Make improvements

- Invent openatemp() API
- Invent O_UNLINK open flag
- Introduce getenv_secure() API
- Remove `git pull` from cosmocc
- Fix utimes() when path is NULL
- Fix mktemp() to never return NULL
- Fix utimensat() UTIME_OMIT on XNU
- Improve utimensat() code for RHEL5
- Turn `argv[0]` C:/ to /C/ on Windows
- Introduce tmpnam() and tmpnam_r() APIs
- Fix more const issues with internal APIs
- Permit utimes() on WIN32 in O_RDONLY mode
- Fix fdopendir() to check fd is a directory
- Fix recent crash regression in landlock make
- Fix futimens(AT_FDCWD, NULL) to return EBADF
- Use workaround so `make -j` doesn't fork bomb
- Rename dontdiscard to __wur (just like glibc)
- Fix st_size for WIN32 symlinks containing UTF-8
- Introduce stdio ext APIs needed by GNU coreutils
- Fix lstat() on WIN32 for symlinks to directories
- Move some constants from normalize.inc to limits.h
- Fix segv with memchr() and memcmp() overlapping page
- Implement POSIX fflush() behavior for reader streams
- Implement AT_SYMLINK_NOFOLLOW for utimensat() on WIN32
- Don't change read-only status of existing files on WIN32
- Correctly handle `0x[^[:xdigit:]]` case in strtol() functions

libc/mem/alg.h

@@ -27,7 +27,7 @@ int mergesort(void *, size_t, size_t, int (*)(const void *, const void *));
 int mergesort_r(void *, size_t, size_t,
                 int (*)(const void *, const void *, void *), void *);
 
-#define __algalloc returnspointerwithnoaliases dontthrow nocallback dontdiscard
+#define __algalloc returnspointerwithnoaliases dontthrow nocallback __wur
 
 int radix_sort_int32(int32_t *, size_t);
 int radix_sort_int64(int64_t *, size_t);

libc/mem/get_current_dir_name.c

@@ -30,7 +30,7 @@
  * @return pointer that must be free()'d, or NULL w/ errno
  * @threadsafe
  */
-dontdiscard char *get_current_dir_name(void) {
+char *get_current_dir_name(void) {
   const char *p;
   if ((p = getenv("PWD")) && _isabspath(p)) {
     return strdup(p);

libc/mem/mem.h

@@ -15,16 +15,16 @@ void free(void *) libcesque;
 void *malloc(size_t) attributeallocsize((1)) mallocesque;
 void *calloc(size_t, size_t) attributeallocsize((1, 2)) mallocesque;
 void *memalign(size_t, size_t) attributeallocalign((1))
-    attributeallocsize((2)) returnspointerwithnoaliases libcesque dontdiscard;
+    attributeallocsize((2)) returnspointerwithnoaliases libcesque __wur;
 void *realloc(void *, size_t) reallocesque;
 void *realloc_in_place(void *, size_t) reallocesque;
-void *reallocarray(void *, size_t, size_t) dontdiscard;
+void *reallocarray(void *, size_t, size_t) __wur;
 void *valloc(size_t) attributeallocsize((1)) vallocesque;
 void *pvalloc(size_t) vallocesque;
 char *strdup(const char *) paramsnonnull() mallocesque;
 char *strndup(const char *, size_t) paramsnonnull() mallocesque;
 void *aligned_alloc(size_t, size_t) attributeallocalign((1))
-    attributeallocsize((2)) returnspointerwithnoaliases libcesque dontdiscard;
+    attributeallocsize((2)) returnspointerwithnoaliases libcesque __wur;
 int posix_memalign(void **, size_t, size_t);
 
 int mallopt(int, int);
@@ -34,7 +34,7 @@ size_t malloc_usable_size(void *);
 void **independent_calloc(size_t, size_t, void **);
 void **independent_comalloc(size_t, size_t *, void **);
 
-wchar_t *wcsdup(const wchar_t *) strlenesque dontdiscard;
+wchar_t *wcsdup(const wchar_t *) strlenesque __wur;
 
 struct mallinfo {
   size_t arena;    /* non-mmapped space allocated from system */