shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
llvm-project/llvm/unittests/Bitcode/BitReaderTest.cpp
Sebastian Neubauer b56df190b0 [BitcodeReader] Allow reading pointer types from old IR 
When opaque pointers are enabled and old IR with typed pointers is read,
the BitcodeReader automatically upgrades all typed pointers to opaque
pointers. This is a lossy conversion, i.e. when a function argument is a
pointer and unused, it’s impossible to reconstruct the original type
behind the pointer.

There are cases where the type information of pointers is needed. One is
reading DXIL, which is bitcode of old LLVM IR and makes a lot of use of
pointers in function signatures.
We’d like to keep using up-to-date llvm to read in and process DXIL, so
in the face of opaque pointers, we need some way to access the type
information of pointers from the read bitcode.

This patch allows extracting type information by supplying functions to
parseBitcodeFile that get called for each function signature or metadata
value. The function can access the type information via the reader’s
type IDs and the getTypeByID and getContainedTypeID functions.
The tests exemplarily shows how type info from pointers can be stored in
metadata for use after the BitcodeReader finished.

Differential Revision: https://reviews.llvm.org/D127728
2023-01-17 13:19:40 +01:00

463 lines
16 KiB
C++
Raw Blame History

//===- llvm/unittest/Bitcode/BitReaderTest.cpp - Tests for BitReader ------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
std::unique_ptr<Module> parseAssembly(LLVMContext &Context,
const char *Assembly) {
SMDiagnostic Error;
std::unique_ptr<Module> M = parseAssemblyString(Assembly, Error, Context);
std::string ErrMsg;
raw_string_ostream OS(ErrMsg);
Error.print("", OS);
// A failure here means that the test itself is buggy.
if (!M)
report_fatal_error(OS.str().c_str());
return M;
}
static void writeModuleToBuffer(std::unique_ptr<Module> Mod,
SmallVectorImpl<char> &Buffer) {
raw_svector_ostream OS(Buffer);
WriteBitcodeToFile(*Mod, OS);
}
static std::unique_ptr<Module> getLazyModuleFromAssembly(LLVMContext &Context,
SmallString<1024> &Mem,
const char *Assembly) {
writeModuleToBuffer(parseAssembly(Context, Assembly), Mem);
Expected<std::unique_ptr<Module>> ModuleOrErr =
getLazyBitcodeModule(MemoryBufferRef(Mem.str(), "test"), Context);
if (!ModuleOrErr)
report_fatal_error("Could not parse bitcode module");
return std::move(ModuleOrErr.get());
}
// Tests that lazy evaluation can parse functions out of order.
TEST(BitReaderTest, MaterializeFunctionsOutOfOrder) {
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem, "define void @f() {\n"
" unreachable\n"
"}\n"
"define void @g() {\n"
" unreachable\n"
"}\n"
"define void @h() {\n"
" unreachable\n"
"}\n"
"define void @j() {\n"
" unreachable\n"
"}\n");
EXPECT_FALSE(verifyModule(*M, &dbgs()));
Function *F = M->getFunction("f");
Function *G = M->getFunction("g");
Function *H = M->getFunction("h");
Function *J = M->getFunction("j");
// Initially all functions are not materialized (no basic blocks).
EXPECT_TRUE(F->empty());
EXPECT_TRUE(G->empty());
EXPECT_TRUE(H->empty());
EXPECT_TRUE(J->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize h.
ASSERT_FALSE(H->materialize());
EXPECT_TRUE(F->empty());
EXPECT_TRUE(G->empty());
EXPECT_FALSE(H->empty());
EXPECT_TRUE(J->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize g.
ASSERT_FALSE(G->materialize());
EXPECT_TRUE(F->empty());
EXPECT_FALSE(G->empty());
EXPECT_FALSE(H->empty());
EXPECT_TRUE(J->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize j.
ASSERT_FALSE(J->materialize());
EXPECT_TRUE(F->empty());
EXPECT_FALSE(G->empty());
EXPECT_FALSE(H->empty());
EXPECT_FALSE(J->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize f.
