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/*
* Copyright 2016 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wasm-emscripten.h"
#include <sstream>
#include "asm_v_wasm.h"
#include "asmjs/shared-constants.h"
#include "ir/import-utils.h"
#include "ir/literal-utils.h"
#include "ir/module-utils.h"
#include "shared-constants.h"
#include "support/debug.h"
#include "wasm-builder.h"
#include "wasm-traversal.h"
#include "wasm.h"
#define DEBUG_TYPE "emscripten"
namespace wasm {
void addExportedFunction(Module& wasm, Function* function) {
wasm.addFunction(function);
auto export_ = new Export;
export_->name = export_->value = function->name;
export_->kind = ExternalKind::Function;
wasm.addExport(export_);
}
// TODO(sbc): There should probably be a better way to do this.
bool isExported(Module& wasm, Name name) {
for (auto& ex : wasm.exports) {
if (ex->value == name) {
return true;
}
}
return false;
}
Global* getStackPointerGlobal(Module& wasm) {
// Assumption: The stack pointer is either imported as __stack_pointer or
// we just assume it's the first non-imported global.
// TODO(sbc): Find a better way to discover the stack pointer. Perhaps the
// linker could export it by name?
for (auto& g : wasm.globals) {
if (g->imported() && g->base == STACK_POINTER) {
return g.get();
}
}
for (auto& g : wasm.globals) {
if (!g->imported()) {
return g.get();
}
}
return nullptr;
}
const Address UNKNOWN_OFFSET(uint32_t(-1));
std::string escape(std::string code) {
// replace newlines quotes with escaped newlines
size_t curr = 0;
while ((curr = code.find("\\n", curr)) != std::string::npos) {
code = code.replace(curr, 2, "\\\\n");
curr += 3; // skip this one
}
curr = 0;
while ((curr = code.find("\\t", curr)) != std::string::npos) {
code = code.replace(curr, 2, "\\\\t");
curr += 3; // skip this one
}
// replace double quotes with escaped single quotes
curr = 0;
while ((curr = code.find('"', curr)) != std::string::npos) {
if (curr == 0 || code[curr - 1] != '\\') {
code = code.replace(curr,
1,
"\\"
"\"");
curr += 2; // skip this one
} else { // already escaped, escape the slash as well
code = code.replace(curr,
1,
"\\"
"\\"
"\"");
curr += 3; // skip this one
}
}
return code;
}
class StringConstantTracker {
public:
StringConstantTracker(Module& wasm) : wasm(wasm) { calcSegmentOffsets(); }
const char* stringAtAddr(Address address) {
for (unsigned i = 0; i < wasm.dataSegments.size(); ++i) {
auto& segment = wasm.dataSegments[i];
Address offset = segmentOffsets[i];
if (offset != UNKNOWN_OFFSET && address >= offset &&
address < offset + segment->data.size()) {
return &segment->data[address - offset];
}
}
Fatal() << "unable to find data for ASM/EM_JS const at: " << address;
return nullptr;
}
std::vector<Address> segmentOffsets; // segment index => address offset
private:
void calcSegmentOffsets() {
std::unordered_map<Name, Address> passiveOffsets;
if (wasm.features.hasBulkMemory()) {
// Fetch passive segment offsets out of memory.init instructions
struct OffsetSearcher : PostWalker<OffsetSearcher> {
std::unordered_map<Name, Address>& offsets;
OffsetSearcher(std::unordered_map<Name, Address>& offsets)
: offsets(offsets) {}
void visitMemoryInit(MemoryInit* curr) {
// The desitination of the memory.init is either a constant
// or the result of an addition with __memory_base in the
// case of PIC code.
auto* dest = curr->dest->dynCast<Const>();
if (!dest) {
auto* add = curr->dest->dynCast<Binary>();
if (!add) {
return;
}
dest = add->left->dynCast<Const>();
if (!dest) {
return;
}
}
auto it = offsets.find(curr->segment);
if (it != offsets.end()) {
Fatal() << "Cannot get offset of passive segment initialized "
"multiple times";
}
offsets[curr->segment] = dest->value.getInteger();
}
} searcher(passiveOffsets);
searcher.walkModule(&wasm);
}
for (unsigned i = 0; i < wasm.dataSegments.size(); ++i) {
auto& segment = wasm.dataSegments[i];
if (segment->isPassive) {
auto it = passiveOffsets.find(segment->name);
if (it != passiveOffsets.end()) {
segmentOffsets.push_back(it->second);
} else {
// This was a non-constant offset (perhaps TLS)
segmentOffsets.push_back(UNKNOWN_OFFSET);
}
} else if (auto* addrConst = segment->offset->dynCast<Const>()) {
auto address = addrConst->value.getUnsigned();
segmentOffsets.push_back(address);
} else {
// TODO(sbc): Wasm shared libraries have data segments with non-const
// offset.
segmentOffsets.push_back(0);
}
}
}
Module& wasm;
};
struct AsmConst {
Address id;
std::string code;
};
} // namespace wasm
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