// Copyright 2009 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.
#include "v8.h"
#include "bootstrapper.h"
#include "codegen-inl.h"
#include "compilation-cache.h"
#include "compiler.h"
#include "debug.h"
#include "fast-codegen.h"
#include "full-codegen.h"
#include "oprofile-agent.h"
#include "rewriter.h"
#include "scopes.h"
#include "usage-analyzer.h"
#include "liveedit.h"
namespace v8 {
namespace internal {
static Handle<Code> MakeCode(Handle<Context> context, CompilationInfo* info) {
FunctionLiteral* function = info->function();
ASSERT(function != NULL);
// Rewrite the AST by introducing .result assignments where needed.
if (!Rewriter::Process(function) || !AnalyzeVariableUsage(function)) {
// Signal a stack overflow by returning a null handle. The stack
// overflow exception will be thrown by the caller.
return Handle<Code>::null();
}
{
// Compute top scope and allocate variables. For lazy compilation
// the top scope only contains the single lazily compiled function,
// so this doesn't re-allocate variables repeatedly.
HistogramTimerScope timer(&Counters::variable_allocation);
Scope* top = info->scope();
while (top->outer_scope() != NULL) top = top->outer_scope();
top->AllocateVariables(context);
}
#ifdef DEBUG
if (Bootstrapper::IsActive() ?
FLAG_print_builtin_scopes :
FLAG_print_scopes) {
info->scope()->Print();
}
#endif
// Optimize the AST.
if (!Rewriter::Optimize(function)) {
// Signal a stack overflow by returning a null handle. The stack
// overflow exception will be thrown by the caller.
return Handle<Code>::null();
}
// Generate code and return it. Code generator selection is governed by
// which backends are enabled and whether the function is considered
// run-once code or not:
//
// --full-compiler enables the dedicated backend for code we expect to be
// run once
// --fast-compiler enables a speculative optimizing backend (for
// non-run-once code)
//
// The normal choice of backend can be overridden with the flags
// --always-full-compiler and --always-fast-compiler, which are mutually
// incompatible.
CHECK(!FLAG_always_full_compiler || !FLAG_always_fast_compiler);
Handle<SharedFunctionInfo> shared = info->shared_info();
bool is_run_once = (shared.is_null())
? info->scope()->is_global_scope()
: (shared->is_toplevel() || shared->try_full_codegen());
if (FLAG_always_full_compiler || (FLAG_full_compiler && is_run_once)) {
FullCodeGenSyntaxChecker checker;
checker.Check(function);
if (checker.has_supported_syntax()) {
return FullCodeGenerator::MakeCode(info);
}
} else if (FLAG_always_fast_compiler ||
(FLAG_fast_compiler && !is_run_once)) {
FastCodeGenSyntaxChecker checker;
checker.Check(info);
if (checker.has_supported_syntax()) {
return FastCodeGenerator::MakeCode(info);
}
}
return CodeGenerator::MakeCode(info);
}
static Handle<JSFunction> MakeFunction(bool is_global,
bool is_eval,
Compiler::ValidationState validate,
Handle<Script> script,
Handle<Context> context,
v8::Extension* extension,
ScriptDataImpl* pre_data) {
CompilationZoneScope zone_scope(DELETE_ON_EXIT);
PostponeInterruptsScope postpone;
ASSERT(!i::Top::global_context().is_null());
script->set_context_data((*i::Top::global_context())->data());
bool is_json = (validate == Compiler::VALIDATE_JSON);
#ifdef ENABLE_DEBUGGER_SUPPORT
if (is_eval || is_json) {
script->set_compilation_type(
is_json ? Smi::FromInt(Script::COMPILATION_TYPE_JSON) :
Smi::FromInt(Script::COMPILATION_TYPE_EVAL));
// For eval scripts add information on the function from which eval was
// called.
if (is_eval) {
StackTraceFrameIterator it;
if (!it.done()) {
script->set_eval_from_shared(
JSFunction::cast(it.frame()->function())->shared());
int offset = static_cast<int>(
it.frame()->pc() - it.frame()->code()->instruction_start());
script->set_eval_from_instructions_offset(Smi::FromInt(offset));
}
}
}
// Notify debugger
Debugger::OnBeforeCompile(script);
#endif
// Only allow non-global compiles for eval.
ASSERT(is_eval || is_global);
// Build AST.
