1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 // This is clang plugin used by gcmole tool. See README for more details.
30 #include "clang/AST/AST.h"
31 #include "clang/AST/ASTConsumer.h"
32 #include "clang/AST/Mangle.h"
33 #include "clang/AST/RecursiveASTVisitor.h"
34 #include "clang/AST/StmtVisitor.h"
35 #include "clang/Frontend/FrontendPluginRegistry.h"
36 #include "clang/Frontend/CompilerInstance.h"
37 #include "llvm/Support/raw_ostream.h"
48 typedef std::string MangledName;
49 typedef std::set<MangledName> CalleesSet;
51 static bool GetMangledName(clang::MangleContext* ctx,
52 const clang::NamedDecl* decl,
53 MangledName* result) {
54 if (!llvm::isa<clang::CXXConstructorDecl>(decl) &&
55 !llvm::isa<clang::CXXDestructorDecl>(decl)) {
56 llvm::SmallVector<char, 512> output;
57 llvm::raw_svector_ostream out(output);
58 ctx->mangleName(decl, out);
59 *result = out.str().str();
67 static bool InV8Namespace(const clang::NamedDecl* decl) {
68 return decl->getQualifiedNameAsString().compare(0, 4, "v8::") == 0;
72 static std::string EXTERNAL("EXTERNAL");
73 static std::string STATE_TAG("enum v8::internal::StateTag");
75 static bool IsExternalVMState(const clang::ValueDecl* var) {
76 const clang::EnumConstantDecl* enum_constant =
77 llvm::dyn_cast<clang::EnumConstantDecl>(var);
78 if (enum_constant != NULL && enum_constant->getNameAsString() == EXTERNAL) {
79 clang::QualType type = enum_constant->getType();
80 return (type.getAsString() == STATE_TAG);
88 explicit Resolver(clang::ASTContext& ctx)
89 : ctx_(ctx), decl_ctx_(ctx.getTranslationUnitDecl()) {
92 Resolver(clang::ASTContext& ctx, clang::DeclContext* decl_ctx)
93 : ctx_(ctx), decl_ctx_(decl_ctx) {
96 clang::DeclarationName ResolveName(const char* n) {
97 clang::IdentifierInfo* ident = &ctx_.Idents.get(n);
98 return ctx_.DeclarationNames.getIdentifier(ident);
101 Resolver ResolveNamespace(const char* n) {
102 return Resolver(ctx_, Resolve<clang::NamespaceDecl>(n));
106 T* Resolve(const char* n) {
107 if (decl_ctx_ == NULL) return NULL;
109 clang::DeclContext::lookup_result result =
110 decl_ctx_->lookup(ResolveName(n));
112 clang::DeclContext::lookup_iterator end = result.end();
113 for (clang::DeclContext::lookup_iterator i = result.begin(); i != end;
115 if (llvm::isa<T>(*i)) return llvm::cast<T>(*i);
122 clang::ASTContext& ctx_;
123 clang::DeclContext* decl_ctx_;
127 class CalleesPrinter : public clang::RecursiveASTVisitor<CalleesPrinter> {
129 explicit CalleesPrinter(clang::MangleContext* ctx) : ctx_(ctx) {
132 virtual bool VisitCallExpr(clang::CallExpr* expr) {
133 const clang::FunctionDecl* callee = expr->getDirectCallee();
134 if (callee != NULL) AnalyzeFunction(callee);
138 virtual bool VisitDeclRefExpr(clang::DeclRefExpr* expr) {
139 // If function mentions EXTERNAL VMState add artificial garbage collection
141 if (IsExternalVMState(expr->getDecl())) AddCallee("CollectGarbage");
145 void AnalyzeFunction(const clang::FunctionDecl* f) {
147 if (InV8Namespace(f) && GetMangledName(ctx_, f, &name)) {
150 const clang::FunctionDecl* body = NULL;
151 if (f->hasBody(body) && !Analyzed(name)) {
153 TraverseStmt(body->getBody());
159 typedef std::map<MangledName, CalleesSet* > Callgraph;
161 bool Analyzed(const MangledName& name) {
162 return callgraph_[name] != NULL;
165 void EnterScope(const MangledName& name) {
166 CalleesSet* callees = callgraph_[name];
