b577c1fe95
R=clemensb@chromium.org Change-Id: Ibd6790a222590fd4dce9f918219a19f01c2e1e0f Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1960293 Reviewed-by: Clemens Backes <clemensb@chromium.org> Reviewed-by: Michael Achenbach <machenbach@chromium.org> Commit-Queue: Michael Starzinger <mstarzinger@chromium.org> Cr-Commit-Position: refs/heads/master@{#65439}
1641 lines
48 KiB
C++
1641 lines
48 KiB
C++
// Copyright 2011 the V8 project authors. All rights reserved.
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following
|
|
// disclaimer in the documentation and/or other materials provided
|
|
// with the distribution.
|
|
// * Neither the name of Google Inc. nor the names of its
|
|
// contributors may be used to endorse or promote products derived
|
|
// from this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
// This is clang plugin used by gcmole tool. See README for more details.
|
|
|
|
#include "clang/AST/AST.h"
|
|
#include "clang/AST/ASTConsumer.h"
|
|
#include "clang/AST/Mangle.h"
|
|
#include "clang/AST/RecursiveASTVisitor.h"
|
|
#include "clang/AST/StmtVisitor.h"
|
|
#include "clang/Frontend/FrontendPluginRegistry.h"
|
|
#include "clang/Frontend/CompilerInstance.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
|
|
#include <bitset>
|
|
#include <fstream>
|
|
#include <iostream>
|
|
#include <map>
|
|
#include <set>
|
|
#include <stack>
|
|
|
|
namespace {
|
|
|
|
bool g_tracing_enabled = false;
|
|
|
|
#define TRACE(str) \
|
|
do { \
|
|
if (g_tracing_enabled) { \
|
|
std::cout << str << std::endl; \
|
|
} \
|
|
} while (false)
|
|
|
|
#define TRACE_LLVM_TYPE(str, type) \
|
|
do { \
|
|
if (g_tracing_enabled) { \
|
|
std::cout << str << " " << type.getAsString() << std::endl; \
|
|
} \
|
|
} while (false)
|
|
|
|
#define TRACE_LLVM_DECL(str, decl) \
|
|
do { \
|
|
if (g_tracing_enabled) { \
|
|
std::cout << str << std::endl; \
|
|
decl->dump(); \
|
|
} \
|
|
} while (false)
|
|
|
|
typedef std::string MangledName;
|
|
typedef std::set<MangledName> CalleesSet;
|
|
typedef std::map<MangledName, MangledName> CalleesMap;
|
|
|
|
static bool GetMangledName(clang::MangleContext* ctx,
|
|
const clang::NamedDecl* decl,
|
|
MangledName* result) {
|
|
if (!llvm::isa<clang::CXXConstructorDecl>(decl) &&
|
|
!llvm::isa<clang::CXXDestructorDecl>(decl)) {
|
|
llvm::SmallVector<char, 512> output;
|
|
llvm::raw_svector_ostream out(output);
|
|
ctx->mangleName(decl, out);
|
|
*result = out.str().str();
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
static bool InV8Namespace(const clang::NamedDecl* decl) {
|
|
return decl->getQualifiedNameAsString().compare(0, 4, "v8::") == 0;
|
|
}
|
|
|
|
|
|
static std::string EXTERNAL("EXTERNAL");
|
|
static std::string STATE_TAG("enum v8::internal::StateTag");
|
|
|
|
static bool IsExternalVMState(const clang::ValueDecl* var) {
|
|
const clang::EnumConstantDecl* enum_constant =
|
|
llvm::dyn_cast<clang::EnumConstantDecl>(var);
|
|
if (enum_constant != NULL && enum_constant->getNameAsString() == EXTERNAL) {
|
|
clang::QualType type = enum_constant->getType();
|
|
return (type.getAsString() == STATE_TAG);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
struct Resolver {
|
|
explicit Resolver(clang::ASTContext& ctx)
|
|
: ctx_(ctx), decl_ctx_(ctx.getTranslationUnitDecl()) {
|
|
}
|
|
|
|
Resolver(clang::ASTContext& ctx, clang::DeclContext* decl_ctx)
|
|
: ctx_(ctx), decl_ctx_(decl_ctx) {
|
|
}
|
|
|
|
clang::DeclarationName ResolveName(const char* n) {
|
|
clang::IdentifierInfo* ident = &ctx_.Idents.get(n);
|
|
return ctx_.DeclarationNames.getIdentifier(ident);
|
|
}
|
|
|
|
Resolver ResolveNamespace(const char* n) {
|
|
return Resolver(ctx_, Resolve<clang::NamespaceDecl>(n));
|
|
}
|
|
|
|
template<typename T>
|
|
T* Resolve(const char* n) {
|
|
if (decl_ctx_ == NULL) return NULL;
|
|
|
|
clang::DeclContext::lookup_result result =
|
|
decl_ctx_->lookup(ResolveName(n));
|
|
|
|
clang::DeclContext::lookup_iterator end = result.end();
|
|
for (clang::DeclContext::lookup_iterator i = result.begin(); i != end;
|
|
i++) {
|
|
if (llvm::isa<T>(*i)) {
|
|
return llvm::cast<T>(*i);
|
|
} else {
|
|
llvm::errs() << "Didn't match declaration template against "
|
|
<< (*i)->getNameAsString() << "\n";
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
clang::CXXRecordDecl* ResolveTemplate(const char* n) {
|
|
clang::NamedDecl* initial_template = Resolve<clang::NamedDecl>(n);
|
|
if (!initial_template) return NULL;
|
|
|
|
clang::NamedDecl* underlying_template =
|
|
initial_template->getUnderlyingDecl();
|
|
if (!underlying_template) {
|
|
llvm::errs() << "Couldn't resolve underlying template\n";
|
|
return NULL;
|
|
}
|
|
const clang::TypeAliasDecl* type_alias_decl =
|
|
llvm::dyn_cast_or_null<clang::TypeAliasDecl>(underlying_template);
|
|
if (!type_alias_decl) {
|
|
llvm::errs() << "Couldn't resolve TypeAliasDecl\n";
|
|
return NULL;
|
|
}
|
|
const clang::Type* type = type_alias_decl->getTypeForDecl();
|
|
if (!type) {
|
|
llvm::errs() << "Couldn't resolve TypeAliasDecl to Type\n";
|
|
return NULL;
|
|
}
|
|
const clang::TypedefType* typedef_type =
|
|
llvm::dyn_cast_or_null<clang::TypedefType>(type);
|
|
if (!typedef_type) {
|
|
llvm::errs() << "Couldn't resolve TypedefType\n";
|
|
return NULL;
|
|
}
|
|
const clang::TypedefNameDecl* typedef_name_decl = typedef_type->getDecl();
|
|
if (!typedef_name_decl) {
|
|
llvm::errs() << "Couldn't resolve TypedefType to TypedefNameDecl\n";
|
|
return NULL;
|
|
}
|
|
|
|
clang::QualType underlying_type = typedef_name_decl->getUnderlyingType();
|
|
if (!llvm::isa<clang::TemplateSpecializationType>(underlying_type)) {
|
|
llvm::errs() << "Couldn't resolve TemplateSpecializationType\n";
|
|
return NULL;
|
|
}
|
|
|
|
const clang::TemplateSpecializationType* templ_specialization_type =
|
|
llvm::cast<clang::TemplateSpecializationType>(underlying_type);
|
|
if (!llvm::isa<clang::RecordType>(templ_specialization_type->desugar())) {
|
|
llvm::errs() << "Couldn't resolve RecordType\n";
|
|
return NULL;
|
|
}
|
|
|
|
const clang::RecordType* record_type =
|
|
llvm::cast<clang::RecordType>(templ_specialization_type->desugar());
|
|
clang::CXXRecordDecl* record_decl =
|
|
llvm::dyn_cast_or_null<clang::CXXRecordDecl>(record_type->getDecl());
|
|
if (!record_decl) {
|
|
llvm::errs() << "Couldn't resolve CXXRecordDecl\n";
|
|
return NULL;
|
|
}
|
|
return record_decl;
|
|
}
|
|
|
|
private:
|
|
clang::ASTContext& ctx_;
|
|
clang::DeclContext* decl_ctx_;
|
|
};
|
|
|
|
|
|
class CalleesPrinter : public clang::RecursiveASTVisitor<CalleesPrinter> {
|
|
public:
|
|
explicit CalleesPrinter(clang::MangleContext* ctx) : ctx_(ctx) {
|
|
}
|
|
|
|
virtual bool VisitCallExpr(clang::CallExpr* expr) {
|
|
const clang::FunctionDecl* callee = expr->getDirectCallee();
|
|
if (callee != NULL) AnalyzeFunction(callee);
|
|
return true;
|
|
}
|
|
|
|
virtual bool VisitDeclRefExpr(clang::DeclRefExpr* expr) {
|
|
// If function mentions EXTERNAL VMState add artificial garbage collection
|
|
// mark.
