[1/2] Sync intprops.h with gnulib
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Message ID 20191031182527.26933-1-adhemerval.zanella@linaro.org
State New
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  • [1/2] Sync intprops.h with gnulib
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Commit Message

Adhemerval Zanella Oct. 31, 2019, 6:25 p.m. UTC
It sync with gnulib commit f5756b919addb9e8ce03f4e61a10e4fcff14874a.
---
 include/intprops.h | 214 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 169 insertions(+), 45 deletions(-)

Comments

Paul Eggert Oct. 31, 2019, 6:46 p.m. UTC | #1
Thanks for syncing intprops.h, timespec-add.c and timespec-sub.c with 
Gnulib. These changes all look good.
Adhemerval Zanella Oct. 31, 2019, 7:37 p.m. UTC | #2
On 31/10/2019 15:46, Paul Eggert wrote:
> Thanks for syncing intprops.h, timespec-add.c and timespec-sub.c with Gnulib. These changes all look good.

Btw, do you recall any gnulib change that it would be profitable
to sync?
Paul Eggert Oct. 31, 2019, 8:53 p.m. UTC | #3
On 10/31/19 12:37 PM, Adhemerval Zanella wrote:
> 
> 
> On 31/10/2019 15:46, Paul Eggert wrote:
>> Thanks for syncing intprops.h, timespec-add.c and timespec-sub.c with Gnulib. These changes all look good.
> 
> Btw, do you recall any gnulib change that it would be profitable
> to sync?

Thanks for asking. The regex code should be brought back into sync, by 
merging these Gnulib changes into glibc:

https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=e58796ff7110de26254fc06afdff21461462be72
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=7ce5f5c77f679f0da1fa15f4fb7c9e103685d079
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=32915b2a8a43825720755113bdffe9f67a591748
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=48f07576b8cd935b48e1050551f45ab1a79b9f01
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=5e407aba1f775d51b25481cb55f324c9868f62d7
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=4e02b30c761c76d04057fa5f6bba71401f9310cd
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=79f8ee4e389f8cb1339f8abed9a7d29816e2a2d4

and while we're on the topic of regex, Andreas's patch for Bug#25149 
should be merged in too; see:

https://sourceware.org/ml/libc-alpha/2019-10/msg00907.html


Also, there's a URL in a mktime.c comment that I should have synced last 
month; I fixed that in glibc just now by installing the attached trivial 
patch.

There's almost surely more stuff, but the regex code ought to be top 
priority in this area, since I'd like Andreas's patch in time for the 
next GNU grep release.

Patch
diff mbox series

diff --git a/include/intprops.h b/include/intprops.h
index 140f6d2a4b..bc7e950a0e 100644
--- a/include/intprops.h
+++ b/include/intprops.h
@@ -111,8 +111,8 @@ 
    Subtract 1 for the sign bit if T is signed, and then add 1 more for
    a minus sign if needed.
 
-   Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is
-   signed, this macro may overestimate the true bound by one byte when
+   Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 1 when its argument is
+   unsigned, this macro may overestimate the true bound by one byte when
    applied to unsigned types of size 2, 4, 16, ... bytes.  */
 #define INT_STRLEN_BOUND(t)                                     \
   (INT_BITS_STRLEN_BOUND (TYPE_WIDTH (t) - _GL_SIGNED_TYPE_OR_EXPR (t)) \
@@ -220,14 +220,26 @@ 
    ? (a) < (min) >> (b)                                 \
    : (max) >> (b) < (a))
 
-/* True if __builtin_add_overflow (A, B, P) works when P is non-null.  */
+/* True if __builtin_add_overflow (A, B, P) and __builtin_sub_overflow
+   (A, B, P) work when P is non-null.  */
 #if 5 <= __GNUC__ && !defined __ICC
-# define _GL_HAS_BUILTIN_OVERFLOW 1
+# define _GL_HAS_BUILTIN_ADD_OVERFLOW 1
+#elif defined __has_builtin
+# define _GL_HAS_BUILTIN_ADD_OVERFLOW __has_builtin (__builtin_add_overflow)
 #else
-# define _GL_HAS_BUILTIN_OVERFLOW 0
+# define _GL_HAS_BUILTIN_ADD_OVERFLOW 0
 #endif
 
