8 files changed, 68 insertions, 0 deletions
diff --git a/lib/ubsan/lit_tests/CMakeLists.txt b/lib/ubsan/lit_tests/CMakeLists.txt
index 7e1a13c78..6abc8a01e 100644
--- a/lib/ubsan/lit_tests/CMakeLists.txt
+++ b/lib/ubsan/lit_tests/CMakeLists.txt
@@ -8,6 +8,7 @@ if(COMPILER_RT_CAN_EXECUTE_TESTS)
   # working binaries.
   set(UBSAN_TEST_DEPS
     ${SANITIZER_COMMON_LIT_TEST_DEPS}
+    asan
     ${UBSAN_RUNTIME_LIBRARIES})
   set(UBSAN_TEST_PARAMS
     ubsan_site_config=${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
diff --git a/lib/ubsan/lit_tests/TypeCheck/Function/function.cpp b/lib/ubsan/lit_tests/TypeCheck/Function/function.cpp
new file mode 100644
index 000000000..feff0f5aa
--- /dev/null
+++ b/lib/ubsan/lit_tests/TypeCheck/Function/function.cpp
@@ -0,0 +1,17 @@
+// RUN: %clangxx -fsanitize=address,function %s -O3 -g -o %t
+// RUN: %t 2>&1 | FileCheck %s
+
+#include <stdint.h>
+
+void f() {}
+
+void g(int x) {}
+
+int main(void) {
+  // CHECK: runtime error: call to function f() through pointer to incorrect function type 'void (*)(int)'
+  // CHECK-NEXT: function.cpp:6: note: f() defined here
+  reinterpret_cast<void (*)(int)>(reinterpret_cast<uintptr_t>(f))(42);
+
+  // CHECK-NOT: runtime error: call to function g
+  reinterpret_cast<void (*)(int)>(reinterpret_cast<uintptr_t>(g))(42);
+}
diff --git a/lib/ubsan/lit_tests/TypeCheck/Function/lit.local.cfg b/lib/ubsan/lit_tests/TypeCheck/Function/lit.local.cfg
new file mode 100644
index 000000000..27c61a343
--- /dev/null
+++ b/lib/ubsan/lit_tests/TypeCheck/Function/lit.local.cfg
@@ -0,0 +1,3 @@
+# The function type checker is only supported on x86 and x86_64 for now.
+if config.root.host_arch not in ['x86', 'x86_64']:
+  config.unsupported = True
diff --git a/lib/ubsan/lit_tests/lit.cfg b/lib/ubsan/lit_tests/lit.cfg
index 4a5bc237b..d96912fe8 100644
--- a/lib/ubsan/lit_tests/lit.cfg
+++ b/lib/ubsan/lit_tests/lit.cfg
@@ -54,6 +54,9 @@ config.substitutions.append( ("%clang ", (" " + config.clang + " ")) )
 config.substitutions.append( ("%clangxx ", (" " + config.clang +
                                             " --driver-mode=g++ ")) )
 
+# Setup path to external LLVM symbolizer.
+config.environment['ASAN_SYMBOLIZER_PATH'] = config.llvm_symbolizer_path
+
 # Default test suffixes.
 config.suffixes = ['.c', '.cc', '.cpp']
 
diff --git a/lib/ubsan/ubsan_diag.cc b/lib/ubsan/ubsan_diag.cc
index e4ca4e4af..968e7790d 100644
--- a/lib/ubsan/ubsan_diag.cc
+++ b/lib/ubsan/ubsan_diag.cc
@@ -26,12 +26,21 @@ Location __ubsan::getCallerLocation(uptr CallerLoc) {
     return Location();
 
   uptr Loc = StackTrace::GetPreviousInstructionPc(CallerLoc);
+  return getFunctionLocation(Loc, 0);
+}
+
+Location __ubsan::getFunctionLocation(uptr Loc, const char **FName) {
+  if (!Loc)
+    return Location();
 
   AddressInfo Info;
   if (!getSymbolizer()->SymbolizeCode(Loc, &Info, 1) ||
       !Info.module || !*Info.module)
     return Location(Loc);
 
+  if (FName && Info.function)
+    *FName = Info.function;
+
   if (!Info.file)
     return ModuleLocation(Info.module, Info.module_offset);
 
diff --git a/lib/ubsan/ubsan_diag.h b/lib/ubsan/ubsan_diag.h
index 16afffdb0..54d15a0cc 100644
--- a/lib/ubsan/ubsan_diag.h
+++ b/lib/ubsan/ubsan_diag.h
@@ -80,6 +80,12 @@ public:
 /// an invalid location or a module location for the caller.
 Location getCallerLocation(uptr CallerLoc = GET_CALLER_PC());
 
+/// Try to obtain a location for the given function pointer. This might fail,
+/// and produce either an invalid location or a module location for the caller.
+/// If FName is non-null and the name of the function is known, set *FName to
+/// the function name, otherwise *FName is unchanged.
+Location getFunctionLocation(uptr Loc, const char **FName);
+
 /// A diagnostic severity level.
 enum DiagLevel {
   DL_Error, ///< An error.
diff --git a/lib/ubsan/ubsan_handlers.cc b/lib/ubsan/ubsan_handlers.cc
index 5ed0d5923..d55643143 100644
--- a/lib/ubsan/ubsan_handlers.cc
+++ b/lib/ubsan/ubsan_handlers.cc
@@ -259,3 +259,23 @@ void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
   __ubsan_handle_load_invalid_value(Data, Val);
   Die();
 }
+
+void __ubsan::__ubsan_handle_function_type_mismatch(
+    FunctionTypeMismatchData *Data,
+    ValueHandle Function) {
+  const char *FName = "(unknown)";
+
+  Location Loc = getFunctionLocation(Function, &FName);
+
+  Diag(Data->Loc, DL_Error,
+       "call to function %0 through pointer to incorrect function type %1")
+    << FName << Data->Type;
+  Diag(Loc, DL_Note, "%0 defined here") << FName;
+}
+
+void __ubsan::__ubsan_handle_function_type_mismatch_abort(
+    FunctionTypeMismatchData *Data,
+    ValueHandle Function) {
+  __ubsan_handle_function_type_mismatch(Data, Function);
+  Die();
+}
diff --git a/lib/ubsan/ubsan_handlers.h b/lib/ubsan/ubsan_handlers.h
index 9406207fa..14e6f04c2 100644
--- a/lib/ubsan/ubsan_handlers.h
+++ b/lib/ubsan/ubsan_handlers.h
@@ -112,6 +112,15 @@ struct InvalidValueData {
 /// \brief Handle a load of an invalid value for the type.
 RECOVERABLE(load_invalid_value, InvalidValueData *Data, ValueHandle Val)
 
+struct FunctionTypeMismatchData {
+  SourceLocation Loc;
+  const TypeDescriptor &Type;
+};
+
+RECOVERABLE(function_type_mismatch,
+            FunctionTypeMismatchData *Data,
+            ValueHandle Val)
+
 }
 
 #endif // UBSAN_HANDLERS_H