impl label system

codegen.c

@@ -1,5 +1,6 @@
 #include "compiler.h"
 #include "helpers/vector.h"
+#include <assert.h>
 #include <stdarg.h>
 #include <stdio.h>
 
@@ -35,6 +36,94 @@ void asm_push(const char *ins, ...) {
   va_end(args);
 }
 
+struct code_generator *codegenerator_new(struct compile_process *process) {
+  struct code_generator *generator = calloc(1, sizeof(struct code_generator));
+  generator->entry_points = vector_create(sizeof(struct codegen_entry_point *));
+  generator->exit_points = vector_create(sizeof(struct codegen_exit_point *));
+  return generator;
+}
+
+void codegen_register_exit_point(int exit_point_id) {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_exit_point *exit_point =
+      calloc(1, sizeof(struct codegen_exit_point));
+  exit_point->id = exit_point_id;
+  vector_push(generator->exit_points, &exit_point);
+}
+
+struct codegen_exit_point *codegen_current_exit_point() {
+  struct code_generator *generator = current_process->generator;
+  return vector_back_ptr_or_null(generator->exit_points);
+}
+
+int codegen_label_count() {
+  static int label_count = 0;
+  return label_count++;
+}
+
+void codegen_begin_exit_point() {
+  int exit_point_id = codegen_label_count();
+  codegen_register_exit_point(exit_point_id);
+}
+
+void codegen_end_exit_point() {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_exit_point *exit_point = codegen_current_exit_point();
+  assert(exit_point);
+  asm_push(".exit_point_%d:", exit_point->id);
+  free(exit_point);
+  vector_pop(generator->exit_points);
+}
+
+void codegen_goto_exit_point() {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_exit_point *exit_point = codegen_current_exit_point();
+  asm_push("jmp .exit_point_%d", exit_point->id);
+}
+
+void codegen_register_entry_point(int entry_point_id) {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_entry_point *entry_point =
+      calloc(1, sizeof(struct codegen_entry_point));
+  entry_point->id = entry_point_id;
+  vector_push(generator->entry_points, &entry_point);
+}
+
+struct codegen_entry_point *codegen_current_entry_point() {
+  struct code_generator *generator = current_process->generator;
+  return vector_back_ptr_or_null(generator->entry_points);
+}
+
+void codegen_begin_entry_point() {
+  int entry_point_id = codegen_label_count();
+  codegen_register_entry_point(entry_point_id);
+  asm_push(".entry_point_%d:", entry_point_id);
+}
+
+void codegen_end_entry_point() {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_entry_point *entry_point = codegen_current_entry_point();
+  assert(entry_point);
+  free(entry_point);
+  vector_pop(generator->entry_points);
+}
+
+void codegen_goto_entry_point() {
+  struct code_generator *generator = current_process->generator;
+  struct codegen_entry_point *entry_point = codegen_current_entry_point();
+  asm_push("jmp .entry_point_%d", entry_point->id);
+}
+
+void codegen_begin_entry_exit_point() {
+  codegen_begin_entry_point();
+  codegen_begin_exit_point();
+}
+
+void codegen_end_entry_exit_point() {
+  codegen_end_entry_point();
+  codegen_end_exit_point();
+}
+
 static const char *asm_keyword_for_size(size_t size, char *tmp_buf) {
   const char *keyword = NULL;
   switch (size) {
@@ -145,5 +234,9 @@ int codegen(struct compile_process *process) {
 
   // generate read only data section
   codegen_generate_rod();
+
+  codegen_begin_entry_exit_point();
+  codegen_goto_entry_point();
+  codegen_end_entry_exit_point();
   return 0;
 }

compiler.h

@@ -142,6 +142,24 @@ struct scope {
   struct scope *parent;
 };
 
+struct codegen_entry_point {
+  // ID of the entry point
+  int id;
+};
+
+struct codegen_exit_point {
+  // ID of the exit point
+  int id;
+};
+
+struct code_generator {
+  // vector of struct codegen_entry_point*
+  struct vector *entry_points;
+
+  // vector of struct codegen_exit_point*
+  struct vector *exit_points;
+};
+
 enum {
   SYMBOL_TYPE_NODE,
   SYMBOL_TYPE_NATIVE_FUNCTION,
@@ -183,6 +201,9 @@ struct compile_process {
     // all symbol tables
     struct vector *tables;
   } symbols;
+
+  // pointer to code generator
+  struct code_generator *generator;
 };
 
 enum { PARSE_ALL_OK, PARSE_GENERAL_ERROR };
@@ -717,5 +738,6 @@ void *fixup_private(struct fixup *fixup);
 bool fixups_resolve(struct fixup_system *system);
 
 int codegen(struct compile_process *process);
+struct code_generator *codegenerator_new(struct compile_process *process);
 
 #endif

cprocess.c

@@ -26,6 +26,7 @@ struct compile_process *compile_process_create(const char *filename,
   process->flags = flags;
   process->cfile.fp = file;
   process->ofile = out_file;
+  process->generator = codegenerator_new(process);
 
   symresolver_init(process);
   symresolver_new_table(process);