Prohibit changes to iseq in principle

1 files changed, 37 insertions, 34 deletions

diff --git a/mrbgems/mruby-eval/src/eval.c b/mrbgems/mruby-eval/src/eval.c
index e8f1d3e95..e2388f026 100644
--- a/mrbgems/mruby-eval/src/eval.c
+++ b/mrbgems/mruby-eval/src/eval.c
@@ -102,25 +102,28 @@ patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
   uint8_t c;
   mrb_code insn;
   int argc = irep_argc(irep);
+  mrb_code *iseq = (mrb_code *)irep->iseq;
+
+  mrb_assert((irep->flags & MRB_ISEQ_NO_FREE) == 0);
 
   for (i = 0; i < irep->ilen; ) {
-    insn = irep->iseq[i];
+    insn = iseq[i];
     switch(insn){
     case OP_EPUSH:
-      b = PEEK_S(irep->iseq+i+1);
+      b = PEEK_S(iseq+i+1);
       patch_irep(mrb, irep->reps[b], bnest + 1, top);
       break;
 
     case OP_LAMBDA:
     case OP_BLOCK:
-      a = PEEK_B(irep->iseq+i+1);
-      b = PEEK_B(irep->iseq+i+2);
+      a = PEEK_B(iseq+i+1);
+      b = PEEK_B(iseq+i+2);
       patch_irep(mrb, irep->reps[b], bnest + 1, top);
       break;
 
     case OP_SEND:
-      b = PEEK_B(irep->iseq+i+2);
-      c = PEEK_B(irep->iseq+i+3);
+      b = PEEK_B(iseq+i+2);
+      c = PEEK_B(iseq+i+3);
       if (c != 0) {
         break;
       }
@@ -128,24 +131,24 @@ patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
         uint16_t arg = search_variable(mrb, irep->syms[b], bnest);
         if (arg != 0) {
           /* must replace */
-          irep->iseq[i] = OP_GETUPVAR;
-          irep->iseq[i+2] = arg >> 8;
-          irep->iseq[i+3] = arg & 0xff;
+          iseq[i] = OP_GETUPVAR;
+          iseq[i+2] = arg >> 8;
+          iseq[i+3] = arg & 0xff;
         }
       }
       break;
 
     case OP_MOVE:
-      a = PEEK_B(irep->iseq+i+1);
-      b = PEEK_B(irep->iseq+i+2);
+      a = PEEK_B(iseq+i+1);
+      b = PEEK_B(iseq+i+2);
       /* src part */
       if (potential_upvar_p(irep->lv, b, argc, irep->nlocals)) {
         uint16_t arg = search_variable(mrb, irep->lv[b - 1].name, bnest);
         if (arg != 0) {
           /* must replace */
-          irep->iseq[i] = insn = OP_GETUPVAR;
-          irep->iseq[i+2] = arg >> 8;
-          irep->iseq[i+3] = arg & 0xff;
+          iseq[i] = insn = OP_GETUPVAR;
+          iseq[i+2] = arg >> 8;
+          iseq[i+3] = arg & 0xff;
         }
       }
       /* dst part */
@@ -153,18 +156,18 @@ patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
         uint16_t arg = search_variable(mrb, irep->lv[a - 1].name, bnest);
         if (arg != 0) {
           /* must replace */
-          irep->iseq[i] = insn = OP_SETUPVAR;
-          irep->iseq[i+1] = (mrb_code)b;
-          irep->iseq[i+2] = arg >> 8;
-          irep->iseq[i+3] = arg & 0xff;
+          iseq[i] = insn = OP_SETUPVAR;
+          iseq[i+1] = (mrb_code)b;
+          iseq[i+2] = arg >> 8;
+          iseq[i+3] = arg & 0xff;
         }
       }
       break;
 
     case OP_GETUPVAR:
-      a = PEEK_B(irep->iseq+i+1);
-      b = PEEK_B(irep->iseq+i+2);
-      c = PEEK_B(irep->iseq+i+3);
+      a = PEEK_B(iseq+i+1);
+      b = PEEK_B(iseq+i+2);
+      c = PEEK_B(iseq+i+3);
       {
         int lev = c+1;
         mrb_irep *tmp = search_irep(top, bnest, lev, irep);
@@ -172,18 +175,18 @@ patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
           uint16_t arg = search_variable(mrb, tmp->lv[b-1].name, bnest);
           if (arg != 0) {
             /* must replace */
-            irep->iseq[i] = OP_GETUPVAR;
-            irep->iseq[i+2] = arg >> 8;
-            irep->iseq[i+3] = arg & 0xff;
+            iseq[i] = OP_GETUPVAR;
+            iseq[i+2] = arg >> 8;
+            iseq[i+3] = arg & 0xff;
           }
         }
       }
       break;
 
     case OP_SETUPVAR:
-      a = PEEK_B(irep->iseq+i+1);
-      b = PEEK_B(irep->iseq+i+2);
-      c = PEEK_B(irep->iseq+i+3);
+      a = PEEK_B(iseq+i+1);
+      b = PEEK_B(iseq+i+2);
+      c = PEEK_B(iseq+i+3);
       {
         int lev = c+1;
         mrb_irep *tmp = search_irep(top, bnest, lev, irep);
@@ -191,25 +194,25 @@ patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
           uint16_t arg = search_variable(mrb, tmp->lv[b-1].name, bnest);
           if (arg != 0) {
             /* must replace */
-            irep->iseq[i] = OP_SETUPVAR;
-            irep->iseq[i+1] = a;
-            irep->iseq[i+2] = arg >> 8;
-            irep->iseq[i+3] = arg & 0xff;
+            iseq[i] = OP_SETUPVAR;
+            iseq[i+1] = a;
+            iseq[i+2] = arg >> 8;
+            iseq[i+3] = arg & 0xff;
           }
         }
       }
       break;
 
     case OP_EXT1:
-      insn = PEEK_B(irep->iseq+i+1);
+      insn = PEEK_B(iseq+i+1);
       i += mrb_insn_size1[insn]+1;
       continue;
     case OP_EXT2:
-      insn = PEEK_B(irep->iseq+i+1);
+      insn = PEEK_B(iseq+i+1);
       i += mrb_insn_size2[insn]+1;
       continue;
     case OP_EXT3:
-      insn = PEEK_B(irep->iseq+i+1);
+      insn = PEEK_B(iseq+i+1);
       i += mrb_insn_size3[insn]+1;
       continue;
     }