168 if (callees == NULL) {
169 callgraph_[name] = callees = new CalleesSet();
172 scopes_.push(callees);
179 void AddCallee(const MangledName& name) {
180 if (!scopes_.empty()) scopes_.top()->insert(name);
183 void PrintCallGraph() {
184 for (Callgraph::const_iterator i = callgraph_.begin(), e = callgraph_.end();
187 std::cout << i->first << "\n";
189 CalleesSet* callees = i->second;
190 for (CalleesSet::const_iterator j = callees->begin(), e = callees->end();
193 std::cout << "\t" << *j << "\n";
199 clang::MangleContext* ctx_;
201 std::stack<CalleesSet* > scopes_;
202 Callgraph callgraph_;
206 class FunctionDeclarationFinder
207 : public clang::ASTConsumer,
208 public clang::RecursiveASTVisitor<FunctionDeclarationFinder> {
210 explicit FunctionDeclarationFinder(clang::DiagnosticsEngine& d,
211 clang::SourceManager& sm,
212 const std::vector<std::string>& args)
215 virtual void HandleTranslationUnit(clang::ASTContext &ctx) {
216 mangle_context_ = clang::ItaniumMangleContext::create(ctx, d_);
217 callees_printer_ = new CalleesPrinter(mangle_context_);
219 TraverseDecl(ctx.getTranslationUnitDecl());
221 callees_printer_->PrintCallGraph();
224 virtual bool VisitFunctionDecl(clang::FunctionDecl* decl) {
225 callees_printer_->AnalyzeFunction(decl);
230 clang::DiagnosticsEngine& d_;
231 clang::SourceManager& sm_;
232 clang::MangleContext* mangle_context_;
234 CalleesPrinter* callees_printer_;
238 static bool loaded = false;
239 static CalleesSet gc_suspects;
242 static void LoadGCSuspects() {
245 std::ifstream fin("gcsuspects");
248 while (fin >> s) gc_suspects.insert(s);
254 static bool KnownToCauseGC(clang::MangleContext* ctx,
255 const clang::FunctionDecl* decl) {
258 if (!InV8Namespace(decl)) return false;
261 if (GetMangledName(ctx, decl, &name)) {
262 return gc_suspects.find(name) != gc_suspects.end();
269 static const int kNoEffect = 0;
270 static const int kCausesGC = 1;
271 static const int kRawDef = 2;
272 static const int kRawUse = 4;
273 static const int kAllEffects = kCausesGC | kRawDef | kRawUse;
279 bool hasGC() { return (effect_ & kCausesGC) != 0; }
280 void setGC() { effect_ |= kCausesGC; }
282 bool hasRawDef() { return (effect_ & kRawDef) != 0; }
283 void setRawDef() { effect_ |= kRawDef; }
285 bool hasRawUse() { return (effect_ & kRawUse) != 0; }
286 void setRawUse() { effect_ |= kRawUse; }
288 static ExprEffect None() { return ExprEffect(kNoEffect, NULL); }
289 static ExprEffect NoneWithEnv(Environment* env) {
290 return ExprEffect(kNoEffect, env);
292 static ExprEffect RawUse() { return ExprEffect(kRawUse, NULL); }
294 static ExprEffect Merge(ExprEffect a, ExprEffect b);
295 static ExprEffect MergeSeq(ExprEffect a, ExprEffect b);
296 ExprEffect Define(const std::string& name);
299 return reinterpret_cast<Environment*>(effect_ & ~kAllEffects);
302 static ExprEffect GC() {
303 return ExprEffect(kCausesGC, NULL);
307 ExprEffect(int effect, Environment* env)
308 : effect_((effect & kAllEffects) |
309 reinterpret_cast<intptr_t>(env)) { }
315 const std::string BAD_EXPR_MSG("Possible problem with evaluation order.");
316 const std::string DEAD_VAR_MSG("Possibly dead variable.");
323 static Environment Unreachable() {
329 static Environment Merge(const Environment& l,
330 const Environment& r) {
331 return Environment(l, r);
334 Environment ApplyEffect(ExprEffect effect) const {