FunctionLiteral* lit =
MakeAST(is_global, script, extension, pre_data, is_json);
// Check for parse errors.
if (lit == NULL) {
ASSERT(Top::has_pending_exception());
return Handle<JSFunction>::null();
}
// Measure how long it takes to do the compilation; only take the
// rest of the function into account to avoid overlap with the
// parsing statistics.
HistogramTimer* rate = is_eval
? &Counters::compile_eval
: &Counters::compile;
HistogramTimerScope timer(rate);
// Compile the code.
CompilationInfo info(lit, script, is_eval);
Handle<Code> code = MakeCode(context, &info);
// Check for stack-overflow exceptions.
if (code.is_null()) {
Top::StackOverflow();
return Handle<JSFunction>::null();
}
#if defined ENABLE_LOGGING_AND_PROFILING || defined ENABLE_OPROFILE_AGENT
// Log the code generation for the script. Check explicit whether logging is
// to avoid allocating when not required.
if (Logger::is_logging() || OProfileAgent::is_enabled()) {
if (script->name()->IsString()) {
SmartPointer<char> data =
String::cast(script->name())->ToCString(DISALLOW_NULLS);
LOG(CodeCreateEvent(is_eval ? Logger::EVAL_TAG : Logger::SCRIPT_TAG,
*code, *data));
OProfileAgent::CreateNativeCodeRegion(*data,
code->instruction_start(),
code->instruction_size());
} else {
LOG(CodeCreateEvent(is_eval ? Logger::EVAL_TAG : Logger::SCRIPT_TAG,
*code, ""));
OProfileAgent::CreateNativeCodeRegion(is_eval ? "Eval" : "Script",
code->instruction_start(),
code->instruction_size());
}
}
#endif
// Allocate function.
Handle<JSFunction> fun =
Factory::NewFunctionBoilerplate(lit->name(),
lit->materialized_literal_count(),
code);
ASSERT_EQ(RelocInfo::kNoPosition, lit->function_token_position());
Compiler::SetFunctionInfo(fun, lit, true, script);
// Hint to the runtime system used when allocating space for initial
// property space by setting the expected number of properties for
// the instances of the function.
SetExpectedNofPropertiesFromEstimate(fun, lit->expected_property_count());
#ifdef ENABLE_DEBUGGER_SUPPORT
// Notify debugger
Debugger::OnAfterCompile(script, fun);
#endif
return fun;
}
static StaticResource<SafeStringInputBuffer> safe_string_input_buffer;
Handle<JSFunction> Compiler::Compile(Handle<String> source,
Handle<Object> script_name,
int line_offset, int column_offset,
v8::Extension* extension,
ScriptDataImpl* input_pre_data,
Handle<Object> script_data,
NativesFlag natives) {
int source_length = source->length();
Counters::total_load_size.Increment(source_length);
Counters::total_compile_size.Increment(source_length);
// The VM is in the COMPILER state until exiting this function.
VMState state(COMPILER);
// Do a lookup in the compilation cache but not for extensions.
Handle<JSFunction> result;
if (extension == NULL) {
result = CompilationCache::LookupScript(source,
script_name,
line_offset,
column_offset);
}
if (result.is_null()) {
// No cache entry found. Do pre-parsing and compile the script.
ScriptDataImpl* pre_data = input_pre_data;
if (pre_data == NULL && source_length >= FLAG_min_preparse_length) {
Access<SafeStringInputBuffer> buf(&safe_string_input_buffer);
buf->Reset(source.location());
pre_data = PreParse(source, buf.value(), extension);
}
// Create a script object describing the script to be compiled.
Handle<Script> script = Factory::NewScript(source);
if (natives == NATIVES_CODE) {
script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
}
if (!script_name.is_null()) {
script->set_name(*script_name);
script->set_line_offset(Smi::FromInt(line_offset));
script->set_column_offset(Smi::FromInt(column_offset));
}
script->set_data(script_data.is_null() ? Heap::undefined_value()
: *script_data);
// Compile the function and add it to the cache.
result = MakeFunction(true,
false,
DONT_VALIDATE_JSON,
script,
Handle<Context>::null(),
extension,
pre_data);
if (extension == NULL && !result.is_null()) {
CompilationCache::PutScript(source, result);
}
// Get rid of the pre-parsing data (if necessary).
if (input_pre_data == NULL && pre_data != NULL) {
delete pre_data;
}
}
if (result.is_null()) Top::ReportPendingMessages();
return result;
}
Handle<JSFunction> Compiler::CompileEval(Handle<String> source,
Handle<Context> context,
bool is_global,
ValidationState validate) {
// Note that if validation is required then no path through this
// function is allowed to return a value without validating that
// the input is legal json.
int source_length = source->length();
Counters::total_eval_size.Increment(source_length);
Counters::total_compile_size.Increment(source_length);
// The VM is in the COMPILER state until exiting this function.