|
|
if (IsExternalVMState(expr->getDecl()))
|
|
AddCallee("CollectGarbage", "CollectGarbage");
|
|
return true;
|
|
}
|
|
|
|
void AnalyzeFunction(const clang::FunctionDecl* f) {
|
|
MangledName name;
|
|
if (InV8Namespace(f) && GetMangledName(ctx_, f, &name)) {
|
|
const std::string& function = f->getNameAsString();
|
|
AddCallee(name, function);
|
|
|
|
const clang::FunctionDecl* body = NULL;
|
|
if (f->hasBody(body) && !Analyzed(name)) {
|
|
EnterScope(name);
|
|
TraverseStmt(body->getBody());
|
|
LeaveScope();
|
|
}
|
|
}
|
|
}
|
|
|
|
typedef std::map<MangledName, CalleesSet* > Callgraph;
|
|
|
|
bool Analyzed(const MangledName& name) {
|
|
return callgraph_[name] != NULL;
|
|
}
|
|
|
|
void EnterScope(const MangledName& name) {
|
|
CalleesSet* callees = callgraph_[name];
|
|
|
|
if (callees == NULL) {
|
|
callgraph_[name] = callees = new CalleesSet();
|
|
}
|
|
|
|
scopes_.push(callees);
|
|
}
|
|
|
|
void LeaveScope() {
|
|
scopes_.pop();
|
|
}
|
|
|
|
void AddCallee(const MangledName& name, const MangledName& function) {
|
|
if (!scopes_.empty()) scopes_.top()->insert(name);
|
|
mangled_to_function_[name] = function;
|
|
}
|
|
|
|
void PrintCallGraph() {
|
|
for (Callgraph::const_iterator i = callgraph_.begin(), e = callgraph_.end();
|
|
i != e;
|
|
++i) {
|
|
std::cout << i->first << "," << mangled_to_function_[i->first] << "\n";
|
|
|
|
CalleesSet* callees = i->second;
|
|
for (CalleesSet::const_iterator j = callees->begin(), e = callees->end();
|
|
j != e;
|
|
++j) {
|
|
std::cout << "\t" << *j << "," << mangled_to_function_[*j] << "\n";
|
|
}
|
|
}
|
|
}
|
|
|
|
private:
|
|
clang::MangleContext* ctx_;
|
|
|
|
std::stack<CalleesSet* > scopes_;
|
|
Callgraph callgraph_;
|
|
CalleesMap mangled_to_function_;
|
|
};
|
|
|
|
|
|
class FunctionDeclarationFinder
|
|
: public clang::ASTConsumer,
|
|
public clang::RecursiveASTVisitor<FunctionDeclarationFinder> {
|
|
public:
|
|
explicit FunctionDeclarationFinder(clang::DiagnosticsEngine& d,
|
|
clang::SourceManager& sm,
|
|
const std::vector<std::string>& args)
|
|
: d_(d), sm_(sm) {}
|
|
|
|
virtual void HandleTranslationUnit(clang::ASTContext &ctx) {
|
|
mangle_context_ = clang::ItaniumMangleContext::create(ctx, d_);
|
|
callees_printer_ = new CalleesPrinter(mangle_context_);
|
|
|
|
TraverseDecl(ctx.getTranslationUnitDecl());
|
|
|
|
callees_printer_->PrintCallGraph();
|
|
}
|
|
|
|
virtual bool VisitFunctionDecl(clang::FunctionDecl* decl) {
|
|
callees_printer_->AnalyzeFunction(decl);
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
clang::DiagnosticsEngine& d_;
|
|
clang::SourceManager& sm_;
|
|
clang::MangleContext* mangle_context_;
|
|
|
|
CalleesPrinter* callees_printer_;
|
|
};
|
|
|
|
static bool gc_suspects_loaded = false;
|
|
static CalleesSet gc_suspects;
|
|
static CalleesSet gc_functions;
|
|
static bool whitelist_loaded = false;
|
|
static CalleesSet suspects_whitelist;
|
|
|
|
static void LoadGCSuspects() {
|
|
if (gc_suspects_loaded) return;
|
|
|
|
std::ifstream fin("gcsuspects");
|
|
std::string mangled, function;
|
|
|
|
while (!fin.eof()) {
|
|
std::getline(fin, mangled, ',');
|
|
gc_suspects.insert(mangled);
|
|
std::getline(fin, function);
|
|
gc_functions.insert(function);
|
|
}
|
|
|
|
gc_suspects_loaded = true;
|
|
}
|
|
|
|
static void LoadSuspectsWhitelist() {
|
|
if (whitelist_loaded) return;
|
|
|
|
std::ifstream fin("tools/gcmole/suspects.whitelist");
|
|
std::string s;
|
|
|
|
while (fin >> s) suspects_whitelist.insert(s);
|
|
|
|
whitelist_loaded = true;
|
|
}
|
|
|
|
// Looks for exact match of the mangled name.
|
|
static bool KnownToCauseGC(clang::MangleContext* ctx,
|
|
const clang::FunctionDecl* decl) {
|
|
LoadGCSuspects();
|
|
|
|
if (!InV8Namespace(decl)) return false;
|
|
|
|
MangledName name;
|
|
if (GetMangledName(ctx, decl, &name)) {
|
|
return gc_suspects.find(name) != gc_suspects.end();
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// Looks for partial match of only the function name.
