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#include "WAVM/Runtime/Linker.h"
#include "WAVM/IR/FeatureSpec.h"
#include "WAVM/IR/Module.h"
#include "WAVM/IR/Validate.h"
#include "WAVM/Inline/Assert.h"
#include "WAVM/Logging/Logging.h"
#include "WAVM/Runtime/Runtime.h"
#include "WAVM/RuntimeABI/RuntimeABI.h"
using namespace WAVM;
using namespace WAVM::IR;
using namespace WAVM::Runtime;
Runtime::StubResolver::StubResolver(Compartment* inCompartment,
StubFunctionBehavior inFunctionBehavior,
bool inLogErrorOnStubGeneration,
ResourceQuotaRefParam inResourceQuota)
: compartment(inCompartment)
, resourceQuota(inResourceQuota)
, functionBehavior(inFunctionBehavior)
, logErrorOnStubGeneration(inLogErrorOnStubGeneration)
{
}
bool Runtime::StubResolver::resolve(const std::string& moduleName,
const std::string& exportName,
IR::ExternType type,
Runtime::Object*& outObject)
{
if(logErrorOnStubGeneration)
{
Log::printf(Log::error,
"Generated stub for missing import %s.%s : %s\n",
moduleName.c_str(),
exportName.c_str(),
asString(type).c_str());
}
return generateStub(
moduleName, exportName, type, outObject, compartment, functionBehavior, resourceQuota);
}
bool Runtime::generateStub(const std::string& moduleName,
const std::string& exportName,
IR::ExternType type,
Runtime::Object*& outObject,
Compartment* compartment,
StubFunctionBehavior functionBehavior,
ResourceQuotaRefParam resourceQuota)
{
// If the import couldn't be resolved, stub it in.
switch(type.kind)
{
case IR::ExternKind::function: {
Serialization::ArrayOutputStream codeStream;
OperatorEncoderStream encoder(codeStream);
if(functionBehavior == StubFunctionBehavior::trap)
{
// Generate a function body that just uses the unreachable op to fault if called.
encoder.unreachable();
}
else
{
// Generate a function body that just returns some reasonable zero value.
for(IR::ValueType result : asFunctionType(type).results())
{
switch(result)
{
case IR::ValueType::i32: encoder.i32_const({0}); break;
case IR::ValueType::i64: encoder.i64_const({0}); break;
case IR::ValueType::f32: encoder.f32_const({0.0f}); break;
case IR::ValueType::f64: encoder.f64_const({0.0}); break;
case IR::ValueType::v128: encoder.v128_const({V128{{0, 0}}}); break;
case IR::ValueType::externref:
encoder.ref_null({IR::ReferenceType::externref});
break;
case IR::ValueType::funcref: encoder.ref_null({IR::ReferenceType::funcref}); break;
case IR::ValueType::none:
case IR::ValueType::any:
default: WAVM_UNREACHABLE();
};
}
}
encoder.end();
// Generate a module for the stub function.
IR::Module stubIRModule(FeatureLevel::wavm);
DisassemblyNames stubModuleNames;
stubIRModule.types.push_back(asFunctionType(type));
stubIRModule.functions.defs.push_back({{0}, {}, std::move(codeStream.getBytes()), {}});
stubIRModule.exports.push_back({"importStub", IR::ExternKind::function, 0});
stubModuleNames.functions.push_back(
{"importStub: " + exportName + " (" + asString(asFunctionType(type)) + ")"});
IR::setDisassemblyNames(stubIRModule, stubModuleNames);
if(WAVM_ENABLE_ASSERTS)
{
try
{
std::shared_ptr<IR::ModuleValidationState> moduleValidationState
= IR::createModuleValidationState(stubIRModule);
IR::validatePreCodeSections(*moduleValidationState);
IR::validateCodeSection(*moduleValidationState);
IR::validatePostCodeSections(*moduleValidationState);
}
catch(const ValidationException& exception)
{
Errors::fatalf("Stub module failed validation: %s", exception.message.c_str());
}
}
// Instantiate the module and return the stub function instance.
auto stubModule = compileModule(stubIRModule);
auto stubInstance
= instantiateModule(compartment, stubModule, {}, "importStub", resourceQuota);
if(!stubInstance) { return false; }
outObject = getInstanceExport(stubInstance, "importStub");
WAVM_ASSERT(outObject);
return true;
}
case IR::ExternKind::memory: {
outObject = asObject(Runtime::createMemory(
compartment, asMemoryType(type), std::string(exportName), resourceQuota));
return outObject != nullptr;
}
case IR::ExternKind::table: {
outObject = asObject(Runtime::createTable(
compartment, asTableType(type), nullptr, std::string(exportName), resourceQuota));
return outObject != nullptr;
}
case IR::ExternKind::global: {
outObject = asObject(Runtime::createGlobal(
compartment, asGlobalType(type), std::string(exportName), resourceQuota));
return outObject != nullptr;
}
case IR::ExternKind::exceptionType: {
outObject = asObject(
Runtime::createExceptionType(compartment, asExceptionType(type), "importStub"));
return outObject != nullptr;
}
case IR::ExternKind::invalid:
default: WAVM_UNREACHABLE();
};
}
template<typename Type, typename ResolvedType>
static void linkImport(const IR::Module& module,
const Import<Type>& import,
ResolvedType resolvedType,
Resolver& resolver,
LinkResult& linkResult)
{
// Ask the resolver for a value for this import.
Object* importValue;
if(resolver.resolve(import.moduleName, import.exportName, resolvedType, importValue))
{
// Sanity check that the resolver returned an object of the right type.
WAVM_ASSERT(importValue);
WAVM_ASSERT(importValue->kind == ObjectKind::dynamicLinkingWeakFunctionImport || isA(importValue, resolvedType));
linkResult.resolvedImports.push_back(importValue);
}
else
{
linkResult.missingImports.push_back({import.moduleName, import.exportName, resolvedType});
linkResult.resolvedImports.push_back(nullptr);
}
}
LinkResult Runtime::linkModule(const IR::Module& module, Resolver& resolver)
{
LinkResult linkResult;
WAVM_ASSERT(module.imports.size()
== module.functions.imports.size() + module.tables.imports.size()
+ module.memories.imports.size() + module.globals.imports.size()
+ module.exceptionTypes.imports.size());
for(const auto& kindIndex : module.imports)
{
switch(kindIndex.kind)
{
case ExternKind::function: {
const auto& functionImport = module.functions.imports[kindIndex.index];
linkImport(module,
functionImport,
module.types[functionImport.type.index],
resolver,
linkResult);
break;
}
case ExternKind::table: {
const auto& tableImport = module.tables.imports[kindIndex.index];
linkImport(module, tableImport, tableImport.type, resolver, linkResult);
break;
}
case ExternKind::memory: {
const auto& memoryImport = module.memories.imports[kindIndex.index];
linkImport(module, memoryImport, memoryImport.type, resolver, linkResult);
break;
}
case ExternKind::global: {
const auto& globalImport = module.globals.imports[kindIndex.index];
linkImport(module, globalImport, globalImport.type, resolver, linkResult);
break;
}
case ExternKind::exceptionType: {
const auto& exceptionTypeImport = module.exceptionTypes.imports[kindIndex.index];
linkImport(module, exceptionTypeImport, exceptionTypeImport.type, resolver, linkResult);
break;
}
case ExternKind::invalid:
default: WAVM_UNREACHABLE();
};
}
linkResult.success = linkResult.missingImports.size() == 0;
return linkResult;
}
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