txr-015 2009-10-15txr-015

1 files changed, 90 insertions, 2 deletions

diff --git a/unwind.h b/unwind.h
index 1cd0792a..574794b2 100644
--- a/unwind.h
+++ b/unwind.h
@@ -24,10 +24,16 @@
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+#ifdef __GNUC__
+#define noreturn __attribute__((noreturn))
+#else
+#define noreturn
+#endif
+
 typedef union uw_frame uw_frame_t;
 typedef enum uw_frtype uw_frtype_t;
 
-enum uw_frtype { UW_BLOCK, UW_ENV };
+enum uw_frtype { UW_BLOCK, UW_ENV, UW_CATCH };
 
 struct uw_common {
   uw_frame_t *up;
@@ -48,20 +54,42 @@ struct uw_dynamic_env {
   obj_t *func_bindings;
 };
 
+struct uw_catch {
+  uw_frame_t *up;
+  uw_frtype_t type;
+  obj_t *matches;
+  obj_t *sym;
+  obj_t *exception;
+  uw_frame_t *cont;
+  int visible;
+  jmp_buf jb;
+};
+
 union uw_frame {
   struct uw_common uw;
   struct uw_block bl;
   struct uw_dynamic_env ev;
+  struct uw_catch ca;
 };
 
-void uw_init(void);
 void uw_push_block(uw_frame_t *, obj_t *tag);
 void uw_push_env(uw_frame_t *);
 obj_t *uw_get_func(obj_t *sym);
 obj_t *uw_set_func(obj_t *sym, obj_t *value);
 obj_t *uw_block_return(obj_t *tag, obj_t *result);
+void uw_push_catch(uw_frame_t *, obj_t *matches);
+noreturn obj_t *uw_throw(obj_t *sym, obj_t *exception);
+noreturn obj_t *uw_throwf(obj_t *sym, const char *fmt, ...);
+noreturn obj_t *uw_errorf(const char *fmt, ...);
+noreturn obj_t *uw_throwcf(obj_t *sym, const char *fmt, ...);
+noreturn obj_t *uw_errorcf(const char *fmt, ...);
+void uw_register_subtype(obj_t *sub, obj_t *super);
+obj_t *uw_exception_subtype_p(obj_t *sub, obj_t *sup);
+void uw_continue(uw_frame_t *curr, uw_frame_t *target);
 void uw_pop_frame(uw_frame_t *);
+void uw_init(void);
 
+noreturn obj_t *type_mismatch(const char *, ...);
 
 #define uw_block_begin(TAG, RESULTVAR)  \
   obj_t *RESULTVAR = nil;               \
@@ -85,3 +113,63 @@ void uw_pop_frame(uw_frame_t *);
 #define uw_env_end                      \
     uw_pop_frame(&uw_env);              \
   }
+
+#define uw_catch_begin(MATCHES, SYMVAR, \
+                       EXCVAR)          \
+  obj_t *SYMVAR = nil;                  \
+  obj_t *EXCVAR = nil;                  \
+  {                                     \
+    uw_frame_t uw_catch;                \
+    uw_push_catch(&uw_catch, MATCHES);  \
+    switch (setjmp(uw_catch.ca.jb)) {   \
+    case 0:
+
+#define uw_do_unwind                    \
+      goto uw_unwind_label
+
+#define uw_catch(SYMVAR, EXCVAR)        \
+      break;                            \
+    case 2:                             \
+      EXCVAR = uw_catch.ca.exception;   \
+      SYMVAR = uw_catch.ca.sym;         \
+
+#define uw_unwind                       \
+      break;                            \
+    uw_unwind_label:                    \
+    case 1:
+
+#define uw_catch_end                    \
+    default:                            \
+      break;                            \
+    }                                   \
+    if (uw_catch.ca.cont)               \
+      uw_continue(&uw_catch,            \
+                  uw_catch.ca.cont);    \
+    uw_pop_frame(&uw_catch);            \
+  }
+
+#define internal_error(STR)             \
+  uw_throwcf(internal_err,              \
+             "%s:%d %s", __FILE__,      \
+             __LINE__, STR)
+
+#define type_assert(EXPR, ARGS)         \
+  if (!(EXPR)) type_mismatch ARGS
+
+#define bug_unless(EXPR)                \
+  if (!(EXPR))                          \
+    internal_error("assertion "         \
+                            #EXPR       \
+                            " failed")
+
+#define numeric_assert(EXPR)            \
+  if (!(EXPR))                          \
+   uw_throwcf(numeric_err, "%s",        \
+              "assertion " #EXPR        \
+              " failed")
+
+#define range_bug_unless(EXPR)          \
+  if (!(EXPR))                          \
+   uw_throwcf(range_err, "%s",          \
+              "assertion" #EXPR         \
+              " failed")