winegcc: generate deterministic temporary filenames

Using xorshift* as pseudorandom number generator. It get initialised
with the environment (sorted by name) and arguments.

Signed-off-by: Marko Semet <marko@marko10-000.de>

tools/winegcc/utils.c

@@ -384,3 +384,159 @@ int spawn(const strarray* prefix, const strarray* args, int ignore_errors)
     strarray_free(arr);
     return status;
 }
+
+/* xorshift* random generator. Source: https://en.wikipedia.org/wiki/Xorshift#xorshift* */
+static uint64_t pseudorandom_state = 1;
+
+static uint64_t pseudorandom_algo(uint64_t* generator_state, uint64_t add_to_state)
+{
+    uint64_t tmp = (*generator_state) + add_to_state;
+    tmp ^= tmp >> 12;
+    tmp ^= tmp << 25;
+    tmp ^= tmp >> 27;
+    (*generator_state) = tmp;
+    return tmp * UINT64_C(0x2545F4914F6CDD1D);
+}
+
+uint64_t pseudorandom(uint64_t add_to_state)
+{
+    return pseudorandom_algo(&pseudorandom_state, add_to_state);
+}
+
+char pseudorandom_char(void)
+{
+    char tmp;
+    tmp = (char) (pseudorandom(0) % 62);
+    if (tmp < 10)
+    {
+        return '0' + tmp;
+    }
+    else if (tmp < 36)
+    {
+        return 'A' + (tmp - 10);
+    }
+    else
+    {
+        return 'a' + (tmp - 36);
+    }
+}
+
+int pseudorandom_tempfile(char* file)
+{
+    /* variables */
+    int result;
+
+    int counter;
+    char *filename_pos;
+
+    char *debug_filename;
+    FILE *debug_file;
+
+    /* replaces Xs */
+    for (filename_pos = file; (*filename_pos) != 0; filename_pos++)
+    {
+        if ((*filename_pos) == 'X')
+        {
+            (*filename_pos) = pseudorandom_char();
+        }
+    }
+
+    /* try to open file */
+    counter = 0;
+    do
+    {
+        result = open(file, O_CREAT | O_EXCL | O_RDWR, 0600);
+        if (result != -1)
+        {
+            break;
+        }
+        sleep(5);
+        counter++;
+    } while (counter <= 12);
+    return result;
+}
+
+void init_random_generator(int argc, char **argv)
+{
+    /* variables */
+    uint64_t generator_state;
+
+    void *argv_data;
+    size_t argv_size;
+
+    unsigned int counter;
+    void *env_data;
+    size_t env_size;
+    char **tmp_envs;
+
+    char *buffer_pos;
+    char **env;
+    size_t length;
+
+    unsigned int i;
+    size_t j;
+
+    /* process environment */
+    generator_state = 1;
+    env_size = 0;
+    {
+        /* sort environment variables */
+        counter = 0;
+        for (env = environ; (*env) != NULL; env++)
+        {
+            counter++;
+            env_size += strlen(*env) + 1;
+        }
+        tmp_envs = (char**) malloc(sizeof(char*) * counter);
+        for (i = 0; i < counter; i++)
+        {
+            tmp_envs[i] = (char*) (environ[i]);
+        }
+        qsort(tmp_envs, counter, sizeof(char*), (int(*)(const void*, const void*)) &strcmp);
+
+        /* and copy them */
+        env_data = malloc(env_size * sizeof(char));
+        buffer_pos = env_data;
+        for (i = 0; i < counter; i++)
+        {
+            length = strlen(tmp_envs[i]) + 1;
+            memcpy(buffer_pos, tmp_envs[i], length);
+            buffer_pos += length;
+        }
+
+        /* add sorted environment to random generator */
+        for (j = 0; j < env_size; j++)
+        {
+            pseudorandom_algo(&generator_state, ((unsigned char*) env_data)[j]);
+        }
+
+        /* free temp environment */
+        free(tmp_envs);
+    }
+
+    /* copy argv */
+    argv_size = 0;
+    for (i = 0; i < argc; i++)
+    {
+        argv_size += strlen(argv[i]) + 1;
+    }
+    argv_data = malloc(sizeof(char) * argv_size);
+    buffer_pos = argv_data;
+    for (i = 0; i < argc; i++)
+    {
+        length = strlen(argv[i]) + 1;
+        memcpy(buffer_pos, argv[i], length);
+        buffer_pos += length;
+    }
+
+    /* add arguments to gnerator */
+    for (j = 0; j < argv_size; j++)
+    {
+        pseudorandom_algo(&generator_state, ((unsigned char*) argv_data)[j]);
+    }
+
+    /* set state and free rest */
+    free(env_data);
+    free(argv_data);
+    pseudorandom_state = generator_state;
+}

tools/winegcc/utils.h

@@ -25,6 +25,8 @@
 #define __attribute__(X)
 #endif
 
+#include <stdint.h>
+
 #ifndef DECLSPEC_NORETURN
 # if defined(_MSC_VER) && (_MSC_VER >= 1200) && !defined(MIDL_PASS)
 #  define DECLSPEC_NORETURN __declspec(noreturn)
@@ -90,3 +92,8 @@ const char *find_binary( const strarray* prefix, const char *name );
 int spawn(const strarray* prefix, const strarray* arr, int ignore_errors);
 
 extern int verbose;
+
+uint64_t pseudorandom(uint64_t add_to_state);
+char pseudorandom_char(void);
+int pseudorandom_tempfile(char* file);
+void init_random_generator(int argc, char **argv);

tools/winegcc/winegcc.c

@@ -299,7 +299,7 @@ static char* get_temp_file(const char* prefix, const char* suffix)
     /* block signals while manipulating the temp files list */
     sigprocmask( SIG_BLOCK, &signal_mask, &old_set );
 #endif
-    fd = mkstemps( tmp, strlen(suffix) );
+    fd = pseudorandom_tempfile(tmp);
     if (fd == -1)
     {
         /* could not create it in current directory, try in TMPDIR */
@@ -308,7 +308,7 @@ static char* get_temp_file(const char* prefix, const char* suffix)
         free(tmp);
         if (!(tmpdir = getenv("TMPDIR"))) tmpdir = "/tmp";
         tmp = strmake("%s/%s-XXXXXX%s", tmpdir, prefix, suffix);
-        fd = mkstemps( tmp, strlen(suffix) );
+        fd = pseudorandom_tempfile(tmp);
         if (fd == -1) error( "could not create temp file\n" );
     }
     close( fd );
@@ -1603,6 +1603,7 @@ int main(int argc, char **argv)
     sigaddset( &signal_mask, SIGTERM );
     sigaddset( &signal_mask, SIGINT );
 #endif
+    init_random_generator(argc, argv);
     init_argv0_dir( argv[0] );
 
     /* setup tmp file removal at exit */