added defer macro

include/tlibc/defer.h

@@ -0,0 +1,81 @@
+/*
+Based on https://github.com/moon-chilled/Defer
+
+Usage:
+
+void foo(){
+    Deferral(16);
+    void* p = malloc(8);
+    Defer(free(p));
+    Return;
+}
+
+*/
+
+#pragma once
+
+#if defined(__GNUC__) || defined(__TINYC__)
+
+#define Deferral(MAX_DEFER_STATEMENTS) \
+    unsigned char _num_deferrals = 0; \
+    void *_defer_return_loc = 0, *_deferrals[MAX_DEFER_STATEMENTS] = {0};
+
+# define Defer(block) _Defer(block, __LINE__)
+# define Return _Return(__LINE__)
+
+#define _defer_token_cat(a, b) a ## b
+
+#define _Defer(block, n) do { \
+	_deferrals[_num_deferrals++] = && _defer_token_cat(_defer_ini, n); \
+	if (0) { \
+		_defer_token_cat(_defer_ini, n): \
+		block; \
+		if (_num_deferrals) { \
+			goto *_deferrals[--_num_deferrals]; \
+		} else { \
+			goto *_defer_return_loc; \
+		} \
+	} \
+} while (0)
+
+#define _Return(n) \
+	if (_num_deferrals \
+        /* this nonsense disables warning Wunused-but-set-variable */ \
+        && _defer_return_loc == _defer_return_loc ) \
+    { \
+		_defer_return_loc = && _defer_token_cat(_defer_fini_, n); \
+		goto *_deferrals[--_num_deferrals]; \
+	} else _defer_token_cat(_defer_fini_, n): \
+        return
+
+#else /* !__GNUC__ && !__TINYCC__ */
+
+#include <setjmp.h>
+
+#ifdef _MSC_VER
+# pragma message("You are using the unsafe longjmp()-based defer implementation.  Expect bugs if you don't know what you're doing.")
+#else
+# warning You are using the unsafe longjmp()-based defer implementation.  Expect bugs if you don't know what you're doing.
+#endif
+
+#define Deferral(MAX_DEFER_STATEMENTS) \
+volatile unsigned char _num_deferrals = 0; \
+jmp_buf _defer_return_loc = {0}, _deferrals[MAX_DEFER_STATEMENTS] = {0};
+
+#define Defer(block) do { \
+	if (setjmp(_deferrals[_num_deferrals++])) { \
+		block; \
+		if (_num_deferrals) { \
+			longjmp(_deferrals[--_num_deferrals], 1); \
+		} else { \
+			longjmp(_defer_return_loc, 1); \
+		} \
+	} \
+} while (0)
+
+#define Return \
+	if (!setjmp(_defer_return_loc)) { \
+		if (_num_deferrals) longjmp(_deferrals[--_num_deferrals], 1); \
+	} else return
+
+#endif /* __GNUC__ */

include/tlibc/errors.h

@@ -2,6 +2,7 @@
 #include "std.h"
 #include "string/str.h"
 #include "collections/List.h"
+#include "defer.h"
 
 typedef struct ErrorCallPos {
     i32 line;
@@ -46,22 +47,41 @@ typedef struct Result_ {
 #define RESULT_VOID (Result_){ .error = NULL, .u = 0 }
 #define RESULT_VALUE(FIELD, V) (Result_){ .error = NULL, .FIELD = V }
 
-#define try(VAR, RSLT_CALL, DEFER_CODE) \
+#define _rname(N) __r_##N
-    Result_ VAR = RSLT_CALL;\
-    if(VAR.error){\
-        Error_addCallPos(VAR.error, ErrorCallPos_here());\
-        DEFER_CODE;\
-        return VAR;\
-    };
 
-#define try_void(RSLT_CALL, DEFER_CODE) { try(__result_void, RSLT_CALL, DEFER_CODE) };
+#define try(VAR, RESULT_FIELD, RSLT_CALL) _try(VAR, RESULT_FIELD, RSLT_CALL, __LINE__)
+#define try_void(RSLT_CALL) _try_void(RSLT_CALL, __LINE__)
+#define try_fatal(VAR, RESULT_FIELD, RSLT_CALL) _try_fatal(VAR, RESULT_FIELD, RSLT_CALL, __LINE__)
+#define try_fatal_void(RSLT_CALL) _try_fatal_void(RSLT_CALL, __LINE__)
 
-#define try_fatal(VAR, RSLT_CALL, DEFER_CODE) \
+#define _try(VAR, RESULT_FIELD, RSLT_CALL, N) \
-    Result_ VAR = RSLT_CALL;\
+    Result_ _rname(N) = RSLT_CALL;\
-    if(VAR.error){\
+    if(_rname(N).error){\
-        Error_addCallPos(VAR.error, ErrorCallPos_here());\
+        Error_addCallPos(_rname(N).error, ErrorCallPos_here());\
-        DEFER_CODE;\
+        Return _rname(N);\
-        Error_printAndExit(VAR.error);\
+    };\
-    };
+    VAR = _rname(N).RESULT_FIELD;
 
-#define try_fatal_void(RSLT_CALL, DEFER_CODE) { try_fatal(__result_void, RSLT_CALL, DEFER_CODE) };
+#define _try_void(RSLT_CALL, N) do {\
+    Result_ _rname(N) = RSLT_CALL;\
+    if(_rname(N).error){\
+        Error_addCallPos(_rname(N).error, ErrorCallPos_here());\
+        Return _rname(N);\
+    };\
+} while(0)
+
+#define _try_fatal(VAR, RESULT_FIELD, RSLT_CALL, N) \
+    Result_ _rname(N) = RSLT_CALL;\
+    if(_rname(N).error){\
+        Error_addCallPos(_rname(N).error, ErrorCallPos_here());\
+        Error_printAndExit(_rname(N).error);\
+    };\
+    VAR = _rname(N).RESULT_FIELD;
+
+#define _try_fatal_void(RSLT_CALL, N) do {\
+    Result_ _rname(N) = RSLT_CALL;\
+    if(_rname(N).error){\
+        Error_addCallPos(_rname(N).error, ErrorCallPos_here());\
+        Error_printAndExit(_rname(N).error);\
+    };\
+} while(0)

src/filesystem/dir.c

@@ -23,20 +23,23 @@ bool dir_exists(cstr path){
 }
 
 Result(bool) dir_create(cstr path){
-    if (dir_exists(path))
+    Deferral(4);
-        return RESULT_VALUE(i, false);
+    if (dir_exists(path)){
+        Return RESULT_VALUE(i, false);
+    }
     
     char* parentDir= str_copy(path_dirname(str_from_cstr((void*)path))).data;
-    try_void(dir_create(parentDir), free(parentDir));
+    Defer(free(parentDir));
-    free(parentDir);
+    try_void(dir_create(parentDir));
+
 #if TLIBC_FS_USE_WINDOWS_H
     if(!CreateDirectory(path, NULL))
 #else
     if(mkdir(path, 0777) == -1)
 #endif
     {
-        return RESULT_ERROR_FMT("Can't create dicectory '%s': %s", path, strerror(errno));
+        Return RESULT_ERROR_FMT("Can't create dicectory '%s': %s", path, strerror(errno));
     }
 
-    return RESULT_VALUE(i, true);
+    Return RESULT_VALUE(i, true);
 }