1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/frontend/BytecodeEmitter.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,289 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef frontend_BytecodeEmitter_h
1.11 +#define frontend_BytecodeEmitter_h
1.12 +
1.13 +/*
1.14 + * JS bytecode generation.
1.15 + */
1.16 +
1.17 +#include "jscntxt.h"
1.18 +#include "jsopcode.h"
1.19 +#include "jsscript.h"
1.20 +
1.21 +#include "frontend/ParseMaps.h"
1.22 +#include "frontend/SourceNotes.h"
1.23 +
1.24 +namespace js {
1.25 +namespace frontend {
1.26 +
1.27 +class FullParseHandler;
1.28 +class ObjectBox;
1.29 +class ParseNode;
1.30 +template <typename ParseHandler> class Parser;
1.31 +class SharedContext;
1.32 +class TokenStream;
1.33 +
1.34 +class CGConstList {
1.35 + Vector<Value> list;
1.36 + public:
1.37 + CGConstList(ExclusiveContext *cx) : list(cx) {}
1.38 + bool append(Value v) { JS_ASSERT_IF(v.isString(), v.toString()->isAtom()); return list.append(v); }
1.39 + size_t length() const { return list.length(); }
1.40 + void finish(ConstArray *array);
1.41 +};
1.42 +
1.43 +struct CGObjectList {
1.44 + uint32_t length; /* number of emitted so far objects */
1.45 + ObjectBox *lastbox; /* last emitted object */
1.46 +
1.47 + CGObjectList() : length(0), lastbox(nullptr) {}
1.48 +
1.49 + unsigned add(ObjectBox *objbox);
1.50 + unsigned indexOf(JSObject *obj);
1.51 + void finish(ObjectArray *array);
1.52 + ObjectBox* find(uint32_t index);
1.53 +};
1.54 +
1.55 +struct CGTryNoteList {
1.56 + Vector<JSTryNote> list;
1.57 + CGTryNoteList(ExclusiveContext *cx) : list(cx) {}
1.58 +
1.59 + bool append(JSTryNoteKind kind, uint32_t stackDepth, size_t start, size_t end);
1.60 + size_t length() const { return list.length(); }
1.61 + void finish(TryNoteArray *array);
1.62 +};
1.63 +
1.64 +struct CGBlockScopeList {
1.65 + Vector<BlockScopeNote> list;
1.66 + CGBlockScopeList(ExclusiveContext *cx) : list(cx) {}
1.67 +
1.68 + bool append(uint32_t scopeObject, uint32_t offset, uint32_t parent);
1.69 + uint32_t findEnclosingScope(uint32_t index);
1.70 + void recordEnd(uint32_t index, uint32_t offset);
1.71 + size_t length() const { return list.length(); }
1.72 + void finish(BlockScopeArray *array);
1.73 +};
1.74 +
1.75 +struct StmtInfoBCE;
1.76 +
1.77 +// Use zero inline elements because these go on the stack and affect how many
1.78 +// nested functions are possible.
1.79 +typedef Vector<jsbytecode, 0> BytecodeVector;
1.80 +typedef Vector<jssrcnote, 0> SrcNotesVector;
1.81 +
1.82 +struct BytecodeEmitter
1.83 +{
1.84 + typedef StmtInfoBCE StmtInfo;
1.85 +
1.86 + SharedContext *const sc; /* context shared between parsing and bytecode generation */
1.87 +
1.88 + BytecodeEmitter *const parent; /* enclosing function or global context */
1.89 +
1.90 + Rooted<JSScript*> script; /* the JSScript we're ultimately producing */
1.91 +
1.92 + struct EmitSection {
1.93 + BytecodeVector code; /* bytecode */
1.94 + SrcNotesVector notes; /* source notes, see below */
1.95 + ptrdiff_t lastNoteOffset; /* code offset for last source note */
1.96 + uint32_t currentLine; /* line number for tree-based srcnote gen */
1.97 + uint32_t lastColumn; /* zero-based column index on currentLine of