|
|
static bool SuspectedToCauseGC(clang::MangleContext* ctx,
|
|
const clang::FunctionDecl* decl) {
|
|
LoadGCSuspects();
|
|
|
|
if (!InV8Namespace(decl)) return false;
|
|
|
|
LoadSuspectsWhitelist();
|
|
if (suspects_whitelist.find(decl->getNameAsString()) !=
|
|
suspects_whitelist.end()) {
|
|
return false;
|
|
}
|
|
|
|
if (gc_functions.find(decl->getNameAsString()) != gc_functions.end()) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static const int kNoEffect = 0;
|
|
static const int kCausesGC = 1;
|
|
static const int kRawDef = 2;
|
|
static const int kRawUse = 4;
|
|
static const int kAllEffects = kCausesGC | kRawDef | kRawUse;
|
|
|
|
class Environment;
|
|
|
|
class ExprEffect {
|
|
public:
|
|
bool hasGC() { return (effect_ & kCausesGC) != 0; }
|
|
void setGC() { effect_ |= kCausesGC; }
|
|
|
|
bool hasRawDef() { return (effect_ & kRawDef) != 0; }
|
|
void setRawDef() { effect_ |= kRawDef; }
|
|
|
|
bool hasRawUse() { return (effect_ & kRawUse) != 0; }
|
|
void setRawUse() { effect_ |= kRawUse; }
|
|
|
|
static ExprEffect None() { return ExprEffect(kNoEffect, NULL); }
|
|
static ExprEffect NoneWithEnv(Environment* env) {
|
|
return ExprEffect(kNoEffect, env);
|
|
}
|
|
static ExprEffect RawUse() { return ExprEffect(kRawUse, NULL); }
|
|
|
|
static ExprEffect Merge(ExprEffect a, ExprEffect b);
|
|
static ExprEffect MergeSeq(ExprEffect a, ExprEffect b);
|
|
ExprEffect Define(const std::string& name);
|
|
|
|
Environment* env() {
|
|
return reinterpret_cast<Environment*>(effect_ & ~kAllEffects);
|
|
}
|
|
|
|
static ExprEffect GC() {
|
|
return ExprEffect(kCausesGC, NULL);
|
|
}
|
|
|
|
private:
|
|
ExprEffect(int effect, Environment* env)
|
|
: effect_((effect & kAllEffects) |
|
|
reinterpret_cast<intptr_t>(env)) { }
|
|
|
|
intptr_t effect_;
|
|
};
|
|
|
|
|
|
const std::string BAD_EXPR_MSG("Possible problem with evaluation order.");
|
|
const std::string DEAD_VAR_MSG("Possibly dead variable.");
|
|
|
|
|
|
class Environment {
|
|
public:
|
|
Environment() = default;
|
|
|
|
static Environment Unreachable() {
|
|
Environment env;
|
|
env.unreachable_ = true;
|
|
return env;
|
|
}
|
|
|
|
static Environment Merge(const Environment& l,
|
|
const Environment& r) {
|
|
Environment out(l);
|
|
out &= r;
|
|
return out;
|
|
}
|
|
|
|
Environment ApplyEffect(ExprEffect effect) const {
|
|
Environment out = effect.hasGC() ? Environment() : Environment(*this);
|
|
if (effect.env()) out |= *effect.env();
|
|
return out;
|
|
}
|
|
|
|
typedef std::map<std::string, int> SymbolTable;
|
|
|
|
bool IsAlive(const std::string& name) const {
|
|
SymbolTable::iterator code = symbol_table_.find(name);
|
|
if (code == symbol_table_.end()) return false;
|
|
return is_live(code->second);
|
|
}
|
|
|
|
bool Equal(const Environment& env) {
|
|
if (unreachable_ && env.unreachable_) return true;
|
|
size_t size = std::max(live_.size(), env.live_.size());
|
|
for (size_t i = 0; i < size; ++i) {
|
|
if (is_live(i) != env.is_live(i)) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
Environment Define(const std::string& name) const {
|
|
return Environment(*this, SymbolToCode(name));
|
|
}
|
|
|
|
void MDefine(const std::string& name) { set_live(SymbolToCode(name)); }
|
|
|
|
static int SymbolToCode(const std::string& name) {
|
|
SymbolTable::iterator code = symbol_table_.find(name);
|
|
|
|
if (code == symbol_table_.end()) {
|
|
int new_code = symbol_table_.size();
|
|
symbol_table_.insert(std::make_pair(name, new_code));
|
|
return new_code;
|
|
}
|
|
|
|
return code->second;
|
|
}
|
|
|
|
static void ClearSymbolTable() {
|
|
for (Environment* e : envs_) delete e;
|
|
envs_.clear();
|
|
symbol_table_.clear();
|
|
}
|
|
|
|
void Print() const {
|
|
bool comma = false;
|
|
std::cout << "{";
|
|
for (auto& e : symbol_table_) {
|
|
if (!is_live(e.second)) continue;
|
|
if (comma) std::cout << ", ";
|
|
std::cout << e.first;
|
|
comma = true;
|
|
}
|
|
std::cout << "}" << std::endl;
|
|
}
|
|
|
|
static Environment* Allocate(const Environment& env) {
|
|
Environment* allocated_env = new Environment(env);
|
|
envs_.push_back(allocated_env);
|
|
return allocated_env;
|
|
}
|
|
|
|
private:
|
|
Environment(const Environment& l, int code)
|
|
: live_(l.live_) {
|
|
set_live(code);
|
|
}
|
|
|
|
void set_live(size_t pos) {
|
|
if (unreachable_) return;
|
|
if (pos >= live_.size()) live_.resize(pos + 1);
|
|
live_[pos] = true;
|
|
}
|
|
|
|
bool is_live(size_t pos) const {
|
|
return unreachable_ || (live_.size() > pos && live_[pos]);
|
|
}
|
|
|
|
Environment& operator|=(const Environment& o) {
|
|
if (o.unreachable_) {
|
|
unreachable_ = true;
|
|
live_.clear();
|
|
} else if (!unreachable_) {
|
|
for (size_t i = 0, e = o.live_.size(); i < e; ++i) {
|
|
if (o.live_[i]) set_live(i);
|
|
}
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
Environment& operator&=(const Environment& o) {
|
|
if (o.unreachable_) return *this;
|
|
if (unreachable_) return *this = o;
|
|
|
|
// Carry over false bits from the tail of o.live_, and reset all bits that
|
|
// are not set in o.live_.
|
|
size_t size = std::max(live_.size(), o.live_.size());
|
|
if (size > live_.size()) live_.resize(size);
|
|
for (size_t i = 0; i < size; ++i) {
|
|
if (live_[i] && (i >= o.live_.size() || !o.live_[i])) live_[i] = false;
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
static SymbolTable symbol_table_;
|
|
static std::vector<Environment*> envs_;
|
|
|
|
std::vector<bool> live_;
|
|
// unreachable_ == true implies live_.empty(), but still is_live(i) returns
|
|
// true for all i.
|
|
bool unreachable_ = false;
|
|
|
|
friend class ExprEffect;
|
|
friend class CallProps;
|
|
};
|
|
|
|
|
|
class CallProps {
|
|
public:
|
|
CallProps() : env_(NULL) { }
|
|
|
|
void SetEffect(int arg, ExprEffect in) {
|
|
if (in.hasGC()) {
|
|
gc_.set(arg);
|
|
}
|
|
if (in.hasRawDef()) raw_def_.set(arg);
|
|
if (in.hasRawUse()) raw_use_.set(arg);
|
|
if (in.env() != NULL) {
|
|
if (env_ == NULL) {
|
|
env_ = in.env();
|
|
} else {
|
|
*env_ |= *in.env();
|
|
}
|
|
}
|
|
}
|
|
|
|
ExprEffect ComputeCumulativeEffect(bool result_is_raw) {
|
|
ExprEffect out = ExprEffect::NoneWithEnv(env_);
|
|
if (gc_.any()) {
|
|
out.setGC();
|
|
}
|
|
if (raw_use_.any()) out.setRawUse();
|
|
if (result_is_raw) out.setRawDef();
|
|
return out;
|
|
}
|
|
|
|
bool IsSafe() {
|
|
if (!gc_.any()) {
|
|
return true;
|
|
}
|
|