VMState state(COMPILER);
// Do a lookup in the compilation cache; if the entry is not there,
// invoke the compiler and add the result to the cache. If we're
// evaluating json we bypass the cache since we can't be sure a
// potential value in the cache has been validated.
Handle<JSFunction> result;
if (validate == DONT_VALIDATE_JSON)
result = CompilationCache::LookupEval(source, context, is_global);
if (result.is_null()) {
// Create a script object describing the script to be compiled.
Handle<Script> script = Factory::NewScript(source);
result = MakeFunction(is_global,
true,
validate,
script,
context,
NULL,
NULL);
if (!result.is_null() && validate != VALIDATE_JSON) {
// For json it's unlikely that we'll ever see exactly the same
// string again so we don't use the compilation cache.
CompilationCache::PutEval(source, context, is_global, result);
}
}
return result;
}
bool Compiler::CompileLazy(CompilationInfo* info) {
CompilationZoneScope zone_scope(DELETE_ON_EXIT);
// The VM is in the COMPILER state until exiting this function.
VMState state(COMPILER);
PostponeInterruptsScope postpone;
// Compute name, source code and script data.
Handle<SharedFunctionInfo> shared = info->shared_info();
Handle<String> name(String::cast(shared->name()));
int start_position = shared->start_position();
int end_position = shared->end_position();
bool is_expression = shared->is_expression();
Counters::total_compile_size.Increment(end_position - start_position);
// Generate the AST for the lazily compiled function. The AST may be
// NULL in case of parser stack overflow.
FunctionLiteral* lit = MakeLazyAST(info->script(),
name,
start_position,
end_position,
is_expression);
// Check for parse errors.
if (lit == NULL) {
ASSERT(Top::has_pending_exception());
return false;
}
info->set_function(lit);
// Measure how long it takes to do the lazy compilation; only take
// the rest of the function into account to avoid overlap with the
// lazy parsing statistics.
HistogramTimerScope timer(&Counters::compile_lazy);
// Compile the code.
Handle<Code> code = MakeCode(Handle<Context>::null(), info);
// Check for stack-overflow exception.
if (code.is_null()) {
Top::StackOverflow();
return false;
}
#if defined ENABLE_LOGGING_AND_PROFILING || defined ENABLE_OPROFILE_AGENT
LogCodeCreateEvent(Logger::LAZY_COMPILE_TAG,
name,
Handle<String>(shared->inferred_name()),
start_position,
info->script(),
code);
#endif
// Update the shared function info with the compiled code.
shared->set_code(*code);
// Set the expected number of properties for instances.
SetExpectedNofPropertiesFromEstimate(shared, lit->expected_property_count());
// Set the optimication hints after performing lazy compilation, as these are
// not set when the function is set up as a lazily compiled function.
shared->SetThisPropertyAssignmentsInfo(
lit->has_only_simple_this_property_assignments(),
*lit->this_property_assignments());
// Check the function has compiled code.
ASSERT(shared->is_compiled());
return true;
}
Handle<JSFunction> Compiler::BuildBoilerplate(FunctionLiteral* literal,
Handle<Script> script,
AstVisitor* caller) {
#ifdef DEBUG
// We should not try to compile the same function literal more than
// once.
literal->mark_as_compiled();
#endif
// Determine if the function can be lazily compiled. This is
// necessary to allow some of our builtin JS files to be lazily
// compiled. These builtins cannot be handled lazily by the parser,
// since we have to know if a function uses the special natives
// syntax, which is something the parser records.
bool allow_lazy = literal->AllowsLazyCompilation() &&
!LiveEditFunctionTracker::IsActive();
// Generate code
Handle<Code> code;
if (FLAG_lazy && allow_lazy) {
code = ComputeLazyCompile(literal->num_parameters());
} else {
// The bodies of function literals have not yet been visited by
// the AST optimizer/analyzer.
if (!Rewriter::Optimize(literal)) {
return Handle<JSFunction>::null();
}
// Generate code and return it. The way that the compilation mode
// is controlled by the command-line flags is described in
// the static helper function MakeCode.
