[clang] [Clang][CodeGen] Emit “trap reasons” on UBSan traps (PR #145967)

[Vitaly Buka via cfe-commits]

================
@@ -85,6 +85,96 @@ enum VariableTypeDescriptorKind : uint16_t {
 //                        Miscellaneous Helper Methods
 //===--------------------------------------------------------------------===//
 
+static llvm::StringRef GetUBSanTrapForHandler(SanitizerHandler ID) {
+  switch (ID) {
+  case SanitizerHandler::AddOverflow:
+    return "Signed integer addition overflowed";
+
+  case SanitizerHandler::BuiltinUnreachable:
+    return "_builtin_unreachable(), execution reached an unreachable program "
+           "point";
+
+  case SanitizerHandler::CFICheckFail:
+    return "Control flow integrity check failed";
+
+  case SanitizerHandler::DivremOverflow:
+    return "Signed integer divide or remainder overflowed";
+
+  case SanitizerHandler::DynamicTypeCacheMiss:
+    return "Dynamic type cache miss, member call made on an object whose "
+           "dynamic type differs from the expected type";
+
+  case SanitizerHandler::FloatCastOverflow:
+    return "Floating-point to integer conversion overflowed";
+
+  case SanitizerHandler::FunctionTypeMismatch:
+    return "Function called with mismatched signature";
+
+  case SanitizerHandler::ImplicitConversion:
+    return "Implicit integer conversion overflowed or lost data";
+
+  case SanitizerHandler::InvalidBuiltin:
+    return "Invalid use of builtin function";
+
+  case SanitizerHandler::InvalidObjCCast:
+    return "Invalid Objective-C cast";
+
+  case SanitizerHandler::LoadInvalidValue:
+    return "Loaded an invalid or uninitialized value for the type";
+
+  case SanitizerHandler::MissingReturn:
+    return "Execution reached the end of a value-returning function without "
+           "returning a value";
+
+  case SanitizerHandler::MulOverflow:
+    return "Signed integer multiplication overflowed";
+
+  case SanitizerHandler::NegateOverflow:
+    return "Signed integer negation overflowed";
+
+  case SanitizerHandler::NullabilityArg:
+    return "Passing null as an argument which is annotated with "
+           "_Nonnull";
+
+  case SanitizerHandler::NullabilityReturn:
+    return "Returning null from a function with a return type annotated with "
+           "_Nonnull";
+
+  case SanitizerHandler::NonnullArg:
+    return "Passing null pointer as an argument which is declared to never be "
+           "null";
+
+  case SanitizerHandler::NonnullReturn:
+    return "Returning null pointer from a function which is declared to never "
+           "return null";
+
+  case SanitizerHandler::OutOfBounds:
+    return "Array index out of bounds";
+
+  case SanitizerHandler::PointerOverflow:
+    return "Pointer arithmetic overflowed bounds";
+
+  case SanitizerHandler::ShiftOutOfBounds:
+    return "Shift exponent is too large for the type";
+
+  case SanitizerHandler::SubOverflow:
+    return "Signed integer subtraction overflowed";
+
+  case SanitizerHandler::TypeMismatch:
+    return "Type mismatch in operation";
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vitalybuka wrote:

Let's not do that and instead fix ambiguity by splitting enum

https://github.com/llvm/llvm-project/pull/145967