335 Environment out = effect.hasGC() ? Environment() : Environment(*this);
336 if (effect.env() != NULL) out.live_ |= effect.env()->live_;
340 typedef std::map<std::string, int> SymbolTable;
342 bool IsAlive(const std::string& name) const {
343 SymbolTable::iterator code = symbol_table_.find(name);
344 if (code == symbol_table_.end()) return false;
345 return live_[code->second];
348 bool Equal(const Environment& env) {
349 return live_ == env.live_;
352 Environment Define(const std::string& name) const {
353 return Environment(*this, SymbolToCode(name));
356 void MDefine(const std::string& name) {
357 live_.set(SymbolToCode(name));
360 static int SymbolToCode(const std::string& name) {
361 SymbolTable::iterator code = symbol_table_.find(name);
363 if (code == symbol_table_.end()) {
364 int new_code = symbol_table_.size();
365 symbol_table_.insert(std::make_pair(name, new_code));
372 static void ClearSymbolTable() {
373 std::vector<Environment*>::iterator end = envs_.end();
374 for (std::vector<Environment*>::iterator i = envs_.begin();
380 symbol_table_.clear();
386 SymbolTable::iterator end = symbol_table_.end();
387 for (SymbolTable::iterator i = symbol_table_.begin();
390 if (live_[i->second]) {
391 if (comma) std::cout << ", ";
392 std::cout << i->first;
399 static Environment* Allocate(const Environment& env) {
400 Environment* allocated_env = new Environment(env);
401 envs_.push_back(allocated_env);
402 return allocated_env;
406 Environment(const Environment& l, const Environment& r)
407 : live_(l.live_ & r.live_) {
410 Environment(const Environment& l, int code)
415 static SymbolTable symbol_table_;
416 static std::vector<Environment* > envs_;
418 static const int kMaxNumberOfLocals = 256;
419 std::bitset<kMaxNumberOfLocals> live_;
421 friend class ExprEffect;
422 friend class CallProps;
428 CallProps() : env_(NULL) { }
430 void SetEffect(int arg, ExprEffect in) {
431 if (in.hasGC()) gc_.set(arg);
432 if (in.hasRawDef()) raw_def_.set(arg);
433 if (in.hasRawUse()) raw_use_.set(arg);
434 if (in.env() != NULL) {
435 if (env_ == NULL) env_ = in.env();
436 env_->live_ |= in.env()->live_;
440 ExprEffect ComputeCumulativeEffect(bool result_is_raw) {
441 ExprEffect out = ExprEffect::NoneWithEnv(env_);
442 if (gc_.any()) out.setGC();
443 if (raw_use_.any()) out.setRawUse();
444 if (result_is_raw) out.setRawDef();
449 if (!gc_.any()) return true;
450 std::bitset<kMaxNumberOfArguments> raw = (raw_def_ | raw_use_);
451 if (!raw.any()) return true;
452 return gc_.count() == 1 && !((raw ^ gc_).any());
456 static const int kMaxNumberOfArguments = 64;
457 std::bitset<kMaxNumberOfArguments> raw_def_;
458 std::bitset<kMaxNumberOfArguments> raw_use_;
459 std::bitset<kMaxNumberOfArguments> gc_;
464 Environment::SymbolTable Environment::symbol_table_;
465 std::vector<Environment* > Environment::envs_;
468 ExprEffect ExprEffect::Merge(ExprEffect a, ExprEffect b) {
469 Environment* a_env = a.env();
470 Environment* b_env = b.env();
471 Environment* out = NULL;
472 if (a_env != NULL && b_env != NULL) {
473 out = Environment::Allocate(*a_env);
474 out->live_ &= b_env->live_;
476 return ExprEffect(a.effect_ | b.effect_, out);
480 ExprEffect ExprEffect::MergeSeq(ExprEffect a, ExprEffect b) {
481 Environment* a_env = b.hasGC() ? NULL : a.env();
482 Environment* b_env = b.env();
