Merge pull request #770 from GustavWi/iar_mbed

Fix IAR serial fgets fgetc

Taken from PR #770:
setbuf(_file, NULL), and std::setvbuf(_file,NULL,_IONBF,NULL) should both give an unbuffered stream (the data is directly written to the input buffer). IAR sets a buffer anyway of size 512 bytes for these calls. Calling setvbuff(_file,buf,_IONBF,NULL) with a buffer that is not a NULL pointer sets the buffer to size one. Which means that as soon as a char is read it is written to the real buffer. If people are interested in looking at this further they can look at the files under ARM/src/dlib: fgets.c, fflush.c, xfrpep.c and xfwprep.c

libraries/mbed/api/Stream.h

@@ -21,6 +21,10 @@
 
 namespace mbed {
 
+extern void mbed_set_unbuffered_stream(FILE *_file);
+extern int mbed_getc(FILE *_file);
+extern char* mbed_gets(char *s, int size, FILE *_file);
+
 class Stream : public FileLike {
 
 public:

libraries/mbed/common/Stream.cpp

@@ -24,7 +24,7 @@ Stream::Stream(const char *name) : FileLike(name), _file(NULL) {
     char buf[12]; /* :0x12345678 + null byte */
     std::sprintf(buf, ":%p", this);
     _file = std::fopen(buf, "w+");
-    setbuf(_file, NULL);
+    mbed_set_unbuffered_stream(_file);
 }
 
 Stream::~Stream() {
@@ -41,11 +41,11 @@ int Stream::puts(const char *s) {
 }
 int Stream::getc() {
     fflush(_file);
-    return std::fgetc(_file);
+    return mbed_getc(_file);   
 }
 char* Stream::gets(char *s, int size) {
     fflush(_file);
-    return std::fgets(s,size,_file);
+    return mbed_gets(s,size,_file);
 }
 
 int Stream::close() {

libraries/mbed/common/retarget.cpp

@@ -480,3 +480,55 @@ extern "C" caddr_t _sbrk(int incr) {
     return (caddr_t) prev_heap;
 }
 #endif
+
+
+namespace mbed {
+
+void mbed_set_unbuffered_stream(FILE *_file) {
+#if defined (__ICCARM__)
+    char buf[2];
+    std::setvbuf(_file,buf,_IONBF,NULL);    
+#else
+    setbuf(_file, NULL);
+#endif
+}
+
+int mbed_getc(FILE *_file){
+#if defined (__ICCARM__)
+    /*This is only valid for unbuffered streams*/
+    int res = std::fgetc(_file);
+    if (res>=0){
+        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
+        _file->_Rend = _file->_Wend;
+        _file->_Next = _file->_Wend;
+    }    
+    return res;
+#else    
+    return std::fgetc(_file);
+#endif   
+}
+
+char* mbed_gets(char*s, int size, FILE *_file){
+#if defined (__ICCARM__)
+    /*This is only valid for unbuffered streams*/
+    char *str = fgets(s,size,_file);
+    if (str!=NULL){
+        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
+        _file->_Rend = _file->_Wend;
+        _file->_Next = _file->_Wend;
+    }
+    return str;
+#else    
+    return std::fgets(s,size,_file);
+#endif
+}
+
+} // namespace mbed
+
+
+
+
+
+
+
+