[CFI] Add CFI-icall pointer type generalization

Summary:
This change allows generalizing pointers in type signatures used for
cfi-icall by enabling the -fsanitize-cfi-icall-generalize-pointers flag.
This works by 1) emitting an additional generalized type signature
metadata node for functions and 2) llvm.type.test()ing for the
generalized type for translation units with the flag specified.

This flag is incompatible with -fsanitize-cfi-cross-dso because it would
require emitting twice as many type hashes which would increase artifact
size.

Reviewers: pcc, eugenis

Reviewed By: pcc

Subscribers: kcc

Differential Revision: https://reviews.llvm.org/D39358

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@317044 91177308-0d34-0410-b5e6-96231b3b80d8

16 files changed, 165 insertions, 16 deletions

diff --git a/docs/ClangCommandLineReference.rst b/docs/ClangCommandLineReference.rst
index 0cc9c71ebe..0a0fce9190 100644
--- a/docs/ClangCommandLineReference.rst
+++ b/docs/ClangCommandLineReference.rst
@@ -740,6 +740,10 @@ Path to blacklist file for sanitizers
 
 Enable control flow integrity (CFI) checks for cross-DSO calls.
 
+.. option:: -fsanitize-cfi-icall-generalize-pointers
+
+Generalize pointers in function type signatures used for Control Flow Integrity (CFI) indirect call checking
+
 .. option:: -fsanitize-coverage=<arg1>,<arg2>..., -fno-sanitize-coverage=<arg1>,<arg2>...
 
 Specify the type of coverage instrumentation for Sanitizers
diff --git a/docs/ControlFlowIntegrity.rst b/docs/ControlFlowIntegrity.rst
index 04fb43a70f..12b4610f8a 100644
--- a/docs/ControlFlowIntegrity.rst
+++ b/docs/ControlFlowIntegrity.rst
@@ -215,6 +215,23 @@ shared library boundaries are handled as if the callee was not compiled with
 
 This scheme is currently only supported on the x86 and x86_64 architectures.
 
+``-fsanitize-cfi-icall-generalize-pointers``
+--------------------------------------------
+
+Mismatched pointer types are a common cause of cfi-icall check failures.
+Translation units compiled with the ``-fsanitize-cfi-icall-generalize-pointers``
+flag relax pointer type checking for call sites in that translation unit,
+applied across all functions compiled with ``-fsanitize=cfi-icall``.
+
+Specifically, pointers in return and argument types are treated as equivalent as
+long as the qualifiers for the type they point to match. For example, ``char*``
+``char**`, and ``int*`` are considered equivalent types. However, ``char*`` and
+``const char*`` are considered separate types.
+
+``-fsanitize-cfi-icall-generalize-pointers`` is not compatible with
+``-fsanitize-cfi-cross-dso``.
+
+
 ``-fsanitize=cfi-icall`` and ``-fsanitize=function``
 ----------------------------------------------------
 
diff --git a/docs/UsersManual.rst b/docs/UsersManual.rst
index 2757ced1c2..023f9f5528 100644
--- a/docs/UsersManual.rst
+++ b/docs/UsersManual.rst
@@ -1147,6 +1147,11 @@ are listed below.
    the behavior of sanitizers in the ``cfi`` group to allow checking
    of cross-DSO virtual and indirect calls.
 
+.. option:: -fsanitize-cfi-icall-generalize-pointers
+
+   Generalize pointers in return and argument types in function type signatures
+   checked by Control Flow Integrity indirect call checking. See
+   :doc:`ControlFlowIntegrity` for more details.
 
