LibC: Add ungetc() and automatically flush streams on fclose().

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/d1e55fb4d95

LibC/fcntl.h

@@ -47,6 +47,8 @@ __BEGIN_DECLS
 #define S_IWOTH 0002
 #define S_IXOTH 0001
 
+#define S_IRWXU (S_IRUSR | S_IWUSR | S_IXUSR)
+
 #define S_IRWXG (S_IRWXU >> 3)
 #define S_IRWXO (S_IRWXG >> 3)
 

LibC/inttypes.h

@@ -6,6 +6,10 @@
 #define PRId16 "d"
 #define PRId32 "d"
 #define PRId64 "lld"
+#define PRIi8 "d"
+#define PRIi16 "d"
+#define PRIi32 "d"
+#define PRIi64 "lld"
 #define PRIu8 "u"
 #define PRIu16 "u"
 #define PRIu32 "u"

LibC/limits.h

@@ -5,7 +5,6 @@
 #define PAGE_SIZE 4096
 
 #define PATH_MAX 4096
-#define BUFSIZ 1024
 
 #define INT_MAX INT32_MAX
 #define INT_MIN INT32_MIN

LibC/locale.h

@@ -10,6 +10,7 @@ enum {
     LC_CTYPE,
     LC_COLLATE,
     LC_TIME,
+    LC_MONETARY,
 };
 
 struct lconv {

LibC/stdint.h

@@ -24,6 +24,16 @@ typedef __INT_FAST16_TYPE__ int_fast16_t;
 typedef __INT_FAST32_TYPE__ int_fast32_t;
 typedef __INT_FAST64_TYPE__ int_fast64_t;
 
+typedef __UINT_LEAST8_TYPE__ uint_least8_t;
+typedef __UINT_LEAST16_TYPE__ uint_least16_t;
+typedef __UINT_LEAST32_TYPE__ uint_least32_t;
+typedef __UINT_LEAST64_TYPE__ uint_least64_t;
+
+typedef __INT_LEAST8_TYPE__ int_least8_t;
+typedef __INT_LEAST16_TYPE__ int_least16_t;
+typedef __INT_LEAST32_TYPE__ int_least32_t;
+typedef __INT_LEAST64_TYPE__ int_least64_t;
+
 #define __int8_t_defined 1
 #define __uint8_t_defined 1
 #define __int16_t_defined 1

LibC/stdio.cpp

@@ -141,9 +141,12 @@ int getchar()
     return getc(stdin);
 }
 
-int ungetc(int, FILE*)
+int ungetc(int c, FILE* stream)
 {
-    ASSERT_NOT_REACHED();
+    ASSERT(stream);
+    stream->have_ungotten = true;
+    stream->ungotten = c;
+    return c;
 }
 
 int fputc(int ch, FILE* stream)
@@ -203,6 +206,18 @@ int ferror(FILE* stream)
 size_t fread(void* ptr, size_t size, size_t nmemb, FILE* stream)
 {
     assert(stream);
+    if (!size)
+        return 0;
+
+    if (stream->have_ungotten) {
+        // FIXME: Support ungotten character even if size != 1.
+        ASSERT(size == 1);
+        ((char*)ptr)[0] = stream->ungotten;
+        stream->have_ungotten = false;
+        --nmemb;
+        ptr = &((char*)ptr)[1];
+    }
+
     ssize_t nread = read(stream->fd, ptr, nmemb * size);
     if (nread < 0)
         return 0;
@@ -388,6 +403,7 @@ FILE* fdopen(int fd, const char* mode)
 
 int fclose(FILE* stream)
 {
+    fflush(stream);
     int rc = close(stream->fd);
     free(stream);
     return rc;

LibC/stdio.h

@@ -7,6 +7,8 @@
 #include <stdarg.h>
 #include <limits.h>
 
+#define BUFSIZ 1024
+
 __BEGIN_DECLS
  #ifndef EOF
 #define EOF (-1)
@@ -28,6 +30,8 @@ struct __STDIO_FILE {
     char* buffer;
     size_t buffer_size;
     size_t buffer_index;
+    bool have_ungotten;
+    char ungotten;
     char default_buffer[BUFSIZ];
 };