std::bitset<kMaxNumberOfArguments> raw = (raw_def_ | raw_use_);
|
|
if (!raw.any()) {
|
|
return true;
|
|
}
|
|
bool result = gc_.count() == 1 && !((raw ^ gc_).any());
|
|
return result;
|
|
}
|
|
|
|
private:
|
|
static const int kMaxNumberOfArguments = 64;
|
|
std::bitset<kMaxNumberOfArguments> raw_def_;
|
|
std::bitset<kMaxNumberOfArguments> raw_use_;
|
|
std::bitset<kMaxNumberOfArguments> gc_;
|
|
Environment* env_;
|
|
};
|
|
|
|
|
|
Environment::SymbolTable Environment::symbol_table_;
|
|
std::vector<Environment*> Environment::envs_;
|
|
|
|
ExprEffect ExprEffect::Merge(ExprEffect a, ExprEffect b) {
|
|
Environment* a_env = a.env();
|
|
Environment* b_env = b.env();
|
|
Environment* out = NULL;
|
|
if (a_env != NULL && b_env != NULL) {
|
|
out = Environment::Allocate(*a_env);
|
|
*out &= *b_env;
|
|
}
|
|
return ExprEffect(a.effect_ | b.effect_, out);
|
|
}
|
|
|
|
|
|
ExprEffect ExprEffect::MergeSeq(ExprEffect a, ExprEffect b) {
|
|
Environment* a_env = b.hasGC() ? NULL : a.env();
|
|
Environment* b_env = b.env();
|
|
Environment* out = (b_env == NULL) ? a_env : b_env;
|
|
if (a_env != NULL && b_env != NULL) {
|
|
out = Environment::Allocate(*b_env);
|
|
*out |= *a_env;
|
|
}
|
|
return ExprEffect(a.effect_ | b.effect_, out);
|
|
}
|
|
|
|
|
|
ExprEffect ExprEffect::Define(const std::string& name) {
|
|
Environment* e = env();
|
|
if (e == NULL) {
|
|
e = Environment::Allocate(Environment());
|
|
}
|
|
e->MDefine(name);
|
|
return ExprEffect(effect_, e);
|
|
}
|
|
|
|
|
|
static std::string THIS ("this");
|
|
|
|
|
|
class FunctionAnalyzer {
|
|
public:
|
|
FunctionAnalyzer(clang::MangleContext* ctx, clang::CXXRecordDecl* object_decl,
|
|
clang::CXXRecordDecl* maybe_object_decl,
|
|
clang::CXXRecordDecl* smi_decl,
|
|
clang::CXXRecordDecl* no_gc_decl,
|
|
clang::CXXRecordDecl* no_heap_access_decl,
|
|
clang::DiagnosticsEngine& d, clang::SourceManager& sm,
|
|
bool dead_vars_analysis)
|
|
: ctx_(ctx),
|
|
object_decl_(object_decl),
|
|
maybe_object_decl_(maybe_object_decl),
|
|
smi_decl_(smi_decl),
|
|
no_gc_decl_(no_gc_decl),
|
|
no_heap_access_decl_(no_heap_access_decl),
|
|
d_(d),
|
|
sm_(sm),
|
|
block_(NULL),
|
|
dead_vars_analysis_(dead_vars_analysis) {}
|
|
|
|
// --------------------------------------------------------------------------
|
|
// Expressions
|
|
// --------------------------------------------------------------------------
|
|
|
|
ExprEffect VisitExpr(clang::Expr* expr, const Environment& env) {
|
|
#define VISIT(type) \
|
|
do { \
|
|
clang::type* concrete_expr = llvm::dyn_cast_or_null<clang::type>(expr); \
|
|
if (concrete_expr != NULL) { \
|
|
return Visit##type(concrete_expr, env); \
|
|
} \
|
|
} while (0);
|
|
|
|
VISIT(AbstractConditionalOperator);
|
|
VISIT(AddrLabelExpr);
|
|
VISIT(ArraySubscriptExpr);
|
|
VISIT(BinaryOperator);
|
|
VISIT(BlockExpr);
|
|
VISIT(CallExpr);
|
|
VISIT(CastExpr);
|
|
VISIT(CharacterLiteral);
|
|
VISIT(ChooseExpr);
|
|
VISIT(CompoundLiteralExpr);
|
|
VISIT(ConstantExpr);
|
|
VISIT(CXXBindTemporaryExpr);
|
|
VISIT(CXXBoolLiteralExpr);
|
|
VISIT(CXXConstructExpr);
|
|
VISIT(CXXDefaultArgExpr);
|
|
VISIT(CXXDeleteExpr);
|
|
VISIT(CXXDependentScopeMemberExpr);
|
|
VISIT(CXXNewExpr);
|
|
VISIT(CXXNoexceptExpr);
|
|
VISIT(CXXNullPtrLiteralExpr);
|
|
VISIT(CXXPseudoDestructorExpr);
|
|
VISIT(CXXScalarValueInitExpr);
|
|
VISIT(CXXThisExpr);
|
|
VISIT(CXXThrowExpr);
|
|
VISIT(CXXTypeidExpr);
|
|
VISIT(CXXUnresolvedConstructExpr);
|
|
VISIT(CXXUuidofExpr);
|
|
VISIT(DeclRefExpr);
|
|
VISIT(DependentScopeDeclRefExpr);
|
|
VISIT(DesignatedInitExpr);
|
|
VISIT(ExprWithCleanups);
|
|
VISIT(ExtVectorElementExpr);
|
|
VISIT(FloatingLiteral);
|
|
VISIT(GNUNullExpr);
|
|
VISIT(ImaginaryLiteral);
|
|
VISIT(ImplicitCastExpr);
|
|
VISIT(ImplicitValueInitExpr);
|
|
VISIT(InitListExpr);
|
|
VISIT(IntegerLiteral);
|
|
VISIT(MaterializeTemporaryExpr);
|
|
VISIT(MemberExpr);
|
|
VISIT(OffsetOfExpr);
|
|
VISIT(OpaqueValueExpr);
|
|
VISIT(OverloadExpr);
|
|
VISIT(PackExpansionExpr);
|
|
VISIT(ParenExpr);
|
|
VISIT(ParenListExpr);
|
|
VISIT(PredefinedExpr);
|
|
VISIT(ShuffleVectorExpr);
|
|
VISIT(SizeOfPackExpr);
|
|
VISIT(StmtExpr);
|
|
VISIT(StringLiteral);
|
|
VISIT(SubstNonTypeTemplateParmPackExpr);
|
|
VISIT(TypeTraitExpr);
|
|
VISIT(UnaryOperator);
|
|
VISIT(UnaryExprOrTypeTraitExpr);
|
|
VISIT(VAArgExpr);
|
|
#undef VISIT
|
|
|
|
return ExprEffect::None();
|
|
}
|
|
|
|
#define DECL_VISIT_EXPR(type) \
|
|
ExprEffect Visit##type (clang::type* expr, const Environment& env)
|
|
|
|
#define IGNORE_EXPR(type) \
|
|
ExprEffect Visit##type (clang::type* expr, const Environment& env) { \
|
|
return ExprEffect::None(); \
|
|
}
|
|
|
|
IGNORE_EXPR(AddrLabelExpr);
|
|
IGNORE_EXPR(BlockExpr);
|
|
IGNORE_EXPR(CharacterLiteral);
|
|
IGNORE_EXPR(ChooseExpr);
|
|
IGNORE_EXPR(CompoundLiteralExpr);
|
|
IGNORE_EXPR(CXXBoolLiteralExpr);
|
|
IGNORE_EXPR(CXXDependentScopeMemberExpr);
|
|
IGNORE_EXPR(CXXNullPtrLiteralExpr);
|
|
IGNORE_EXPR(CXXPseudoDestructorExpr);
|
|
IGNORE_EXPR(CXXScalarValueInitExpr);
|
|
IGNORE_EXPR(CXXNoexceptExpr);
|
|
IGNORE_EXPR(CXXTypeidExpr);
|
|
IGNORE_EXPR(CXXUnresolvedConstructExpr);
|
|
IGNORE_EXPR(CXXUuidofExpr);
|
|
IGNORE_EXPR(DependentScopeDeclRefExpr);
|
|
IGNORE_EXPR(DesignatedInitExpr);
|
|
IGNORE_EXPR(ExtVectorElementExpr);
|
|
IGNORE_EXPR(FloatingLiteral);
|
|
IGNORE_EXPR(ImaginaryLiteral);
|
|
IGNORE_EXPR(IntegerLiteral);
|
|
IGNORE_EXPR(OffsetOfExpr);
|
|
IGNORE_EXPR(ImplicitValueInitExpr);
|
|
IGNORE_EXPR(PackExpansionExpr);
|
|
IGNORE_EXPR(PredefinedExpr);
|
|
IGNORE_EXPR(ShuffleVectorExpr);
|
|
IGNORE_EXPR(SizeOfPackExpr);
|
|
IGNORE_EXPR(StmtExpr);
|
|
IGNORE_EXPR(StringLiteral);
|
|
IGNORE_EXPR(SubstNonTypeTemplateParmPackExpr);
|
|
IGNORE_EXPR(TypeTraitExpr);
|
|
IGNORE_EXPR(VAArgExpr);
|
|
IGNORE_EXPR(GNUNullExpr);
|
|
IGNORE_EXPR(OverloadExpr);
|
|
|
|
DECL_VISIT_EXPR(CXXThisExpr) {
|
|
return Use(expr, expr->getType(), THIS, env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(AbstractConditionalOperator) {
|
|
Environment after_cond = env.ApplyEffect(VisitExpr(expr->getCond(), env));
|
|
return ExprEffect::Merge(VisitExpr(expr->getTrueExpr(), after_cond),
|
|
VisitExpr(expr->getFalseExpr(), after_cond));
|
|
}
|
|
|
|
DECL_VISIT_EXPR(ArraySubscriptExpr) {
|
|
clang::Expr* exprs[2] = {expr->getBase(), expr->getIdx()};
|
|
return Parallel(expr, 2, exprs, env);
|
|
}
|
|
|
|