 .. option:: -fstrict-vtable-pointers
 
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index eef0eca713..e3476c721a 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -914,6 +914,9 @@ def fno_sanitize_cfi_cross_dso : Flag<["-"], "fno-sanitize-cfi-cross-dso">,
                                  Flags<[CoreOption, DriverOption]>,
                                  Group<f_clang_Group>,
                                  HelpText<"Disable control flow integrity (CFI) checks for cross-DSO calls.">;
+def fsanitize_cfi_icall_generalize_pointers : Flag<["-"], "fsanitize-cfi-icall-generalize-pointers">,
+                                              Group<f_clang_Group>,
+                                              HelpText<"Generalize pointers in CFI indirect call type signature checks">;
 def fsanitize_stats : Flag<["-"], "fsanitize-stats">,
                               Group<f_clang_Group>,
                               HelpText<"Enable sanitizer statistics gathering.">;
diff --git a/include/clang/Driver/SanitizerArgs.h b/include/clang/Driver/SanitizerArgs.h
index 52b6698857..19309c3f3b 100644
--- a/include/clang/Driver/SanitizerArgs.h
+++ b/include/clang/Driver/SanitizerArgs.h
@@ -32,6 +32,7 @@ class SanitizerArgs {
   int MsanTrackOrigins = 0;
   bool MsanUseAfterDtor = false;
   bool CfiCrossDso = false;
+  bool CfiICallGeneralizePointers = false;
   int AsanFieldPadding = 0;
   bool SharedRuntime = false;
   bool AsanUseAfterScope = true;
diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index 8cac8e45c8..8f2aae2f14 100644
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -154,6 +154,8 @@ CODEGENOPT(SanitizeMemoryUseAfterDtor, 1, 0) ///< Enable use-after-delete detect
 CODEGENOPT(SanitizeCfiCrossDso, 1, 0) ///< Enable cross-dso support in CFI.
 CODEGENOPT(SanitizeMinimalRuntime, 1, 0) ///< Use "_minimal" sanitizer runtime for
                                          ///< diagnostics.
+CODEGENOPT(SanitizeCfiICallGeneralizePointers, 1, 0) ///< Generalize pointer types in
+                                                     ///< CFI icall function signatures
 CODEGENOPT(SanitizeCoverageType, 2, 0) ///< Type of sanitizer coverage
                                        ///< instrumentation.
 CODEGENOPT(SanitizeCoverageIndirectCalls, 1, 0) ///< Enable sanitizer coverage
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index d3b03e556f..88116f7d81 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -4475,7 +4475,12 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee
     SanitizerScope SanScope(this);
     EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
 
-    llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
+    llvm::Metadata *MD;
+    if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
+      MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
+    else
+      MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
+
     llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
 
     llvm::Value *CalleePtr = Callee.getFunctionPointer();
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 2254f3e70d..b2a18a03f2 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1152,6 +1152,7 @@ void CodeGenModule::CreateFunctionTypeMetadata(const FunctionDecl *FD,
 
   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
   F->addTypeMetadata(0, MD);
+  F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
 
   // Emit a hash-based bit set entry for cross-DSO calls.
   if (CodeGenOpts.SanitizeCfiCrossDso)
@@ -4543,6 +4544,60 @@ llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
   return InternalId;
 }
 
+// Generalize pointer types to a void pointer with the qualifiers of the
+// originally pointed-to type, e.g. 'const char *' and 'char * const *'
+// generalize to 'const void *' while 'char *' and 'const char **' generalize to
+// 'void *'.
+static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
+  if (!Ty->isPointerType())
+    return Ty;
+
+  return Ctx.getPointerType(
+      QualType(Ctx.VoidTy).withCVRQualifiers(
+          Ty->getPointeeType().getCVRQualifiers()));
+}
+
+// Apply type generalization to a FunctionType's return and argument types
+static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
+  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
+    SmallVector<QualType, 8> GeneralizedParams;
+    for (auto &Param : FnType->param_types())
+      GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
+
+    return Ctx.getFunctionType(
+        GeneralizeType(Ctx, FnType->getReturnType()),
+        GeneralizedParams, FnType->getExtProtoInfo());
+  }
+
+  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
+    return Ctx.getFunctionNoProtoType(
+        GeneralizeType(Ctx, FnType->getReturnType()));
+
+  llvm_unreachable("Encountered unknown FunctionType");
+}
+
+llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
+  T = GeneralizeFunctionType(getContext(), T);
+
+  llvm::Metadata *&InternalId = GeneralizedMetadataIdMap[T.getCanonicalType()];
+  if (InternalId)
+    return InternalId;
+
+  if (isExternallyVisible(T->getLinkage())) {
+    std::string OutName;
+    llvm::raw_string_ostream Out(OutName);
+    getCXXABI().getMangleContext().mangleTypeName(T, Out);
+    Out << ".generalized";
+
+    InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
+  } else {
+    InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
+                                           llvm::ArrayRef<llvm::Metadata *>());
+  }
+
+  return InternalId;
+}
+
 /// Returns whether this module needs the "all-vtables" type identifier.
 bool CodeGenModule::NeedAllVtablesTypeId() const {
   // Returns true if at least one of vtable-based CFI checkers is enabled and
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 21bab6cfa0..7a47c576c0 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -497,7 +497,9 @@ private:
   /// Mapping from canonical types to their metadata identifiers. We need to
   /// maintain this mapping because identifiers may be formed from distinct
   /// MDNodes.
-  llvm::DenseMap<QualType, llvm::Metadata *> MetadataIdMap;
+  typedef llvm::DenseMap<QualType, llvm::Metadata *> MetadataTypeMap;
+  MetadataTypeMap MetadataIdMap;
+  MetadataTypeMap GeneralizedMetadataIdMap;
 
 public:
   CodeGenModule(ASTContext &C, const HeaderSearchOptions &headersearchopts,
@@ -1209,6 +1211,11 @@ public:
   /// internal identifiers).
   llvm::Metadata *CreateMetadataIdentifierForType(QualType T);
 
