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[SanitizerCoverage][NFC] Use appendToUsed instead of include 

Summary:
Use appendToUsed instead of include to ensure that
SanitizerCoverage's constructors are not stripped.

Also, use isOSBinFormatCOFF() to determine if target
binary format is COFF.

Reviewers: pcc

Reviewed By: pcc

Subscribers: hiraditya

Differential Revision: https://reviews.llvm.org/D56369

llvm-svn: 351118
This commit is contained in:
Jonathan Metzman 2019-01-14 21:02:02 +00:00
parent 6e39af016f
commit e159a0dd1a
2 changed files with 18 additions and 16 deletions
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23
llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
View File

@ -264,7 +264,7 @@ SanitizerCoverageModule::CreateSecStartEnd(Module &M, const char *Section,
SecEnd->setVisibility(GlobalValue::HiddenVisibility);
IRBuilder<> IRB(M.getContext());
Value *SecEndPtr = IRB.CreatePointerCast(SecEnd, Ty);
if (TargetTriple.getObjectFormat() != Triple::COFF)
if (!TargetTriple.isOSBinFormatCOFF())
return std::make_pair(IRB.CreatePointerCast(SecStart, Ty), SecEndPtr);
// Account for the fact that on windows-msvc __start_* symbols actually
@ -293,24 +293,15 @@ Function *SanitizerCoverageModule::CreateInitCallsForSections(
appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority);
}
if (TargetTriple.getObjectFormat() == Triple::COFF) {
if (TargetTriple.isOSBinFormatCOFF()) {
// In COFF files, if the contructors are set as COMDAT (they are because
// COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced
// functions and data) is used, the constructors get stripped. To prevent
// this, give the constructors weak ODR linkage and tell the linker to
// always include the sancov constructor. This way the linker can
// deduplicate the constructors but always leave one copy.
// this, give the constructors weak ODR linkage and ensure the linker knows
// to include the sancov constructor. This way the linker can deduplicate
// the constructors but always leave one copy.
CtorFunc->setLinkage(GlobalValue::WeakODRLinkage);
SmallString<20> PartialIncDirective("/include:");
// Get constructor's mangled name in order to support i386.
SmallString<40> MangledName;
Mangler().getNameWithPrefix(MangledName, CtorFunc, true);
Twine IncDirective = PartialIncDirective + MangledName;
Metadata *Args[1] = {MDString::get(*C, IncDirective.str())};
MDNode *MetadataNode = MDNode::get(*C, Args);
NamedMDNode *NamedMetadata =
M.getOrInsertNamedMetadata("llvm.linker.options");
NamedMetadata->addOperand(MetadataNode);
appendToUsed(M, CtorFunc);
}
return CtorFunc;
}
@ -833,7 +824,7 @@ void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
std::string
SanitizerCoverageModule::getSectionName(const std::string &Section) const {
if (TargetTriple.getObjectFormat() == Triple::COFF) {
if (TargetTriple.isOSBinFormatCOFF()) {
if (Section == SanCovCountersSectionName)
return ".SCOV$CM";
if (Section == SanCovPCsSectionName)

11
llvm/test/Instrumentation/SanitizerCoverage/coff-used-ctor.ll Normal file
View File

@ -0,0 +1,11 @@
; Checks that sancov.module_ctor is marked used.
; RUN: opt < %s -sancov -sanitizer-coverage-level=1 -sanitizer-coverage-inline-8bit-counters=1 -sanitizer-coverage-pc-table=1 -S | FileCheck %s
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc19.14.26433"
define void @foo() {
entry:
ret void
}
; CHECK: @llvm.used = appending global {{.*}} @sancov.module_ctor