do not abort when meet a compilation error

include/picrin.h

@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 #include <stdbool.h>
+#include <setjmp.h>
 
 #include "picconf.h"
 #include "picrin/value.h"
@@ -34,6 +35,9 @@ typedef struct {
   struct pic_irep **irep;
   size_t ilen, icapa;
 
+  jmp_buf *jmp;
+  const char *errmsg;
+
   struct heap_page *heap;
   struct pic_object *arena[PIC_ARENA_SIZE];
   int arena_idx;
@@ -68,7 +72,7 @@ struct pic_proc *pic_codegen(pic_state *, pic_value, struct pic_env *);
 
 void pic_abort(pic_state *, const char *);
 void pic_raise(pic_state *, pic_value);
-void pic_error(pic_state *, const char *, ...);
+void pic_error(pic_state *, const char *);
 
 void pic_debug(pic_state *, pic_value);
 

src/codegen.c

@@ -204,7 +204,7 @@ pic_gen(pic_state *pic, struct pic_irep *irep, pic_value obj, struct pic_env *en
 
     b = env_lookup(pic, obj, env, &depth, &idx);
     if (! b) {
-      pic_abort(pic, "unbound variable");
+      pic_error(pic, "unbound variable");
     }
 
     if (depth == -1) {		/* global */
@@ -218,7 +218,7 @@ pic_gen(pic_state *pic, struct pic_irep *irep, pic_value obj, struct pic_env *en
       irep->clen++;
     }
     else {			/* nonlocal */
-      pic_abort(pic, "reference to closed variable not supported");
+      pic_error(pic, "reference to closed variable not supported");
     }
     break;
   }
@@ -362,7 +362,7 @@ pic_gen(pic_state *pic, struct pic_irep *irep, pic_value obj, struct pic_env *en
   case PIC_TT_PROC:
   case PIC_TT_UNDEF:
   case PIC_TT_PORT: {
-    pic_abort(pic, "invalid expression given");
+    pic_error(pic, "invalid expression given");
   }
   }
 }
@@ -438,6 +438,17 @@ pic_codegen(pic_state *pic, pic_value obj, struct pic_env *env)
   proc->cfunc_p = false;
   proc->u.irep = irep = new_irep(pic);
 
+  if (! pic->jmp) {
+    jmp_buf jmp;
+
+    pic->jmp = &jmp;
+    if (setjmp(*pic->jmp) != 0) {
+      /* error occured */
+
+      pic->jmp = NULL;
+      return NULL;
+    }
+  }
   pic_gen(pic, irep, obj, env);
   irep->code[irep->clen].insn = OP_STOP;
   irep->clen++;

src/error.c

@@ -3,6 +3,17 @@
 
 #include "picrin.h"
 
+void
+pic_error(pic_state *pic, const char *msg)
+{
+  pic->errmsg = msg;
+  if (! pic->jmp) {
+    puts(msg);
+    abort();
+  }
+  longjmp(*pic->jmp, 1);
+}
+
 void
 pic_abort(pic_state *pic, const char *msg)
 {

src/main.c

@@ -66,13 +66,11 @@ main()
     /* read */
     r = pic_parse(pic, code, &v);
     if (! r) {			/* wait for more input */
-      pic_gc_arena_restore(pic, ai);
-      continue;
+      goto next;
     }
     code[0] = '\0';
     if (pic_undef_p(v)) {	/* parse error */
-      pic_gc_arena_restore(pic, ai);
-      continue;
+      goto next;
     }
 
 #if DEBUG
@@ -83,6 +81,11 @@ main()
 
     /* eval */
     proc = pic_codegen(pic, v, pic->global_env);
+    if (proc == NULL) {
+      printf("compilation error: %s\n", pic->errmsg);
+      pic->errmsg = NULL;
+      goto next;
+    }
     v = pic_run(pic, proc, pic_nil_value());
 
     /* print */
@@ -90,6 +93,7 @@ main()
     pic_debug(pic, v);
     printf("\n");
 
+  next:
     pic_gc_arena_restore(pic, ai);
   }
 

src/state.c

@@ -51,6 +51,10 @@ pic_open()
   pic->glen = 0;
   pic->gcapa = PIC_GLOBALS_SIZE;
 
+  /* error handling */
+  pic->jmp = NULL;
+  pic->errmsg = NULL;
+
   /* GC arena */
   pic->arena_idx = 0;