added macros for old symbol resolvers

Author: Antibioticss

include/tinyhook.h

@@ -54,6 +54,10 @@ TH_VIS int write_mem(void *destination, const void *source, size_t len);
 /* symbol resolve */
 TH_VIS void *symbol_resolve(uint32_t image_index, const char *symbol_name, uint resolve_type);
 
+#define symtbl_solve(image_index, symbol_name)  symbol_resolve(image_index, symbol_name, RESOLVE_SYMTAB)
+#define symexp_solve(image_index, symbol_name)  symbol_resolve(image_index, symbol_name, RESOLVE_EXPORT)
+#define symstub_solve(image_index, symbol_name) symbol_resolve(image_index, symbol_name, RESOLVE_STUB)
+
 #ifdef __cplusplus
 }
 #endif

src/interpose.c

@@ -17,6 +17,10 @@ int tiny_interpose(uint32_t image_index, const char *symbol_name, void *replacem
     intptr_t image_slide = _dyld_get_image_vmaddr_slide(image_index);
     struct mach_header_64 *mh_header = (struct mach_header_64 *)_dyld_get_image_header(image_index);
     struct load_command *ld_command = (void *)mh_header + sizeof(struct mach_header_64);
+    if (mh_header == NULL) {
+        LOG_ERROR("parse_macho: image_index %d out of range!", image_index);
+        return -1;
+    }
 
     int nsym_sect = 0;
     bool sect_isconst[5];

src/objcrt.c

@@ -26,7 +26,9 @@ Method ocrt_method(char type, const char *cls, const char *sel) {
 void *ocrt_impl(char type, const char *cls, const char *sel) {
     ARG_CHECK(cls != NULL);
     ARG_CHECK(sel != NULL);
-    return method_getImplementation(ocrt_method(type, cls, sel));
+    Method method = ocrt_method(type, cls, sel);
+    if (method == NULL) return NULL;
+    return method_getImplementation(method);
 }
 
 static Method ensure_method(const char *cls, const char *sel) {