[Scummvm-git-logs] scummvm master -> 663333de4ec82261d13757c0ade4cb51f9cd4d55

[lephilousophe]

This automated email contains information about 1 new commit which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
663333de4e BACKENDS: ANDROID: Fix memchr calls


Commit: 663333de4ec82261d13757c0ade4cb51f9cd4d55
    https://github.com/scummvm/scummvm/commit/663333de4ec82261d13757c0ade4cb51f9cd4d55
Author: Le Philousophe (lephilousophe at users.noreply.github.com)
Date: 2025-01-13T13:23:06+01:00

Commit Message:
BACKENDS: ANDROID: Fix memchr calls

Android libc (Bionic) had a bug in their memchr function where the
needle wasn't considered as an unsigned char for Android below 6.0
except for aarch64 where the implementation was in assembly and behaves
correctly.
This means that on every impacted platform, passing a needle made of a
char >= 0x80 makes memchr never find a match because the value is signed
extended.
Make sure we avoid this case by forcing a cast to unsigned char before
passing an int.

Changed paths:
    backends/platform/android/portdefs.h


diff --git a/backends/platform/android/portdefs.h b/backends/platform/android/portdefs.h
index 4fddaa38593..9b764e539f5 100644
--- a/backends/platform/android/portdefs.h
+++ b/backends/platform/android/portdefs.h
@@ -47,4 +47,14 @@ int rpl_vsnprintf(char *text, size_t maxlen, const char *fmt, va_list ap);
 
 #define vsnprintf rpl_vsnprintf
 
+// Bionic libc up to Android 6/API 23 (excluded) is non-conformant with ANSI C.
+// It compares with integer character without casting it to unsigned char as required.
+// On AArch64, another (optimized) implementation is used which behaves properly.
+// If char is unsigned the problem does not exist.
+// strchr calls are also replaced by memchr calls when the compiler knows the haystack size.
+#if !defined(__CHAR_UNSIGNED__) && !defined(__aarch64__)
+#define memchr(s,c,n) memchr(s, (unsigned char)(c), n)
+#define strchr(s,c) strchr(s, (unsigned char)(c))
+#endif
+
 #endif // _PORTDEFS_H_