. */
+struct gcov_ctr_summary