Ensure that the test version of the command line tool is stable for benchmarking (#2076)

Some benchmark suites contain test cases that have nonreproducible
behaviour. This is mostly caused by relying on "now" when dealing
with dates or timestamps, instead of using a fixed moment. (A
notorious example is the crypto-aes.js test case of the sunspider
bechmark suite, where the heap memory consumption can vary between
34K-41K heap because of using `(new Date()).getTime()`.)

This commit renames the jerry-minimal command line tool to
jerry-test (to better reflect its purpose) and adds extra code,
which intercepts some calls to libc (`gettimeofday`, `rand`) and
pins their results to some fixed values. This makes the tool
useless in a general case but ensures stable results when
benchmarking -- for which it is mostly used.

As a side effect, the commit also changes jerry-libc by making all
libc functions weak symbols to allow their override from
application code.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-libc/jerry-libc-printf.c

@@ -469,7 +469,7 @@ libc_printf_write_u_o_x_X (FILE *stream, /**< stream pointer */
  *
  * @return number of characters printed
  */
-int
+int __attr_weak___
 vfprintf (FILE *stream, /**< stream pointer */
           const char *format, /**< format string */
           va_list args) /**< arguments */
@@ -719,7 +719,7 @@ vfprintf (FILE *stream, /**< stream pointer */
  *
  * @return number of characters printed
  */
-int
+int __attr_weak___
 fprintf (FILE *stream, /**< stream pointer */
          const char *format, /**< format string */
          ...) /**< parameters' values */
@@ -740,7 +740,7 @@ fprintf (FILE *stream, /**< stream pointer */
  *
  * @return number of characters printed
  */
-int
+int __attr_weak___
 printf (const char *format, /**< format string */
         ...) /**< parameters' values */
 {

jerry-libc/jerry-libc.c

@@ -56,7 +56,7 @@ CALL_PRAGMA (GCC optimize ("-fno-tree-loop-distribute-patterns"))
  *
  * @return @a s
  */
-void * __attr_used___
+void * __attr_weak___ __attr_used___
 memset (void *s, /**< area to set values in */
         int c, /**< value to set */
         size_t n) /**< area size */
@@ -77,7 +77,7 @@ memset (void *s, /**< area to set values in */
  *         <0, if first area's content is lexicographically less, than second area's content;
  *         >0, otherwise
  */
-int
+int __attr_weak___
 memcmp (const void *s1, /**< first area */
         const void *s2, /**< second area */
         size_t n) /**< area size */
@@ -100,7 +100,7 @@ memcmp (const void *s1, /**< first area */
  *
  * @return the dest pointer's value
  */
-void *  __attr_used___
+void * __attr_weak___ __attr_used___
 memcpy (void *s1, /**< destination */
         const void *s2, /**< source */
         size_t n) /**< bytes number */
@@ -139,7 +139,7 @@ memcpy (void *s1, /**< destination */
  *
  * @return the dest pointer's value
  */
-void * __attr_used___
+void * __attr_weak___ __attr_used___
 memmove (void *s1, /**< destination */
          const void *s2, /**< source */
          size_t n) /**< bytes number */
@@ -182,7 +182,7 @@ CALL_PRAGMA (GCC diagnostic pop)
  * @return an integer less than, equal to, or greater than zero if s1 is found, respectively,
  *         to be less than, to match, or be greater than s2.
  */
-int
+int __attr_weak___
 strcmp (const char *s1, /**< first string */
         const char *s2) /**< second string */
 {
@@ -205,7 +205,7 @@ strcmp (const char *s1, /**< first string */
  * @return an integer less than, equal to, or greater than zero if the first n character of s1 is found, respectively,
  *         to be less than, to match, or be greater than the first n character of s2.
  */
-int
+int __attr_weak___
 strncmp (const char *s1, /**< first string */
          const char *s2, /**< second string */
          size_t n) /**< maximum number of characters to compare */
@@ -234,7 +234,7 @@ strncmp (const char *s1, /**< first string */
  *
  * @return a pointer to the destination string dest.
  */
-char * __attr_used___
+char * __attr_weak___ __attr_used___
 strncpy (char *dest, /**< destination string */
          const char *src, /**< source string */
          size_t n) /**< maximum number of characters to copy */
@@ -258,7 +258,7 @@ strncpy (char *dest, /**< destination string */
  *
  * @return the length.
  */
-size_t
+size_t __attr_weak___
 strlen (const char *s) /**< string */
 {
   size_t i = 0;
@@ -278,7 +278,7 @@ strlen (const char *s) /**< string */
  *
  * @return integer in range [0; RAND_MAX]
  */
-int
+int __attr_weak___
 rand (void)
 {
   uint32_t intermediate = libc_random_gen_state[0] ^ (libc_random_gen_state[0] << 11);
@@ -297,7 +297,7 @@ rand (void)
 /**
  * Initialize pseudo-random number generator with the specified seed value
  */
-void
+void __attr_weak___
 srand (unsigned int seed) /**< new seed */
 {
   libc_random_gen_state[0] = (uint32_t) ((seed * 14316555781)
@@ -325,7 +325,7 @@ srand (unsigned int seed) /**< new seed */
  *
  * @return the integer value of str.
  */
-long int
+long int __attr_weak___
 strtol (const char *nptr, /**< string representation of an integer number */
         char **endptr, /**< [out] the address of the first non-number character */
         int base) /**< numerical base or radix (MUST be 10) */

