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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/snapshot/static-roots-gen.h"
#include <fstream>
#include "src/common/globals.h"
#include "src/common/ptr-compr-inl.h"
#include "src/execution/isolate.h"
#include "src/objects/instance-type-inl.h"
#include "src/objects/instance-type.h"
#include "src/objects/objects-definitions.h"
#include "src/objects/visitors.h"
#include "src/roots/roots-inl.h"
#include "src/roots/roots.h"
namespace v8 {
namespace internal {
class StaticRootsTableGenImpl {
public:
explicit StaticRootsTableGenImpl(Isolate* isolate) {
// Collect all roots
ReadOnlyRoots ro_roots(isolate);
{
RootIndex pos = RootIndex::kFirstReadOnlyRoot;
#define ADD_ROOT(_, value, CamelName) \
{ \
Tagged_t ptr = V8HeapCompressionScheme::CompressObject( \
ro_roots.unchecked_##value().ptr()); \
sorted_roots_[ptr].push_back(pos); \
camel_names_[RootIndex::k##CamelName] = #CamelName; \
++pos; \
}
READ_ONLY_ROOT_LIST(ADD_ROOT)
#undef ADD_ROOT
}
}
const std::map<Tagged_t, std::list<RootIndex>>& sorted_roots() {
return sorted_roots_;
}
const std::string& camel_name(RootIndex idx) { return camel_names_.at(idx); }
private:
std::map<Tagged_t, std::list<RootIndex>> sorted_roots_;
std::unordered_map<RootIndex, std::string> camel_names_;
};
void StaticRootsTableGen::write(Isolate* isolate, const char* file) {
CHECK_WITH_MSG(!V8_STATIC_ROOTS_BOOL,
"Re-generating the table of roots is only supported in builds "
"with v8_enable_static_roots disabled");
CHECK(V8_STATIC_ROOTS_GENERATION_BOOL);
CHECK(file);
static_assert(static_cast<int>(RootIndex::kFirstReadOnlyRoot) == 0);
std::ofstream out(file, std::ios::binary);
out << "// Copyright 2022 the V8 project authors. All rights reserved.\n"
<< "// Use of this source code is governed by a BSD-style license "
"that can be\n"
<< "// found in the LICENSE file.\n"
<< "\n"
<< "// This file is automatically generated by "
"`tools/dev/gen-static-roots.py`. Do\n// not edit manually.\n"
<< "\n"
<< "#ifndef V8_ROOTS_STATIC_ROOTS_H_\n"
<< "#define V8_ROOTS_STATIC_ROOTS_H_\n"
<< "\n"
<< "#include \"src/common/globals.h\"\n"
<< "\n"
<< "#if V8_STATIC_ROOTS_BOOL\n"
<< "\n"
<< "#include \"src/roots/roots.h\"\n"
<< "\n"
<< "// Disabling Wasm or Intl invalidates the contents of "
"static-roots.h.\n"
<< "// TODO(olivf): To support static roots for multiple build "
"configurations we\n"
<< "// will need to generate target specific versions of "
"this file.\n"
<< "static_assert(V8_ENABLE_WEBASSEMBLY);\n"
<< "static_assert(V8_INTL_SUPPORT);\n"
<< "\n"
<< "namespace v8 {\n"
<< "namespace internal {\n"
<< "\n"
<< "struct StaticReadOnlyRoot {\n";
// Output a symbol for every root. Ordered by ptr to make it easier to see the
// memory layout of the read only page.
const auto size = static_cast<int>(RootIndex::kReadOnlyRootsCount);
StaticRootsTableGenImpl gen(isolate);
for (auto& entry : gen.sorted_roots()) {
Tagged_t ptr = entry.first;
const std::list<RootIndex>& roots = entry.second;
for (RootIndex root : roots) {
static const char* kPreString = " static constexpr Tagged_t k";
const std::string& name = gen.camel_name(root);
size_t ptr_len = ceil(log2(ptr) / 4.0);
// Full line is: "kPreString|name = 0x.....;"
size_t len = strlen(kPreString) + name.length() + 5 + ptr_len + 1;
out << kPreString << name << " =";
if (len > 80) out << "\n ";
out << " 0x" << std::hex << ptr << std::dec << ";\n";
}
}
out << "};\n";
// Output in order of roots table
out << "\nstatic constexpr std::array<Tagged_t, " << size
<< "> StaticReadOnlyRootsPointerTable = {\n";
{
#define ENTRY(_1, _2, CamelName) \
out << " StaticReadOnlyRoot::k" << #CamelName << ",\n";
READ_ONLY_ROOT_LIST(ENTRY)
#undef ENTRY
out << "};\n";
}
out << "\n"
<< "} // namespace internal\n"
<< "} // namespace v8\n"
<< "#endif // V8_STATIC_ROOTS_BOOL\n"
<< "#endif // V8_ROOTS_STATIC_ROOTS_H_\n";
}
} // namespace internal
} // namespace v8
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