bool IsRawPointerVar(clang::Expr* expr, std::string* var_name) {
|
|
if (llvm::isa<clang::DeclRefExpr>(expr)) {
|
|
*var_name =
|
|
llvm::cast<clang::DeclRefExpr>(expr)->getDecl()->getNameAsString();
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
DECL_VISIT_EXPR(BinaryOperator) {
|
|
clang::Expr* lhs = expr->getLHS();
|
|
clang::Expr* rhs = expr->getRHS();
|
|
clang::Expr* exprs[2] = {lhs, rhs};
|
|
|
|
switch (expr->getOpcode()) {
|
|
case clang::BO_Comma:
|
|
return Sequential(expr, 2, exprs, env);
|
|
|
|
case clang::BO_LAnd:
|
|
case clang::BO_LOr:
|
|
return ExprEffect::Merge(VisitExpr(lhs, env), VisitExpr(rhs, env));
|
|
|
|
default:
|
|
return Parallel(expr, 2, exprs, env);
|
|
}
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXBindTemporaryExpr) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(MaterializeTemporaryExpr) {
|
|
return VisitExpr(expr->GetTemporaryExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXConstructExpr) {
|
|
return VisitArguments<>(expr, env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXDefaultArgExpr) {
|
|
return VisitExpr(expr->getExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXDeleteExpr) {
|
|
return VisitExpr(expr->getArgument(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXNewExpr) { return VisitExpr(expr->getInitializer(), env); }
|
|
|
|
DECL_VISIT_EXPR(ExprWithCleanups) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CXXThrowExpr) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(ImplicitCastExpr) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(ConstantExpr) { return VisitExpr(expr->getSubExpr(), env); }
|
|
|
|
DECL_VISIT_EXPR(InitListExpr) {
|
|
return Sequential(expr, expr->getNumInits(), expr->getInits(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(MemberExpr) {
|
|
return VisitExpr(expr->getBase(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(OpaqueValueExpr) {
|
|
return VisitExpr(expr->getSourceExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(ParenExpr) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(ParenListExpr) {
|
|
return Parallel(expr, expr->getNumExprs(), expr->getExprs(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(UnaryOperator) {
|
|
// TODO(gcmole): We are treating all expressions that look like
|
|
// {&raw_pointer_var} as definitions of {raw_pointer_var}. This should be
|
|
// changed to recognize less generic pattern:
|
|
//
|
|
// if (maybe_object->ToObject(&obj)) return maybe_object;
|
|
//
|
|
if (expr->getOpcode() == clang::UO_AddrOf) {
|
|
std::string var_name;
|
|
if (IsRawPointerVar(expr->getSubExpr(), &var_name)) {
|
|
return ExprEffect::None().Define(var_name);
|
|
}
|
|
}
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(UnaryExprOrTypeTraitExpr) {
|
|
if (expr->isArgumentType()) {
|
|
return ExprEffect::None();
|
|
}
|
|
|
|
return VisitExpr(expr->getArgumentExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(CastExpr) {
|
|
return VisitExpr(expr->getSubExpr(), env);
|
|
}
|
|
|
|
DECL_VISIT_EXPR(DeclRefExpr) {
|
|
return Use(expr, expr->getDecl(), env);
|
|
}
|
|
|
|
// Represents a node in the AST {parent} whose children {exprs} have
|
|
// undefined order of evaluation, e.g. array subscript or a binary operator.
|
|
ExprEffect Parallel(clang::Expr* parent, int n, clang::Expr** exprs,
|
|
const Environment& env) {
|
|
CallProps props;
|
|
|
|
for (int i = 0; i < n; ++i) {
|
|
props.SetEffect(i, VisitExpr(exprs[i], env));
|
|
}
|
|
|
|
if (!props.IsSafe()) ReportUnsafe(parent, BAD_EXPR_MSG);
|
|
|
|
return props.ComputeCumulativeEffect(
|
|
RepresentsRawPointerType(parent->getType()));
|
|
}
|
|
|
|
// Represents a node in the AST {parent} whose children {exprs} are
|
|
// executed in sequence, e.g. a switch statement or an initializer list.
|
|
ExprEffect Sequential(clang::Stmt* parent, int n, clang::Expr** exprs,
|
|
const Environment& env) {
|
|
ExprEffect out = ExprEffect::None();
|
|
Environment out_env = env;
|
|
for (int i = 0; i < n; ++i) {
|
|
out = ExprEffect::MergeSeq(out, VisitExpr(exprs[i], out_env));
|
|
out_env = out_env.ApplyEffect(out);
|
|
}
|
|
return out;
|
|
}
|
|
|
|
// Represents a node in the AST {parent} which uses the variable {var_name},
|
|
// e.g. this expression or operator&.
|
|
// Here we observe the type in {var_type} of a previously declared variable
|
|
// and if it's a raw heap object type, we do the following:
|
|
// 1. If it got stale due to GC since its declaration, we report it as such.
|
|
// 2. Mark its raw usage in the ExprEffect returned by this function.
|
|
ExprEffect Use(const clang::Expr* parent,
|
|
const clang::QualType& var_type,
|
|
const std::string& var_name,
|
|
const Environment& env) {
|
|
if (RepresentsRawPointerType(var_type)) {
|
|
// We currently care only about our internal pointer types and not about
|
|
// raw C++ pointers, because normally special care is taken when storing
|
|
// raw pointers to the managed heap. Furthermore, checking for raw
|
|
// pointers produces too many false positives in the dead variable
|
|
// analysis.
|
|
if (IsInternalPointerType(var_type) && !env.IsAlive(var_name) &&
|
|
!HasActiveGuard() && dead_vars_analysis_) {
|
|
ReportUnsafe(parent, DEAD_VAR_MSG);
|
|
}
|
|
return ExprEffect::RawUse();
|
|
}
|
|
return ExprEffect::None();
|
|
}
|
|
|
|
ExprEffect Use(const clang::Expr* parent,
|
|
const clang::ValueDecl* var,
|
|
const Environment& env) {
|
|
if (IsExternalVMState(var)) {
|
|
return ExprEffect::GC();
|
|
}
|
|
return Use(parent, var->getType(), var->getNameAsString(), env);
|
|
}
|
|
|
|
|
|
template<typename ExprType>
|
|
ExprEffect VisitArguments(ExprType* call, const Environment& env) {
|
|
CallProps props;
|
|
VisitArguments<>(call, &props, env);
|
|
if (!props.IsSafe()) ReportUnsafe(call, BAD_EXPR_MSG);
|
|
return props.ComputeCumulativeEffect(
|
|
RepresentsRawPointerType(call->getType()));
|
|
}
|
|
|
|
template<typename ExprType>
|
|
void VisitArguments(ExprType* call,
|
|
CallProps* props,
|
|
const Environment& env) {
|
|
for (unsigned arg = 0; arg < call->getNumArgs(); arg++) {
|
|
props->SetEffect(arg + 1, VisitExpr(call->getArg(arg), env));
|
|
}
|
|
}
|
|
|
|
// After visiting the receiver and the arguments of the {call} node, this
|
|
// function might report a GC-unsafe usage (due to the undefined evaluation
|
|
// order of the receiver and the rest of the arguments).