1.98 + last SRC_COLSPAN-annotated opcode */
1.99 +
1.100 + EmitSection(ExclusiveContext *cx, uint32_t lineNum)
1.101 + : code(cx), notes(cx), lastNoteOffset(0), currentLine(lineNum), lastColumn(0)
1.102 + {}
1.103 + };
1.104 + EmitSection prolog, main, *current;
1.105 +
1.106 + /* the parser */
1.107 + Parser<FullParseHandler> *const parser;
1.108 +
1.109 + HandleScript evalCaller; /* scripted caller info for eval and dbgapi */
1.110 +
1.111 + StmtInfoBCE *topStmt; /* top of statement info stack */
1.112 + StmtInfoBCE *topScopeStmt; /* top lexical scope statement */
1.113 + Rooted<NestedScopeObject *> staticScope;
1.114 + /* compile time scope chain */
1.115 +
1.116 + OwnedAtomIndexMapPtr atomIndices; /* literals indexed for mapping */
1.117 + unsigned firstLine; /* first line, for JSScript::initFromEmitter */
1.118 +
1.119 + int32_t stackDepth; /* current stack depth in script frame */
1.120 + uint32_t maxStackDepth; /* maximum stack depth so far */
1.121 +
1.122 + uint32_t arrayCompDepth; /* stack depth of array in comprehension */
1.123 +
1.124 + unsigned emitLevel; /* js::frontend::EmitTree recursion level */
1.125 +
1.126 + CGConstList constList; /* constants to be included with the script */
1.127 +
1.128 + CGObjectList objectList; /* list of emitted objects */
1.129 + CGObjectList regexpList; /* list of emitted regexp that will be
1.130 + cloned during execution */
1.131 + CGTryNoteList tryNoteList; /* list of emitted try notes */
1.132 + CGBlockScopeList blockScopeList;/* list of emitted block scope notes */
1.133 +
1.134 + uint16_t typesetCount; /* Number of JOF_TYPESET opcodes generated */
1.135 +
1.136 + bool hasSingletons:1; /* script contains singleton initializer JSOP_OBJECT */
1.137 +
1.138 + bool emittingForInit:1; /* true while emitting init expr of for; exclude 'in' */
1.139 +
1.140 + bool emittingRunOnceLambda:1; /* true while emitting a lambda which is only
1.141 + expected to run once. */
1.142 + bool lazyRunOnceLambda:1; /* true while lazily emitting a script for
1.143 + * a lambda which is only expected to run once. */
1.144 +
1.145 + bool isRunOnceLambda();
1.146 +
1.147 + bool insideEval:1; /* True if compiling an eval-expression or a function
1.148 + nested inside an eval. */
1.149 +
1.150 + const bool hasGlobalScope:1; /* frontend::CompileScript's scope chain is the
1.151 + global object */
1.152 +
1.153 + enum EmitterMode {
1.154 + Normal,
1.155 +
1.156 + /*
1.157 + * Emit JSOP_GETINTRINSIC instead of JSOP_NAME and assert that
1.158 + * JSOP_NAME and JSOP_*GNAME don't ever get emitted. See the comment
1.159 + * for the field |selfHostingMode| in Parser.h for details.
1.160 + */
1.161 + SelfHosting,
1.162 +
1.163 + /*
1.164 + * Check the static scope chain of the root function for resolving free
1.165 + * variable accesses in the script.
1.166 + */
1.167 + LazyFunction
1.168 + };
1.169 +
1.170 + const EmitterMode emitterMode;
1.171 +
1.172 + /*
1.173 + * Note that BytecodeEmitters are magic: they own the arena "top-of-stack"
1.174 + * space above their tempMark points. This means that you cannot alloc from
1.175 + * tempLifoAlloc and save the pointer beyond the next BytecodeEmitter
1.176 + * destruction.
