add result style error handling

1 files changed, 32 insertions, 0 deletions

diff --git a/src/utils.c b/src/utils.c
index fdd8452..2a0e286 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -2,6 +2,7 @@
 
 #include <stdio.h>
 #include <assert.h>
+#include <stdarg.h>
 
 struct allocator {
     void** bufs;
@@ -39,4 +40,35 @@ void * allocate(struct allocator * alct, size_t size) {
     return ptr;
 }
 
+char* safe_sprintf(struct allocator *alct, const char* format, ...) {
+    va_list args;
+    va_list args_copy;
+    int length;
+    char* buffer;
 
+    va_start(args, format);
+    va_copy(args_copy, args);
+    
+    length = vsnprintf(NULL, 0, format, args);
+    
+    if (length < 0) {
+        va_end(args);
+        va_end(args_copy);
+        return NULL;
+    }
+
+    buffer = (char*)allocate(alct, length + 1);
+
+    if (buffer == NULL) {
+        va_end(args);
+        va_end(args_copy);
+        return NULL;
+    }
+
+    vsprintf(buffer, format, args_copy);
+
+    va_end(args);
+    va_end(args_copy);
+    
+    return buffer;
+}