let to_ascii_max and to_ascii_max_decimal be variables

Summary: No strict need for them to be functions.

Differential Revision: D27484949

fbshipit-source-id: f0fbc91aa9940720bbd3b685b730acc314bf122d

folly/experimental/symbolizer/SignalHandler.cpp

@@ -171,13 +171,13 @@ void flush() {
 }
 
 void printDec(uint64_t val) {
-  char buf[to_ascii_size_max_decimal<uint64_t>()];
+  char buf[to_ascii_size_max_decimal<uint64_t>];
   size_t n = to_ascii_decimal(buf, val);
   gStackTracePrinter->print(StringPiece(buf, n));
 }
 
 void printHex(uint64_t val) {
-  char buf[2 + to_ascii_size_max<16, uint64_t>()];
+  char buf[2 + to_ascii_size_max<16, uint64_t>];
   auto out = buf + 0;
   *out++ = '0';
   *out++ = 'x';

folly/experimental/symbolizer/SymbolizePrinter.cpp

@@ -113,7 +113,7 @@ void SymbolizePrinter::print(const SymbolizedFrame& frame) {
       }
       doPrint(fileBuf);
 
-      char buf[to_ascii_size_max_decimal<decltype(frame.location.line)>()];
+      char buf[to_ascii_size_max_decimal<decltype(frame.location.line)>];
       uint32_t n = to_ascii_decimal(buf, frame.location.line);
       doPrint(":");
       doPrint(StringPiece(buf, n));

folly/experimental/symbolizer/Symbolizer.cpp

@@ -57,7 +57,7 @@ namespace symbolizer {
 namespace {
 template <typename PrintFunc>
 void printAsyncStackInfo(PrintFunc print) {
-  char buf[to_ascii_size_max<16, uint64_t>()];
+  char buf[to_ascii_size_max<16, uint64_t>];
   auto printHex = [&print, &buf](uint64_t val) {
     print("0x");
     print(StringPiece(buf, to_ascii_lower<16>(buf, val)));

folly/lang/SafeAssert.cpp

@@ -519,7 +519,7 @@ void flushStderr() {
 [[noreturn]] FOLLY_COLD void safe_assert_terminate_v(
     safe_assert_arg const* arg_, int const error, va_list msg) noexcept {
   auto const& arg = *arg_;
-  char buf[to_ascii_size_max_decimal<uint64_t>()];
+  char buf[to_ascii_size_max_decimal<uint64_t>];
 
   writeStderr("\n\nAssertion failure: ");
   writeStderr(arg.expr + 1, strlen(arg.expr) - 2);

folly/lang/ToAscii.h

@@ -333,22 +333,16 @@ FOLLY_ALWAYS_INLINE size_t to_ascii_with_table(char* out, uint64_t v) {
 //
 //  In base 10, u64 requires at most 20 bytes, u32 at most 10, u16 at most 5,
 //  and u8 at most 3.
-//
-//  async-signal-safe
 template <uint64_t Base, typename I>
-constexpr size_t to_ascii_size_max() {
-  return detail::to_ascii_powers<Base, I>::size;
-}
+FOLLY_INLINE_VARIABLE constexpr size_t to_ascii_size_max =
+    detail::to_ascii_powers<Base, I>::size;
 
 //  to_ascii_size_max_decimal
 //
 //  An alias to to_ascii_size_max<10>.
-//
-//  async-signal-safe
 template <typename I>
-constexpr size_t to_ascii_size_max_decimal() {
-  return to_ascii_size_max<10, I>();
-}
+FOLLY_INLINE_VARIABLE constexpr size_t to_ascii_size_max_decimal =
+    to_ascii_size_max<10, I>;
 
 //  to_ascii_size
 //
@@ -392,7 +386,7 @@ size_t to_ascii_with(char* outb, char const* oute, uint64_t v) {
 }
 template <uint64_t Base, typename Alphabet, size_t N>
 size_t to_ascii_with(char (&out)[N], uint64_t v) {
-  static_assert(N >= to_ascii_size_max<Base, decltype(v)>(), "out too small");
+  static_assert(N >= to_ascii_size_max<Base, decltype(v)>, "out too small");
   return detail::to_ascii_with_table<Base, Alphabet>(out, v);
 }
 

folly/lang/test/ToAsciiBench.cpp

@@ -150,7 +150,7 @@ static void to_ascii_size_go(size_t iters, size_t index, F f) {
 
 template <uint64_t Base, typename F>
 static void to_ascii_go(size_t iters, size_t index, F f) {
-  char out[1 + folly::to_ascii_size_max<Base, uint64_t>()];
+  char out[1 + folly::to_ascii_size_max<Base, uint64_t>];
   while (iters--) {
     auto const v = inputs<Base>::data[index] + (iters % 8);
     auto const size = folly::to_ascii_size<Base>(v);

folly/lang/test/ToAsciiTest.cpp

@@ -117,17 +117,17 @@ TEST_F(ToAsciiTest, to_ascii_powers_u64_8) {
 }
 
 TEST_F(ToAsciiTest, to_ascii_size_max_u64_16) {
-  constexpr auto const actual = folly::to_ascii_size_max<16, uint64_t>();
+  constexpr auto const actual = folly::to_ascii_size_max<16, uint64_t>;
   EXPECT_EQ(16, actual);
 }
 
 TEST_F(ToAsciiTest, to_ascii_size_max_u64_10) {
-  constexpr auto const actual = folly::to_ascii_size_max<10, uint64_t>();
+  constexpr auto const actual = folly::to_ascii_size_max<10, uint64_t>;
   EXPECT_EQ(20, actual);
 }
 
 TEST_F(ToAsciiTest, to_ascii_size_max_u64_8) {
-  constexpr auto const actual = folly::to_ascii_size_max<8, uint64_t>();
+  constexpr auto const actual = folly::to_ascii_size_max<8, uint64_t>;
   EXPECT_EQ(22, actual);
 }
 
@@ -232,7 +232,7 @@ static void to_ascii_compare(F _) {
   for (auto const n : inputs<Base>::data) {
     auto const expected = std::to_string(n);
     SCOPED_TRACE(expected);
-    std::string actual(folly::to_ascii_size_max<Base, uint64_t>(), '\0');
+    std::string actual(folly::to_ascii_size_max<Base, uint64_t>, '\0');
     auto const size = _(&actual[0], n);
     EXPECT_EQ(expected.size(), size);
     EXPECT_EQ(expected, actual.substr(0, size));