From fdedd57c60d35bed3e6cde12084b7abe08153ed3 Mon Sep 17 00:00:00 2001
From: janekptacijarabaci <janekptacijarabaci@seznam.cz>
Date: Sat, 24 Mar 2018 12:28:12 +0100
Subject: Bug 1147371: Implement JSOP_PICK and JSOP_UNPICK in the expression
 decompiler

Issue #74
---
 js/src/jsopcode.cpp      | 28 ++++++++++++++++++++++++++++
 js/src/jsopcode.h        |  1 +
 js/src/jsopcodeinlines.h |  3 ++-
 3 files changed, 31 insertions(+), 1 deletion(-)

(limited to 'js/src')

diff --git a/js/src/jsopcode.cpp b/js/src/jsopcode.cpp
index 31bbfb471..eadbca4f8 100644
--- a/js/src/jsopcode.cpp
+++ b/js/src/jsopcode.cpp
@@ -460,6 +460,34 @@ BytecodeParser::simulateOp(JSOp op, uint32_t offset, uint32_t* offsetStack, uint
             offsetStack[stackDepth] = tmp;
         }
         break;
+
+      case JSOP_PICK: {
+        jsbytecode* pc = script_->offsetToPC(offset);
+        unsigned n = GET_UINT8(pc);
+        MOZ_ASSERT(ndefs == n + 1);
+        if (offsetStack) {
+            uint32_t top = stackDepth + n;
+            uint32_t tmp = offsetStack[stackDepth];
+            for (uint32_t i = stackDepth; i < top; i++)
+                offsetStack[i] = offsetStack[i + 1];
+            offsetStack[top] = tmp;
+        }
+        break;
+      }
+
+      case JSOP_UNPICK: {
+        jsbytecode* pc = script_->offsetToPC(offset);
+        unsigned n = GET_UINT8(pc);
+        MOZ_ASSERT(ndefs == n + 1);
+        if (offsetStack) {
+            uint32_t top = stackDepth + n;
+            uint32_t tmp = offsetStack[top];
+            for (uint32_t i = top; i > stackDepth; i--)
+                offsetStack[i] = offsetStack[i - 1];
+            offsetStack[stackDepth] = tmp;
+        }
+        break;
+      }
     }
     stackDepth += ndefs;
     return stackDepth;
diff --git a/js/src/jsopcode.h b/js/src/jsopcode.h
index 4f7859665..e56eebb2d 100644
--- a/js/src/jsopcode.h
+++ b/js/src/jsopcode.h
@@ -423,6 +423,7 @@ BytecodeFallsThrough(JSOp op)
       case JSOP_RETRVAL:
       case JSOP_FINALYIELDRVAL:
       case JSOP_THROW:
+      case JSOP_THROWMSG:
       case JSOP_TABLESWITCH:
         return false;
       case JSOP_GOSUB:
diff --git a/js/src/jsopcodeinlines.h b/js/src/jsopcodeinlines.h
index cf9c8357a..5b0ce0cf9 100644
--- a/js/src/jsopcodeinlines.h
+++ b/js/src/jsopcodeinlines.h
@@ -27,6 +27,7 @@ GetDefCount(JSScript* script, unsigned offset)
       case JSOP_AND:
         return 1;
       case JSOP_PICK:
+      case JSOP_UNPICK:
         /*
          * Pick pops and pushes how deep it looks in the stack + 1
          * items. i.e. if the stack were |a b[2] c[1] d[0]|, pick 2
@@ -44,7 +45,7 @@ GetUseCount(JSScript* script, unsigned offset)
 {
     jsbytecode* pc = script->offsetToPC(offset);
 
-    if (JSOp(*pc) == JSOP_PICK)
+    if (JSOp(*pc) == JSOP_PICK || JSOp(*pc) == JSOP_UNPICK)
         return pc[1] + 1;
     if (CodeSpec[*pc].nuses == -1)
         return StackUses(script, pc);
-- 
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