483 Environment* out = (b_env == NULL) ? a_env : b_env;
484 if (a_env != NULL && b_env != NULL) {
485 out = Environment::Allocate(*b_env);
486 out->live_ |= a_env->live_;
488 return ExprEffect(a.effect_ | b.effect_, out);
492 ExprEffect ExprEffect::Define(const std::string& name) {
493 Environment* e = env();
495 e = Environment::Allocate(Environment());
498 return ExprEffect(effect_, e);
502 static std::string THIS ("this");
505 class FunctionAnalyzer {
507 FunctionAnalyzer(clang::MangleContext* ctx,
508 clang::DeclarationName handle_decl_name,
509 clang::CXXRecordDecl* object_decl,
510 clang::CXXRecordDecl* smi_decl, clang::DiagnosticsEngine& d,
511 clang::SourceManager& sm, bool dead_vars_analysis)
513 handle_decl_name_(handle_decl_name),
514 object_decl_(object_decl),
519 dead_vars_analysis_(dead_vars_analysis) {}
522 // --------------------------------------------------------------------------
524 // --------------------------------------------------------------------------
526 ExprEffect VisitExpr(clang::Expr* expr, const Environment& env) {
527 #define VISIT(type) \
529 clang::type* concrete_expr = llvm::dyn_cast_or_null<clang::type>(expr); \
530 if (concrete_expr != NULL) { \
531 return Visit##type(concrete_expr, env); \
535 VISIT(AbstractConditionalOperator);
536 VISIT(AddrLabelExpr);
537 VISIT(ArraySubscriptExpr);
538 VISIT(BinaryOperator);
542 VISIT(CharacterLiteral);
544 VISIT(CompoundLiteralExpr);
545 VISIT(CXXBindTemporaryExpr);
546 VISIT(CXXBoolLiteralExpr);
547 VISIT(CXXConstructExpr);
548 VISIT(CXXDefaultArgExpr);
549 VISIT(CXXDeleteExpr);
550 VISIT(CXXDependentScopeMemberExpr);
552 VISIT(CXXNoexceptExpr);
553 VISIT(CXXNullPtrLiteralExpr);
554 VISIT(CXXPseudoDestructorExpr);
555 VISIT(CXXScalarValueInitExpr);
558 VISIT(CXXTypeidExpr);
559 VISIT(CXXUnresolvedConstructExpr);
560 VISIT(CXXUuidofExpr);
562 VISIT(DependentScopeDeclRefExpr);
563 VISIT(DesignatedInitExpr);
564 VISIT(ExprWithCleanups);
565 VISIT(ExtVectorElementExpr);
566 VISIT(FloatingLiteral);
568 VISIT(ImaginaryLiteral);
569 VISIT(ImplicitValueInitExpr);
571 VISIT(IntegerLiteral);
574 VISIT(OpaqueValueExpr);
576 VISIT(PackExpansionExpr);
578 VISIT(ParenListExpr);
579 VISIT(PredefinedExpr);
580 VISIT(ShuffleVectorExpr);
581 VISIT(SizeOfPackExpr);
583 VISIT(StringLiteral);
584 VISIT(SubstNonTypeTemplateParmPackExpr);
585 VISIT(TypeTraitExpr);
586 VISIT(UnaryOperator);
590 return ExprEffect::None();
593 #define DECL_VISIT_EXPR(type) \
594 ExprEffect Visit##type (clang::type* expr, const Environment& env)
596 #define IGNORE_EXPR(type) \
597 ExprEffect Visit##type (clang::type* expr, const Environment& env) { \
598 return ExprEffect::None(); \
601 IGNORE_EXPR(AddrLabelExpr);
602 IGNORE_EXPR(BlockExpr);
603 IGNORE_EXPR(CharacterLiteral);
604 IGNORE_EXPR(ChooseExpr);
605 IGNORE_EXPR(CompoundLiteralExpr);
606 IGNORE_EXPR(CXXBoolLiteralExpr);
607 IGNORE_EXPR(CXXDependentScopeMemberExpr);
608 IGNORE_EXPR(CXXNullPtrLiteralExpr);
609 IGNORE_EXPR(CXXPseudoDestructorExpr);
610 IGNORE_EXPR(CXXScalarValueInitExpr);
611 IGNORE_EXPR(CXXNoexceptExpr);
612 IGNORE_EXPR(CXXTypeidExpr);
613 IGNORE_EXPR(CXXUnresolvedConstructExpr);
614 IGNORE_EXPR(CXXUuidofExpr);
615 IGNORE_EXPR(DependentScopeDeclRefExpr);
616 IGNORE_EXPR(DesignatedInitExpr);
617 IGNORE_EXPR(ExtVectorElementExpr);
618 IGNORE_EXPR(FloatingLiteral);
619 IGNORE_EXPR(ImaginaryLiteral);
620 IGNORE_EXPR(IntegerLiteral);
