[ubsan] Diagnose invalid uses of builtins (compiler-rt)

[vsk]

Summary

Compiler-rt changes and tests to go along with: D34590

lib/ubsan/ubsan_checks.inc

 UBSAN_CHECK(InsufficientObjectSize, "insufficient-object-size", "object-size")
 UBSAN_CHECK(SignedIntegerOverflow, "signed-integer-overflow",
             "signed-integer-overflow")
 UBSAN_CHECK(UnsignedIntegerOverflow, "unsigned-integer-overflow",
             "unsigned-integer-overflow")
 UBSAN_CHECK(IntegerDivideByZero, "integer-divide-by-zero",
             "integer-divide-by-zero")
 UBSAN_CHECK(FloatDivideByZero, "float-divide-by-zero", "float-divide-by-zero")
+UBSAN_CHECK(InvalidBuiltin, "invalid-builtin-use", "invalid-builtin-use")
 UBSAN_CHECK(InvalidShiftBase, "invalid-shift-base", "shift-base")
 UBSAN_CHECK(InvalidShiftExponent, "invalid-shift-exponent", "shift-exponent")
 UBSAN_CHECK(OutOfBoundsIndex, "out-of-bounds-index", "bounds")
 UBSAN_CHECK(UnreachableCall, "unreachable-call", "unreachable")
 UBSAN_CHECK(MissingReturn, "missing-return", "return")
 UBSAN_CHECK(NonPositiveVLAIndex, "non-positive-vla-index", "vla-bound")
 UBSAN_CHECK(FloatCastOverflow, "float-cast-overflow", "float-cast-overflow")
 UBSAN_CHECK(InvalidBoolLoad, "invalid-bool-load", "bool")
 UBSAN_CHECK(InvalidEnumLoad, "invalid-enum-load", "enum")
 UBSAN_CHECK(FunctionTypeMismatch, "function-type-mismatch", "function")
 UBSAN_CHECK(InvalidNullReturn, "invalid-null-return",
             "returns-nonnull-attribute")
 UBSAN_CHECK(InvalidNullArgument, "invalid-null-argument", "nonnull-attribute")
 UBSAN_CHECK(DynamicTypeMismatch, "dynamic-type-mismatch", "vptr")
 UBSAN_CHECK(CFIBadType, "cfi-bad-type", "cfi")

lib/ubsan/ubsan_handlers.h

 struct InvalidValueData {
   SourceLocation Loc;
   const TypeDescriptor &Type;
 };
 
 /// \brief Handle a load of an invalid value for the type.
 RECOVERABLE(load_invalid_value, InvalidValueData *Data, ValueHandle Val)
 
+/// Known builtin check kinds.
+/// Keep in sync with the enum of the same name in CodeGenFunction.h
+enum BuiltinCheckKind : unsigned char {
+  BCK_CTZPassedZero,
+  BCK_CLZPassedZero,
+};
+
+struct InvalidBuiltinData {
+  SourceLocation Loc;
+  unsigned char Kind;
+};
+
+/// Handle a builtin called in an invalid way.
+RECOVERABLE(invalid_builtin, InvalidBuiltinData *Data)
+
 struct FunctionTypeMismatchData {
   SourceLocation Loc;
   const TypeDescriptor &Type;
 };
 
 RECOVERABLE(function_type_mismatch,
             FunctionTypeMismatchData *Data,
             ValueHandle Val)

lib/ubsan/ubsan_handlers.cc

 }
 void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
                                                       ValueHandle Val) {
   GET_REPORT_OPTIONS(true);
   handleLoadInvalidValue(Data, Val, Opts);
   Die();
 }
 
+static void handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) {
+  SourceLocation Loc = Data->Loc.acquire();
+  ErrorType ET = ErrorType::InvalidBuiltin;
+
+  if (ignoreReport(Loc, Opts, ET))
+    return;
+
+  ScopedReport R(Opts, Loc, ET);
+
+  Diag(Loc, DL_Error,
+       "passing zero to %0, which is not a valid argument")
+    << ((Data->Kind == BCK_CTZPassedZero) ? "ctz()" : "clz()");
+}
+
+void __ubsan::__ubsan_handle_invalid_builtin(InvalidBuiltinData *Data) {
+  GET_REPORT_OPTIONS(true);
+  handleInvalidBuiltin(Data, Opts);
+}
+void __ubsan::__ubsan_handle_invalid_builtin_abort(InvalidBuiltinData *Data) {
+  GET_REPORT_OPTIONS(true);
+  handleInvalidBuiltin(Data, Opts);
+  Die();
+}
+
 static void handleFunctionTypeMismatch(FunctionTypeMismatchData *Data,
                                        ValueHandle Function,
                                        ReportOptions Opts) {
   SourceLocation CallLoc = Data->Loc.acquire();
   ErrorType ET = ErrorType::FunctionTypeMismatch;
 