ASSERT_FALSE(F->materialize());
EXPECT_FALSE(F->empty());
EXPECT_FALSE(G->empty());
EXPECT_FALSE(H->empty());
EXPECT_FALSE(J->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
}
TEST(BitReaderTest, MaterializeFunctionsStrictFP) {
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem, "define double @foo(double %a) {\n"
" %result = call double @bar(double %a) strictfp\n"
" ret double %result\n"
"}\n"
"declare double @bar(double)\n");
Function *Foo = M->getFunction("foo");
ASSERT_FALSE(Foo->materialize());
EXPECT_FALSE(Foo->empty());
for (auto &BB : *Foo) {
auto It = BB.begin();
while (It != BB.end()) {
Instruction &I = *It;
++It;
if (auto *Call = dyn_cast<CallBase>(&I)) {
EXPECT_FALSE(Call->isStrictFP());
EXPECT_TRUE(Call->isNoBuiltin());
}
}
}
EXPECT_FALSE(verifyModule(*M, &dbgs()));
}
TEST(BitReaderTest, MaterializeConstrainedFPStrictFP) {
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem,
"define double @foo(double %a) {\n"
" %result = call double @llvm.experimental.constrained.sqrt.f64(double "
"%a, metadata !\"round.tonearest\", metadata !\"fpexcept.strict\") "
"strictfp\n"
" ret double %result\n"
"}\n"
"declare double @llvm.experimental.constrained.sqrt.f64(double, "
"metadata, metadata)\n");
Function *Foo = M->getFunction("foo");
ASSERT_FALSE(Foo->materialize());
EXPECT_FALSE(Foo->empty());
for (auto &BB : *Foo) {
auto It = BB.begin();
while (It != BB.end()) {
Instruction &I = *It;
++It;
if (auto *Call = dyn_cast<CallBase>(&I)) {
EXPECT_TRUE(Call->isStrictFP());
EXPECT_FALSE(Call->isNoBuiltin());
}
}
}
EXPECT_FALSE(verifyModule(*M, &dbgs()));
}
TEST(BitReaderTest, MaterializeFunctionsForBlockAddr) { // PR11677
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem, "@table = constant i8* blockaddress(@func, %bb)\n"
"define void @func() {\n"
" unreachable\n"
"bb:\n"
" unreachable\n"
"}\n");
EXPECT_FALSE(verifyModule(*M, &dbgs()));
EXPECT_FALSE(M->getFunction("func")->empty());
}
TEST(BitReaderTest, MaterializeFunctionsForBlockAddrInFunctionBefore) {
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem, "define i8* @before() {\n"
" ret i8* blockaddress(@func, %bb)\n"
"}\n"
"define void @other() {\n"
" unreachable\n"
"}\n"
"define void @func() {\n"
" unreachable\n"
"bb:\n"
" unreachable\n"
"}\n");
EXPECT_TRUE(M->getFunction("before")->empty());
EXPECT_TRUE(M->getFunction("func")->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize @before, pulling in @func.
EXPECT_FALSE(M->getFunction("before")->materialize());
EXPECT_FALSE(M->getFunction("func")->empty());
EXPECT_TRUE(M->getFunction("other")->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
}
TEST(BitReaderTest, MaterializeFunctionsForBlockAddrInFunctionAfter) {
SmallString<1024> Mem;
LLVMContext Context;
std::unique_ptr<Module> M = getLazyModuleFromAssembly(
Context, Mem, "define void @func() {\n"
" unreachable\n"
"bb:\n"
" unreachable\n"
"}\n"
"define void @other() {\n"
" unreachable\n"
"}\n"
"define i8* @after() {\n"
" ret i8* blockaddress(@func, %bb)\n"
"}\n");
EXPECT_TRUE(M->getFunction("after")->empty());
EXPECT_TRUE(M->getFunction("func")->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
// Materialize @after, pulling in @func.