-/* True if __builtin_add_overflow_p (A, B, C) works.  */
+/* True if __builtin_mul_overflow (A, B, P) works when P is non-null.  */
+#ifdef __clang__
+/* Work around Clang bug <https://bugs.llvm.org/show_bug.cgi?id=16404>.  */
+# define _GL_HAS_BUILTIN_MUL_OVERFLOW 0
+#else
+# define _GL_HAS_BUILTIN_MUL_OVERFLOW _GL_HAS_BUILTIN_ADD_OVERFLOW
+#endif
+
+/* True if __builtin_add_overflow_p (A, B, C) works, and similarly for
+   __builtin_mul_overflow_p and __builtin_mul_overflow_p.  */
 #define _GL_HAS_BUILTIN_OVERFLOW_P (7 <= __GNUC__)
 
 /* The _GL*_OVERFLOW macros have the same restrictions as the
@@ -281,7 +293,9 @@ 
 
    The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators
    might not yield numerically correct answers due to arithmetic overflow.
-   The INT_<op>_WRAPV macros also store the low-order bits of the answer.
+   The INT_<op>_WRAPV macros compute the low-order bits of the sum,
+   difference, and product of two C integers, and return 1 if these
+   low-order bits are not numerically correct.
    These macros work correctly on all known practical hosts, and do not rely
    on undefined behavior due to signed arithmetic overflow.
 
@@ -309,9 +323,11 @@ 
    arguments should not have side effects.
 
    The WRAPV macros are not constant expressions.  They support only
-   +, binary -, and *.  The result type must be signed.
+   +, binary -, and *.  Because the WRAPV macros convert the result,
+   they report overflow in different circumstances than the OVERFLOW
+   macros do.
 
-   These macros are tuned for their last argument being a constant.
+   These macros are tuned for their last input argument being a constant.
 
    Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
    A % B, and A << B would overflow, respectively.  */
@@ -347,19 +363,33 @@ 
 
 /* Store the low-order bits of A + B, A - B, A * B, respectively, into *R.
    Return 1 if the result overflows.  See above for restrictions.  */
-#define INT_ADD_WRAPV(a, b, r) \
-  _GL_INT_OP_WRAPV (a, b, r, +, __builtin_add_overflow, INT_ADD_OVERFLOW)
-#define INT_SUBTRACT_WRAPV(a, b, r) \
-  _GL_INT_OP_WRAPV (a, b, r, -, __builtin_sub_overflow, INT_SUBTRACT_OVERFLOW)
-#define INT_MULTIPLY_WRAPV(a, b, r) \
-  _GL_INT_OP_WRAPV (a, b, r, *, __builtin_mul_overflow, INT_MULTIPLY_OVERFLOW)
+#if _GL_HAS_BUILTIN_ADD_OVERFLOW
+# define INT_ADD_WRAPV(a, b, r) __builtin_add_overflow (a, b, r)
+# define INT_SUBTRACT_WRAPV(a, b, r) __builtin_sub_overflow (a, b, r)
+#else
+# define INT_ADD_WRAPV(a, b, r) \
+   _GL_INT_OP_WRAPV (a, b, r, +, _GL_INT_ADD_RANGE_OVERFLOW)
+# define INT_SUBTRACT_WRAPV(a, b, r) \
+   _GL_INT_OP_WRAPV (a, b, r, -, _GL_INT_SUBTRACT_RANGE_OVERFLOW)
+#endif
+#if _GL_HAS_BUILTIN_MUL_OVERFLOW
+/* Work around GCC bug 91450.  */
+# define INT_MULTIPLY_WRAPV(a, b, r) \
+   ((!_GL_SIGNED_TYPE_OR_EXPR (*(r)) && EXPR_SIGNED (a) && EXPR_SIGNED (b) \
+     && _GL_INT_MULTIPLY_RANGE_OVERFLOW (a, b, 0, (__typeof__ (*(r))) -1)) \
+    ? ((void) __builtin_mul_overflow (a, b, r), 1) \
+    : __builtin_mul_overflow (a, b, r))
+#else
+# define INT_MULTIPLY_WRAPV(a, b, r) \
+   _GL_INT_OP_WRAPV (a, b, r, *, _GL_INT_MULTIPLY_RANGE_OVERFLOW)
+#endif
 
 /* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390.  See:
    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193
    https://llvm.org/bugs/show_bug.cgi?id=25390
    For now, assume all versions of GCC-like compilers generate bogus
-   warnings for _Generic.  This matters only for older compilers that
-   lack __builtin_add_overflow.  */
+   warnings for _Generic.  This matters only for compilers that
+   lack relevant builtins.  */
 #if __GNUC__
 # define _GL__GENERIC_BOGUS 1
 #else
@@ -367,53 +397,100 @@ 
 #endif
 
