Skip to content

Import utils cleanup #1226

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kripken merged 1 commit into from
Oct 17, 2017
Merged

Import utils cleanup #1226

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions src/ast/import-utils.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,13 +25,13 @@ namespace wasm {
namespace ImportUtils {
// find an import by the module.base that is being imported.
// return the internal name
inline Name getImport(Module& wasm, Name module, Name base) {
inline Import* getImport(Module& wasm, Name module, Name base) {
for (auto& import : wasm.imports) {
if (import->module == module && import->base == base) {
return import->name;
return import.get();
}
}
return Name();
return nullptr;
}
};

Expand Down
15 changes: 9 additions & 6 deletions src/passes/SafeHeap.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -114,8 +114,9 @@ struct SafeHeap : public Pass {

void addImports(Module* module) {
// imports
dynamicTopPtr = ImportUtils::getImport(*module, ENV, DYNAMICTOP_PTR_IMPORT);
if (!dynamicTopPtr.is()) {
if (auto* existing = ImportUtils::getImport(*module, ENV, DYNAMICTOP_PTR_IMPORT)) {
dynamicTopPtr = existing->name;
} else {
auto* import = new Import;
import->name = dynamicTopPtr = DYNAMICTOP_PTR_IMPORT;
import->module = ENV;
Expand All @@ -124,8 +125,9 @@ struct SafeHeap : public Pass {
import->globalType = i32;
module->addImport(import);
}
segfault = ImportUtils::getImport(*module, ENV, SEGFAULT_IMPORT);
if (!segfault.is()) {
if (auto* existing = ImportUtils::getImport(*module, ENV, SEGFAULT_IMPORT)) {
dynamicTopPtr = existing->name;
} else {
auto* import = new Import;
import->name = segfault = SEGFAULT_IMPORT;
import->module = ENV;
Expand All @@ -134,8 +136,9 @@ struct SafeHeap : public Pass {
import->functionType = ensureFunctionType("v", module)->name;
module->addImport(import);
}
alignfault = ImportUtils::getImport(*module, ENV, ALIGNFAULT_IMPORT);
if (!alignfault.is()) {
if (auto* existing = ImportUtils::getImport(*module, ENV, ALIGNFAULT_IMPORT)) {
dynamicTopPtr = existing->name;
} else {
auto* import = new Import;
import->name = alignfault = ALIGNFAULT_IMPORT;
import->module = ENV;
Expand Down
60 changes: 38 additions & 22 deletions src/tools/wasm-ctor-eval.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,8 @@
#include "wasm-builder.h"
#include "ast/memory-utils.h"
#include "ast/global-utils.h"
#include "ast/import-utils.h"
#include "ast/literal-utils.h"

using namespace wasm;

Expand Down Expand Up @@ -78,11 +80,6 @@ class EvallingGlobalManager {
}
throw FailToEvalException(std::string("tried to access a dangerous (import-initialized) global: ") + name.str + extra);
}
if (sealed) {
if (globals.find(name) == globals.end()) {
throw FailToEvalException(std::string("tried to access missing global: ") + name.str);
}
}
return globals[name];
}

Expand Down Expand Up @@ -114,6 +111,13 @@ class EvallingGlobalManager {
}
};

enum {
// put the stack in some ridiculously high location
STACK_START = 0x40000000,
// use a ridiculously large stack size
STACK_SIZE = 32 * 1024 * 1024
};

class EvallingModuleInstance : public ModuleInstanceBase<EvallingGlobalManager, EvallingModuleInstance> {
public:
EvallingModuleInstance(Module& wasm, ExternalInterface* externalInterface) : ModuleInstanceBase(wasm, externalInterface) {
Expand All @@ -138,13 +142,6 @@ class EvallingModuleInstance : public ModuleInstanceBase<EvallingGlobalManager,
}
}

enum {
// put the stack in some ridiculously high location
STACK_START = 0x40000000,
// use a ridiculously large stack size
STACK_SIZE = 32 * 1024 * 1024
};

std::vector<char> stack;

// create C stack space for us to use. We do *NOT* care about their contents,
Expand All @@ -153,13 +150,6 @@ class EvallingModuleInstance : public ModuleInstanceBase<EvallingGlobalManager,
void setupEnvironment() {
// prepare scratch memory
stack.resize(STACK_SIZE);
// fill usable values for stack imports
if (auto* stackTop = GlobalUtils::getGlobalInitializedToImport(wasm, "env", "STACKTOP")) {
globals[stackTop->name] = Literal(int32_t(STACK_START));
}
if (auto* stackMax = GlobalUtils::getGlobalInitializedToImport(wasm, "env", "STACK_MAX")) {
globals[stackMax->name] = Literal(int32_t(STACK_START));
}
// tell the module to accept writes up to the stack end
auto total = STACK_START + STACK_SIZE;
memorySize = total / Memory::kPageSize;
Expand All @@ -181,6 +171,32 @@ struct CtorEvalExternalInterface : EvallingModuleInstance::ExternalInterface {
}

void importGlobals(EvallingGlobalManager& globals, Module& wasm_) override {
// fill usable values for stack imports, and globals initialized to them
if (auto* stackTop = ImportUtils::getImport(wasm_, "env", "STACKTOP")) {
globals[stackTop->name] = Literal(int32_t(STACK_START));
if (auto* stackTop = GlobalUtils::getGlobalInitializedToImport(wasm_, "env", "STACKTOP")) {
globals[stackTop->name] = Literal(int32_t(STACK_START));
}
}
if (auto* stackMax = ImportUtils::getImport(wasm_, "env", "STACK_MAX")) {
globals[stackMax->name] = Literal(int32_t(STACK_START));
if (auto* stackMax = GlobalUtils::getGlobalInitializedToImport(wasm_, "env", "STACK_MAX")) {
globals[stackMax->name] = Literal(int32_t(STACK_START));
}
}
// fill in fake values for everything else, which is dangerous to use
for (auto& global : wasm_.globals) {
if (globals.find(global->name) == globals.end()) {
globals[global->name] = LiteralUtils::makeLiteralZero(global->type);
}
}
for (auto& import : wasm_.imports) {
if (import->kind == ExternalKind::Global) {
if (globals.find(import->name) == globals.end()) {
globals[import->name] = LiteralUtils::makeLiteralZero(import->globalType);
}
}
}
}

Literal callImport(Import *import, LiteralList& arguments) override {
Expand Down Expand Up @@ -248,9 +264,9 @@ struct CtorEvalExternalInterface : EvallingModuleInstance::ExternalInterface {
template <typename T>
T* getMemory(Address address) {
// if memory is on the stack, use the stack
if (address >= instance->STACK_START) {
Address relative = address - instance->STACK_START;
if (relative + sizeof(T) > instance->STACK_SIZE) {
if (address >= STACK_START) {
Address relative = address - STACK_START;
if (relative + sizeof(T) > STACK_SIZE) {
throw FailToEvalException("stack usage too high");
}
// in range, all is good, use the stack
Expand Down