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authorwm4 <wm4@nowhere>2014-07-01 23:10:38 +0200
committerwm4 <wm4@nowhere>2014-07-01 23:11:08 +0200
commit9a210ca2d50e02bf045866bbb2f44a33a3c48cd9 (patch)
tree9f685c66c9d3b2e968416c7f60d30ea56ab1f9bb /misc
parent0208ad4f3b4d2331b8242bb6fb12a9a4475ccae6 (diff)
downloadmpv-9a210ca2d50e02bf045866bbb2f44a33a3c48cd9.tar.bz2
mpv-9a210ca2d50e02bf045866bbb2f44a33a3c48cd9.tar.xz
Audit and replace all ctype.h uses
Something like "char *s = ...; isdigit(s[0]);" triggers undefined behavior, because char can be signed, and thus s[0] can be a negative value. The is*() functions require unsigned char _or_ EOF. EOF is a special value outside of unsigned char range, thus the argument to the is*() functions can't be a char. This undefined behavior can actually trigger crashes if the implementation of these functions e.g. uses lookup tables, which are then indexed with out-of-range values. Replace all <ctype.h> uses with our own custom mp_is*() functions added with misc/ctype.h. As a bonus, these functions are locale-independent. (Although currently, we _require_ C locale for other reasons.)
Diffstat (limited to 'misc')
-rw-r--r--misc/ctype.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/misc/ctype.h b/misc/ctype.h
new file mode 100644
index 0000000000..cbff799285
--- /dev/null
+++ b/misc/ctype.h
@@ -0,0 +1,19 @@
+#ifndef MP_CTYPE_H_
+#define MP_CTYPE_H_
+
+// Roughly follows C semantics, but doesn't account for EOF, allows char as
+// parameter, and is locale independent (always uses "C" locale).
+
+static inline int mp_isprint(char c) { return (unsigned char)c >= 32; }
+static inline int mp_isspace(char c) { return c == ' ' || c == '\f' || c == '\n' ||
+ c == '\r' || c == '\t' || c =='\v'; }
+static inline int mp_isupper(char c) { return c >= 'A' && c <= 'Z'; }
+static inline int mp_islower(char c) { return c >= 'a' && c <= 'z'; }
+static inline int mp_isdigit(char c) { return c >= '0' && c <= '9'; }
+static inline int mp_isalpha(char c) { return mp_isupper(c) || mp_islower(c); }
+static inline int mp_isalnum(char c) { return mp_isalpha(c) || mp_isdigit(c); }
+
+static inline char mp_tolower(char c) { return mp_isupper(c) ? c - 'A' + 'a' : c; }
+static inline char mp_toupper(char c) { return mp_islower(c) ? c - 'a' + 'A' : c; }
+
+#endif