+  /// Create a metadata identifier for the generalization of the given type.
+  /// This may either be an MDString (for external identifiers) or a distinct
+  /// unnamed MDNode (for internal identifiers).
+  llvm::Metadata *CreateMetadataIdentifierGeneralized(QualType T);
+
   /// Create and attach type metadata to the given function.
   void CreateFunctionTypeMetadata(const FunctionDecl *FD, llvm::Function *F);
 
diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index 037989680f..32c1c43a5b 100644
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -520,6 +520,13 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     // Without PIE, external function address may resolve to a PLT record, which
     // can not be verified by the target module.
     NeedPIE |= CfiCrossDso;
+    CfiICallGeneralizePointers =
+        Args.hasArg(options::OPT_fsanitize_cfi_icall_generalize_pointers);
+
+    if (CfiCrossDso && CfiICallGeneralizePointers)
+      D.Diag(diag::err_drv_argument_not_allowed_with)
+          << "-fsanitize-cfi-cross-dso"
+          << "-fsanitize-cfi-icall-generalize-pointers";
   }
 
   Stats = Args.hasFlag(options::OPT_fsanitize_stats,
@@ -807,6 +814,9 @@ void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
   if (CfiCrossDso)
     CmdArgs.push_back("-fsanitize-cfi-cross-dso");
 
+  if (CfiICallGeneralizePointers)
+    CmdArgs.push_back("-fsanitize-cfi-icall-generalize-pointers");
+
   if (Stats)
     CmdArgs.push_back("-fsanitize-stats");
 
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 19e26c18bf..2c0d99b4be 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -839,6 +839,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
                    false);
   Opts.SanitizeMinimalRuntime = Args.hasArg(OPT_fsanitize_minimal_runtime);
   Opts.SanitizeCfiCrossDso = Args.hasArg(OPT_fsanitize_cfi_cross_dso);
+  Opts.SanitizeCfiICallGeneralizePointers =
+      Args.hasArg(OPT_fsanitize_cfi_icall_generalize_pointers);
   Opts.SanitizeStats = Args.hasArg(OPT_fsanitize_stats);
   if (Arg *A = Args.getLastArg(OPT_fsanitize_address_use_after_scope,
                                OPT_fno_sanitize_address_use_after_scope)) {
diff --git a/test/CodeGen/cfi-icall-cross-dso.c b/test/CodeGen/cfi-icall-cross-dso.c
index 636a9e4aed..43ab0e73b1 100644
--- a/test/CodeGen/cfi-icall-cross-dso.c
+++ b/test/CodeGen/cfi-icall-cross-dso.c
@@ -46,7 +46,7 @@ void caller(void (*f)()) {
 // Check that we emit both string and hash based type entries for static void g(),
 // and don't emit them for the declaration of h().
 
-// CHECK: define internal void @g({{.*}} !type [[TVOID:![0-9]+]] !type [[TVOID_ID:![0-9]+]]
+// CHECK: define internal void @g({{.*}} !type [[TVOID:![0-9]+]] !type [[TVOID_GENERALIZED:![0-9]+]] !type [[TVOID_ID:![0-9]+]]
 static void g(void) {}
 
 // CHECK: declare void @h({{[^!]*$}}
@@ -60,9 +60,9 @@ Fn h1() {
   return &h;
 }
 
-// CHECK: define void @bar({{.*}} !type [[TNOPROTO:![0-9]+]] !type [[TNOPROTO_ID:![0-9]+]]
+// CHECK: define void @bar({{.*}} !type [[TNOPROTO:![0-9]+]] !type [[TNOPROTO_GENERALIZED:![0-9]+]] !type [[TNOPROTO_ID:![0-9]+]]
 // ITANIUM: define available_externally void @foo({{[^!]*$}}
-// MS: define linkonce_odr void @foo({{.*}} !type [[TNOPROTO]] !type [[TNOPROTO_ID]]
+// MS: define linkonce_odr void @foo({{.*}} !type [[TNOPROTO]] !type [[TNOPROTO_GENERALIZED:![0-9]+]] !type [[TNOPROTO_ID]]
 inline void foo() {}
 void bar() { foo(); }
 
@@ -71,11 +71,15 @@ void bar() { foo(); }
 // Check that the type entries are correct.
 