|
|
ExprEffect VisitCallExpr(clang::CallExpr* call,
|
|
const Environment& env) {
|
|
CallProps props;
|
|
|
|
clang::CXXMemberCallExpr* memcall =
|
|
llvm::dyn_cast_or_null<clang::CXXMemberCallExpr>(call);
|
|
if (memcall != NULL) {
|
|
clang::Expr* receiver = memcall->getImplicitObjectArgument();
|
|
props.SetEffect(0, VisitExpr(receiver, env));
|
|
}
|
|
|
|
std::string var_name;
|
|
clang::CXXOperatorCallExpr* opcall =
|
|
llvm::dyn_cast_or_null<clang::CXXOperatorCallExpr>(call);
|
|
if (opcall != NULL && opcall->isAssignmentOp() &&
|
|
IsRawPointerVar(opcall->getArg(0), &var_name)) {
|
|
// TODO(gcmole): We are treating all assignment operator calls with
|
|
// the left hand side looking like {raw_pointer_var} as safe independent
|
|
// of the concrete assignment operator implementation. This should be
|
|
// changed to be more narrow only if the assignment operator of the base
|
|
// {Object} or {HeapObject} class was used, which we know to be safe.
|
|
props.SetEffect(1, VisitExpr(call->getArg(1), env).Define(var_name));
|
|
} else {
|
|
VisitArguments<>(call, &props, env);
|
|
}
|
|
|
|
if (!props.IsSafe()) ReportUnsafe(call, BAD_EXPR_MSG);
|
|
|
|
ExprEffect out = props.ComputeCumulativeEffect(
|
|
RepresentsRawPointerType(call->getType()));
|
|
|
|
clang::FunctionDecl* callee = call->getDirectCallee();
|
|
if (callee != NULL) {
|
|
if (KnownToCauseGC(ctx_, callee)) {
|
|
out.setGC();
|
|
}
|
|
|
|
// Support for virtual methods that might be GC suspects.
|
|
clang::CXXMethodDecl* method =
|
|
llvm::dyn_cast_or_null<clang::CXXMethodDecl>(callee);
|
|
if (method != NULL && method->isVirtual()) {
|
|
clang::CXXMemberCallExpr* memcall =
|
|
llvm::dyn_cast_or_null<clang::CXXMemberCallExpr>(call);
|
|
if (memcall != NULL) {
|
|
clang::CXXMethodDecl* target = method->getDevirtualizedMethod(
|
|
memcall->getImplicitObjectArgument(), false);
|
|
if (target != NULL) {
|
|
if (KnownToCauseGC(ctx_, target)) {
|
|
out.setGC();
|
|
}
|
|
} else {
|
|
// According to the documentation, {getDevirtualizedMethod} might
|
|
// return NULL, in which case we still want to use the partial
|
|
// match of the {method}'s name against the GC suspects in order
|
|
// to increase coverage.
|
|
if (SuspectedToCauseGC(ctx_, method)) {
|
|
out.setGC();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return out;
|
|
}
|
|
|
|
// --------------------------------------------------------------------------
|
|
// Statements
|
|
// --------------------------------------------------------------------------
|
|
|
|
Environment VisitStmt(clang::Stmt* stmt, const Environment& env) {
|
|
#define VISIT(type) \
|
|
do { \
|
|
clang::type* concrete_stmt = llvm::dyn_cast_or_null<clang::type>(stmt); \
|
|
if (concrete_stmt != NULL) { \
|
|
return Visit##type(concrete_stmt, env); \
|
|
} \
|
|
} while (0);
|
|
|
|
if (clang::Expr* expr = llvm::dyn_cast_or_null<clang::Expr>(stmt)) {
|
|
return env.ApplyEffect(VisitExpr(expr, env));
|
|
}
|
|
|
|
VISIT(AsmStmt);
|
|
VISIT(BreakStmt);
|
|
VISIT(CompoundStmt);
|
|
VISIT(ContinueStmt);
|
|
VISIT(CXXCatchStmt);
|
|
VISIT(CXXTryStmt);
|
|
VISIT(DeclStmt);
|
|
VISIT(DoStmt);
|
|
VISIT(ForStmt);
|
|
VISIT(GotoStmt);
|
|
VISIT(IfStmt);
|
|
VISIT(IndirectGotoStmt);
|
|
VISIT(LabelStmt);
|
|
VISIT(NullStmt);
|
|
VISIT(ReturnStmt);
|
|
VISIT(CaseStmt);
|
|
VISIT(DefaultStmt);
|
|
VISIT(SwitchStmt);
|
|
VISIT(WhileStmt);
|
|
#undef VISIT
|
|
|
|
return env;
|
|
}
|
|
|
|
#define DECL_VISIT_STMT(type) \
|
|
Environment Visit##type (clang::type* stmt, const Environment& env)
|
|
|
|
#define IGNORE_STMT(type) \
|
|
Environment Visit##type (clang::type* stmt, const Environment& env) { \
|
|
return env; \
|
|
}
|
|
|
|
IGNORE_STMT(IndirectGotoStmt);
|
|
IGNORE_STMT(NullStmt);
|
|
IGNORE_STMT(AsmStmt);
|
|
|
|
// We are ignoring control flow for simplicity.
|
|
IGNORE_STMT(GotoStmt);
|
|
IGNORE_STMT(LabelStmt);
|
|
|
|
// We are ignoring try/catch because V8 does not use them.
|
|
IGNORE_STMT(CXXCatchStmt);
|
|
IGNORE_STMT(CXXTryStmt);
|
|
|
|
class Block {
|
|
public:
|
|
Block(const Environment& in,
|
|
FunctionAnalyzer* owner)
|
|
: in_(in),
|
|
out_(Environment::Unreachable()),
|
|
changed_(false),
|
|
owner_(owner) {
|
|
parent_ = owner_->EnterBlock(this);
|
|
}
|
|
|
|
~Block() {
|
|
owner_->LeaveBlock(parent_);
|
|
}
|
|
|
|
void MergeIn(const Environment& env) {
|
|
Environment old_in = in_;
|
|
in_ = Environment::Merge(in_, env);
|
|
changed_ = !old_in.Equal(in_);
|
|
}
|
|
|
|
bool changed() {
|
|
if (changed_) {
|
|
changed_ = false;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
const Environment& in() {
|
|
return in_;
|
|
}
|
|
|
|
const Environment& out() {
|
|
return out_;
|
|
}
|
|
|
|
void MergeOut(const Environment& env) {
|
|
out_ = Environment::Merge(out_, env);
|
|
}
|
|
|
|
void Sequential(clang::Stmt* a, clang::Stmt* b, clang::Stmt* c) {
|
|
Environment a_out = owner_->VisitStmt(a, in());
|
|
Environment b_out = owner_->VisitStmt(b, a_out);
|
|
Environment c_out = owner_->VisitStmt(c, b_out);
|
|
MergeOut(c_out);
|
|
}
|
|
|
|
void Sequential(clang::Stmt* a, clang::Stmt* b) {
|
|
Environment a_out = owner_->VisitStmt(a, in());
|
|
Environment b_out = owner_->VisitStmt(b, a_out);
|
|
MergeOut(b_out);
|
|
}
|
|
|
|
void Loop(clang::Stmt* a, clang::Stmt* b, clang::Stmt* c) {
|
|
Sequential(a, b, c);
|
|
MergeIn(out());
|
|
}
|
|
|
|
void Loop(clang::Stmt* a, clang::Stmt* b) {
|
|
Sequential(a, b);
|
|
MergeIn(out());
|
|
}
|
|
|
|
|
|
private:
|
|
Environment in_;
|
|
Environment out_;
|
|
bool changed_;
|
|
FunctionAnalyzer* owner_;
|
|
Block* parent_;
|
|
};
|
|
|
|
|