621 IGNORE_EXPR(OffsetOfExpr);
622 IGNORE_EXPR(ImplicitValueInitExpr);
623 IGNORE_EXPR(PackExpansionExpr);
624 IGNORE_EXPR(PredefinedExpr);
625 IGNORE_EXPR(ShuffleVectorExpr);
626 IGNORE_EXPR(SizeOfPackExpr);
627 IGNORE_EXPR(StmtExpr);
628 IGNORE_EXPR(StringLiteral);
629 IGNORE_EXPR(SubstNonTypeTemplateParmPackExpr);
630 IGNORE_EXPR(TypeTraitExpr);
631 IGNORE_EXPR(VAArgExpr);
632 IGNORE_EXPR(GNUNullExpr);
633 IGNORE_EXPR(OverloadExpr);
635 DECL_VISIT_EXPR(CXXThisExpr) {
636 return Use(expr, expr->getType(), THIS, env);
639 DECL_VISIT_EXPR(AbstractConditionalOperator) {
640 Environment after_cond = env.ApplyEffect(VisitExpr(expr->getCond(), env));
641 return ExprEffect::Merge(VisitExpr(expr->getTrueExpr(), after_cond),
642 VisitExpr(expr->getFalseExpr(), after_cond));
645 DECL_VISIT_EXPR(ArraySubscriptExpr) {
646 clang::Expr* exprs[2] = {expr->getBase(), expr->getIdx()};
647 return Par(expr, 2, exprs, env);
650 bool IsRawPointerVar(clang::Expr* expr, std::string* var_name) {
651 if (llvm::isa<clang::DeclRefExpr>(expr)) {
653 llvm::cast<clang::DeclRefExpr>(expr)->getDecl()->getNameAsString();
659 DECL_VISIT_EXPR(BinaryOperator) {
660 clang::Expr* lhs = expr->getLHS();
661 clang::Expr* rhs = expr->getRHS();
662 clang::Expr* exprs[2] = {lhs, rhs};
664 switch (expr->getOpcode()) {
665 case clang::BO_Comma:
666 return Seq(expr, 2, exprs, env);
670 return ExprEffect::Merge(VisitExpr(lhs, env), VisitExpr(rhs, env));
672 case clang::BO_Assign: {
673 std::string var_name;
674 if (IsRawPointerVar(lhs, &var_name)) {
675 return VisitExpr(rhs, env).Define(var_name);
677 return Par(expr, 2, exprs, env);
681 return Par(expr, 2, exprs, env);
685 DECL_VISIT_EXPR(CXXBindTemporaryExpr) {
686 return VisitExpr(expr->getSubExpr(), env);
689 DECL_VISIT_EXPR(CXXConstructExpr) {
690 return VisitArguments<>(expr, env);
693 DECL_VISIT_EXPR(CXXDefaultArgExpr) {
694 return VisitExpr(expr->getExpr(), env);
697 DECL_VISIT_EXPR(CXXDeleteExpr) {
698 return VisitExpr(expr->getArgument(), env);
701 DECL_VISIT_EXPR(CXXNewExpr) { return VisitExpr(expr->getInitializer(), env); }
703 DECL_VISIT_EXPR(ExprWithCleanups) {
704 return VisitExpr(expr->getSubExpr(), env);
707 DECL_VISIT_EXPR(CXXThrowExpr) {
708 return VisitExpr(expr->getSubExpr(), env);
711 DECL_VISIT_EXPR(InitListExpr) {
712 return Seq(expr, expr->getNumInits(), expr->getInits(), env);
715 DECL_VISIT_EXPR(MemberExpr) {
716 return VisitExpr(expr->getBase(), env);
719 DECL_VISIT_EXPR(OpaqueValueExpr) {
720 return VisitExpr(expr->getSourceExpr(), env);
723 DECL_VISIT_EXPR(ParenExpr) {
724 return VisitExpr(expr->getSubExpr(), env);
727 DECL_VISIT_EXPR(ParenListExpr) {
728 return Par(expr, expr->getNumExprs(), expr->getExprs(), env);
731 DECL_VISIT_EXPR(UnaryOperator) {
732 // TODO We are treating all expressions that look like &raw_pointer_var
733 // as definitions of raw_pointer_var. This should be changed to
734 // recognize less generic pattern:
736 // if (maybe_object->ToObject(&obj)) return maybe_object;
738 if (expr->getOpcode() == clang::UO_AddrOf) {
739 std::string var_name;
740 if (IsRawPointerVar(expr->getSubExpr(), &var_name)) {
741 return ExprEffect::None().Define(var_name);
744 return VisitExpr(expr->getSubExpr(), env);
747 DECL_VISIT_EXPR(CastExpr) {
748 return VisitExpr(expr->getSubExpr(), env);
751 DECL_VISIT_EXPR(DeclRefExpr) {
752 return Use(expr, expr->getDecl(), env);
755 ExprEffect Par(clang::Expr* parent,
758 const Environment& env) {
761 for (int i = 0; i < n; ++i) {
762 props.SetEffect(i, VisitExpr(exprs[i], env));
765 if (!props.IsSafe()) ReportUnsafe(parent, BAD_EXPR_MSG);
767 return props.ComputeCumulativeEffect(IsRawPointerType(parent->getType()));
770 ExprEffect Seq(clang::Stmt* parent,
773 const Environment& env) {
774 ExprEffect out = ExprEffect::None();
775 Environment out_env = env;
776 for (int i = 0; i < n; ++i) {
777 out = ExprEffect::MergeSeq(out, VisitExpr(exprs[i], out_env));
778 out_env = out_env.ApplyEffect(out);
783 ExprEffect Use(const clang::Expr* parent,
784 const clang::QualType& var_type,
785 const std::string& var_name,
786 const Environment& env) {
787 if (IsRawPointerType(var_type)) {
788 if (!env.IsAlive(var_name) && dead_vars_analysis_) {
789 ReportUnsafe(parent, DEAD_VAR_MSG);
791 return ExprEffect::RawUse();
793 return ExprEffect::None();
796 ExprEffect Use(const clang::Expr* parent,
797 const clang::ValueDecl* var,
798 const Environment& env) {
799 if (IsExternalVMState(var)) {
800 return ExprEffect::GC();
802 return Use(parent, var->getType(), var->getNameAsString(), env);
806 template<typename ExprType>
807 ExprEffect VisitArguments(ExprType* call, const Environment& env) {
809 VisitArguments<>(call, &props, env);
810 if (!props.IsSafe()) ReportUnsafe(call, BAD_EXPR_MSG);
811 return props.ComputeCumulativeEffect(IsRawPointerType(call->getType()));
814 template<typename ExprType>
815 void VisitArguments(ExprType* call,
817 const Environment& env) {
818 for (unsigned arg = 0; arg < call->getNumArgs(); arg++) {
819 props->SetEffect(arg + 1, VisitExpr(call->getArg(arg), env));
824 ExprEffect VisitCallExpr(clang::CallExpr* call,
825 const Environment& env) {
828 clang::CXXMemberCallExpr* memcall =
829 llvm::dyn_cast_or_null<clang::CXXMemberCallExpr>(call);
830 if (memcall != NULL) {
831 clang::Expr* receiver = memcall->getImplicitObjectArgument();
832 props.SetEffect(0, VisitExpr(receiver, env));
835 VisitArguments<>(call, &props, env);
837 if (!props.IsSafe()) ReportUnsafe(call, BAD_EXPR_MSG);
840 props.ComputeCumulativeEffect(IsRawPointerType(call->getType()));
842 clang::FunctionDecl* callee = call->getDirectCallee();
843 if ((callee != NULL) && KnownToCauseGC(ctx_, callee)) {
850 // --------------------------------------------------------------------------
852 // --------------------------------------------------------------------------
854 Environment VisitStmt(clang::Stmt* stmt, const Environment& env) {
855 #define VISIT(type) \
857 clang::type* concrete_stmt = llvm::dyn_cast_or_null<clang::type>(stmt); \
858 if (concrete_stmt != NULL) { \
859 return Visit##type(concrete_stmt, env); \
863 if (clang::Expr* expr = llvm::dyn_cast_or_null<clang::Expr>(stmt)) {
864 return env.ApplyEffect(VisitExpr(expr, env));
878 VISIT(IndirectGotoStmt);
891 #define DECL_VISIT_STMT(type) \
892 Environment Visit##type (clang::type* stmt, const Environment& env)
894 #define IGNORE_STMT(type) \
895 Environment Visit##type (clang::type* stmt, const Environment& env) { \
899 IGNORE_STMT(IndirectGotoStmt);
900 IGNORE_STMT(NullStmt);
901 IGNORE_STMT(AsmStmt);
903 // We are ignoring control flow for simplicity.
904 IGNORE_STMT(GotoStmt);
905 IGNORE_STMT(LabelStmt);
907 // We are ignoring try/catch because V8 does not use them.
908 IGNORE_STMT(CXXCatchStmt);
909 IGNORE_STMT(CXXTryStmt);
913 Block(const Environment& in,
914 FunctionAnalyzer* owner)
916 out_(Environment::Unreachable()),
919 parent_ = owner_->EnterBlock(this);
923 owner_->LeaveBlock(parent_);
926 void MergeIn(const Environment& env) {
927 Environment old_in = in_;
928 in_ = Environment::Merge(in_, env);
929 changed_ = !old_in.Equal(in_);
940 const Environment& in() {
944 const Environment& out() {
948 void MergeOut(const Environment& env) {
949 out_ = Environment::Merge(out_, env);
952 void Seq(clang::Stmt* a, clang::Stmt* b, clang::Stmt* c) {
953 Environment a_out = owner_->VisitStmt(a, in());
954 Environment b_out = owner_->VisitStmt(b, a_out);
955 Environment c_out = owner_->VisitStmt(c, b_out);
959 void Seq(clang::Stmt* a, clang::Stmt* b) {
960 Environment a_out = owner_->VisitStmt(a, in());
961 Environment b_out = owner_->VisitStmt(b, a_out);
965 void Loop(clang::Stmt* a, clang::Stmt* b, clang::Stmt* c) {
970 void Loop(clang::Stmt* a, clang::Stmt* b) {
980 FunctionAnalyzer* owner_;
985 DECL_VISIT_STMT(BreakStmt) {
986 block_->MergeOut(env);
987 return Environment::Unreachable();
990 DECL_VISIT_STMT(ContinueStmt) {
991 block_->MergeIn(env);
992 return Environment::Unreachable();
995 DECL_VISIT_STMT(CompoundStmt) {
996 Environment out = env;
997 clang::CompoundStmt::body_iterator end = stmt->body_end();
998 for (clang::CompoundStmt::body_iterator s = stmt->body_begin();
1001 out = VisitStmt(*s, out);
1006 DECL_VISIT_STMT(WhileStmt) {
1007 Block block (env, this);
1009 block.Loop(stmt->getCond(), stmt->getBody());
1010 } while (block.changed());
1014 DECL_VISIT_STMT(DoStmt) {
1015 Block block (env, this);
1017 block.Loop(stmt->getBody(), stmt->getCond());
1018 } while (block.changed());
1022 DECL_VISIT_STMT(ForStmt) {
1023 Block block (VisitStmt(stmt->getInit(), env), this);
1025 block.Loop(stmt->getCond(),
1028 } while (block.changed());
1032 DECL_VISIT_STMT(IfStmt) {
1033 Environment cond_out = VisitStmt(stmt->getCond(), env);
1034 Environment then_out = VisitStmt(stmt->getThen(), cond_out);
1035 Environment else_out = VisitStmt(stmt->getElse(), cond_out);
1036 return Environment::Merge(then_out, else_out);
1039 DECL_VISIT_STMT(SwitchStmt) {
1040 Block block (env, this);
1041 block.Seq(stmt->getCond(), stmt->getBody());
1045 DECL_VISIT_STMT(CaseStmt) {
1046 Environment in = Environment::Merge(env, block_->in());
1047 Environment after_lhs = VisitStmt(stmt->getLHS(), in);
1048 return VisitStmt(stmt->getSubStmt(), after_lhs);
1051 DECL_VISIT_STMT(DefaultStmt) {
1052 Environment in = Environment::Merge(env, block_->in());
1053 return VisitStmt(stmt->getSubStmt(), in);
1056 DECL_VISIT_STMT(ReturnStmt) {
1057 VisitExpr(stmt->getRetValue(), env);
1058 return Environment::Unreachable();
1061 const clang::TagType* ToTagType(const clang::Type* t) {
1064 } else if (llvm::isa<clang::TagType>(t)) {
1065 return llvm::cast<clang::TagType>(t);
1066 } else if (llvm::isa<clang::SubstTemplateTypeParmType>(t)) {
1067 return ToTagType(llvm::cast<clang::SubstTemplateTypeParmType>(t)
1068 ->getReplacementType()
1075 bool IsDerivedFrom(clang::CXXRecordDecl* record,
1076 clang::CXXRecordDecl* base) {
1077 return (record == base) || record->isDerivedFrom(base);
1080 bool IsRawPointerType(clang::QualType qtype) {
1081 const clang::PointerType* type =
1082 llvm::dyn_cast_or_null<clang::PointerType>(qtype.getTypePtrOrNull());
1083 if (type == NULL) return false;
1085 const clang::TagType* pointee =
1086 ToTagType(type->getPointeeType().getTypePtr());
1087 if (pointee == NULL) return false;
1089 clang::CXXRecordDecl* record =
1090 llvm::dyn_cast_or_null<clang::CXXRecordDecl>(pointee->getDecl());
1091 if (record == NULL) return false;
1093 if (!InV8Namespace(record)) return false;
1095 if (!record->hasDefinition()) return false;
1097 record = record->getDefinition();
1099 return IsDerivedFrom(record, object_decl_) &&
1100 !IsDerivedFrom(record, smi_decl_);
1103 Environment VisitDecl(clang::Decl* decl, const Environment& env) {
1104 if (clang::VarDecl* var = llvm::dyn_cast<clang::VarDecl>(decl)) {
1105 Environment out = var->hasInit() ? VisitStmt(var->getInit(), env) : env;
1107 if (IsRawPointerType(var->getType())) {
1108 out = out.Define(var->getNameAsString());
1113 // TODO: handle other declarations?
