lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant

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* lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
@ 2024-08-13  9:00 kernel test robot
  2024-08-13 14:38 ` Alexander Lobakin
  0 siblings, 1 reply; 4+ messages in thread
From: kernel test robot @ 2024-08-13  9:00 UTC (permalink / raw)
  To: Alexander Lobakin
  Cc: oe-kbuild-all, linux-kernel, Przemek Kitszel, Yury Norov

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d74da846046aeec9333e802f5918bd3261fb5509
commit: 7adaf37f7f104a7ee5f150af491674ccbbfc4114 lib/bitmap: add compile-time test for __assign_bit() optimization
date:   4 months ago
config: um-randconfig-r132-20240812 (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408131601.Aj9JmK7K-lkp@intel.com/

All errors (new ones prefixed by >>):

>> lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
    1278 |         BUILD_BUG_ON(!__builtin_constant_p(~var));
         |         ^
   include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
      50 |         BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
         |         ^
   include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
      39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
         |                                     ^
   include/linux/compiler_types.h:460:2: note: expanded from macro 'compiletime_assert'
     460 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ^
   include/linux/compiler_types.h:448:2: note: expanded from macro '_compiletime_assert'
     448 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ^
   include/linux/compiler_types.h:441:4: note: expanded from macro '__compiletime_assert'
     441 |                         prefix ## suffix();                             \
         |                         ^
   <scratch space>:193:1: note: expanded from here
     193 | __compiletime_assert_127
         | ^
   1 error generated.


