Bug 719294 - Eliminate the bytecode space optimization where it omits the starting line number. r=luke

As per this comment:

/*
 * Special case: function definition needs no line number note because
 * the function's script contains its starting line number.
 */

But this is the only reason why you need a JSContext in js_PCToLineNumber, and I have a user that needs to do the lookup without a context.

--HG--
extra : rebase_source : 0807e755d5d7c1ecd6837ca4f6b8d4cc53e3f0b2

js/src/frontend/BytecodeEmitter.cpp

@@ -5116,6 +5116,8 @@ EmitFunc(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn)
                        "global functions can't have upvars, so they are never flat");
             if (!EmitFunctionOp(cx, JSOP_DEFFUN, index, bce))
                 return false;
+            if (!UpdateLineNumberNotes(cx, bce, pn->pn_pos.begin.lineno))
+                return false;
             bce->switchToMain();
         }
 

js/src/jscntxt.cpp

@@ -359,7 +359,7 @@ PopulateReportBlame(JSContext *cx, JSErrorReport *report)
     for (FrameRegsIter iter(cx); !iter.done(); ++iter) {
         if (iter.fp()->isScriptFrame()) {
             report->filename = iter.fp()->script()->filename;
-            report->lineno = js_PCToLineNumber(cx, iter.fp()->script(), iter.pc());
+            report->lineno = PCToLineNumber(iter.fp()->script(), iter.pc());
             report->originPrincipals = iter.fp()->script()->originPrincipals;
             break;
         }

js/src/jsdbgapi.cpp

@@ -351,7 +351,7 @@ JS_ClearAllWatchPoints(JSContext *cx)
 JS_PUBLIC_API(unsigned)
 JS_PCToLineNumber(JSContext *cx, JSScript *script, jsbytecode *pc)
 {
-    return js_PCToLineNumber(cx, script, pc);
+    return js::PCToLineNumber(script, pc);
 }
 
 JS_PUBLIC_API(jsbytecode *)

js/src/jsexn.cpp

@@ -343,7 +343,7 @@ InitExnPrivate(JSContext *cx, JSObject *exnObject, JSString *message,
             }
             if (fp->isScriptFrame()) {
                 frame.filename = fp->script()->filename;
-                frame.ulineno = js_PCToLineNumber(cx, fp->script(), i.pc());
+                frame.ulineno = PCToLineNumber(fp->script(), i.pc());
             } else {
                 frame.ulineno = 0;
                 frame.filename = NULL;
@@ -783,7 +783,7 @@ Exception(JSContext *cx, unsigned argc, Value *vp)
         if (!ToUint32(cx, args[2], &lineno))
             return false;
     } else {
-        lineno = iter.done() ? 0 : js_PCToLineNumber(cx, iter.fp()->script(), iter.pc());
+        lineno = iter.done() ? 0 : PCToLineNumber(iter.fp()->script(), iter.pc());
     }
 
     int exnType = args.callee().toFunction()->getExtendedSlot(0).toInt32();

js/src/jsscript.cpp

@@ -1571,28 +1571,18 @@ js_GetSrcNoteCached(JSContext *cx, JSScript *script, jsbytecode *pc)
 }
 
 unsigned
-js_PCToLineNumber(JSContext *cx, JSScript *script, jsbytecode *pc)
+js::PCToLineNumber(unsigned startLine, jssrcnote *notes, jsbytecode *code, jsbytecode *pc)
 {
-    /* Cope with StackFrame.pc value prior to entering js_Interpret. */
-    if (!pc)
-        return 0;
+    unsigned lineno = startLine;
 
