Revert r227247 and r227228: "Add weak symbol support to RuntimeDyld".

This has wider implications than I expected when I reviewed the patch: It can
cause JIT crashes where clients have used the default value for AbortOnFailure
during symbol lookup. I'm currently investigating alternative approaches and I
hope to have this back in tree soon.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227287 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Lang Hames 2015-01-28 01:30:37 +00:00
parent e0f25c2962
commit 2edbad28d2
7 changed files with 2 additions and 94 deletions

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@ -168,7 +168,6 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
uint32_t Flags = I->getFlags();
bool IsCommon = Flags & SymbolRef::SF_Common;
bool IsWeak = Flags & SymbolRef::SF_Weak;
if (IsCommon)
CommonSymbols.push_back(*I);
else {
@ -189,11 +188,6 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
continue;
StringRef SectionData;
Check(SI->getContents(SectionData));
// TODO: It make make sense to delay emitting the section for weak
// symbols until they are actually required, but that's not possible
// currently, because we only know whether we will need the symbol
// in resolveRelocations, which happens after we have already finalized
// the Load.
bool IsCode = SI->isText();
unsigned SectionID =
findOrEmitSection(Obj, *SI, IsCode, LocalSections);
@ -204,11 +198,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
SymbolInfo::Visibility Vis =
(Flags & SymbolRef::SF_Exported) ?
SymbolInfo::Default : SymbolInfo::Hidden;
if (!IsWeak) {
GlobalSymbolTable[Name] = SymbolInfo(SectionID, SectOffset, Vis);
} else {
WeakSymbolTable[Name] = SymbolInfo(SectionID, SectOffset, Vis);
}
GlobalSymbolTable[Name] = SymbolInfo(SectionID, SectOffset, Vis);
}
}
}
@ -778,21 +768,6 @@ void RuntimeDyldImpl::resolveExternalSymbols() {
SymInfo.getOffset();
}
// If we didn't find the symbol yet, and it is present in the weak symbol
// table, the definition from this object file needs to be used, so emit
// it now
if (!Addr) {
RTDyldSymbolTable::const_iterator Loc = WeakSymbolTable.find(Name);
if (Loc != WeakSymbolTable.end()) {
SymbolInfo SymInfo = Loc->second;
Addr = getSectionLoadAddress(SymInfo.getSectionID()) + SymInfo.getOffset();
// Since the weak symbol is now, materialized, add it to the
// GlobalSymbolTable. If somebody later asks the ExecutionEngine
// for the address of this symbol that's where it'll look
GlobalSymbolTable[Name] = SymInfo;
}
}
// FIXME: Implement error handling that doesn't kill the host program!
if (!Addr)
report_fatal_error("Program used external function '" + Name +
@ -809,7 +784,6 @@ void RuntimeDyldImpl::resolveExternalSymbols() {
ExternalSymbolRelocations.erase(i);
}
WeakSymbolTable.clear();
}
//===----------------------------------------------------------------------===//

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@ -947,7 +947,6 @@ relocation_iterator RuntimeDyldELF::processRelocationRef(
break;
}
case SymbolRef::ST_Data:
case SymbolRef::ST_Function:
case SymbolRef::ST_Unknown: {
Value.SymbolName = TargetName.data();
Value.Addend = Addend;

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@ -203,9 +203,6 @@ protected:
// A global symbol table for symbols from all loaded modules.
RTDyldSymbolTable GlobalSymbolTable;
// Like the global symbol table but for weak symbols
RTDyldSymbolTable WeakSymbolTable;
// Keep a map of common symbols to their info pairs
typedef std::vector<SymbolRef> CommonSymbolList;

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@ -1,6 +1,5 @@
set(LLVM_LINK_COMPONENTS
Analysis
AsmParser
Core
ExecutionEngine
IPO

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@ -13,7 +13,6 @@
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/MCJIT.h"
#include "llvm/Support/DynamicLibrary.h"
#include "MCJITTestBase.h"
#include "gtest/gtest.h"
@ -200,45 +199,4 @@ TEST_F(MCJITTest, multiple_decl_lookups) {
EXPECT_EQ(A, B) << "Repeat calls to getPointerToFunction fail.";
}
// Test weak symbol linking when the weak symbol is present in a shared
// library
TEST_F(MCJITTest, weak_symbol_present) {
SKIP_UNSUPPORTED_PLATFORM;
int FakeWeakSymbol;
llvm::sys::DynamicLibrary::AddSymbol("FakeWeakSymbol", &FakeWeakSymbol);
createJITFromAssembly(
"$FakeWeakSymbol = comdat any\n"
"@FakeWeakSymbol = linkonce_odr global i32 42, comdat, align 4\n"
"define i32 @weak_test(i32* %arg) {\n"
" %r = icmp eq i32* %arg, @FakeWeakSymbol\n"
" %ret = zext i1 %r to i32\n"
" ret i32 %ret\n"
" }");
uint64_t Addr = TheJIT->getFunctionAddress("weak_test");;
EXPECT_TRUE(Addr != 0);
int32_t(*FuncPtr)(int32_t *) = (int32_t(*)(int32_t *))Addr;
EXPECT_EQ(FuncPtr(&FakeWeakSymbol),1);
EXPECT_TRUE(TheJIT->getGlobalValueAddress("FakeWeakSymbol") == 0);
}
// Test weak symbol linking when the weak symbol is not present in a
// shared library
TEST_F(MCJITTest, weak_symbol_absent) {
SKIP_UNSUPPORTED_PLATFORM;
SMDiagnostic Error;
createJITFromAssembly(
" $FakeWeakSymbol2 = comdat any\n"
" @FakeWeakSymbol2 = linkonce_odr global i32 42, comdat, align 4\n"
" define i32* @get_weak() {\n"
" ret i32* @FakeWeakSymbol2\n"
" }\n");
void*(*FuncPtr)() =
(void*(*)(void))TheJIT->getFunctionAddress("get_weak");
EXPECT_EQ(FuncPtr(),(void*)TheJIT->getGlobalValueAddress("FakeWeakSymbol2"));
}
}

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@ -18,7 +18,6 @@
#define LLVM_UNITTESTS_EXECUTIONENGINE_MCJIT_MCJITTESTBASE_H
#include "MCJITTestAPICommon.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/Config/config.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/SectionMemoryManager.h"
@ -28,8 +27,6 @@
#include "llvm/IR/Module.h"
#include "llvm/IR/TypeBuilder.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
@ -341,22 +338,6 @@ protected:
assert(TheJIT.get() != NULL && "error creating MCJIT with EngineBuilder");
}
void createJITFromAssembly(const char *Test) {
SMDiagnostic Error;
M = parseAssemblyString(Test, Error, Context);
M->setTargetTriple(Triple::normalize(BuilderTriple));
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());
createJIT(std::move(M));
}
CodeGenOpt::Level OptLevel;
Reloc::Model RelocModel;
CodeModel::Model CodeModel;

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@ -9,7 +9,7 @@
LEVEL = ../../..
TESTNAME = MCJIT
LINK_COMPONENTS := core asmparser ipo mcjit native support
LINK_COMPONENTS := core ipo mcjit native support
include $(LEVEL)/Makefile.config
include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest