str: provide checks for ctype.h char functions, and strstr and strchr functions.

[ccan] / ccan / str / str.h

diff --git a/ccan/str/str.h b/ccan/str/str.h
index 70fe26c74fad3905b3acf2efd8ac0b792ba766a5..54afca0f21c2afc671a7d0f5ad356e4fe1604b0f 100644 (file)
--- a/ccan/str/str.h
+++ b/ccan/str/str.h
@@ -1,7 +1,9 @@
 #ifndef CCAN_STR_H
 #define CCAN_STR_H
+#include "config.h"
 #include <string.h>
 #include <stdbool.h>
+#include <ctype.h>
 
 /**
  * streq - Are two strings equal?
@@ -11,7 +13,7 @@
  * This macro is arguably more readable than "!strcmp(a, b)".
  *
  * Example:
- *     if (streq(str, ""))
+ *     if (streq(somestring, ""))
  *             printf("String is empty!\n");
  */
 #define streq(a,b) (strcmp((a),(b)) == 0)
@@ -22,8 +24,8 @@
  * @prefix: prefix to look for at start of str
  *
  * Example:
- *     if (strstarts(str, "foo"))
- *             printf("String %s begins with 'foo'!\n", str);
+ *     if (strstarts(somestring, "foo"))
+ *             printf("String %s begins with 'foo'!\n", somestring);
  */
 #define strstarts(str,prefix) (strncmp((str),(prefix),strlen(prefix)) == 0)
 
@@ -33,8 +35,8 @@
  * @postfix: postfix to look for at end of str
  *
  * Example:
- *     if (strends(str, "foo"))
- *             printf("String %s end with 'foo'!\n", str);
+ *     if (strends(somestring, "foo"))
+ *             printf("String %s end with 'foo'!\n", somestring);
  */
 static inline bool strends(const char *str, const char *postfix)
 {
@@ -55,4 +57,79 @@ static inline bool strends(const char *str, const char *postfix)
 #define stringify(expr)                stringify_1(expr)
 /* Double-indirection required to stringify expansions */
 #define stringify_1(expr)      #expr
+
+/**
+ * strcount - Count number of (non-overlapping) occurrences of a substring.
+ * @haystack: a C string
+ * @needle: a substring
+ *
+ * Example:
+ *     int i;
+ *      i = strcount("aaa aaa", "a");  // i = 6;
+ *      i = strcount("aaa aaa", "ab"); // i = 0;
+ *      i = strcount("aaa aaa", "aa"); // i = 2;
+ */
+size_t strcount(const char *haystack, const char *needle);
+
+#include <ccan/str/str_debug.h>
+
+/* These checks force things out of line, hence they are under DEBUG. */
+#ifdef CCAN_STR_DEBUG
+#include <ccan/build_assert/build_assert.h>
+
+/* These are commonly misused: they take -1 or an *unsigned* char value. */
+#undef isalnum
+#undef isalpha
+#undef isascii
+#undef isblank
+#undef iscntrl
+#undef isdigit
+#undef isgraph
+#undef islower
+#undef isprint
+#undef ispunct
+#undef isspace
+#undef isupper
+#undef isxdigit
+
+/* You can use a char if char is unsigned. */
+#if HAVE_BUILTIN_TYPES_COMPATIBLE_P && HAVE_TYPEOF
+#define str_check_arg_(i)                                              \
+       ((i) + BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(typeof(i), \
+                                                                 char) \
+                                   || (char)255 > 0))
+#else
+#define str_check_arg_(i) (i)
+#endif
+
+#define isalnum(i) str_isalnum(str_check_arg_(i))
+#define isalpha(i) str_isalpha(str_check_arg_(i))
+#define isascii(i) str_isascii(str_check_arg_(i))
+#define isblank(i) str_isblank(str_check_arg_(i))
+#define iscntrl(i) str_iscntrl(str_check_arg_(i))
+#define isdigit(i) str_isdigit(str_check_arg_(i))
+#define isgraph(i) str_isgraph(str_check_arg_(i))
+#define islower(i) str_islower(str_check_arg_(i))
+#define isprint(i) str_isprint(str_check_arg_(i))
+#define ispunct(i) str_ispunct(str_check_arg_(i))
+#define isspace(i) str_isspace(str_check_arg_(i))
+#define isupper(i) str_isupper(str_check_arg_(i))
+#define isxdigit(i) str_isxdigit(str_check_arg_(i))
+
+#if HAVE_TYPEOF
+/* With GNU magic, we can make const-respecting standard string functions. */
+#undef strstr
+#undef strchr
+#undef strrchr
+
+/* + 0 is needed to decay array into pointer. */
+#define strstr(haystack, needle)                                       \
+       ((typeof((haystack) + 0))str_strstr((haystack), (needle)))
+#define strchr(haystack, c)                                    \
+       ((typeof((haystack) + 0))str_strchr((haystack), (c)))
+#define strrchr(haystack, c)                                   \
+       ((typeof((haystack) + 0))str_strrchr((haystack), (c)))
+#endif
+#endif /* CCAN_STR_DEBUG */
+
 #endif /* CCAN_STR_H */