[libFuzzer] Port to Windows
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.
Patch By: metzman
Reviewers: morehouse, rnk
Reviewed By: morehouse, rnk
Subscribers: #sanitizers, delcypher, morehouse, kcc, eraman
Differential Revision: https://reviews.llvm.org/D51022
llvm-svn: 341082
diff --git a/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
index c0b219d..1f97e90 100644
--- a/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
+++ b/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -273,9 +273,20 @@
auto SecStart = SecStartEnd.first;
auto SecEnd = SecStartEnd.second;
Function *CtorFunc;
+ Value *SecStartPtr = nullptr;
+ // Account for the fact that on windows-msvc __start_* symbols actually
+ // point to a uint64_t before the start of the array.
+ if (TargetTriple.getObjectFormat() == Triple::COFF) {
+ auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy);
+ auto GEP = IRB.CreateGEP(SecStartI8Ptr,
+ ConstantInt::get(IntptrTy, sizeof(uint64_t)));
+ SecStartPtr = IRB.CreatePointerCast(GEP, Ty);
+ } else {
+ SecStartPtr = IRB.CreatePointerCast(SecStart, Ty);
+ }
std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions(
M, SanCovModuleCtorName, InitFunctionName, {Ty, Ty},
- {IRB.CreatePointerCast(SecStart, Ty), IRB.CreatePointerCast(SecEnd, Ty)});
+ {SecStartPtr, IRB.CreatePointerCast(SecEnd, Ty)});
if (TargetTriple.supportsCOMDAT()) {
// Use comdat to dedup CtorFunc.
@@ -397,9 +408,20 @@
Function *InitFunction = declareSanitizerInitFunction(
M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy});
IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator());
- IRBCtor.CreateCall(InitFunction,
- {IRB.CreatePointerCast(SecStartEnd.first, IntptrPtrTy),
- IRB.CreatePointerCast(SecStartEnd.second, IntptrPtrTy)});
+ Value *SecStartPtr = nullptr;
+ // Account for the fact that on windows-msvc __start_pc_table actually
+ // points to a uint64_t before the start of the PC table.
+ if (TargetTriple.getObjectFormat() == Triple::COFF) {
+ auto SecStartI8Ptr = IRB.CreatePointerCast(SecStartEnd.first, Int8PtrTy);
+ auto GEP = IRB.CreateGEP(SecStartI8Ptr,
+ ConstantInt::get(IntptrTy, sizeof(uint64_t)));
+ SecStartPtr = IRB.CreatePointerCast(GEP, IntptrPtrTy);
+ } else {
+ SecStartPtr = IRB.CreatePointerCast(SecStartEnd.first, IntptrPtrTy);
+ }
+ IRBCtor.CreateCall(
+ InitFunction,
+ {SecStartPtr, IRB.CreatePointerCast(SecStartEnd.second, IntptrPtrTy)});
}
// We don't reference these arrays directly in any of our runtime functions,
// so we need to prevent them from being dead stripped.
@@ -809,8 +831,13 @@
std::string
SanitizerCoverageModule::getSectionName(const std::string &Section) const {
- if (TargetTriple.getObjectFormat() == Triple::COFF)
- return ".SCOV$M";
+ if (TargetTriple.getObjectFormat() == Triple::COFF) {
+ if (Section == SanCovCountersSectionName)
+ return ".SCOV$CM";
+ if (Section == SanCovPCsSectionName)
+ return ".SCOVP$M";
+ return ".SCOV$GM"; // For SanCovGuardsSectionName.
+ }
if (TargetTriple.isOSBinFormatMachO())
return "__DATA,__" + Section;
return "__" + Section;