perf_counter tools: add in basic glue from Git

First very raw version at having a central 'perf' command and
a list of subcommands:

  perf top
  perf stat
  perf record
  perf report
  ...

This is done by picking up Git's collection of utility functions,
and hacking them to build fine in this new environment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/perf_counter/util.h b/Documentation/perf_counter/util.h
new file mode 100644
index 0000000..13f8bdc
--- /dev/null
+++ b/Documentation/perf_counter/util.h
@@ -0,0 +1,394 @@
+#ifndef GIT_COMPAT_UTIL_H
+#define GIT_COMPAT_UTIL_H
+
+#define _FILE_OFFSET_BITS 64
+
+#ifndef FLEX_ARRAY
+/*
+ * See if our compiler is known to support flexible array members.
+ */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+# define FLEX_ARRAY /* empty */
+#elif defined(__GNUC__)
+# if (__GNUC__ >= 3)
+#  define FLEX_ARRAY /* empty */
+# else
+#  define FLEX_ARRAY 0 /* older GNU extension */
+# endif
+#endif
+
+/*
+ * Otherwise, default to safer but a bit wasteful traditional style
+ */
+#ifndef FLEX_ARRAY
+# define FLEX_ARRAY 1
+#endif
+#endif
+
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+
+#ifdef __GNUC__
+#define TYPEOF(x) (__typeof__(x))
+#else
+#define TYPEOF(x)
+#endif
+
+#define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (sizeof(x) * 8 - (bits))))
+#define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
+
+/* Approximation of the length of the decimal representation of this type. */
+#define decimal_length(x)	((int)(sizeof(x) * 2.56 + 0.5) + 1)
+
+#if !defined(__APPLE__) && !defined(__FreeBSD__)  && !defined(__USLC__) && !defined(_M_UNIX)
+#define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
+#define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
+#endif
+#define _ALL_SOURCE 1
+#define _GNU_SOURCE 1
+#define _BSD_SOURCE 1
+
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <time.h>
+#include <signal.h>
+#include <fnmatch.h>
+#include <assert.h>
+#include <regex.h>
+#include <utime.h>
+#ifndef __MINGW32__
+#include <sys/wait.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#ifndef NO_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <inttypes.h>
+#if defined(__CYGWIN__)
+#undef _XOPEN_SOURCE
+#include <grp.h>
+#define _XOPEN_SOURCE 600
+#include "compat/cygwin.h"
+#else
+#undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
+#include <grp.h>
+#define _ALL_SOURCE 1
+#endif
+#else 	/* __MINGW32__ */
+/* pull in Windows compatibility stuff */
+#include "compat/mingw.h"
+#endif	/* __MINGW32__ */
+
+#ifndef NO_ICONV
+#include <iconv.h>
+#endif
+
+#ifndef NO_OPENSSL
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#endif
+
+/* On most systems <limits.h> would have given us this, but
+ * not on some systems (e.g. GNU/Hurd).
+ */
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+#ifndef PRIuMAX
+#define PRIuMAX "llu"
+#endif
+
+#ifndef PRIu32
+#define PRIu32 "u"
+#endif
+
+#ifndef PRIx32
+#define PRIx32 "x"
+#endif
+
+#ifndef PATH_SEP
+#define PATH_SEP ':'
+#endif
+
+#ifndef STRIP_EXTENSION
+#define STRIP_EXTENSION ""
+#endif
+
+#ifndef has_dos_drive_prefix
+#define has_dos_drive_prefix(path) 0
+#endif
+
+#ifndef is_dir_sep
+#define is_dir_sep(c) ((c) == '/')
+#endif
+
+#ifdef __GNUC__
+#define NORETURN __attribute__((__noreturn__))
+#else
+#define NORETURN
+#ifndef __attribute__
+#define __attribute__(x)
+#endif
+#endif
+
+/* General helper functions */
+extern void usage(const char *err) NORETURN;
+extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
+extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
+extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
+
+extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
+
+extern int prefixcmp(const char *str, const char *prefix);
+extern time_t tm_to_time_t(const struct tm *tm);
+
+static inline const char *skip_prefix(const char *str, const char *prefix)
+{
+	size_t len = strlen(prefix);
+	return strncmp(str, prefix, len) ? NULL : str + len;
+}
+
+#if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
+
+#ifndef PROT_READ
+#define PROT_READ 1
+#define PROT_WRITE 2
+#define MAP_PRIVATE 1
+#define MAP_FAILED ((void*)-1)
+#endif
+
+#define mmap git_mmap
+#define munmap git_munmap
+extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+extern int git_munmap(void *start, size_t length);
+
+#else /* NO_MMAP || USE_WIN32_MMAP */
+
+#include <sys/mman.h>
+
+#endif /* NO_MMAP || USE_WIN32_MMAP */
+
+#ifdef NO_MMAP
+
+/* This value must be multiple of (pagesize * 2) */
+#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
+
+#else /* NO_MMAP */
+
+/* This value must be multiple of (pagesize * 2) */
+#define DEFAULT_PACKED_GIT_WINDOW_SIZE \
+	(sizeof(void*) >= 8 \
+		?  1 * 1024 * 1024 * 1024 \
+		: 32 * 1024 * 1024)
