[libc-commits] [libc] 1d1f230 - [libc] Define long long limits if not defined

[Alex Brachet via libc-commits]

Author: Alex Brachet
Date: 2023-08-30T23:03:36Z
New Revision: 1d1f230c92eee7d13288f70431ee2fc171d9e0d7

URL: https://github.com/llvm/llvm-project/commit/1d1f230c92eee7d13288f70431ee2fc171d9e0d7
DIFF: https://github.com/llvm/llvm-project/commit/1d1f230c92eee7d13288f70431ee2fc171d9e0d7.diff

LOG: [libc] Define long long limits if not defined

Some older gcc toolchains don't define these on 32 bit platforms. This
is a problem for pigweed which uses an older gcc toolchain and targets
32 bit.

Differential Revision: https://reviews.llvm.org/D157112

Added: 
    

Modified: 
    libc/src/__support/CPP/limits.h

Removed: 
    


################################################################################
diff  --git a/libc/src/__support/CPP/limits.h b/libc/src/__support/CPP/limits.h
index dce0bebdd2cd2c..e42414523a76df 100644
--- a/libc/src/__support/CPP/limits.h
+++ b/libc/src/__support/CPP/limits.h
@@ -14,6 +14,14 @@
 namespace __llvm_libc {
 namespace cpp {
 
+// Some older gcc distributions don't define these for 32 bit targets.
+#ifndef LLONG_MAX
+constexpr size_t LLONG_BIT_WIDTH = sizeof(long long) * 8;
+constexpr long long LLONG_MAX = ~0LL ^ (1LL << LLONG_BIT_WIDTH - 1);
+constexpr long long LLONG_MIN = 1LL << LLONG_BIT_WIDTH - 1;
+constexpr unsigned long long ULLONG_MAX = ~0ULL;
+#endif
+
 template <class T> class numeric_limits {
 public:
   static constexpr T max();