Changeset 1040 for cpp/frams/util

Timestamp:

11/30/20 04:32:21 (4 years ago)

Author:

Maciej Komosinski

Message:

Follow-up to r897: A workaround for Android bug in vsnprintf() and vsprintf() in SString, ​https://github.com/android-ndk/ndk/issues/879

Location:

cpp/frams/util

Files:

• sstring-simple.cpp (modified) (2 diffs)
• sstring.cpp (modified) (1 diff)

cpp/frams/util/sstring-simple.cpp

@@ -4 +4 @@
 #include <assert.h>
 #include <common/nonstd_math.h>
+
+#ifdef __ANDROID__
+#include <android/log.h> //only needed to print error messages related to a workaround for Android bug
+#endif
 
 
@@ -273 +277 @@
                 if (n < 0 && size >= (1 << 24)) //wants more than 16M
                 {
-                        buf[size - 1] = 0; //just to ensure there is at least some ending \0 in memory... who knows what buggy vsnprintf() did.
-                        __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "Giving up due to Android bug: vsnprintf() wants more than %d bytes, it used %zu bytes, for format='%s'", size, strlen(buf), format);
+                        p[size - 1] = 0; //just to ensure there is at least some ending \0 in memory... who knows what buggy vsnprintf() did.
+                        __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "Giving up due to Android bug: vsnprintf() wants more than %d bytes, it used %zu bytes, for format='%s'", size, strlen(p), format);
                         //in my tests, it always used 0 bytes, so it produced a 0-length string: ""
-                        va_copy(ap_copy, ap);
-                        n = vsprintf(buf, format, ap_copy); //hoping 16M is enough
-                        va_end(ap_copy);
-                        __android_log_print(ANDROID_LOG_INFO, LOG_APP_NAME, "Fallback to vsprintf() produced string: '%s'", buf);
+                        va_start(ap, format);
+                        n = vsnprintf(p, size, format, ap); //hoping 16M is enough
+                        va_end(ap);
+                        __android_log_print(ANDROID_LOG_INFO, LOG_APP_NAME, "Fallback to vsprintf() produced string: '%s'", p);
                         if (n < 0) //vsprintf was also buggy. If we were strict, we should abort the app now.
                         {
-                                strcpy(buf, "[STR_ERR] "); //a special prefix just to indicate the returned string is incorrect
-                                strcat(buf, format); //append and return the original formatting string
-                                __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "vsprintf() also failed, using the incorrect resulting string: '%s'", buf);
+                                strcpy(p, "[STR_ERR] "); //a special prefix just to indicate the returned string is incorrect
+                                strcat(p, format); //append and return the original formatting string
+                                __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "vsprintf() also failed, using the incorrect resulting string: '%s'", p);
                         }
-                        n = strlen(buf); //pretend vsnprintf() or vsprintf() was OK to exit the endless loop
+                        n = strlen(p); //pretend vsnprintf() or vsprintf() was OK to exit the endless loop
         }
 #endif

cpp/frams/util/sstring.cpp

@@ -417 +417 @@
                 if (n < 0 && size >= (1 << 24)) //wants more than 16M
                 {
-                        buf[size - 1] = 0; //just to ensure there is at least some ending \0 in memory... who knows what buggy vsnprintf() did.
-                        __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "Giving up due to Android bug: vsnprintf() wants more than %d bytes, it used %zu bytes, for format='%s'", size, strlen(buf), format);
+                        p[size - 1] = 0; //just to ensure there is at least some ending \0 in memory... who knows what buggy vsnprintf() did.
+                        __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "Giving up due to Android bug: vsnprintf() wants more than %d bytes, it used %zu bytes, for format='%s'", size, strlen(p), format);
                         //in my tests, it always used 0 bytes, so it produced a 0-length string: ""
-                        va_copy(ap_copy, ap);
-                        n = vsprintf(buf, format, ap_copy); //hoping 16M is enough
-                        va_end(ap_copy);
-                        __android_log_print(ANDROID_LOG_INFO, LOG_APP_NAME, "Fallback to vsprintf() produced string: '%s'", buf);
+                        va_start(ap, format);
+                        n = vsnprintf(p, size, format, ap); //hoping 16M is enough
+                        va_end(ap);
+                        __android_log_print(ANDROID_LOG_INFO, LOG_APP_NAME, "Fallback to vsprintf() produced string: '%s'", p);
                         if (n < 0) //vsprintf was also buggy. If we were strict, we should abort the app now.
                         {
-                                strcpy(buf, "[STR_ERR] "); //a special prefix just to indicate the returned string is incorrect
-                                strcat(buf, format); //append and return the original formatting string
-                                __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "vsprintf() also failed, using the incorrect resulting string: '%s'", buf);
+                                strcpy(p, "[STR_ERR] "); //a special prefix just to indicate the returned string is incorrect
+                                strcat(p, format); //append and return the original formatting string
+                                __android_log_print(ANDROID_LOG_ERROR, LOG_APP_NAME, "vsprintf() also failed, using the incorrect resulting string: '%s'", p);
                         }
-                        n = strlen(buf); //pretend vsnprintf() or vsprintf() was OK to exit the endless loop
+                        n = strlen(p); //pretend vsnprintf() or vsprintf() was OK to exit the endless loop
                 }
 #endif