+
+#endif /* NO_MMAP */
+
+#ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
+#define on_disk_bytes(st) ((st).st_size)
+#else
+#define on_disk_bytes(st) ((st).st_blocks * 512)
+#endif
+
+#define DEFAULT_PACKED_GIT_LIMIT \
+	((1024L * 1024L) * (sizeof(void*) >= 8 ? 8192 : 256))
+
+#ifdef NO_PREAD
+#define pread git_pread
+extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
+#endif
+/*
+ * Forward decl that will remind us if its twin in cache.h changes.
+ * This function is used in compat/pread.c.  But we can't include
+ * cache.h there.
+ */
+extern ssize_t read_in_full(int fd, void *buf, size_t count);
+
+#ifdef NO_SETENV
+#define setenv gitsetenv
+extern int gitsetenv(const char *, const char *, int);
+#endif
+
+#ifdef NO_MKDTEMP
+#define mkdtemp gitmkdtemp
+extern char *gitmkdtemp(char *);
+#endif
+
+#ifdef NO_UNSETENV
+#define unsetenv gitunsetenv
+extern void gitunsetenv(const char *);
+#endif
+
+#ifdef NO_STRCASESTR
+#define strcasestr gitstrcasestr
+extern char *gitstrcasestr(const char *haystack, const char *needle);
+#endif
+
+#ifdef NO_STRLCPY
+#define strlcpy gitstrlcpy
+extern size_t gitstrlcpy(char *, const char *, size_t);
+#endif
+
+#ifdef NO_STRTOUMAX
+#define strtoumax gitstrtoumax
+extern uintmax_t gitstrtoumax(const char *, char **, int);
+#endif
+
+#ifdef NO_HSTRERROR
+#define hstrerror githstrerror
+extern const char *githstrerror(int herror);
+#endif
+
+#ifdef NO_MEMMEM
+#define memmem gitmemmem
+void *gitmemmem(const void *haystack, size_t haystacklen,
+                const void *needle, size_t needlelen);
+#endif
+
+#ifdef FREAD_READS_DIRECTORIES
+#ifdef fopen
+#undef fopen
+#endif
+#define fopen(a,b) git_fopen(a,b)
+extern FILE *git_fopen(const char*, const char*);
+#endif
+
+#ifdef SNPRINTF_RETURNS_BOGUS
+#define snprintf git_snprintf
+extern int git_snprintf(char *str, size_t maxsize,
+			const char *format, ...);
+#define vsnprintf git_vsnprintf
+extern int git_vsnprintf(char *str, size_t maxsize,
+			 const char *format, va_list ap);
+#endif
+
+#ifdef __GLIBC_PREREQ
+#if __GLIBC_PREREQ(2, 1)
+#define HAVE_STRCHRNUL
+#endif
+#endif
+
+#ifndef HAVE_STRCHRNUL
+#define strchrnul gitstrchrnul
+static inline char *gitstrchrnul(const char *s, int c)
+{
+	while (*s && *s != c)
+		s++;
+	return (char *)s;
+}
+#endif
+
+static inline size_t xsize_t(off_t len)
+{
+	return (size_t)len;
+}
+
+static inline int has_extension(const char *filename, const char *ext)
+{
+	size_t len = strlen(filename);
+	size_t extlen = strlen(ext);
+	return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
+}
+
+/* Sane ctype - no locale, and works with signed chars */
+#undef isascii
+#undef isspace
+#undef isdigit
+#undef isalpha
+#undef isalnum
+#undef tolower
+#undef toupper
+extern unsigned char sane_ctype[256];
+#define GIT_SPACE 0x01
+#define GIT_DIGIT 0x02
+#define GIT_ALPHA 0x04
+#define GIT_GLOB_SPECIAL 0x08
+#define GIT_REGEX_SPECIAL 0x10
+#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
+#define isascii(x) (((x) & ~0x7f) == 0)
+#define isspace(x) sane_istest(x,GIT_SPACE)
+#define isdigit(x) sane_istest(x,GIT_DIGIT)
+#define isalpha(x) sane_istest(x,GIT_ALPHA)
+#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
+#define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
+#define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
+#define tolower(x) sane_case((unsigned char)(x), 0x20)
+#define toupper(x) sane_case((unsigned char)(x), 0)
+
+static inline int sane_case(int x, int high)
+{
+	if (sane_istest(x, GIT_ALPHA))
+		x = (x & ~0x20) | high;
+	return x;
+}
+
+static inline int strtoul_ui(char const *s, int base, unsigned int *result)
+{
+	unsigned long ul;
+	char *p;
+
+	errno = 0;
+	ul = strtoul(s, &p, base);
+	if (errno || *p || p == s || (unsigned int) ul != ul)
+		return -1;
+	*result = ul;
+	return 0;
+}
+
+static inline int strtol_i(char const *s, int base, int *result)
+{
+	long ul;
+	char *p;
+
+	errno = 0;
+	ul = strtol(s, &p, base);
+	if (errno || *p || p == s || (int) ul != ul)
+		return -1;
+	*result = ul;
+	return 0;
+}
+
+#ifdef INTERNAL_QSORT
+void git_qsort(void *base, size_t nmemb, size_t size,
+	       int(*compar)(const void *, const void *));
+#define qsort git_qsort
+#endif
+
+#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
+# define FORCE_DIR_SET_GID S_ISGID
+#else
+# define FORCE_DIR_SET_GID 0
+#endif
+
+#ifdef NO_NSEC
+#undef USE_NSEC
+#define ST_CTIME_NSEC(st) 0
+#define ST_MTIME_NSEC(st) 0
+#else
+#ifdef USE_ST_TIMESPEC
+#define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
+#define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
+#else
+#define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
+#define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
+#endif
+#endif
+
+#endif