Bug 838813 part 3 - Remove SRC_DECL. r=njn.

--HG--
extra : rebase_source : d2b807c7d8b981734db6ffc7735fb71777f307ad

js/src/frontend/BytecodeEmitter.cpp

@@ -3173,7 +3173,6 @@ EmitVariables(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn, VarEmitOption
     ptrdiff_t off = -1, noteIndex = -1;
     ParseNode *next;
     for (ParseNode *pn2 = pn->pn_head; ; pn2 = next) {
-        bool first = pn2 == pn->pn_head;
         next = pn2->pn_next;
 
         ParseNode *pn3;
@@ -3334,14 +3333,6 @@ EmitVariables(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn, VarEmitOption
         }
 
         JS_ASSERT_IF(pn2->isDefn(), pn3 == pn2->pn_expr);
-        if (first && NewSrcNote2(cx, bce, SRC_DECL,
-                                 (pn->isOp(JSOP_DEFCONST))
-                                 ? SRC_DECL_CONST
-                                 : (pn->isOp(JSOP_DEFVAR))
-                                 ? SRC_DECL_VAR
-                                 : SRC_DECL_LET) < 0) {
-            return false;
-        }
         if (!pn2->pn_cookie.isFree()) {
             if (!EmitVarOp(cx, pn2, op, bce))
                 return false;
@@ -4164,7 +4155,7 @@ EmitIf(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
  *  destructure z
  *  pick 1
  *  pop               -1
- *  enterlet0                     SRC_DECL + offset to leaveblockexpr
+ *  enterlet0
  *  evaluate e        +1
  *  leaveblockexpr    -3          SRC_PCBASE + offset to evaluate a
  *
@@ -4177,8 +4168,6 @@ EmitIf(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
  * object from which to find let var names. These forward offsets require
  * backpatching, which is handled by LetNotes.
  *
- * The SRC_DECL offset allows recursive decompilation of 'e'.
- *
  * The SRC_PCBASE allows js_DecompileValueGenerator to walk backwards from
  * JSOP_LEAVEBLOCKEXPR to the beginning of the let and is only needed for
  * let-expressions.
@@ -4221,10 +4210,6 @@ EmitLet(JSContext *cx, BytecodeEmitter *bce, ParseNode *pnLet)
     if (!letNotes.update(cx, bce, bce->offset()))
         return false;
 
-    ptrdiff_t declNote = NewSrcNote(cx, bce, SRC_DECL);
-    if (declNote < 0)
-        return false;
-
     ptrdiff_t bodyBegin = bce->offset();
     if (!EmitEnterBlock(cx, bce, letBody, JSOP_ENTERLET0))
         return false;
@@ -4244,13 +4229,7 @@ EmitLet(JSContext *cx, BytecodeEmitter *bce, ParseNode *pnLet)
     ptrdiff_t bodyEnd = bce->offset();
     JS_ASSERT(bodyEnd > bodyBegin);
 
-    if (!PopStatementBCE(cx, bce))
-        return false;
-
-    ptrdiff_t o = PackLetData((bodyEnd - bodyBegin) -
-                              (JSOP_ENTERLET0_LENGTH + JSOP_LEAVEBLOCK_LENGTH),
-                              letNotes.isGroupAssign());
-    return SetSrcNoteOffset(cx, bce, declNote, 0, o);
+    return PopStatementBCE(cx, bce);
 }
 #endif
 
@@ -4439,12 +4418,6 @@ EmitForIn(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn, ptrdiff_t top)
         return false;
 
     ptrdiff_t tmp2 = bce->offset();
-    if (forHead->pn_kid1 && NewSrcNote2(cx, bce, SRC_DECL,
-                                        (forHead->pn_kid1->isOp(JSOP_DEFVAR))
-                                        ? SRC_DECL_VAR
-                                        : SRC_DECL_LET) < 0) {
-        return false;
-    }
     if (Emit1(cx, bce, JSOP_POP) < 0)
         return false;
 
@@ -6674,7 +6647,7 @@ CGConstList::finish(ConstArray *array)
 
 /*
  * We should try to get rid of offsetBias (always 0 or 1, where 1 is
- * JSOP_{NOP,POP}_LENGTH), which is used only by SRC_FOR and SRC_DECL.
+ * JSOP_{NOP,POP}_LENGTH), which is used only by SRC_FOR.
  */
 JS_FRIEND_DATA(JSSrcNoteSpec) js_SrcNoteSpec[] = {
     {"null",            0},

js/src/frontend/BytecodeEmitter.h

@@ -271,7 +271,6 @@ enum SrcNoteType {
                                    array literal: [1,2,,];
                                    JSOP_DUP continuing destructuring pattern;
                                    JSOP_POP at end of for-in */
-    SRC_DECL        = 6,        /* type of a declaration (var, const, let*) */
     SRC_DESTRUCT    = 6,        /* JSOP_DUP starting a destructuring assignment
                                    operation, with SRC_DECL_* offset operand */
     SRC_PCDELTA     = 7,        /* distance forward from comma-operator to
@@ -305,7 +304,7 @@ enum SrcNoteType {
 };
 
 /*
- * Constants for the SRC_DECL source note.
+ * Constants for the SRC_DESTRUCTLET source note.
  *
  * NB: the var_prefix array in jsopcode.c depends on these dense indexes from
  * SRC_DECL_VAR through SRC_DECL_LET.
@@ -436,28 +435,6 @@ BytecodeEmitter::countFinalSourceNotes()
     return cnt;
 }
 
-/*
- * To avoid offending js_SrcNoteSpec[SRC_DECL].arity, pack the two data needed
- * to decompile let into one ptrdiff_t:
- *   offset: offset to the LEAVEBLOCK(EXPR) op (not including ENTER/LEAVE)
- *   groupAssign: whether this was an optimized group assign ([x,y] = [a,b])
- */
-inline ptrdiff_t PackLetData(size_t offset, bool groupAssign)
-{
-    JS_ASSERT(offset <= (size_t(-1) >> 1));
-    return ptrdiff_t(offset << 1) | ptrdiff_t(groupAssign);
-}
-
-inline size_t LetDataToOffset(ptrdiff_t w)
-{
-    return size_t(w) >> 1;
-}
-
-inline bool LetDataToGroupAssign(ptrdiff_t w)
-{
-    return size_t(w) & 1;
-}
-
 } /* namespace frontend */
 } /* namespace js */
 

js/src/jsopcode.cpp

@@ -56,8 +56,6 @@ using namespace js;
 using namespace js::gc;
 
 using js::frontend::IsIdentifier;
-using js::frontend::LetDataToGroupAssign;
-using js::frontend::LetDataToOffset;
 using mozilla::ArrayLength;
 
 /*

js/src/shell/js.cpp

@@ -1753,7 +1753,6 @@ SrcNotes(JSContext *cx, HandleScript script, Sprinter *sp)
           case SRC_WHILE:
           case SRC_PCBASE:
           case SRC_PCDELTA:
-          case SRC_DECL:
           case SRC_BRACE:
             Sprint(sp, " offset %u", unsigned(js_GetSrcNoteOffset(sn, 0)));
             break;