implement "low hanging fruit" from C11

based on Gregor's patch sent to the list. includes:
- stdalign.h
- removing gets in C11 mode
- adding aligned_alloc and adjusting other functions to use it
- adding 'x' flag to fopen for exclusive mode

diff --git a/include/stdalign.h b/include/stdalign.h
new file mode 100644 (file)
index 0000000..b6e50ae
--- /dev/null
+++ b/include/stdalign.h
@@ -0,0 +1,15 @@
+#ifndef _STDALIGN_H
+#define _STDALIGN_H
+
+/* this whole header only works in C11 or with compiler extensions */
+#if __STDC_VERSION__ < 201112L && defined( __GNUC__)
+#define _Alignas(t) __attribute__((__aligned__(t)))
+#define _Alignof(t) __alignof__(t)
+#endif
+
+#define alignas _Alignas
+#define alignof _Alignof
+#define __alignas_is_defined 1
+#define __alignof_is_defined 1
+
+#endif

diff --git a/include/stdio.h b/include/stdio.h
index 19ab8bc..9aa2f78 100644 (file)
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -90,7 +90,9 @@ int putc(int, FILE *);
 int putchar(int);
 
 char *fgets(char *, int, FILE *);
+#if __STDC_VERSION__ < 201112L
 char *gets(char *);
+#endif
 
 int fputs(const char *, FILE *);
 int puts(const char *);

diff --git a/include/stdlib.h b/include/stdlib.h
index c1d93e7..1749cb3 100644 (file)
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -38,6 +38,7 @@ void *malloc (size_t);
 void *calloc (size_t, size_t);
 void *realloc (void *, size_t);
 void free (void *);
+void *aligned_alloc(size_t alignment, size_t size);
 
 void abort (void);
 int atexit (void (*) (void));

diff --git a/src/malloc/aligned_alloc.c b/src/malloc/aligned_alloc.c
new file mode 100644 (file)
index 0000000..d623420
--- /dev/null
+++ b/src/malloc/aligned_alloc.c
@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <errno.h>
+
+/* This function should work with most dlmalloc-like chunk bookkeeping
+ * systems, but it's only guaranteed to work with the native implementation
+ * used in this library. */
+
+void *aligned_alloc(size_t align, size_t len)
+{
+       unsigned char *mem, *new, *end;
+       size_t header, footer;
+
+       if ((align & -align & -sizeof(void *)) != align) {
+               errno = EINVAL;
+               return NULL;
+       }
+
+       if (len > SIZE_MAX - align) {
+               errno = ENOMEM;
+               return NULL;
+       }
+
+       if (align <= 4*sizeof(size_t)) {
+               if (!(mem = malloc(len)))
+                       return NULL;
+               return mem;
+       }
+
+       if (!(mem = malloc(len + align-1)))
+               return NULL;
+
+       header = ((size_t *)mem)[-1];
+       end = mem + (header & -8);
+       footer = ((size_t *)end)[-2];
+       new = (void *)((uintptr_t)mem + align-1 & -align);
+
+       if (!(header & 7)) {
+               ((size_t *)new)[-2] = ((size_t *)mem)[-2] + (new-mem);
+               ((size_t *)new)[-1] = ((size_t *)mem)[-1] - (new-mem);
+               return new;
+       }
+
+       ((size_t *)mem)[-1] = header&7 | new-mem;
+       ((size_t *)new)[-2] = footer&7 | new-mem;
+       ((size_t *)new)[-1] = header&7 | end-new;
+       ((size_t *)end)[-2] = footer&7 | end-new;
+
+       if (new != mem) free(mem);
+       return new;
+}

diff --git a/src/malloc/memalign.c b/src/malloc/memalign.c
index 61f456e..a594c63 100644 (file)
--- a/src/malloc/memalign.c
+++ b/src/malloc/memalign.c
@@ -3,11 +3,5 @@
 
 void *memalign(size_t align, size_t len)
 {
-       void *mem;
-       int ret;
-       if ((ret = posix_memalign(&mem, align, len))) {
-               errno = ret;
-               return 0;
-       }
-       return mem;
+       return aligned_alloc(align, len);
 }

diff --git a/src/malloc/posix_memalign.c b/src/malloc/posix_memalign.c
index 2ae928c..42cf274 100644 (file)
--- a/src/malloc/posix_memalign.c
+++ b/src/malloc/posix_memalign.c
@@ -1,47 +1,10 @@
 #include <stdlib.h>
-#include <stdint.h>
 #include <errno.h>
 
-/* This function should work with most dlmalloc-like chunk bookkeeping
- * systems, but it's only guaranteed to work with the native implementation
- * used in this library. */
-
 int posix_memalign(void **res, size_t align, size_t len)
 {
-       unsigned char *mem, *new, *end;
-       size_t header, footer;
-
-       if ((align & -align & -sizeof(void *)) != align) return EINVAL;
-       if (len > SIZE_MAX - align) return ENOMEM;
-
-       if (align <= 4*sizeof(size_t)) {
-               if (!(mem = malloc(len)))
-                       return errno;
-               *res = mem;
-               return 0;
-       }
-
-       if (!(mem = malloc(len + align-1)))
-               return errno;
-
-       header = ((size_t *)mem)[-1];
-       end = mem + (header & -8);
-       footer = ((size_t *)end)[-2];
-       new = (void *)((uintptr_t)mem + align-1 & -align);
-
-       if (!(header & 7)) {
-               ((size_t *)new)[-2] = ((size_t *)mem)[-2] + (new-mem);
-               ((size_t *)new)[-1] = ((size_t *)mem)[-1] - (new-mem);
-               *res = new;
-               return 0;
-       }
-
-       ((size_t *)mem)[-1] = header&7 | new-mem;
-       ((size_t *)new)[-2] = footer&7 | new-mem;
-       ((size_t *)new)[-1] = header&7 | end-new;
-       ((size_t *)end)[-2] = footer&7 | end-new;
-
-       if (new != mem) free(mem);
-       *res = new;
+       void *mem = aligned_alloc(align, len);
+       if (!mem) return errno;
+       *res = mem;
        return 0;
 }

diff --git a/src/stdio/fopen.c b/src/stdio/fopen.c
index 084cc73..0d5b1af 100644 (file)
--- a/src/stdio/fopen.c
+++ b/src/stdio/fopen.c
@@ -5,7 +5,6 @@ FILE *fopen(const char *filename, const char *mode)
        FILE *f;
        int fd;
        int flags;
-       int plus = !!strchr(mode, '+');
 
        /* Check for valid initial mode character */
        if (!strchr("rwa", *mode)) {
@@ -14,9 +13,10 @@ FILE *fopen(const char *filename, const char *mode)
        }
 
        /* Compute the flags to pass to open() */
-       if (plus) flags = O_RDWR;
+       if (strchr(mode, '+')) flags = O_RDWR;
        else if (*mode == 'r') flags = O_RDONLY;
        else flags = O_WRONLY;
+       if (strchr(mode, 'x')) flags |= O_EXCL;
        if (*mode != 'r') flags |= O_CREAT;
        if (*mode == 'w') flags |= O_TRUNC;
        if (*mode == 'a') flags |= O_APPEND;