   if (ignoreReport(CallLoc, Opts, ET))
     return;

lib/ubsan/ubsan_interface.inc

 INTERFACE_FUNCTION(__ubsan_handle_cfi_check_fail)
 INTERFACE_FUNCTION(__ubsan_handle_cfi_check_fail_abort)
 INTERFACE_FUNCTION(__ubsan_handle_divrem_overflow)
 INTERFACE_FUNCTION(__ubsan_handle_divrem_overflow_abort)
 INTERFACE_FUNCTION(__ubsan_handle_float_cast_overflow)
 INTERFACE_FUNCTION(__ubsan_handle_float_cast_overflow_abort)
 INTERFACE_FUNCTION(__ubsan_handle_function_type_mismatch)
 INTERFACE_FUNCTION(__ubsan_handle_function_type_mismatch_abort)
+INTERFACE_FUNCTION(__ubsan_handle_invalid_builtin)
+INTERFACE_FUNCTION(__ubsan_handle_invalid_builtin_abort)
 INTERFACE_FUNCTION(__ubsan_handle_load_invalid_value)
 INTERFACE_FUNCTION(__ubsan_handle_load_invalid_value_abort)
 INTERFACE_FUNCTION(__ubsan_handle_missing_return)
 INTERFACE_FUNCTION(__ubsan_handle_mul_overflow)
 INTERFACE_FUNCTION(__ubsan_handle_mul_overflow_abort)
 INTERFACE_FUNCTION(__ubsan_handle_negate_overflow)
 INTERFACE_FUNCTION(__ubsan_handle_negate_overflow_abort)
 INTERFACE_FUNCTION(__ubsan_handle_nonnull_arg)

test/ubsan/TestCases/Misc/builtins.cpp

+// REQUIRES: arch=x86_64
+//
+// RUN: %clangxx -fsanitize=builtin -w %s -O3 -o %t
+// RUN: %run %t 2>&1 | FileCheck %s --check-prefix=RECOVER
+// RUN: %clangxx -fsanitize=builtin -fno-sanitize-recover=builtin -w %s -O3 -o %t.abort
+// RUN: not %run %t.abort 2>&1 | FileCheck %s --check-prefix=ABORT
+
+void check_ctz(int n) {
+  // ABORT: builtins.cpp:[[@LINE+2]]:17: runtime error: passing zero to ctz(), which is not a valid argument
+  // RECOVER: builtins.cpp:[[@LINE+1]]:17: runtime error: passing zero to ctz(), which is not a valid argument
+  __builtin_ctz(n);
+
+  // RECOVER: builtins.cpp:[[@LINE+1]]:18: runtime error: passing zero to ctz(), which is not a valid argument
+  __builtin_ctzl(n);
+
+  // RECOVER: builtins.cpp:[[@LINE+1]]:19: runtime error: passing zero to ctz(), which is not a valid argument
+  __builtin_ctzll(n);
+}
+
+void check_clz(int n) {
+  // RECOVER: builtins.cpp:[[@LINE+1]]:17: runtime error: passing zero to clz(), which is not a valid argument
+  __builtin_clz(n);
+
+  // RECOVER: builtins.cpp:[[@LINE+1]]:18: runtime error: passing zero to clz(), which is not a valid argument
+  __builtin_clzl(n);
+
+  // RECOVER: builtins.cpp:[[@LINE+1]]:19: runtime error: passing zero to clz(), which is not a valid argument
+  __builtin_clzll(n);
+}
+
+int main() {
+  check_ctz(0);
+  check_clz(0);
+  return 0;
+}

test/ubsan/lit.common.cfg

 # Check that the host supports UndefinedBehaviorSanitizer tests
 if config.host_os not in ['Linux', 'Darwin', 'FreeBSD', 'Windows']:
   config.unsupported = True
 
 # Allow tests to use REQUIRES=stable-runtime.  For use when you cannot use XFAIL
 # because the test hangs or fails on one configuration and not the other.
 if config.target_arch.startswith('arm') == False and config.target_arch != 'aarch64':
   config.available_features.add('stable-runtime')
+
+config.available_features.add('arch=' + config.target_arch)