[clang] 0fecac1 - [Clang] [AVR] Fix USHRT_MAX for 16-bit int.
Daniel Thornburgh via cfe-commits
cfe-commits at lists.llvm.org
Mon Feb 27 12:04:35 PST 2023
Author: Daniel Thornburgh
Date: 2023-02-27T12:04:26-08:00
New Revision: 0fecac18ffad476b5a4682770f6d8b1f0f176b40
URL: https://github.com/llvm/llvm-project/commit/0fecac18ffad476b5a4682770f6d8b1f0f176b40
DIFF: https://github.com/llvm/llvm-project/commit/0fecac18ffad476b5a4682770f6d8b1f0f176b40.diff
LOG: [Clang] [AVR] Fix USHRT_MAX for 16-bit int.
For AVR, the definition of USHRT_MAX overflows.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D144218
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/Headers/limits.h
clang/test/Headers/limits.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index b4c64c4e6051..1cc9e4efac1f 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -237,6 +237,13 @@ AIX Support
WebAssembly Support
^^^^^^^^^^^^^^^^^^^
+AVR Support
+^^^^^^^^^^^
+- The definition of ``USHRT_MAX`` in the freestanding ``<limits.h>`` no longer
+ overflows on AVR (where ``sizeof(int) == sizeof(unsigned short)``). The type
+ of ``USHRT_MAX`` is now ``unsigned int`` instead of ``int``, as required by
+ the C standard.
+
DWARF Support in Clang
----------------------
diff --git a/clang/lib/Headers/limits.h b/clang/lib/Headers/limits.h
index 32cc901b26be..354e031a9d7b 100644
--- a/clang/lib/Headers/limits.h
+++ b/clang/lib/Headers/limits.h
@@ -52,7 +52,11 @@
#define LONG_MIN (-__LONG_MAX__ -1L)
#define UCHAR_MAX (__SCHAR_MAX__*2 +1)
-#define USHRT_MAX (__SHRT_MAX__ *2 +1)
+#if __SHRT_WIDTH__ < __INT_WIDTH__
+#define USHRT_MAX (__SHRT_MAX__ * 2 + 1)
+#else
+#define USHRT_MAX (__SHRT_MAX__ * 2U + 1U)
+#endif
#define UINT_MAX (__INT_MAX__ *2U +1U)
#define ULONG_MAX (__LONG_MAX__ *2UL+1UL)
diff --git a/clang/test/Headers/limits.cpp b/clang/test/Headers/limits.cpp
index 730a73982631..fbf6ed0f751c 100644
--- a/clang/test/Headers/limits.cpp
+++ b/clang/test/Headers/limits.cpp
@@ -3,14 +3,40 @@
// RUN: %clang_cc1 -std=c++11 -ffreestanding -fsyntax-only -verify %s
// RUN: %clang_cc1 -std=c17 -ffreestanding -fsyntax-only -verify -x c %s
// RUN: %clang_cc1 -std=c2x -ffreestanding -fsyntax-only -verify -x c %s
+
+// Specifically test 16-bit int platforms.
+// RUN: %clang_cc1 -triple=avr -ffreestanding -fsyntax-only -verify -x c %s
+// RUN: %clang_cc1 -triple=avr -std=c++11 -ffreestanding -fsyntax-only -verify %s
+
// expected-no-diagnostics
#include <limits.h>
+#if __cplusplus
+#define EXPR_TYPE_IS(EXPR, TYP) __is_same(__typeof(EXPR), TYP)
+#else
+#define EXPR_TYPE_IS(EXPR, TYP) _Generic(EXPR, TYP: 1, default: 0)
+#endif
+
_Static_assert(SCHAR_MAX == -(SCHAR_MIN+1), "");
+_Static_assert(EXPR_TYPE_IS(SCHAR_MAX, int), "");
+#if SCHAR_MAX
+#endif
+
_Static_assert(SHRT_MAX == -(SHRT_MIN+1), "");
+_Static_assert(EXPR_TYPE_IS(SHRT_MAX, int), "");
+#if SHRT_MAX
+#endif
+
_Static_assert(INT_MAX == -(INT_MIN+1), "");
+_Static_assert(EXPR_TYPE_IS(INT_MAX, int), "");
+#if INT_MAX
+#endif
+
_Static_assert(LONG_MAX == -(LONG_MIN+1L), "");
+_Static_assert(EXPR_TYPE_IS(LONG_MAX, long), "");
+#if LONG_MAX
+#endif
_Static_assert(SCHAR_MAX == UCHAR_MAX/2, "");
_Static_assert(SHRT_MAX == USHRT_MAX/2, "");
@@ -18,26 +44,84 @@ _Static_assert(INT_MAX == UINT_MAX/2, "");
_Static_assert(LONG_MAX == ULONG_MAX/2, "");
_Static_assert(SCHAR_MIN == -SCHAR_MAX-1, "");
+_Static_assert(EXPR_TYPE_IS(SCHAR_MIN, int), "");
+#if SCHAR_MIN
+#endif
+
_Static_assert(SHRT_MIN == -SHRT_MAX-1, "");
+_Static_assert(EXPR_TYPE_IS(SHRT_MIN, int), "");
+#if SHRT_MIN
+#endif
+
_Static_assert(INT_MIN == -INT_MAX-1, "");
+_Static_assert(EXPR_TYPE_IS(INT_MIN, int), "");
+#if INT_MIN
+#endif
+
_Static_assert(LONG_MIN == -LONG_MAX-1L, "");
+_Static_assert(EXPR_TYPE_IS(LONG_MIN, long), "");
+#if LONG_MIN
+#endif
_Static_assert(UCHAR_MAX == (unsigned char)~0ULL, "");
+_Static_assert(UCHAR_MAX <= INT_MAX ?