1117 DECL_VISIT_STMT(DeclStmt) {
1118 Environment out = env;
1119 clang::DeclStmt::decl_iterator end = stmt->decl_end();
1120 for (clang::DeclStmt::decl_iterator decl = stmt->decl_begin();
1123 out = VisitDecl(*decl, out);
1129 void DefineParameters(const clang::FunctionDecl* f,
1132 clang::FunctionDecl::param_const_iterator end = f->param_end();
1133 for (clang::FunctionDecl::param_const_iterator p = f->param_begin();
1136 env->MDefine((*p)->getNameAsString());
1141 void AnalyzeFunction(const clang::FunctionDecl* f) {
1142 const clang::FunctionDecl* body = NULL;
1143 if (f->hasBody(body)) {
1145 DefineParameters(body, &env);
1146 VisitStmt(body->getBody(), env);
1147 Environment::ClearSymbolTable();
1151 Block* EnterBlock(Block* block) {
1152 Block* parent = block_;
1157 void LeaveBlock(Block* block) {
1162 void ReportUnsafe(const clang::Expr* expr, const std::string& msg) {
1163 d_.Report(clang::FullSourceLoc(expr->getExprLoc(), sm_),
1164 d_.getCustomDiagID(clang::DiagnosticsEngine::Warning, "%0"))
1169 clang::MangleContext* ctx_;
1170 clang::DeclarationName handle_decl_name_;
1171 clang::CXXRecordDecl* object_decl_;
1172 clang::CXXRecordDecl* smi_decl_;
1174 clang::DiagnosticsEngine& d_;
1175 clang::SourceManager& sm_;
1178 bool dead_vars_analysis_;
1182 class ProblemsFinder : public clang::ASTConsumer,
1183 public clang::RecursiveASTVisitor<ProblemsFinder> {
1185 ProblemsFinder(clang::DiagnosticsEngine& d, clang::SourceManager& sm,
1186 const std::vector<std::string>& args)
1187 : d_(d), sm_(sm), dead_vars_analysis_(false) {
1188 for (unsigned i = 0; i < args.size(); ++i) {
1189 if (args[i] == "--dead-vars") {
1190 dead_vars_analysis_ = true;
1195 virtual void HandleTranslationUnit(clang::ASTContext &ctx) {
1198 clang::CXXRecordDecl* object_decl =
1199 r.ResolveNamespace("v8").ResolveNamespace("internal").
1200 Resolve<clang::CXXRecordDecl>("Object");
1202 clang::CXXRecordDecl* smi_decl =
1203 r.ResolveNamespace("v8").ResolveNamespace("internal").
1204 Resolve<clang::CXXRecordDecl>("Smi");
1206 if (object_decl != NULL) object_decl = object_decl->getDefinition();
1208 if (smi_decl != NULL) smi_decl = smi_decl->getDefinition();
1210 if (object_decl != NULL && smi_decl != NULL) {
1211 function_analyzer_ = new FunctionAnalyzer(
1212 clang::ItaniumMangleContext::create(ctx, d_), r.ResolveName("Handle"),
1213 object_decl, smi_decl, d_, sm_, dead_vars_analysis_);
1214 TraverseDecl(ctx.getTranslationUnitDecl());
1216 if (object_decl == NULL) {
1217 llvm::errs() << "Failed to resolve v8::internal::Object\n";
1219 if (smi_decl == NULL) {
1220 llvm::errs() << "Failed to resolve v8::internal::Smi\n";
1225 virtual bool VisitFunctionDecl(clang::FunctionDecl* decl) {
1226 function_analyzer_->AnalyzeFunction(decl);
1231 clang::DiagnosticsEngine& d_;
1232 clang::SourceManager& sm_;
1233 bool dead_vars_analysis_;
1235 FunctionAnalyzer* function_analyzer_;
1239 template<typename ConsumerType>
1240 class Action : public clang::PluginASTAction {
1242 clang::ASTConsumer *CreateASTConsumer(clang::CompilerInstance &CI,
1243 llvm::StringRef InFile) {
1244 return new ConsumerType(CI.getDiagnostics(), CI.getSourceManager(), args_);
1247 bool ParseArgs(const clang::CompilerInstance &CI,
1248 const std::vector<std::string>& args) {
1253 void PrintHelp(llvm::raw_ostream& ros) {
1256 std::vector<std::string> args_;
1262 static clang::FrontendPluginRegistry::Add<Action<ProblemsFinder> >
1263 FindProblems("find-problems", "Find GC-unsafe places.");
1265 static clang::FrontendPluginRegistry::Add<
1266 Action<FunctionDeclarationFinder> >
1267 DumpCallees("dump-callees", "Dump callees for each function.");