[SanitizerCoverage] Support opaque pointers

Pass element type rather than pointer type to some functions, so we know which type to use for the global variables.
llvm · Jun 28, 2021 · 7ac0442 · 7ac0442
1 parent 6d6f35e
commit 7ac0442
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Showing 2 changed files with 34 additions and 10 deletions.
diff --git a/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -336,12 +336,12 @@ ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section,
                                           ? GlobalVariable::ExternalLinkage
                                           : GlobalVariable::ExternalWeakLinkage;
   GlobalVariable *SecStart =
-      new GlobalVariable(M, Ty->getPointerElementType(), false, Linkage,
-                         nullptr, getSectionStart(Section));
+      new GlobalVariable(M, Ty, false, Linkage, nullptr,
+                         getSectionStart(Section));
   SecStart->setVisibility(GlobalValue::HiddenVisibility);
   GlobalVariable *SecEnd =
-      new GlobalVariable(M, Ty->getPointerElementType(), false, Linkage,
-                         nullptr, getSectionEnd(Section));
+      new GlobalVariable(M, Ty, false, Linkage, nullptr,
+                         getSectionEnd(Section));
   SecEnd->setVisibility(GlobalValue::HiddenVisibility);
   IRBuilder<> IRB(M.getContext());
   if (!TargetTriple.isOSBinFormatCOFF())
@@ -352,7 +352,8 @@ ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section,
   auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy);
   auto GEP = IRB.CreateGEP(Int8Ty, SecStartI8Ptr,
                            ConstantInt::get(IntptrTy, sizeof(uint64_t)));
-  return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEnd);
+  return std::make_pair(IRB.CreatePointerCast(GEP, PointerType::getUnqual(Ty)),
+                        SecEnd);
 }
 
 Function *ModuleSanitizerCoverage::CreateInitCallsForSections(
@@ -362,8 +363,9 @@ Function *ModuleSanitizerCoverage::CreateInitCallsForSections(
   auto SecStart = SecStartEnd.first;
   auto SecEnd = SecStartEnd.second;
   Function *CtorFunc;
+  Type *PtrTy = PointerType::getUnqual(Ty);
   std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions(
-      M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd});
+      M, CtorName, InitFunctionName, {PtrTy, PtrTy}, {SecStart, SecEnd});
   assert(CtorFunc->getName() == CtorName);
 
   if (TargetTriple.supportsCOMDAT()) {
@@ -488,19 +490,19 @@ bool ModuleSanitizerCoverage::instrumentModule(
 
   if (FunctionGuardArray)
     Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName,
-                                      SanCovTracePCGuardInitName, Int32PtrTy,
+                                      SanCovTracePCGuardInitName, Int32Ty,
                                       SanCovGuardsSectionName);
   if (Function8bitCounterArray)
     Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName,
-                                      SanCov8bitCountersInitName, Int8PtrTy,
+                                      SanCov8bitCountersInitName, Int8Ty,
                                       SanCovCountersSectionName);
   if (FunctionBoolArray) {
     Ctor = CreateInitCallsForSections(M, SanCovModuleCtorBoolFlagName,
-                                      SanCovBoolFlagInitName, Int1PtrTy,
+                                      SanCovBoolFlagInitName, Int1Ty,
                                       SanCovBoolFlagSectionName);
   }
   if (Ctor && Options.PCTable) {
-    auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy);
+    auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrTy);
     FunctionCallee InitFunction = declareSanitizerInitFunction(
         M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy});
     IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator());

diff --git a/llvm/test/Instrumentation/SanitizerCoverage/opaque-ptr.ll b/llvm/test/Instrumentation/SanitizerCoverage/opaque-ptr.ll
@@ -0,0 +1,22 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
+; RUN: opt < %s -passes='module(sancov-module)' -sanitizer-coverage-level=1 -force-opaque-pointers -S | FileCheck %s
+
+;.
+; CHECK: @[[__SANCOV_LOWEST_STACK:[a-zA-Z0-9_$"\\.-]+]] = external thread_local(initialexec) global i64
+; CHECK: @[[__SANCOV_GEN_:[a-zA-Z0-9_$"\\.-]+]] = private global [1 x i32] zeroinitializer, section "__sancov_guards", comdat($foo), align 4
+; CHECK: @[[__START___SANCOV_GUARDS:[a-zA-Z0-9_$"\\.-]+]] = extern_weak hidden global i32
+; CHECK: @[[__STOP___SANCOV_GUARDS:[a-zA-Z0-9_$"\\.-]+]] = extern_weak hidden global i32
+; CHECK: @[[LLVM_GLOBAL_CTORS:[a-zA-Z0-9_$"\\.-]+]] = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 2, ptr @sancov.module_ctor_trace_pc_guard, ptr @sancov.module_ctor_trace_pc_guard }]
+; CHECK: @[[LLVM_COMPILER_USED:[a-zA-Z0-9_$"\\.-]+]] = appending global [1 x ptr] [ptr @__sancov_gen_], section "llvm.metadata"
+;.
+define void @foo(i32* %a) {
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:    call void @__sanitizer_cov_trace_pc_guard(ptr @__sancov_gen_) #[[ATTR1:[0-9]+]]
+; CHECK-NEXT:    ret void
+;
+  ret void
+}
+;.
+; CHECK: attributes #[[ATTR0:[0-9]+]] = { nounwind }
+; CHECK: attributes #[[ATTR1]] = { nomerge }
+;.