|
DECL_VISIT_STMT(BreakStmt) {
|
|
block_->MergeOut(env);
|
|
return Environment::Unreachable();
|
|
}
|
|
|
|
DECL_VISIT_STMT(ContinueStmt) {
|
|
block_->MergeIn(env);
|
|
return Environment::Unreachable();
|
|
}
|
|
|
|
DECL_VISIT_STMT(CompoundStmt) {
|
|
scopes_.push_back(GCGuard(stmt, false));
|
|
Environment out = env;
|
|
clang::CompoundStmt::body_iterator end = stmt->body_end();
|
|
for (clang::CompoundStmt::body_iterator s = stmt->body_begin();
|
|
s != end;
|
|
++s) {
|
|
out = VisitStmt(*s, out);
|
|
}
|
|
scopes_.pop_back();
|
|
return out;
|
|
}
|
|
|
|
DECL_VISIT_STMT(WhileStmt) {
|
|
Block block (env, this);
|
|
do {
|
|
block.Loop(stmt->getCond(), stmt->getBody());
|
|
} while (block.changed());
|
|
return block.out();
|
|
}
|
|
|
|
DECL_VISIT_STMT(DoStmt) {
|
|
Block block (env, this);
|
|
do {
|
|
block.Loop(stmt->getBody(), stmt->getCond());
|
|
} while (block.changed());
|
|
return block.out();
|
|
}
|
|
|
|
DECL_VISIT_STMT(ForStmt) {
|
|
Block block (VisitStmt(stmt->getInit(), env), this);
|
|
do {
|
|
block.Loop(stmt->getCond(),
|
|
stmt->getBody(),
|
|
stmt->getInc());
|
|
} while (block.changed());
|
|
return block.out();
|
|
}
|
|
|
|
DECL_VISIT_STMT(IfStmt) {
|
|
Environment cond_out = VisitStmt(stmt->getCond(), env);
|
|
Environment then_out = VisitStmt(stmt->getThen(), cond_out);
|
|
Environment else_out = VisitStmt(stmt->getElse(), cond_out);
|
|
return Environment::Merge(then_out, else_out);
|
|
}
|
|
|
|
DECL_VISIT_STMT(SwitchStmt) {
|
|
Block block (env, this);
|
|
block.Sequential(stmt->getCond(), stmt->getBody());
|
|
return block.out();
|
|
}
|
|
|
|
DECL_VISIT_STMT(CaseStmt) {
|
|
Environment in = Environment::Merge(env, block_->in());
|
|
Environment after_lhs = VisitStmt(stmt->getLHS(), in);
|
|
return VisitStmt(stmt->getSubStmt(), after_lhs);
|
|
}
|
|
|
|
DECL_VISIT_STMT(DefaultStmt) {
|
|
Environment in = Environment::Merge(env, block_->in());
|
|
return VisitStmt(stmt->getSubStmt(), in);
|
|
}
|
|
|
|
DECL_VISIT_STMT(ReturnStmt) {
|
|
VisitExpr(stmt->getRetValue(), env);
|
|
return Environment::Unreachable();
|
|
}
|
|
|
|
const clang::TagType* ToTagType(const clang::Type* t) {
|
|
if (t == NULL) {
|
|
return NULL;
|
|
} else if (llvm::isa<clang::TagType>(t)) {
|
|
return llvm::cast<clang::TagType>(t);
|
|
} else if (llvm::isa<clang::SubstTemplateTypeParmType>(t)) {
|
|
return ToTagType(llvm::cast<clang::SubstTemplateTypeParmType>(t)
|
|
->getReplacementType()
|
|
.getTypePtr());
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
bool IsDerivedFrom(const clang::CXXRecordDecl* record,
|
|
const clang::CXXRecordDecl* base) {
|
|
return (record == base) || record->isDerivedFrom(base);
|
|
}
|
|
|
|
const clang::CXXRecordDecl* GetDefinitionOrNull(
|
|
const clang::CXXRecordDecl* record) {
|
|
if (record == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
if (!InV8Namespace(record)) return NULL;
|
|
|
|
if (!record->hasDefinition()) {
|
|
return NULL;
|
|
}
|
|
|
|
return record->getDefinition();
|
|
}
|
|
|
|
bool IsDerivedFromInternalPointer(const clang::CXXRecordDecl* record) {
|
|
const clang::CXXRecordDecl* definition = GetDefinitionOrNull(record);
|
|
if (!definition) {
|
|
return false;
|
|
}
|
|
|
|
bool result = (IsDerivedFrom(record, object_decl_) &&
|
|
!IsDerivedFrom(record, smi_decl_)) ||
|
|
IsDerivedFrom(record, maybe_object_decl_);
|
|
return result;
|
|
}
|
|
|
|
bool IsRawPointerType(const clang::PointerType* type) {
|
|
const clang::CXXRecordDecl* record = type->getPointeeCXXRecordDecl();
|
|
bool result = IsDerivedFromInternalPointer(record);
|
|
TRACE("is raw " << result << " " << record->getNameAsString());
|
|
return result;
|
|
}
|
|
|
|
bool IsInternalPointerType(clang::QualType qtype) {
|
|
// Not yet assigned pointers can't get moved by the GC.
|
|
if (qtype.isNull()) {
|
|
return false;
|
|
}
|
|
// nullptr can't get moved by the GC.
|
|
if (qtype->isNullPtrType()) {
|
|
return false;
|
|
}
|
|
|
|
const clang::CXXRecordDecl* record = qtype->getAsCXXRecordDecl();
|
|
bool result = IsDerivedFromInternalPointer(record);
|
|
TRACE_LLVM_TYPE("is internal " << result, qtype);
|
|
return result;
|
|
}
|
|
|
|
// Returns weather the given type is a raw pointer or a wrapper around
|
|
// such. For V8 that means Object and MaybeObject instances.
|
|
bool RepresentsRawPointerType(clang::QualType qtype) {
|
|
const clang::PointerType* pointer_type =
|
|
llvm::dyn_cast_or_null<clang::PointerType>(qtype.getTypePtrOrNull());
|
|
if (pointer_type != NULL) {
|
|
return IsRawPointerType(pointer_type);
|
|
} else {
|
|
return IsInternalPointerType(qtype);
|
|
}
|
|
}
|
|
|
|
bool IsGCGuard(clang::QualType qtype) {
|
|
if (qtype.isNull()) {
|
|
return false;
|
|
}
|
|
if (qtype->isNullPtrType()) {
|
|
return false;
|
|
}
|
|
|
|
const clang::CXXRecordDecl* record = qtype->getAsCXXRecordDecl();
|
|
const clang::CXXRecordDecl* definition = GetDefinitionOrNull(record);
|
|
|
|
if (!definition) {
|
|
return false;
|
|
}
|
|
|
|
return (no_gc_decl_ && IsDerivedFrom(definition, no_gc_decl_)) ||
|
|
(no_heap_access_decl_ &&
|
|
IsDerivedFrom(definition, no_heap_access_decl_));
|
|
}
|
|
|
|
Environment VisitDecl(clang::Decl* decl, Environment& env) {
|
|
if (clang::VarDecl* var = llvm::dyn_cast<clang::VarDecl>(decl)) {
|
|
Environment out = var->hasInit() ? VisitStmt(var->getInit(), env) : env;
|
|
|
|
if (RepresentsRawPointerType(var->getType())) {
|
|
out = out.Define(var->getNameAsString());
|
|
}
|
|
if (IsGCGuard(var->getType())) {
|
|
scopes_.back().has_guard = true;
|
|
}
|
|
|
|
return out;
|
|
}
|
|
// TODO(gcmole): handle other declarations?