 /* Store the low-order bits of A <op> B into *R, where OP specifies
-   the operation.  BUILTIN is the builtin operation, and OVERFLOW the
-   overflow predicate.  Return 1 if the result overflows.  See above
-   for restrictions.  */
-#if _GL_HAS_BUILTIN_OVERFLOW
-# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) builtin (a, b, r)
-#elif 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS
-# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+   the operation and OVERFLOW the overflow predicate.  Return 1 if the
+   result overflows.  See above for restrictions.  */
+#if 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS
+# define _GL_INT_OP_WRAPV(a, b, r, op, overflow) \
    (_Generic \
     (*(r), \
      signed char: \
        _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
                         signed char, SCHAR_MIN, SCHAR_MAX), \
+     unsigned char: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                        unsigned char, 0, UCHAR_MAX), \
      short int: \
        _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
                         short int, SHRT_MIN, SHRT_MAX), \
+     unsigned short int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                        unsigned short int, 0, USHRT_MAX), \
      int: \
        _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
                         int, INT_MIN, INT_MAX), \
+     unsigned int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                        unsigned int, 0, UINT_MAX), \
      long int: \
        _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
                         long int, LONG_MIN, LONG_MAX), \
+     unsigned long int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                        unsigned long int, 0, ULONG_MAX), \
      long long int: \
        _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
-                        long long int, LLONG_MIN, LLONG_MAX)))
+                        long long int, LLONG_MIN, LLONG_MAX), \
+     unsigned long long int: \
+       _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+                        unsigned long long int, 0, ULLONG_MAX)))
 #else
-# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+/* Store the low-order bits of A <op> B into *R, where OP specifies
+   the operation and OVERFLOW the overflow predicate.  If *R is
+   signed, its type is ST with bounds SMIN..SMAX; otherwise its type
+   is UT with bounds U..UMAX.  ST and UT are narrower than int.
+   Return 1 if the result overflows.  See above for restrictions.  */
+# if _GL_HAVE___TYPEOF__
+#  define _GL_INT_OP_WRAPV_SMALLISH(a,b,r,op,overflow,st,smin,smax,ut,umax) \
+    (TYPE_SIGNED (__typeof__ (*(r))) \
+     ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, st, smin, smax) \
+     : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, ut, 0, umax))
+# else
+#  define _GL_INT_OP_WRAPV_SMALLISH(a,b,r,op,overflow,st,smin,smax,ut,umax) \
+    (overflow (a, b, smin, smax) \
+     ? (overflow (a, b, 0, umax) \
+        ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st), 1) \
+        : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st)) < 0) \
+     : (overflow (a, b, 0, umax) \
+        ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st)) >= 0 \
+        : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st), 0)))
+# endif
+
+# define _GL_INT_OP_WRAPV(a, b, r, op, overflow) \
    (sizeof *(r) == sizeof (signed char) \
-    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
-                       signed char, SCHAR_MIN, SCHAR_MAX) \
+    ? _GL_INT_OP_WRAPV_SMALLISH (a, b, r, op, overflow, \
+                                 signed char, SCHAR_MIN, SCHAR_MAX, \
+                                 unsigned char, UCHAR_MAX) \
     : sizeof *(r) == sizeof (short int) \
-    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
-                       short int, SHRT_MIN, SHRT_MAX) \
+    ? _GL_INT_OP_WRAPV_SMALLISH (a, b, r, op, overflow, \
+                                 short int, SHRT_MIN, SHRT_MAX, \
+                                 unsigned short int, USHRT_MAX) \
     : sizeof *(r) == sizeof (int) \
-    ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
-                       int, INT_MIN, INT_MAX) \
+    ? (EXPR_SIGNED (*(r)) \
+       ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                          int, INT_MIN, INT_MAX) \
+       : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+                          unsigned int, 0, UINT_MAX)) \
     : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow))
 # ifdef LLONG_MAX
 #  define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
     (sizeof *(r) == sizeof (long int) \
-     ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
-                        long int, LONG_MIN, LONG_MAX) \
-     : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
-                        long long int, LLONG_MIN, LLONG_MAX))
+     ? (EXPR_SIGNED (*(r)) \
+        ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                           long int, LONG_MIN, LONG_MAX) \
+        : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                           unsigned long int, 0, ULONG_MAX)) \
+     : (EXPR_SIGNED (*(r)) \
+        ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+                           long long int, LLONG_MIN, LLONG_MAX) \
+        : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+                           unsigned long long int, 0, ULLONG_MAX)))
 # else
 #  define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
-    _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
-                     long int, LONG_MIN, LONG_MAX)
+    (EXPR_SIGNED (*(r)) \
+     ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                        long int, LONG_MIN, LONG_MAX) \
+     : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+                        unsigned long int, 0, ULONG_MAX))
 # endif
 #endif
 