1.177 + */
1.178 + BytecodeEmitter(BytecodeEmitter *parent, Parser<FullParseHandler> *parser, SharedContext *sc,
1.179 + HandleScript script, bool insideEval, HandleScript evalCaller,
1.180 + bool hasGlobalScope, uint32_t lineNum, EmitterMode emitterMode = Normal);
1.181 + bool init();
1.182 +
1.183 + bool isAliasedName(ParseNode *pn);
1.184 +
1.185 + MOZ_ALWAYS_INLINE
1.186 + bool makeAtomIndex(JSAtom *atom, jsatomid *indexp) {
1.187 + AtomIndexAddPtr p = atomIndices->lookupForAdd(atom);
1.188 + if (p) {
1.189 + *indexp = p.value();
1.190 + return true;
1.191 + }
1.192 +
1.193 + jsatomid index = atomIndices->count();
1.194 + if (!atomIndices->add(p, atom, index))
1.195 + return false;
1.196 +
1.197 + *indexp = index;
1.198 + return true;
1.199 + }
1.200 +
1.201 + bool isInLoop();
1.202 + bool checkSingletonContext();
1.203 +
1.204 + bool needsImplicitThis();
1.205 +
1.206 + void tellDebuggerAboutCompiledScript(ExclusiveContext *cx);
1.207 +
1.208 + inline TokenStream *tokenStream();
1.209 +
1.210 + BytecodeVector &code() const { return current->code; }
1.211 + jsbytecode *code(ptrdiff_t offset) const { return current->code.begin() + offset; }
1.212 + ptrdiff_t offset() const { return current->code.end() - current->code.begin(); }
1.213 + ptrdiff_t prologOffset() const { return prolog.code.end() - prolog.code.begin(); }
1.214 + void switchToMain() { current = &main; }
1.215 + void switchToProlog() { current = &prolog; }
1.216 +
1.217 + SrcNotesVector ¬es() const { return current->notes; }
1.218 + ptrdiff_t lastNoteOffset() const { return current->lastNoteOffset; }
1.219 + unsigned currentLine() const { return current->currentLine; }
1.220 + unsigned lastColumn() const { return current->lastColumn; }
1.221 +
1.222 + bool reportError(ParseNode *pn, unsigned errorNumber, ...);
1.223 + bool reportStrictWarning(ParseNode *pn, unsigned errorNumber, ...);
1.224 + bool reportStrictModeError(ParseNode *pn, unsigned errorNumber, ...);
1.225 +};
1.226 +
1.227 +/*
1.228 + * Emit one bytecode.
1.229 + */
1.230 +ptrdiff_t
1.231 +Emit1(ExclusiveContext *cx, BytecodeEmitter *bce, JSOp op);
1.232 +
1.233 +/*
1.234 + * Emit two bytecodes, an opcode (op) with a byte of immediate operand (op1).
1.235 + */
1.236 +ptrdiff_t
1.237 +Emit2(ExclusiveContext *cx, BytecodeEmitter *bce, JSOp op, jsbytecode op1);
1.238 +
1.239 +/*
1.240 + * Emit three bytecodes, an opcode with two bytes of immediate operands.
1.241 + */
1.242 +ptrdiff_t
1.243 +Emit3(ExclusiveContext *cx, BytecodeEmitter *bce, JSOp op, jsbytecode op1, jsbytecode op2);
1.244 +
1.245 +/*
1.246 + * Emit (1 + extra) bytecodes, for N bytes of op and its immediate operand.
1.247 + */
1.248 +ptrdiff_t
1.249 +EmitN(ExclusiveContext *cx, BytecodeEmitter *bce, JSOp op, size_t extra);
1.250 +
1.251 +/*
1.252 + * Emit code into bce for the tree rooted at pn.
1.253 + */
1.254 +bool
1.255 +EmitTree(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNode *pn);
1.256 +
1.257 +/*
1.258 + * Emit function code using bce for the tree rooted at body.
1.259 + */
1.260 +bool
1.261 +EmitFunctionScript(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNode *body);
1.262 +
1.263 +/*
1.264 + * Append a new source note of the given type (and therefore size) to bce's
1.265 + * notes dynamic array, updating bce->noteCount. Return the new note's index
1.266 + * within the array pointed at by bce->current->notes. Return -1 if out of
1.267 + * memory.
1.268 + */
1.269 +int
1.270 +NewSrcNote(ExclusiveContext *cx, BytecodeEmitter *bce, SrcNoteType type);
1.271 +
1.272 +int
1.273 +NewSrcNote2(ExclusiveContext *cx, BytecodeEmitter *bce, SrcNoteType type, ptrdiff_t offset);
1.274 +
1.275 +int
1.276 +NewSrcNote3(ExclusiveContext *cx, BytecodeEmitter *bce, SrcNoteType type, ptrdiff_t offset1,
1.277 + ptrdiff_t offset2);
1.278 +
1.279 +/* NB: this function can add at most one extra extended delta note. */
1.280 +bool
1.281 +AddToSrcNoteDelta(ExclusiveContext *cx, BytecodeEmitter *bce, jssrcnote *sn, ptrdiff_t delta);
1.282 +
1.283 +bool
1.284 +FinishTakingSrcNotes(ExclusiveContext *cx, BytecodeEmitter *bce, uint32_t *out);
1.285 +
1.286 +void
1.287 +CopySrcNotes(BytecodeEmitter *bce, jssrcnote *destination, uint32_t nsrcnotes);
1.288 +
1.289 +} /* namespace frontend */
1.290 +} /* namespace js */
1.291 +
1.292 +#endif /* frontend_BytecodeEmitter_h */