     /*
-     * Special case: function definition needs no line number note because
-     * the function's script contains its starting line number.
+     * Walk through source notes accumulating their deltas, keeping track of
+     * line-number notes, until we pass the note for pc's offset within
+     * script->code.
      */
-    if (*pc == JSOP_DEFFUN)
-        return script->getFunction(GET_UINT32_INDEX(pc))->script()->lineno;
-
-    /*
-     * General case: walk through source notes accumulating their deltas,
-     * keeping track of line-number notes, until we pass the note for pc's
-     * offset within script->code.
-     */
-    unsigned lineno = script->lineno;
     ptrdiff_t offset = 0;
-    ptrdiff_t target = pc - script->code;
-    for (jssrcnote *sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) {
+    ptrdiff_t target = pc - code;
+    for (jssrcnote *sn = notes; !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) {
         offset += SN_DELTA(sn);
         SrcNoteType type = (SrcNoteType) SN_TYPE(sn);
         if (type == SRC_SETLINE) {
@@ -1605,9 +1595,20 @@ js_PCToLineNumber(JSContext *cx, JSScript *script, jsbytecode *pc)
         if (offset > target)
             break;
     }
+
     return lineno;
 }
 
+unsigned
+js::PCToLineNumber(JSScript *script, jsbytecode *pc)
+{
+    /* Cope with StackFrame.pc value prior to entering js_Interpret. */
+    if (!pc)
+        return 0;
+
+    return PCToLineNumber(script->lineno, script->notes(), script->code, pc);
+}
+
 /* The line number limit is the same as the jssrcnote offset limit. */
 #define SN_LINE_LIMIT   (SN_3BYTE_OFFSET_FLAG << 16)
 
@@ -1680,7 +1681,7 @@ namespace js {
 unsigned
 CurrentLine(JSContext *cx)
 {
-    return js_PCToLineNumber(cx, cx->fp()->script(), cx->regs().pc);
+    return PCToLineNumber(cx->fp()->script(), cx->regs().pc);
 }
 
 void
@@ -1700,7 +1701,7 @@ CurrentScriptFileLineOriginSlow(JSContext *cx, const char **file, unsigned *line
 
     JSScript *script = iter.fp()->script();
     *file = script->filename;
-    *linenop = js_PCToLineNumber(cx, iter.fp()->script(), iter.pc());
+    *linenop = PCToLineNumber(iter.fp()->script(), iter.pc());
     *origin = script->originPrincipals;
 }
 

js/src/jsscript.h

@@ -902,9 +902,6 @@ CheckScript(JSScript *script, JSScript *prev)
 extern jssrcnote *
 js_GetSrcNoteCached(JSContext *cx, JSScript *script, jsbytecode *pc);
 
-extern unsigned
-js_PCToLineNumber(JSContext *cx, JSScript *script, jsbytecode *pc);
-
 extern jsbytecode *
 js_LineNumberToPC(JSScript *script, unsigned lineno);
 
@@ -913,6 +910,12 @@ js_GetScriptLineExtent(JSScript *script);
 
 namespace js {
 
+extern unsigned
+PCToLineNumber(JSScript *script, jsbytecode *pc);
+
+extern unsigned
+PCToLineNumber(unsigned startLine, jssrcnote *notes, jsbytecode *code, jsbytecode *pc);
+
 extern unsigned
 CurrentLine(JSContext *cx);
 

js/src/jsxml.cpp

@@ -1790,7 +1790,7 @@ ParseXMLSource(JSContext *cx, JSString *src)
         op = (JSOp) *i.pc();
         if (op == JSOP_TOXML || op == JSOP_TOXMLLIST) {
             filename = i.fp()->script()->filename;
-            lineno = js_PCToLineNumber(cx, i.fp()->script(), i.pc());
+            lineno = PCToLineNumber(i.fp()->script(), i.pc());
             for (endp = srcp + srclen; srcp < endp; srcp++) {
                 if (*srcp == '\n')
                     --lineno;

js/src/methodjit/InvokeHelpers.cpp

@@ -800,7 +800,7 @@ js_InternalInterpret(void *returnData, void *returnType, void *returnReg, js::VM
 
 #ifdef JS_METHODJIT_SPEW
     JaegerSpew(JSpew_Recompile, "interpreter rejoin (file \"%s\") (line \"%d\") (op %s) (opline \"%d\")\n",
-               script->filename, script->lineno, OpcodeNames[op], js_PCToLineNumber(cx, script, pc));
+               script->filename, script->lineno, OpcodeNames[op], PCToLineNumber(script, pc));
 #endif
 
     uint32_t nextDepth = UINT32_MAX;