 // ITANIUM: [[TVOID]] = !{i64 0, !"_ZTSFvvE"}
+// ITANIUM: [[TVOID_GENERALIZED]] = !{i64 0, !"_ZTSFvvE.generalized"}
 // ITANIUM: [[TVOID_ID]] = !{i64 0, i64 9080559750644022485}
 // ITANIUM: [[TNOPROTO]] = !{i64 0, !"_ZTSFvE"}
+// ITANIUM: [[TNOPROTO_GENERALIZED]] = !{i64 0, !"_ZTSFvE.generalized"}
 // ITANIUM: [[TNOPROTO_ID]] = !{i64 0, i64 6588678392271548388}
 
 // MS: [[TVOID]] = !{i64 0, !"?6AXXZ"}
+// MS: [[TVOID_GENERALIZED]] = !{i64 0, !"?6AXXZ.generalized"}
 // MS: [[TVOID_ID]] = !{i64 0, i64 5113650790573562461}
 // MS: [[TNOPROTO]] = !{i64 0, !"?6AX@Z"}
+// MS: [[TNOPROTO_GENERALIZED]] = !{i64 0, !"?6AX@Z.generalized"}
 // MS: [[TNOPROTO_ID]] = !{i64 0, i64 4195979634929632483}
diff --git a/test/CodeGen/cfi-icall-generalize.c b/test/CodeGen/cfi-icall-generalize.c
new file mode 100644
index 0000000000..c7c7b30a7a
--- /dev/null
+++ b/test/CodeGen/cfi-icall-generalize.c
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fsanitize=cfi-icall -fsanitize-trap=cfi-icall -emit-llvm -o - %s | FileCheck --check-prefix=CHECK --check-prefix=UNGENERALIZED %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux -fsanitize=cfi-icall -fsanitize-trap=cfi-icall -fsanitize-cfi-icall-generalize-pointers -emit-llvm -o - %s | FileCheck --check-prefix=CHECK --check-prefix=GENERALIZED %s
+
+// Test that const char* is generalized to const void* and that const char** is
+// generalized to void*
+
+// CHECK: define i32** @f({{.*}} !type [[TYPE:![0-9]+]] !type [[TYPE_GENERALIZED:![0-9]+]]
+int** f(const char *a, const char **b) {
+  return (int**)0;
+}
+
+void g(int** (*fp)(const char *, const char **)) {
+  // UNGENERALIZED: call i1 @llvm.type.test(i8* {{.*}}, metadata !"_ZTSFPPiPKcPS2_E")
+  // GENERALIZED: call i1 @llvm.type.test(i8* {{.*}}, metadata !"_ZTSFPvPKvS_E.generalized")
+  fp(0, 0);
+}
+
+// CHECK: [[TYPE]] = !{i64 0, !"_ZTSFPPiPKcPS2_E"}
+// CHECK: [[TYPE_GENERALIZED]] = !{i64 0, !"_ZTSFPvPKvS_E.generalized"}
diff --git a/test/CodeGen/cfi-icall.c b/test/CodeGen/cfi-icall.c
index ed34f4f44b..5f346b66e8 100644
--- a/test/CodeGen/cfi-icall.c
+++ b/test/CodeGen/cfi-icall.c
@@ -3,22 +3,26 @@
 
 // Tests that we assign appropriate identifiers to unprototyped functions.
 
-// CHECK: define void @f({{.*}} !type [[TVOID:![0-9]+]]
+// CHECK: define void @f({{.*}} !type [[TVOID:![0-9]+]] !type [[TVOID_GENERALIZED:![0-9]+]]
 void f() {
 }
 
 void xf();
 
-// CHECK: define void @g({{.*}} !type [[TINT:![0-9]+]]
+// CHECK: define void @g({{.*}} !type [[TINT:![0-9]+]] !type [[TINT_GENERALIZED:![0-9]+]]
 void g(int b) {
   void (*fp)() = b ? f : xf;
   // ITANIUM: call i1 @llvm.type.test(i8* {{.*}}, metadata !"_ZTSFvE")
   fp();
 }
 
-// CHECK: declare !type [[TVOID:![0-9]+]] void @xf({{.*}}
+// CHECK: declare !type [[TVOID]] !type [[TVOID_GENERALIZED]] void @xf({{.*}}
 
