Ease dealing with tagged enum ErrorDescription with some macros.

[filcab]

Summary

Added a macro to enumerate the (error name, error member name) pairs. This way,
when adding an error, we only need to add the pair to one place (plus add its
implementation, or course).

[vitalybuka]

It saves 9 line of code, but makes it less readable.
I strongly prefer existing code.

[vitalybuka]

lib/asan/asan_errors.h

122 ↗

(On Diff #69246)

Seems like no one on our side likes this macros, but I don't yet see a better solution.
I can just advice small improvements:

We can sacrifice snake case for a simpler macros with just one argument.
Also moving #defines makes code better structured.

// clang-format off
#define ASAN_FOR_EACH_ERROR_KIND(macro)  \
    macro(StackOverflow)                 \
    macro(DeadlySignal)                  \
    macro(DoubleFree)                    \
    macro(NewDeleteSizeMismatch)
// clang-format on

#define ASAN_DEFINE_ERROR_KIND(name) kErrorKind##name,
#define ASAN_ERROR_DESCRIPTION_MEMBER(name) Error##name name;
#define ASAN_ERROR_DESCRIPTION_CONSTRUCTOR(name) \
  ErrorDescription(Error##name const &e) : kind(kErrorKind##name), name(e) {}
#define ASAN_ERROR_DESCRIPTION_PRINT(name) \
  case kErrorKind##name:                   \
    return name.Print();

enum ErrorKind {
  kErrorKindInvalid = 0,
  ASAN_FOR_EACH_ERROR_KIND(ASAN_DEFINE_ERROR_KIND)
};

struct ErrorDescription {
  ErrorKind kind;
  union {
    ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_MEMBER)
  };

  ErrorDescription() { internal_memset(this, 0, sizeof(*this)); }
  ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_CONSTRUCTOR)

  bool IsValid() { return kind != kErrorKindInvalid; }
  void Print() {
    switch (kind) {
      ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_PRINT)
      case kErrorKindInvalid:
        CHECK(0);
    }
    CHECK(0);
  }
};

#undef ASAN_FOR_EACH_ERROR_KIND
#undef ASAN_DEFINE_ERROR_KIND
#undef ASAN_ERROR_DESCRIPTION_MEMBER
#undef ASAN_ERROR_DESCRIPTION_CONSTRUCTOR
#undef ASAN_ERROR_DESCRIPTION_PRINT

[filcab]

Updated macro with review comments.

[vitalybuka]

LGTM

compiler-rt/trunk/lib/asan/asan_errors.h

ErrorNewDeleteSizeMismatch(u32 tid, BufferedStackTrace *stack, uptr addr,
       : ErrorBase(tid), free_stack(stack), delete_size(delete_size_) {
     GetHeapAddressInformation(addr, 1, &addr_description);
     scariness.Clear();
     scariness.Scare(10, "new-delete-type-mismatch");
   }
   void Print();
 };
 
+// clang-format off
+#define ASAN_FOR_EACH_ERROR_KIND(macro) \
+  macro(StackOverflow)                  \
+  macro(DeadlySignal)                   \
+  macro(DoubleFree)                     \
+  macro(NewDeleteSizeMismatch)
+// clang-format on
+
+#define ASAN_DEFINE_ERROR_KIND(name) kErrorKind##name,
+#define ASAN_ERROR_DESCRIPTION_MEMBER(name) Error##name name;
+#define ASAN_ERROR_DESCRIPTION_CONSTRUCTOR(name) \
+  ErrorDescription(Error##name const &e) : kind(kErrorKind##name), name(e) {}
+#define ASAN_ERROR_DESCRIPTION_PRINT(name) \
+  case kErrorKind##name:                   \
+    return name.Print();
+
 enum ErrorKind {
   kErrorKindInvalid = 0,
-  kErrorKindStackOverflow,
-  kErrorKindDeadlySignal,
-  kErrorKindDoubleFree,
-  kErrorKindNewDeleteSizeMismatch,
+  ASAN_FOR_EACH_ERROR_KIND(ASAN_DEFINE_ERROR_KIND)
 };
 
 struct ErrorDescription {
   ErrorKind kind;
   // We're using a tagged union because it allows us to have a trivially
   // copiable type and use the same structures as the public interface.
   //
   // We can add a wrapper around it to make it "more c++-like", but that would
   // add a lot of code and the benefit wouldn't be that big.
   union {
-    ErrorStackOverflow stack_overflow;
-    ErrorDeadlySignal deadly_signal;
-    ErrorDoubleFree double_free;
-    ErrorNewDeleteSizeMismatch new_delete_size_mismatch;
+    ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_MEMBER)
   };
+
   ErrorDescription() { internal_memset(this, 0, sizeof(*this)); }
-  ErrorDescription(const ErrorStackOverflow &e)  // NOLINT
-      : kind(kErrorKindStackOverflow),
-        stack_overflow(e) {}
-  ErrorDescription(const ErrorDeadlySignal &e)  // NOLINT
-      : kind(kErrorKindDeadlySignal),
-        deadly_signal(e) {}
-  ErrorDescription(const ErrorDoubleFree &e)  // NOLINT
-      : kind(kErrorKindDoubleFree),
-        double_free(e) {}
-  ErrorDescription(const ErrorNewDeleteSizeMismatch &e)  // NOLINT
-      : kind(kErrorKindNewDeleteSizeMismatch),
-        new_delete_size_mismatch(e) {}
+  ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_CONSTRUCTOR)
 
   bool IsValid() { return kind != kErrorKindInvalid; }
   void Print() {
     switch (kind) {
-      case kErrorKindStackOverflow:
-        stack_overflow.Print();
-        return;
-      case kErrorKindDeadlySignal:
-        deadly_signal.Print();
-        return;
-      case kErrorKindDoubleFree:
-        double_free.Print();
-        return;
-      case kErrorKindNewDeleteSizeMismatch:
-        new_delete_size_mismatch.Print();
-        return;
+      ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_PRINT)
       case kErrorKindInvalid:
         CHECK(0);
     }
     CHECK(0);
   }
 };
 
+#undef ASAN_FOR_EACH_ERROR_KIND
+#undef ASAN_DEFINE_ERROR_KIND
+#undef ASAN_ERROR_DESCRIPTION_MEMBER
+#undef ASAN_ERROR_DESCRIPTION_CONSTRUCTOR
+#undef ASAN_ERROR_DESCRIPTION_PRINT
+
 }  // namespace __asan
 
 #endif  // ASAN_ERRORS_H