CompilationInfo info(literal, script, false);
CHECK(!FLAG_always_full_compiler || !FLAG_always_fast_compiler);
bool is_run_once = literal->try_full_codegen();
bool is_compiled = false;
if (FLAG_always_full_compiler || (FLAG_full_compiler && is_run_once)) {
FullCodeGenSyntaxChecker checker;
checker.Check(literal);
if (checker.has_supported_syntax()) {
code = FullCodeGenerator::MakeCode(&info);
is_compiled = true;
}
} else if (FLAG_always_fast_compiler ||
(FLAG_fast_compiler && !is_run_once)) {
// Since we are not lazily compiling we do not have a receiver to
// specialize for.
FastCodeGenSyntaxChecker checker;
checker.Check(&info);
if (checker.has_supported_syntax()) {
code = FastCodeGenerator::MakeCode(&info);
is_compiled = true;
}
}
if (!is_compiled) {
// We fall back to the classic V8 code generator.
code = CodeGenerator::MakeCode(&info);
}
// Check for stack-overflow exception.
if (code.is_null()) {
caller->SetStackOverflow();
return Handle<JSFunction>::null();
}
// Function compilation complete.
#if defined ENABLE_LOGGING_AND_PROFILING || defined ENABLE_OPROFILE_AGENT
LogCodeCreateEvent(Logger::FUNCTION_TAG,
literal->name(),
literal->inferred_name(),
literal->start_position(),
script,
code);
#endif
}
// Create a boilerplate function.
Handle<JSFunction> function =
Factory::NewFunctionBoilerplate(literal->name(),
literal->materialized_literal_count(),
code);
SetFunctionInfo(function, literal, false, script);
#ifdef ENABLE_DEBUGGER_SUPPORT
// Notify debugger that a new function has been added.
Debugger::OnNewFunction(function);
#endif
// Set the expected number of properties for instances and return
// the resulting function.
SetExpectedNofPropertiesFromEstimate(function,
literal->expected_property_count());
return function;
}
// Sets the function info on a function.
// The start_position points to the first '(' character after the function name
// in the full script source. When counting characters in the script source the
// the first character is number 0 (not 1).
void Compiler::SetFunctionInfo(Handle<JSFunction> fun,
FunctionLiteral* lit,
bool is_toplevel,
Handle<Script> script) {
fun->shared()->set_length(lit->num_parameters());
fun->shared()->set_formal_parameter_count(lit->num_parameters());
fun->shared()->set_script(*script);
fun->shared()->set_function_token_position(lit->function_token_position());
fun->shared()->set_start_position(lit->start_position());
fun->shared()->set_end_position(lit->end_position());
fun->shared()->set_is_expression(lit->is_expression());
fun->shared()->set_is_toplevel(is_toplevel);
fun->shared()->set_inferred_name(*lit->inferred_name());
fun->shared()->SetThisPropertyAssignmentsInfo(
lit->has_only_simple_this_property_assignments(),
*lit->this_property_assignments());
fun->shared()->set_try_full_codegen(lit->try_full_codegen());
}
#if defined ENABLE_LOGGING_AND_PROFILING || defined ENABLE_OPROFILE_AGENT
void Compiler::LogCodeCreateEvent(Logger::LogEventsAndTags tag,
Handle<String> name,
Handle<String> inferred_name,
int start_position,
Handle<Script> script,
Handle<Code> code) {
// Log the code generation. If source information is available
// include script name and line number. Check explicitly whether
// logging is enabled as finding the line number is not free.
if (Logger::is_logging() || OProfileAgent::is_enabled()) {
Handle<String> func_name(name->length() > 0 ? *name : *inferred_name);
if (script->name()->IsString()) {
int line_num = GetScriptLineNumber(script, start_position) + 1;
LOG(CodeCreateEvent(tag, *code, *func_name,
String::cast(script->name()), line_num));
OProfileAgent::CreateNativeCodeRegion(*func_name,
String::cast(script->name()),
line_num,
code->instruction_start(),
code->instruction_size());
} else {
LOG(CodeCreateEvent(tag, *code, *func_name));
OProfileAgent::CreateNativeCodeRegion(*func_name,
code->instruction_start(),
code->instruction_size());
}
}
}
#endif
} } // namespace v8::internal