 // ITANIUM-DAG: [[TVOID]] = !{i64 0, !"_ZTSFvE"}
+// ITANIUM-DAG: [[TVOID_GENERALIZED]] = !{i64 0, !"_ZTSFvE.generalized"}
 // ITANIUM-DAG: [[TINT]] = !{i64 0, !"_ZTSFviE"}
+// ITANIUM-DAG: [[TINT_GENERALIZED]] = !{i64 0, !"_ZTSFviE.generalized"}
 // MS-DAG: [[TVOID]] = !{i64 0, !"?6AX@Z"}
+// MS-DAG: [[TVOID_GENERALIZED]] = !{i64 0, !"?6AX@Z.generalized"}
 // MS-DAG: [[TINT]] = !{i64 0, !"?6AXH@Z"}
+// MS-DAG: [[TINT_GENERALIZED]] = !{i64 0, !"?6AXH@Z.generalized"}
diff --git a/test/CodeGenCXX/cfi-icall.cpp b/test/CodeGenCXX/cfi-icall.cpp
index c3c6ed309c..5f5778fc1f 100644
--- a/test/CodeGenCXX/cfi-icall.cpp
+++ b/test/CodeGenCXX/cfi-icall.cpp
@@ -8,19 +8,22 @@ namespace {
 
 struct S {};
 
-void f(S *s) {
+void f(S s) {
 }
 
 }
 
 void g() {
-  void (*fp)(S *) = f;
-  // CHECK: call i1 @llvm.type.test(i8* {{.*}}, metadata [[VOIDS:![0-9]+]])
-  fp(0);
+  struct S s;
+  void (*fp)(S) = f;
+  // CHECK: call i1 @llvm.type.test(i8* {{.*}}, metadata [[VOIDS1:![0-9]+]])
+  fp(s);
 }
 
-// ITANIUM: define internal void @_ZN12_GLOBAL__N_11fEPNS_1SE({{.*}} !type [[TS:![0-9]+]]
-// MS: define internal void @"\01?f@?A@@YAXPEAUS@?A@@@Z"({{.*}} !type [[TS:![0-9]+]]
+// ITANIUM: define internal void @_ZN12_GLOBAL__N_11fENS_1SE({{.*}} !type [[TS1:![0-9]+]] !type [[TS2:![0-9]+]]
+// MS: define internal void @"\01?f@?A@@YAXUS@?A@@@Z"({{.*}} !type [[TS1:![0-9]+]] !type [[TS2:![0-9]+]]
 
-// CHECK: [[VOIDS]] = distinct !{}
-// CHECK: [[TS]] = !{i64 0, [[VOIDS]]}
+// CHECK: [[VOIDS1]] = distinct !{}
+// CHECK: [[TS1]] = !{i64 0, [[VOIDS1]]}
+// CHECK: [[TS2]] = !{i64 0, [[VOIDS2:![0-9]+]]}
+// CHECK: [[VOIDS2]] = distinct !{}
diff --git a/test/Driver/fsanitize.c b/test/Driver/fsanitize.c
index 92d5c5da72..dcca96ff3a 100644
--- a/test/Driver/fsanitize.c
+++ b/test/Driver/fsanitize.c
@@ -480,6 +480,14 @@
 // CHECK-CFI-NO-CROSS-DSO: -emit-llvm-bc
 // CHECK-CFI-NO-CROSS-DSO-NOT: -fsanitize-cfi-cross-dso
 
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi-icall -fsanitize-cfi-icall-generalize-pointers -fvisibility=hidden -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-GENERALIZE-POINTERS
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi-icall -fvisibility=hidden -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-CFI-GENERALIZE-POINTERS
+// CHECK-CFI-GENERALIZE-POINTERS: -fsanitize-cfi-icall-generalize-pointers
+// CHECK-NO-CFI-GENERALIZE-POINTERS-NOT: -fsanitize-cfi-icall-generalize-pointers
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi-icall -fsanitize-cfi-icall-generalize-pointers -fsanitize-cfi-cross-dso -fvisibility=hidden -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-GENERALIZE-AND-CROSS-DSO
+// CHECK-CFI-GENERALIZE-AND-CROSS-DSO: error: invalid argument '-fsanitize-cfi-cross-dso' not allowed with '-fsanitize-cfi-icall-generalize-pointers'
+
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi -fsanitize-stats -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-STATS
 // CHECK-CFI-STATS: -fsanitize-stats