@@ -422,13 +499,7 @@ 
    overflow problems.  *R's type is T, with extrema TMIN and TMAX.
    T must be a signed integer type.  Return 1 if the result overflows.  */
 #define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \
-  (sizeof ((a) op (b)) < sizeof (t) \
-   ? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \
-   : _GL_INT_OP_CALC1 (a, b, r, op, overflow, ut, t, tmin, tmax))
-#define _GL_INT_OP_CALC1(a, b, r, op, overflow, ut, t, tmin, tmax) \
-  ((overflow (a, b) \
-    || (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \
-    || (tmax) < ((a) op (b))) \
+  (overflow (a, b, tmin, tmax) \
    ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 1) \
    : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 0))
 
@@ -452,4 +523,57 @@ 
 #define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t) \
   ((t) ((ut) (a) op (ut) (b)))
 
+/* Return true if the numeric values A + B, A - B, A * B fall outside
+   the range TMIN..TMAX.  Arguments should be integer expressions
+   without side effects.  TMIN should be signed and nonpositive.
+   TMAX should be positive, and should be signed unless TMIN is zero.  */
+#define _GL_INT_ADD_RANGE_OVERFLOW(a, b, tmin, tmax) \
+  ((b) < 0 \
+   ? (((tmin) \
+       ? ((EXPR_SIGNED (_GL_INT_CONVERT (a, (tmin) - (b))) || (b) < (tmin)) \
+          && (a) < (tmin) - (b)) \
+       : (a) <= -1 - (b)) \
+      || ((EXPR_SIGNED (a) ? 0 <= (a) : (tmax) < (a)) && (tmax) < (a) + (b))) \
+   : (a) < 0 \
+   ? (((tmin) \
+       ? ((EXPR_SIGNED (_GL_INT_CONVERT (b, (tmin) - (a))) || (a) < (tmin)) \
+          && (b) < (tmin) - (a)) \
+       : (b) <= -1 - (a)) \
+      || ((EXPR_SIGNED (_GL_INT_CONVERT (a, b)) || (tmax) < (b)) \
+          && (tmax) < (a) + (b))) \
+   : (tmax) < (b) || (tmax) - (b) < (a))
+#define _GL_INT_SUBTRACT_RANGE_OVERFLOW(a, b, tmin, tmax) \
+  (((a) < 0) == ((b) < 0) \
+   ? ((a) < (b) \
+      ? !(tmin) || -1 - (tmin) < (b) - (a) - 1 \
+      : (tmax) < (a) - (b)) \
+   : (a) < 0 \
+   ? ((!EXPR_SIGNED (_GL_INT_CONVERT ((a) - (tmin), b)) && (a) - (tmin) < 0) \
+      || (a) - (tmin) < (b)) \
+   : ((! (EXPR_SIGNED (_GL_INT_CONVERT (tmax, b)) \
+          && EXPR_SIGNED (_GL_INT_CONVERT ((tmax) + (b), a))) \
+       && (tmax) <= -1 - (b)) \
+      || (tmax) + (b) < (a)))
+#define _GL_INT_MULTIPLY_RANGE_OVERFLOW(a, b, tmin, tmax) \
+  ((b) < 0 \
+   ? ((a) < 0 \
+      ? (EXPR_SIGNED (_GL_INT_CONVERT (tmax, b)) \
+         ? (a) < (tmax) / (b) \
+         : ((INT_NEGATE_OVERFLOW (b) \
+             ? _GL_INT_CONVERT (b, tmax) >> (TYPE_WIDTH (b) - 1) \
+             : (tmax) / -(b)) \
+            <= -1 - (a))) \
+      : INT_NEGATE_OVERFLOW (_GL_INT_CONVERT (b, tmin)) && (b) == -1 \
+      ? (EXPR_SIGNED (a) \
+         ? 0 < (a) + (tmin) \
+         : 0 < (a) && -1 - (tmin) < (a) - 1) \
+      : (tmin) / (b) < (a)) \
+   : (b) == 0 \
+   ? 0 \
+   : ((a) < 0 \
+      ? (INT_NEGATE_OVERFLOW (_GL_INT_CONVERT (a, tmin)) && (a) == -1 \
+         ? (EXPR_SIGNED (b) ? 0 < (b) + (tmin) : -1 - (tmin) < (b) - 1) \
+         : (tmin) / (a) < (b)) \
+      : (tmax) / (b) < (a)))
+
 #endif /* _GL_INTPROPS_H */