EXPECT_FALSE(M->getFunction("after")->materialize());
EXPECT_FALSE(M->getFunction("func")->empty());
EXPECT_TRUE(M->getFunction("other")->empty());
EXPECT_FALSE(verifyModule(*M, &dbgs()));
}
// Helper function to convert type metadata to a string for testing
static std::string mdToString(Metadata *MD) {
std::string S;
if (auto *VMD = dyn_cast<ValueAsMetadata>(MD)) {
if (VMD->getType()->isPointerTy()) {
S += "ptr";
return S;
}
}
if (auto *TMD = dyn_cast<MDTuple>(MD)) {
S += "!{";
for (unsigned I = 0; I < TMD->getNumOperands(); I++) {
if (I != 0)
S += ", ";
S += mdToString(TMD->getOperand(I).get());
}
S += "}";
} else if (auto *SMD = dyn_cast<MDString>(MD)) {
S += "!'";
S += SMD->getString();
S += "'";
} else if (auto *I = mdconst::dyn_extract<ConstantInt>(MD)) {
S += std::to_string(I->getZExtValue());
} else if (auto *P = mdconst::dyn_extract<PoisonValue>(MD)) {
auto *Ty = P->getType();
if (Ty->isIntegerTy()) {
S += "i";
S += std::to_string(Ty->getIntegerBitWidth());
} else if (Ty->isStructTy()) {
S += "%";
S += Ty->getStructName();
} else {
llvm_unreachable("unhandled poison metadata");
}
} else {
llvm_unreachable("unhandled metadata");
}
return S;
}
// Recursively look into a (pointer) type and the the type.
// For primitive types it's a poison value of the type, for a pointer it's a
// metadata tuple with the addrspace and the referenced type. For a function,
// it's a tuple where the first element is the string "function", the second
// element is the return type or the string "void" and the following elements
// are the argument types.
static Metadata *getTypeMetadataEntry(unsigned TypeID, LLVMContext &Context,
GetTypeByIDTy GetTypeByID,
GetContainedTypeIDTy GetContainedTypeID) {
Type *Ty = GetTypeByID(TypeID);
if (auto *FTy = dyn_cast<FunctionType>(Ty)) {
// Save the function signature as metadata
SmallVector<Metadata *> SignatureMD;
SignatureMD.push_back(MDString::get(Context, "function"));
// Return type
if (FTy->getReturnType()->isVoidTy())
SignatureMD.push_back(MDString::get(Context, "void"));
else
SignatureMD.push_back(getTypeMetadataEntry(GetContainedTypeID(TypeID, 0),
Context, GetTypeByID,
GetContainedTypeID));
// Arguments
for (unsigned I = 0; I != FTy->getNumParams(); ++I)
SignatureMD.push_back(
getTypeMetadataEntry(GetContainedTypeID(TypeID, I + 1), Context,
GetTypeByID, GetContainedTypeID));
return MDTuple::get(Context, SignatureMD);
}
if (!Ty->isPointerTy())
return ConstantAsMetadata::get(PoisonValue::get(Ty));
// Return !{<addrspace>, <inner>} for pointer
SmallVector<Metadata *, 2> MD;
MD.push_back(ConstantAsMetadata::get(ConstantInt::get(
Type::getInt32Ty(Context), Ty->getPointerAddressSpace())));
MD.push_back(getTypeMetadataEntry(GetContainedTypeID(TypeID, 0), Context,
GetTypeByID, GetContainedTypeID));
return MDTuple::get(Context, MD);
}
// Test that when reading bitcode with typed pointers and upgrading them to
// opaque pointers, the type information of function signatures can be extracted
// and stored in metadata.
TEST(BitReaderTest, AccessFunctionTypeInfo) {
SmallString<1024> Mem;
LLVMContext WriteContext;
writeModuleToBuffer(
parseAssembly(
WriteContext,
"define void @func() {\n"
" unreachable\n"
"}\n"
"declare i32 @func_header()\n"
"declare i8* @ret_ptr()\n"
"declare i8* @ret_and_arg_ptr(i32 addrspace(8)*)\n"
"declare i8 addrspace(1)* @double_ptr(i32* addrspace(2)*, i32***)\n"),
Mem);
LLVMContext Context;
Context.setOpaquePointers(true);
ParserCallbacks Callbacks;
// Supply a callback that stores the signature of a function into metadata,
// so that the types behind pointers can be accessed.
// Each function gets a !types metadata, which is a tuple with one element
// for a non-void return type and every argument. For primitive types it's
// a poison value of the type, for a pointer it's a metadata tuple with
// the addrspace and the referenced type.
