[ubsan] Suppression by type for -fsanitize=enum (#114754)

Similar to #107332.

clang/docs/ReleaseNotes.rst

@@ -872,10 +872,9 @@ Sanitizers
   This new flag should allow those projects to enable integer sanitizers with
   less noise.
 
-- Arithmetic overflow sanitizers ``-fsanitize=signed-integer-overflow`` and
-  ``-fsanitize=unsigned-integer-overflow`` as well as the implicit integer
-  truncation sanitizers ``-fsanitize=implicit-signed-integer-truncation`` and
-  ``-fsanitize=implicit-unsigned-integer-truncation`` now properly support the
+- ``-fsanitize=signed-integer-overflow``, ``-fsanitize=unsigned-integer-overflow``,
+  ``-fsanitize=implicit-signed-integer-truncation``, ``-fsanitize=implicit-unsigned-integer-truncation``,
+  ``-fsanitize=enum`` now properly support the
   "type" prefix within `Sanitizer Special Case Lists (SSCL)
   <https://clang.llvm.org/docs/SanitizerSpecialCaseList.html>`_. See that link
   for examples.

clang/docs/SanitizerSpecialCaseList.rst

@@ -16,8 +16,9 @@ Goal and usage
 ==============
 
 Users of sanitizer tools, such as :doc:`AddressSanitizer`,
-:doc:`ThreadSanitizer`, :doc:`MemorySanitizer` or :doc:`UndefinedBehaviorSanitizer`
-may want to disable or alter some checks for certain source-level entities to:
+:doc:`HardwareAssistedAddressSanitizerDesign`, :doc:`ThreadSanitizer`,
+:doc:`MemorySanitizer` or :doc:`UndefinedBehaviorSanitizer` may want to disable
+or alter some checks for certain source-level entities to:
 
 * speedup hot function, which is known to be correct;
 * ignore a function that does some low-level magic (e.g. walks through the
@@ -51,11 +52,10 @@ Example
 Usage with UndefinedBehaviorSanitizer
 =====================================
 
-The arithmetic overflow sanitizers ``unsigned-integer-overflow`` and
-``signed-integer-overflow`` as well as the implicit integer truncation
-sanitizers ``implicit-signed-integer-truncation`` and
-``implicit-unsigned-integer-truncation`` support the ability to adjust
-instrumentation based on type.
+``unsigned-integer-overflow``, ``signed-integer-overflow``,
+``implicit-signed-integer-truncation``,
+``implicit-unsigned-integer-truncation``, and ``enum`` sanitizers support the
+ability to adjust instrumentation based on type.
 
 By default, supported sanitizers will have their instrumentation disabled for
 types specified within an ignorelist.

clang/lib/CodeGen/CGExpr.cpp

@@ -1941,6 +1941,10 @@ bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
       cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
     return false;
 
+  if (NeedsEnumCheck &&
+      getContext().isTypeIgnoredBySanitizer(SanitizerKind::Enum, Ty))
+    return false;
+
   llvm::APInt Min, End;
   if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
     return true;

clang/test/CodeGen/ubsan-type-ignorelist-enum.test

@@ -0,0 +1,33 @@
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsanitize=enum -fsanitize-ignorelist=%t/ignorelist -emit-llvm %t/test.cpp -o - | FileCheck %s --implicit-check-not="call void @__ubsan_handle"
+
+//--- ignorelist
+[enum]
+type:IgnoreEnum
+
+//--- test.cpp
+enum IgnoreEnum {
+  A,
+  B,
+  C,
+};
+
+// CHECK-LABEL: define dso_local noundef i32 @_Z6ignore10IgnoreEnum
+int ignore(IgnoreEnum v) {
+  return v;
+}
+
+
+enum CheckEnum {
+  X,
+  Y,
+  Z,
+};
+
+// CHECK-LABEL: define dso_local noundef i32 @_Z5check9CheckEnum
+// CHECK: call void @__ubsan_handle_load_invalid_value_abort
+int check(CheckEnum v) {
+  return v;
+}