+ EXPR_TYPE_IS(UCHAR_MAX, int) :
+ EXPR_TYPE_IS(UCHAR_MAX, unsigned int), "");
+#if UCHAR_MAX
+#endif
+
_Static_assert(USHRT_MAX == (unsigned short)~0ULL, "");
+_Static_assert(USHRT_MAX <= INT_MAX ?
+ EXPR_TYPE_IS(USHRT_MAX, int) :
+ EXPR_TYPE_IS(USHRT_MAX, unsigned int), "");
+#if USHRT_MAX
+#endif
+
_Static_assert(UINT_MAX == (unsigned int)~0ULL, "");
+_Static_assert(EXPR_TYPE_IS(UINT_MAX, unsigned int), "");
+#if UINT_MAX
+#endif
+
_Static_assert(ULONG_MAX == (unsigned long)~0ULL, "");
+_Static_assert(EXPR_TYPE_IS(ULONG_MAX, unsigned long), "");
+#if ULONG_MAX
+#endif
_Static_assert(MB_LEN_MAX >= 1, "");
+#if MB_LEN_MAX
+#endif
_Static_assert(CHAR_BIT >= 8, "");
+#if CHAR_BIT
+#endif
_Static_assert(CHAR_MIN == (((char)-1 < (char)0) ? -CHAR_MAX-1 : 0), "");
+_Static_assert(EXPR_TYPE_IS(CHAR_MIN, int), "");
+#if CHAR_MIN
+#endif
+
_Static_assert(CHAR_MAX == (((char)-1 < (char)0) ? -(CHAR_MIN+1) : (char)~0ULL), "");
+_Static_assert(CHAR_MAX <= INT_MAX ?
+ EXPR_TYPE_IS(CHAR_MAX, int) :
+ EXPR_TYPE_IS(CHAR_MAX, unsigned int), "");
+#if CHAR_MAX
+#endif
#if __STDC_VERSION__ >= 199901 || __cplusplus >= 201103L
_Static_assert(LLONG_MAX == -(LLONG_MIN+1LL), "");
+_Static_assert(EXPR_TYPE_IS(LLONG_MAX, long long), "");
+#if LLONG_MAX
+#endif
+
_Static_assert(LLONG_MIN == -LLONG_MAX-1LL, "");
+#if LLONG_MIN
+#endif
+_Static_assert(EXPR_TYPE_IS(LLONG_MIN, long long), "");
+
_Static_assert(ULLONG_MAX == (unsigned long long)~0ULL, "");
+_Static_assert(EXPR_TYPE_IS(ULLONG_MAX, unsigned long long), "");
+#if ULLONG_MAX
+#endif
#else
int LLONG_MIN, LLONG_MAX, ULLONG_MAX; // Not defined.
#endif
@@ -47,35 +131,61 @@ int LLONG_MIN, LLONG_MAX, ULLONG_MAX; // Not defined.
#if __STDC_VERSION__ >= 202000L
/* Validate the standard requirements. */
_Static_assert(BOOL_WIDTH >= 1);
+#if BOOL_WIDTH
+#endif
_Static_assert(CHAR_WIDTH == CHAR_BIT);
_Static_assert(CHAR_WIDTH / CHAR_BIT == sizeof(char));
+#if CHAR_WIDTH
+#endif
_Static_assert(SCHAR_WIDTH == CHAR_BIT);
_Static_assert(SCHAR_WIDTH / CHAR_BIT == sizeof(signed char));
+#if SCHAR_WIDTH
+#endif
_Static_assert(UCHAR_WIDTH == CHAR_BIT);
_Static_assert(UCHAR_WIDTH / CHAR_BIT == sizeof(unsigned char));
+#if UCHAR_WIDTH
+#endif
_Static_assert(USHRT_WIDTH >= 16);
_Static_assert(USHRT_WIDTH / CHAR_BIT == sizeof(unsigned short));
+#if USHRT_WIDTH
+#endif
_Static_assert(SHRT_WIDTH == USHRT_WIDTH);
_Static_assert(SHRT_WIDTH / CHAR_BIT == sizeof(signed short));
+#if SHRT_WIDTH
+#endif
_Static_assert(UINT_WIDTH >= 16);
_Static_assert(UINT_WIDTH / CHAR_BIT == sizeof(unsigned int));
+#if UINT_WIDTH
+#endif
_Static_assert(INT_WIDTH == UINT_WIDTH);
_Static_assert(INT_WIDTH / CHAR_BIT == sizeof(signed int));
+#if INT_WIDTH
+#endif
_Static_assert(ULONG_WIDTH >= 32);
_Static_assert(ULONG_WIDTH / CHAR_BIT == sizeof(unsigned long));
+#if ULONG_WIDTH
+#endif
_Static_assert(LONG_WIDTH == ULONG_WIDTH);
_Static_assert(LONG_WIDTH / CHAR_BIT == sizeof(signed long));
+#if LONG_WIDTH
+#endif
_Static_assert(ULLONG_WIDTH >= 64);
_Static_assert(ULLONG_WIDTH / CHAR_BIT == sizeof(unsigned long long));
+#if ULLONG_WIDTH
+#endif
_Static_assert(LLONG_WIDTH == ULLONG_WIDTH);
_Static_assert(LLONG_WIDTH / CHAR_BIT == sizeof(signed long long));
+#if LLONG_WIDTH
+#endif
_Static_assert(BITINT_MAXWIDTH >= ULLONG_WIDTH);
+#if BITINT_MAXWIDTH
+#endif
#else
/* None of these are defined. */
int BOOL_WIDTH, CHAR_WIDTH, SCHAR_WIDTH, UCHAR_WIDTH, USHRT_WIDTH, SHRT_WIDTH,
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