Callbacks.ValueType = [&](Value *V, unsigned TypeID,
GetTypeByIDTy GetTypeByID,
GetContainedTypeIDTy GetContainedTypeID) {
if (auto *F = dyn_cast<Function>(V)) {
auto *MD = getTypeMetadataEntry(TypeID, F->getContext(), GetTypeByID,
GetContainedTypeID);
F->setMetadata("types", cast<MDNode>(MD));
}
};
Expected<std::unique_ptr<Module>> ModuleOrErr =
parseBitcodeFile(MemoryBufferRef(Mem.str(), "test"), Context, Callbacks);
if (!ModuleOrErr)
report_fatal_error("Could not parse bitcode module");
std::unique_ptr<Module> M = std::move(ModuleOrErr.get());
EXPECT_EQ(mdToString(M->getFunction("func")->getMetadata("types")),
"!{!'function', !'void'}");
EXPECT_EQ(mdToString(M->getFunction("func_header")->getMetadata("types")),
"!{!'function', i32}");
EXPECT_EQ(mdToString(M->getFunction("ret_ptr")->getMetadata("types")),
"!{!'function', !{0, i8}}");
EXPECT_EQ(mdToString(M->getFunction("ret_and_arg_ptr")->getMetadata("types")),
"!{!'function', !{0, i8}, !{8, i32}}");
EXPECT_EQ(mdToString(M->getFunction("double_ptr")->getMetadata("types")),
"!{!'function', !{1, i8}, !{2, !{0, i32}}, !{0, !{0, !{0, i32}}}}");
}
// Test that when reading bitcode with typed pointers and upgrading them to
// opaque pointers, the type information of pointers in metadata can be
// extracted and stored in metadata.
TEST(BitReaderTest, AccessMetadataTypeInfo) {
SmallString<1024> Mem;
LLVMContext WriteContext;
writeModuleToBuffer(
parseAssembly(WriteContext,
"%dx.types.f32 = type { float }\n"
"declare void @main()\n"
"!md = !{!0}\n"
"!md2 = !{!1}\n"
"!0 = !{i32 2, %dx.types.f32 addrspace(1)* undef, void ()* "
"@main, void() addrspace(3)* null}\n"
"!1 = !{i8*(i32* addrspace(2)*) addrspace(4)* undef, "
"i32*** undef}\n"),
Mem);
LLVMContext Context;
Context.setOpaquePointers(true);
ParserCallbacks Callbacks;
// Supply a callback that stores types from metadata,
// so that the types behind pointers can be accessed.
// Non-pointer entries are ignored. Values with a pointer type are
// replaced by a metadata tuple with {original value, type md}. We cannot
// save the metadata outside because after conversion to opaque pointers,
// entries are not distinguishable anymore (e.g. i32* and i8* are both
// upgraded to ptr).
Callbacks.MDType = [&](Metadata **Val, unsigned TypeID,
GetTypeByIDTy GetTypeByID,
GetContainedTypeIDTy GetContainedTypeID) {
auto *OrigVal = cast<ValueAsMetadata>(*Val);
if (OrigVal->getType()->isPointerTy()) {
// Ignore function references, their signature can be saved like
// in the test above
if (!isa<Function>(OrigVal->getValue())) {
SmallVector<Metadata *> Tuple;
Tuple.push_back(OrigVal);
Tuple.push_back(getTypeMetadataEntry(GetContainedTypeID(TypeID, 0),
OrigVal->getContext(), GetTypeByID,
GetContainedTypeID));
*Val = MDTuple::get(OrigVal->getContext(), Tuple);
}
}
};
Expected<std::unique_ptr<Module>> ModuleOrErr =
parseBitcodeFile(MemoryBufferRef(Mem.str(), "test"), Context, Callbacks);
if (!ModuleOrErr)
report_fatal_error("Could not parse bitcode module");
std::unique_ptr<Module> M = std::move(ModuleOrErr.get());
EXPECT_EQ(
mdToString(M->getNamedMetadata("md")->getOperand(0)),
"!{2, !{ptr, %dx.types.f32}, ptr, !{ptr, !{!'function', !'void'}}}");
EXPECT_EQ(mdToString(M->getNamedMetadata("md2")->getOperand(0)),
"!{!{ptr, !{!'function', !{0, i8}, !{2, !{0, i32}}}}, !{ptr, !{0, "
"!{0, i32}}}}");
}
} // end namespace
Reference in New Issue View Git Blame Copy Permalink