|
|
return env;
|
|
}
|
|
|
|
DECL_VISIT_STMT(DeclStmt) {
|
|
Environment out = env;
|
|
clang::DeclStmt::decl_iterator end = stmt->decl_end();
|
|
for (clang::DeclStmt::decl_iterator decl = stmt->decl_begin();
|
|
decl != end;
|
|
++decl) {
|
|
out = VisitDecl(*decl, out);
|
|
}
|
|
return out;
|
|
}
|
|
|
|
|
|
void DefineParameters(const clang::FunctionDecl* f,
|
|
Environment* env) {
|
|
env->MDefine(THIS);
|
|
clang::FunctionDecl::param_const_iterator end = f->param_end();
|
|
for (clang::FunctionDecl::param_const_iterator p = f->param_begin();
|
|
p != end;
|
|
++p) {
|
|
env->MDefine((*p)->getNameAsString());
|
|
}
|
|
}
|
|
|
|
|
|
void AnalyzeFunction(const clang::FunctionDecl* f) {
|
|
const clang::FunctionDecl* body = NULL;
|
|
if (f->hasBody(body)) {
|
|
Environment env;
|
|
DefineParameters(body, &env);
|
|
VisitStmt(body->getBody(), env);
|
|
Environment::ClearSymbolTable();
|
|
}
|
|
}
|
|
|
|
Block* EnterBlock(Block* block) {
|
|
Block* parent = block_;
|
|
block_ = block;
|
|
return parent;
|
|
}
|
|
|
|
void LeaveBlock(Block* block) {
|
|
block_ = block;
|
|
}
|
|
|
|
bool HasActiveGuard() {
|
|
for (auto s : scopes_) {
|
|
if (s.has_guard) return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
private:
|
|
void ReportUnsafe(const clang::Expr* expr, const std::string& msg) {
|
|
d_.Report(clang::FullSourceLoc(expr->getExprLoc(), sm_),
|
|
d_.getCustomDiagID(clang::DiagnosticsEngine::Warning, "%0"))
|
|
<< msg;
|
|
}
|
|
|
|
|
|
clang::MangleContext* ctx_;
|
|
clang::CXXRecordDecl* object_decl_;
|
|
clang::CXXRecordDecl* maybe_object_decl_;
|
|
clang::CXXRecordDecl* smi_decl_;
|
|
clang::CXXRecordDecl* no_gc_decl_;
|
|
clang::CXXRecordDecl* no_heap_access_decl_;
|
|
|
|
clang::DiagnosticsEngine& d_;
|
|
clang::SourceManager& sm_;
|
|
|
|
Block* block_;
|
|
bool dead_vars_analysis_;
|
|
|
|
struct GCGuard {
|
|
clang::CompoundStmt* stmt = NULL;
|
|
bool has_guard = false;
|
|
|
|
GCGuard(clang::CompoundStmt* stmt_, bool has_guard_)
|
|
: stmt(stmt_), has_guard(has_guard_) {}
|
|
};
|
|
std::vector<GCGuard> scopes_;
|
|
};
|
|
|
|
class ProblemsFinder : public clang::ASTConsumer,
|
|
public clang::RecursiveASTVisitor<ProblemsFinder> {
|
|
public:
|
|
ProblemsFinder(clang::DiagnosticsEngine& d, clang::SourceManager& sm,
|
|
const std::vector<std::string>& args)
|
|
: d_(d), sm_(sm), dead_vars_analysis_(false) {
|
|
for (unsigned i = 0; i < args.size(); ++i) {
|
|
if (args[i] == "--dead-vars") {
|
|
dead_vars_analysis_ = true;
|
|
}
|
|
if (args[i] == "--verbose") {
|
|
g_tracing_enabled = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
virtual void HandleTranslationUnit(clang::ASTContext &ctx) {
|
|
Resolver r(ctx);
|
|
|
|
// It is a valid situation that no_gc_decl == NULL when the
|
|
// DisallowHeapAllocation is not included and can't be resolved.
|
|
// This is gracefully handled in the FunctionAnalyzer later.
|
|
clang::CXXRecordDecl* no_gc_decl =
|
|
r.ResolveNamespace("v8")
|
|
.ResolveNamespace("internal")
|
|
.ResolveTemplate("DisallowHeapAllocation");
|
|
|
|
clang::CXXRecordDecl* no_heap_access_decl =
|
|
r.ResolveNamespace("v8")
|
|
.ResolveNamespace("internal")
|
|
.Resolve<clang::CXXRecordDecl>("DisallowHeapAccess");
|
|
|
|
clang::CXXRecordDecl* object_decl =
|
|
r.ResolveNamespace("v8").ResolveNamespace("internal").
|
|
Resolve<clang::CXXRecordDecl>("Object");
|
|
|
|
clang::CXXRecordDecl* maybe_object_decl =
|
|
r.ResolveNamespace("v8")
|
|
.ResolveNamespace("internal")
|
|
.Resolve<clang::CXXRecordDecl>("MaybeObject");
|
|
|
|
clang::CXXRecordDecl* smi_decl =
|
|
r.ResolveNamespace("v8").ResolveNamespace("internal").
|
|
Resolve<clang::CXXRecordDecl>("Smi");
|
|
|
|
if (object_decl != NULL) object_decl = object_decl->getDefinition();
|
|
|
|
if (maybe_object_decl != NULL)
|
|
maybe_object_decl = maybe_object_decl->getDefinition();
|
|
|
|
if (smi_decl != NULL) smi_decl = smi_decl->getDefinition();
|
|
|
|
if (no_heap_access_decl != NULL)
|
|
no_heap_access_decl = no_heap_access_decl->getDefinition();
|
|
|
|
if (object_decl != NULL && smi_decl != NULL && maybe_object_decl != NULL) {
|
|
function_analyzer_ = new FunctionAnalyzer(
|
|
clang::ItaniumMangleContext::create(ctx, d_), object_decl,
|
|
maybe_object_decl, smi_decl, no_gc_decl, no_heap_access_decl, d_, sm_,
|
|
dead_vars_analysis_);
|
|
TraverseDecl(ctx.getTranslationUnitDecl());
|
|
} else {
|
|
if (object_decl == NULL) {
|
|
llvm::errs() << "Failed to resolve v8::internal::Object\n";
|
|
}
|
|
if (maybe_object_decl == NULL) {
|
|
llvm::errs() << "Failed to resolve v8::internal::MaybeObject\n";
|
|
}
|
|
if (smi_decl == NULL) {
|
|
llvm::errs() << "Failed to resolve v8::internal::Smi\n";
|
|
}
|
|
}
|
|
}
|
|
|
|
virtual bool VisitFunctionDecl(clang::FunctionDecl* decl) {
|
|
// Don't print tracing from includes, otherwise the output is too big.
|
|
bool tracing = g_tracing_enabled;
|
|
const auto& fileID = sm_.getFileID(decl->getLocation());
|
|
if (fileID != sm_.getMainFileID()) {
|
|
g_tracing_enabled = false;
|
|
}
|
|
|
|
TRACE("Visiting function " << decl->getNameAsString());
|
|
function_analyzer_->AnalyzeFunction(decl);
|
|
|
|
g_tracing_enabled = tracing;
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
clang::DiagnosticsEngine& d_;
|
|
clang::SourceManager& sm_;
|
|
bool dead_vars_analysis_;
|
|
|
|
FunctionAnalyzer* function_analyzer_;
|
|
};
|
|
|
|
|
|
template<typename ConsumerType>
|
|
class Action : public clang::PluginASTAction {
|
|
protected:
|
|
virtual std::unique_ptr<clang::ASTConsumer> CreateASTConsumer(
|
|
clang::CompilerInstance& CI, llvm::StringRef InFile) {
|
|
return std::unique_ptr<clang::ASTConsumer>(
|
|
new ConsumerType(CI.getDiagnostics(), CI.getSourceManager(), args_));
|
|
}
|
|
|
|
bool ParseArgs(const clang::CompilerInstance &CI,
|
|
const std::vector<std::string>& args) {
|
|
args_ = args;
|
|
return true;
|
|
}
|
|
|
|
void PrintHelp(llvm::raw_ostream& ros) {
|
|
}
|
|
private:
|
|
std::vector<std::string> args_;
|
|
};
|
|
|
|
|
|
}
|
|
|
|
static clang::FrontendPluginRegistry::Add<Action<ProblemsFinder> >
|
|
FindProblems("find-problems", "Find GC-unsafe places.");
|
|
|
|
static clang::FrontendPluginRegistry::Add<
|
|
Action<FunctionDeclarationFinder> >
|
|
DumpCallees("dump-callees", "Dump callees for each function.");
|
|
|
|
#undef TRACE
|
|
#undef TRACE_LLVM_TYPE
|
|
#undef TRACE_LLVM_DECL
|
|
#undef DECL_VISIT_EXPR
|
|
#undef IGNORE_EXPR
|
|
#undef DECL_VISIT_STMT
|
|
#undef IGNORE_STMT
|