jerry-libc/target/posix/jerry-libc-target.c

@@ -48,7 +48,7 @@ long int syscall_3 (long int syscall_no, long int arg1, long int arg2, long int
 /**
  * Exit - cause normal process termination with specified status code
  */
-void __attr_noreturn___ __attr_used___
+void __attr_weak___ __attr_noreturn___ __attr_used___
 exit (int status) /**< status code */
 {
 #ifdef ENABLE_INIT_FINI
@@ -71,7 +71,7 @@ exit (int status) /**< status code */
  * Abort current process, producing an abnormal program termination.
  * The function raises the SIGABRT signal.
  */
-void __attr_noreturn___ __attr_used___
+void __attr_weak___ __attr_noreturn___ __attr_used___
 abort (void)
 {
   syscall_1 (SYSCALL_NO (close), (long int) stdin);
@@ -92,7 +92,7 @@ abort (void)
  * @return 0 - upon successful completion,
  *         non-zero value - otherwise.
  */
-int __attr_used___
+int __attr_weak___ __attr_used___
 raise (int sig) /**< signal number */
 {
   return (int) syscall_2 (SYSCALL_NO (kill), syscall_0 (SYSCALL_NO (getpid)), sig);
@@ -104,7 +104,7 @@ raise (int sig) /**< signal number */
  * @return FILE pointer - upon successful completion,
  *         NULL - otherwise.
  */
-FILE *
+FILE * __attr_weak___
 fopen (const char *path, /**< file path */
        const char *mode) /**< file open mode */
 {
@@ -193,7 +193,7 @@ fopen (const char *path, /**< file path */
  * @return 0 - upon successful completion,
  *         non-zero value - otherwise.
  */
-int
+int __attr_weak___
 fclose (FILE *fp) /**< stream pointer */
 {
   syscall_2 (SYSCALL_NO (close), (long int) fp, 0);
@@ -206,7 +206,7 @@ fclose (FILE *fp) /**< stream pointer */
  *
  * @return number of elements read
  */
-size_t
+size_t __attr_weak___
 fread (void *ptr, /**< address of buffer to read to */
        size_t size, /**< size of elements to read */
        size_t nmemb, /**< number of elements to read */
@@ -239,7 +239,7 @@ fread (void *ptr, /**< address of buffer to read to */
  *
  * @return number of elements written
  */
-size_t
+size_t __attr_weak___
 fwrite (const void *ptr, /**< data to write */
         size_t size, /**< size of elements to write */
         size_t nmemb, /**< number of elements */
@@ -271,7 +271,7 @@ fwrite (const void *ptr, /**< data to write */
  *
  * @return 0 if success, -1 otherwise
  */
-int
+int __attr_weak___
 gettimeofday (void *tp,  /**< struct timeval */
               void *tzp) /**< struct timezone */
 {