Multifile support

Author: noahhaasis

.vscode/launch.json

@@ -9,7 +9,7 @@
             "type": "cppdbg",
             "request": "launch",
             "program": "${workspaceFolder}/bin/main",
-            "args": ["test/Main.class"],
+            "args": ["Main"],
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}",
             "environment": [],

bin/main

@@ -2,14 +2,17 @@
 
 #include "buffer.h"
 
+#include <dirent.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <assert.h>
 
-ClassLoader ClassLoader_create() {
+ClassLoader ClassLoader_create(char **classpath, u64 num_paths) {
   return (ClassLoader) {
-    .loaded_classes = HashMap_create()
+    .classpath = classpath,
+    .loaded_classes = HashMap_create(),
+    .num_paths = num_paths
   };
 }
 
@@ -145,45 +148,60 @@ Class *Class_from_class_file(ClassFile *class_file) {
   return class;
 }
 
-// TODO:
-// Class_get_method(char *method_name, u32 method_name_length)
-
 char *filename_from_classname(String classname) {
-  int filename_length = classname.length + 6 + 1;
   char *file_extension = ".class";
+  int filename_length = classname.length + strlen(file_extension) + 1;
   char *filename = malloc(filename_length);
 
   memcpy(filename, classname.bytes, classname.length);
-  memcpy(filename + classname.length, file_extension, 6);
+  memcpy(filename + classname.length, file_extension, strlen(file_extension));
   filename[filename_length-1] = '\0';
 
   return filename;
 }
 
+char *find_classfile_in_classpath(ClassLoader loader, String classname) {
+  char *classfile_name = filename_from_classname(classname);
+
+  for (u32 i = 0; i < loader.num_paths; ++i) {
+    char *dir_path = loader.classpath[i];
+
+    DIR *dirp = opendir(dir_path);
+    struct dirent *file_info = NULL;
+    while ((file_info = readdir(dirp))) {
+      if (strcmp(classfile_name, file_info->d_name) == 0) {
+        u32 dir_len = strlen(dir_path);
+        u32 classfile_name_len = strlen(classfile_name);
+        
+        char *full_path = malloc(dir_len + classfile_name_len + 2);
+        memcpy(full_path, dir_path, dir_len);
+        full_path[dir_len] = '/';
+        memcpy(full_path + dir_len + 1, classfile_name, classfile_name_len);
+        full_path[dir_len+classfile_name_len+1] = '\0';
+
+        return full_path;
+      }
+    }
+  }
+
+  free(classfile_name);
+  return NULL;
+}
+
 /* Loads a class from it's class file and convert it into its runtime representation.
  * Then execute the intitialization code. (<clinit>)
  */
 Class *load_class(ClassLoader loader, String classname) {
-  char *filename = filename_from_classname(classname);
-  ClassFile *class_file = parse_class_file(filename);
-  free(filename);
-
-  if (!class_file) return NULL;
-
-  Class *class = Class_from_class_file(class_file);
-  HashMap_insert(loader.loaded_classes, classname, class);
-
-  return class;
-}
+  char *path = find_classfile_in_classpath(loader, classname);
+  if (!path) {
+    return NULL;
+  }
+  ClassFile *class_file = parse_class_file(path);
+  free(path);
 
-Class *load_class_from_file(ClassLoader loader, String classname, String filename) {
-  char *filename_nt = String_to_null_terminated(filename);
-  ClassFile *class_file = parse_class_file(filename_nt);
-  free(filename_nt);
   if (!class_file) return NULL;
 
   Class *class = Class_from_class_file(class_file);
-
   HashMap_insert(loader.loaded_classes, classname, class);
 
   return class;

src/class_loader.c

@@ -7,14 +7,17 @@
 typedef struct Class Class;
 
 typedef struct {
+  // List of directories. Not owned
+  char **classpath;
+  u64 num_paths;
+
   // Map<String, class>
   HashMap *loaded_classes;
 } ClassLoader;
 
-ClassLoader ClassLoader_create();
+ClassLoader ClassLoader_create(char **classpath, u64 num_paths);
 
 Class *load_class(ClassLoader loader, String classname);
-Class *load_class_from_file(ClassLoader loader, String classname, String filename);
 
 Class *get_class(ClassLoader loader, String classname);
 

src/class_loader.h

@@ -15,6 +15,7 @@ int main(int argc, char **argv) {
     return -1;
   }
 
+  /*
   ClassFile *class_file = parse_class_file(argv[1]);
   if (!class_file) {
     printf("Failed to parse class file \"%s\"\n", argv[1]);
@@ -44,13 +45,14 @@ int main(int argc, char **argv) {
       printf("source file name: \"%.*s\"\n", constant.as.utf8_info.length, constant.as.utf8_info.bytes);
     }
   }
+  */
 
   // method_info fac_info = find_method(class_file, "main", 4);
   // code_attribute *code_attr = find_code(class_file, fac_info);
   // assert(code_attr != NULL);
-  execute_main(argv[1]);
+  // free_class_file(class_file);
 
-  free_class_file(class_file);
+  execute_main(argv[1]);
 
   return 0;
 }

src/main.c

@@ -2,6 +2,7 @@
 
 #include "buffer.h"
 
+#include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -60,15 +61,22 @@ void free_frame(Frame frame) {
   if (frame.locals) free(frame.locals);
 }
 
-void execute_main(char *filename) {
-  ClassLoader class_loader = ClassLoader_create();
+void execute_main(char *class_name) {
+  char cwd[256];
+  getcwd(cwd, 256);
+  ClassLoader class_loader = ClassLoader_create(
+      (char *[]){ "/home/haschisch/Projects/cl/test", cwd }, 2);
 
-  Class *main_class = load_class_from_file(
+  Class *main_class = load_class(
       class_loader,
-      (String) { .bytes = "Main", .length = 4 },// TODO: Classname
-      (String) { .bytes = filename, .length = strlen(filename) }
+      String_from_null_terminated(class_name)
     );
 
+  if (!main_class) {
+    fprintf(stderr, "Failed to load class \"%s\"\n", class_name);
+    return;
+  }
+
   // call <clinit>
   Method *clinit = HashMap_get(
       main_class->method_map,
@@ -116,12 +124,20 @@ intern Class *load_class_and_field_name_from_field_ref(
         });
     if (!class) {
       // load and initialize class
-      load_class(
+      class = load_class(
         class_loader, 
         (String) {
           .bytes = (char *)class_name.as.utf8_info.bytes, 
           .length = class_name.as.utf8_info.length
         });
+      
+      Method *clinit = HashMap_get(
+        class->method_map,
+        (String) {
+          .bytes = "<clinit>",
+          .length = strlen("<clinit>")
+        });
+      execute(class_loader, clinit);
       // TODO: Initialize
     }
 

src/parse_instructions.c

@@ -11,11 +11,16 @@ public static void main(String[] args) {
     five();
     fac(5);
     fib(5);
+    two();
 
     Main main = new Main();
     main.getThree();
   }
 
+  public static int two() {
+    return Two.TWO;
+  }
+
   public static int fac(int n) {
     if (n == 0) return 0;
 
@@ -40,8 +45,4 @@ public static int fib(int i) {
     }
     return fib(i-1) + fib(i-2);
   }
-
-  public static void test() {
-    if (MyField > 10) { return; }
-  }
 }

src/runtime.c

@@ -0,0 +1,3 @@
+class Two {
+  public static int TWO = 2;
+}