winebuild: generate deterministic temp filenames

Using the xorshift* pseudo random generator for the filenames.

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

tools/winebuild/build.h

@@ -27,6 +27,7 @@
 # error You must include config.h to use this header
 #endif
 
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -352,6 +353,11 @@ extern void put_qword( unsigned int val );
 extern void put_pword( unsigned int val );
 extern void align_output( unsigned int align );
 
+extern uint64_t pseudorandom(uint64_t add_to_state);
+extern char pseudorandom_char(void);
+extern int pseudorandom_tempfile(char* file);
+extern void init_random_generator(int argc, char **argv);
+
 /* global variables */
 
 extern int current_line;

tools/winebuild/main.c

@@ -666,6 +666,7 @@ int main(int argc, char **argv)
     signal( SIGTERM, exit_on_signal );
     signal( SIGINT, exit_on_signal );
 
+    init_random_generator(argc, argv);
     argv = parse_options( argc, argv, spec );
     atexit( cleanup );  /* make sure we remove the output file on exit */
 

tools/winebuild/utils.c

@@ -514,13 +514,13 @@ char *get_temp_file_name( const char *prefix, const char *suffix )
     strcpy( name + (ext - prefix), ".XXXXXX" );
     strcat( name, suffix );
 
-    if ((fd = mkstemps( name, strlen(suffix) )) == -1)
+    if ((fd = pseudorandom_tempfile(name)) == -1)
     {
         strcpy( name, "/tmp/" );
         memcpy( name + 5, basename, ext - basename );
         strcpy( name + 5 + (ext - basename), ".XXXXXX" );
         strcat( name, suffix );
-        if ((fd = mkstemps( name, strlen(suffix) )) == -1)
+        if ((fd = pseudorandom_tempfile(name)) == -1)
             fatal_error( "could not generate a temp file\n" );
     }
 
@@ -1275,3 +1275,96 @@ const char *get_asm_string_section(void)
     default:             return ".section .rodata";
     }
 }
+
+/* xorshift* random generator. Source: https://en.wikipedia.org/wiki/Xorshift#xorshift* */
+static uint64_t pseudorandom_state = 1;
+extern char **environ;
+
+uint64_t pseudorandom(uint64_t add_to_state)
+{
+    uint64_t tmp = pseudorandom_state + add_to_state;
+    tmp ^= tmp >> 12;
+    tmp ^= tmp << 25;
+    tmp ^= tmp >> 27;
+    pseudorandom_state = tmp;
+    return tmp * UINT64_C(0x2545F4914F6CDD1D);
+}
+
+char pseudorandom_char(void)
+{
+    char 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)
+{
+    /* replaces Xs */
+    for (char* tmp = file; (*tmp) != 0; tmp++)
+    {
+        if ((*tmp) == 'X')
+        {
+            (*tmp) = pseudorandom_char();
+        }
+    }
+
+    /* try to open file */
+    return open(file, O_CREAT | O_EXCL | O_RDWR, 0600);
+}
+
+void init_random_generator(int argc, char **argv)
+{
+    /* process environment */
+    {
+        /* copy environment variables and sort them */
+        char **tmp_envs;
+        unsigned int counter = 0;
+        for (const char **env = environ; (*env) != 0; env++, counter++) {}
+        tmp_envs = (char**) malloc(sizeof(char*) * counter);
+        for (unsigned int i = 0; i < counter; i++)
+        {
+            size_t length = strlen(environ[i]) + 1;
+            char* tmp = malloc(length);
+            memcpy(tmp, environ[i], length);
+            tmp_envs[i] = tmp;
+        }
+        qsort(tmp_envs, counter, sizeof(char*), (int(*)(const void*, const void*)) &strcmp);
+
+        /* add sorted environment to random generator */
+        for (unsigned int i = 0; i < counter; i++)
+        {
+            size_t j_max = strlen(tmp_envs[i]);
+            for (size_t j = 0; j < j_max; j++)
+            {
+                pseudorandom(tmp_envs[i][j]);
+            }
+        }
+
+        /* free temp environment */
+        for (unsigned int i = 0; i < counter; i++)
+        {
+            free(tmp_envs[i]);
+        }
+        free(tmp_envs);
+    }
+
+    /* process argv */
+    for (int i = 0; i < argc; i++)
+    {
+        size_t j_max = strlen(argv[i]);
+        for (size_t j = 0; j < j_max; j++)
+        {
+            pseudorandom(argv[i][j]);
+        }
+    }
+}