[scudo] Use templated builtins to avoid assumptions on SCUDO_WORDSIZE

[ddcc]

Summary

Platforms may define uintptr_t differently, so just use template overrides to select the appropriate builtin

[ddcc]

@vitalybuka ping

[vitalybuka]

compiler-rt/lib/scudo/standalone/wrappers_c_checks.h

50

Looks like not it's going to accept even signed or float types, but will not optimize unsigned long long
maybe just cast in existing implementation?
_builtin_umull_overflow(Size, N, reinterpret_cast<unsigned long*>Product);

[ddcc]

Use cast instead of template

[vitalybuka]

compiler-rt/lib/scudo/standalone/wrappers_c_checks.h

47–48

same here?

compiler-rt/lib/scudo/standalone/wrappers_c_checks.h

 // and a multiple of sizeof(void *).
 inline bool checkPosixMemalignAlignment(uptr Alignment) {
   return Alignment == 0 || !isPowerOfTwo(Alignment) ||
          !isAligned(Alignment, sizeof(void *));
 }
 
 // Returns true if calloc(Size, N) overflows on Size*N calculation. Use a
 // builtin supported by recent clang & GCC if it exists, otherwise fallback to a
 // costly division.
-inline bool checkForCallocOverflow(uptr Size, uptr N, uptr *Product) {
-#if __has_builtin(__builtin_umull_overflow) && (SCUDO_WORDSIZE == 64U)
-  return __builtin_umull_overflow(Size, N, Product);
-#elif __has_builtin(__builtin_umul_overflow) && (SCUDO_WORDSIZE == 32U)
-  return __builtin_umul_overflow(Size, N, Product);
-#else
+template <typename T = scudo::uptr>
+inline bool checkForCallocOverflow(T Size, T N, T *Product) {
   *Product = Size * N;
   if (!Size)
     return false;
   return (*Product / Size) != N;
+}
+
+#if __has_builtin(__builtin_umull_overflow)
+template <>
+inline bool checkForCallocOverflow<unsigned long>(unsigned long Size,
+                                                  unsigned long N,
+                                                  unsigned long *Product) {
+  return __builtin_umull_overflow(Size, N, Product);
+}
 #endif
+
+#if __has_builtin(__builtin_umul_overflow)
+template <>
+inline bool checkForCallocOverflow<unsigned int>(unsigned int Size,
+                                                 unsigned int N,
+                                                 unsigned int *Product) {
+  return __builtin_umul_overflow(Size, N, Product);
 }
+#endif
 
 // Returns true if the size passed to pvalloc overflows when rounded to the next
 // multiple of PageSize.
 inline bool checkForPvallocOverflow(uptr Size, uptr PageSize) {
   return roundUpTo(Size, PageSize) < Size;
 }
 
 } // namespace scudo
 
 #endif // SCUDO_CHECKS_H_