[llvm] r340860 - [libFuzzer] Port to Windows

[Matt Morehouse via llvm-commits]

Author: morehouse
Date: Tue Aug 28 11:34:32 2018
New Revision: 340860

URL: http://llvm.org/viewvc/llvm-project?rev=340860&view=rev
Log:
[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: morehouse, kcc, eraman

Differential Revision: https://reviews.llvm.org/D51022

Added:
    llvm/trunk/test/Instrumentation/SanitizerCoverage/coff-pc-table-inline-8bit-counters.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp?rev=340860&r1=340859&r2=340860&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp Tue Aug 28 11:34:32 2018
@@ -273,9 +273,15 @@ Function *SanitizerCoverageModule::Creat
   auto SecStart = SecStartEnd.first;
   auto SecEnd = SecStartEnd.second;
   Function *CtorFunc;
+  auto SecStartPtr = IRB.CreatePointerCast(SecStart, Ty);
+  // 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)
+    SecStartPtr = IRB.CreateAdd(SecStartPtr,
+                                ConstantInt::get(IntptrTy, sizeof(uint64_t)));
   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 +403,15 @@ bool SanitizerCoverageModule::runOnModul
     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)});
+    auto SecStartPtr = IRB.CreatePointerCast(SecStartEnd.first, IntptrPtrTy);
+    // 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)
+      SecStartPtr = IRB.CreateAdd(SecStartPtr,
+                                  ConstantInt::get(IntptrTy, sizeof(uint64_t)));
+    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 +821,13 @@ void SanitizerCoverageModule::InjectCove
 
 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;

Added: llvm/trunk/test/Instrumentation/SanitizerCoverage/coff-pc-table-inline-8bit-counters.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/SanitizerCoverage/coff-pc-table-inline-8bit-counters.ll?rev=340860&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/SanitizerCoverage/coff-pc-table-inline-8bit-counters.ll (added)
+++ llvm/trunk/test/Instrumentation/SanitizerCoverage/coff-pc-table-inline-8bit-counters.ll Tue Aug 28 11:34:32 2018
@@ -0,0 +1,12 @@
+; Checks that the PC and 8-bit Counter Arrays are placed in their own sections in COFF binaries.
+; 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-DAG: section ".SCOV{{\$}}CM",
+; CHECK-DAG: section ".SCOVP{{\$}}M",