vim +1278 lib/test_bitmap.c

291f93ca339f5b Barry Song        2021-08-06  1227  
2356d198d2b4dd Yury Norov        2023-07-17  1228  /*
2356d198d2b4dd Yury Norov        2023-07-17  1229   * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled.
2356d198d2b4dd Yury Norov        2023-07-17  1230   * To workaround it, GCOV is force-disabled in Makefile for this configuration.
2356d198d2b4dd Yury Norov        2023-07-17  1231   */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1232  static void __init test_bitmap_const_eval(void)
dc34d5036692c6 Alexander Lobakin 2022-06-24  1233  {
dc34d5036692c6 Alexander Lobakin 2022-06-24  1234  	DECLARE_BITMAP(bitmap, BITS_PER_LONG);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1235  	unsigned long initvar = BIT(2);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1236  	unsigned long bitopvar = 0;
dc34d5036692c6 Alexander Lobakin 2022-06-24  1237  	unsigned long var = 0;
dc34d5036692c6 Alexander Lobakin 2022-06-24  1238  	int res;
dc34d5036692c6 Alexander Lobakin 2022-06-24  1239  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1240  	/*
dc34d5036692c6 Alexander Lobakin 2022-06-24  1241  	 * Compilers must be able to optimize all of those to compile-time
dc34d5036692c6 Alexander Lobakin 2022-06-24  1242  	 * constants on any supported optimization level (-O2, -Os) and any
dc34d5036692c6 Alexander Lobakin 2022-06-24  1243  	 * architecture. Otherwise, trigger a build bug.
dc34d5036692c6 Alexander Lobakin 2022-06-24  1244  	 * The whole function gets optimized out then, there's nothing to do
dc34d5036692c6 Alexander Lobakin 2022-06-24  1245  	 * in runtime.
dc34d5036692c6 Alexander Lobakin 2022-06-24  1246  	 */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1247  
7adaf37f7f104a Alexander Lobakin 2024-03-27  1248  	/* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1249  	bitmap_clear(bitmap, 0, BITS_PER_LONG);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1250  	if (!test_bit(7, bitmap))
dc34d5036692c6 Alexander Lobakin 2022-06-24  1251  		bitmap_set(bitmap, 5, 2);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1252  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1253  	/* Equals to `unsigned long bitopvar = BIT(20)` */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1254  	__change_bit(31, &bitopvar);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1255  	bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1256  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1257  	/* Equals to `unsigned long var = BIT(25)` */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1258  	var |= BIT(25);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1259  	if (var & BIT(0))
dc34d5036692c6 Alexander Lobakin 2022-06-24  1260  		var ^= GENMASK(9, 6);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1261  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1262  	/* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1263  	res = bitmap_weight(bitmap, 20);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1264  	BUILD_BUG_ON(!__builtin_constant_p(res));
dc34d5036692c6 Alexander Lobakin 2022-06-24  1265  	BUILD_BUG_ON(res != 2);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1266  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1267  	/* !(BIT(31) & BIT(18)) == 1 */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1268  	res = !test_bit(18, &bitopvar);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1269  	BUILD_BUG_ON(!__builtin_constant_p(res));
dc34d5036692c6 Alexander Lobakin 2022-06-24  1270  	BUILD_BUG_ON(!res);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1271  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1272  	/* BIT(2) & GENMASK(14, 8) == 0 */
dc34d5036692c6 Alexander Lobakin 2022-06-24  1273  	res = initvar & GENMASK(14, 8);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1274  	BUILD_BUG_ON(!__builtin_constant_p(res));
dc34d5036692c6 Alexander Lobakin 2022-06-24  1275  	BUILD_BUG_ON(res);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1276  
dc34d5036692c6 Alexander Lobakin 2022-06-24  1277  	/* ~BIT(25) */
dc34d5036692c6 Alexander Lobakin 2022-06-24 @1278  	BUILD_BUG_ON(!__builtin_constant_p(~var));
dc34d5036692c6 Alexander Lobakin 2022-06-24  1279  	BUILD_BUG_ON(~var != ~BIT(25));
7adaf37f7f104a Alexander Lobakin 2024-03-27  1280  
7adaf37f7f104a Alexander Lobakin 2024-03-27  1281  	/* ~BIT(25) | BIT(25) == ~0UL */
7adaf37f7f104a Alexander Lobakin 2024-03-27  1282  	bitmap_complement(&var, &var, BITS_PER_LONG);
7adaf37f7f104a Alexander Lobakin 2024-03-27  1283  	__assign_bit(25, &var, true);
7adaf37f7f104a Alexander Lobakin 2024-03-27  1284  
7adaf37f7f104a Alexander Lobakin 2024-03-27  1285  	/* !(~(~0UL)) == 1 */
7adaf37f7f104a Alexander Lobakin 2024-03-27  1286  	res = bitmap_full(&var, BITS_PER_LONG);
7adaf37f7f104a Alexander Lobakin 2024-03-27  1287  	BUILD_BUG_ON(!__builtin_constant_p(res));
7adaf37f7f104a Alexander Lobakin 2024-03-27  1288  	BUILD_BUG_ON(!res);
dc34d5036692c6 Alexander Lobakin 2022-06-24  1289  }
dc34d5036692c6 Alexander Lobakin 2022-06-24  1290  

:::::: The code at line 1278 was first introduced by commit
:::::: dc34d5036692c614eef23c1130ee42a201c316bf lib: test_bitmap: add compile-time optimization/evaluations assertions

:::::: TO: Alexander Lobakin <alexandr.lobakin@intel.com>
:::::: CC: Yury Norov <yury.norov@gmail.com>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
  2024-08-13  9:00 lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var) kernel test robot
@ 2024-08-13 14:38 ` Alexander Lobakin
  2024-08-13 19:47   ` Yury Norov
  0 siblings, 1 reply; 4+ messages in thread
From: Alexander Lobakin @ 2024-08-13 14:38 UTC (permalink / raw)
  To: Yury Norov, Kees Cook, Nick Desaulniers
  Cc: oe-kbuild-all, linux-kernel, Przemek Kitszel, kernel test robot,
	llvm

From: Kernel Test Robot <lkp@intel.com>
Date: Tue, 13 Aug 2024 17:00:56 +0800

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   d74da846046aeec9333e802f5918bd3261fb5509
> commit: 7adaf37f7f104a7ee5f150af491674ccbbfc4114 lib/bitmap: add compile-time test for __assign_bit() optimization
> date:   4 months ago
> config: um-randconfig-r132-20240812 (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/config)
> compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202408131601.Aj9JmK7K-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
>>> lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
>     1278 |         BUILD_BUG_ON(!__builtin_constant_p(~var));
>          |         ^
>    include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
>       50 |         BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
>          |         ^
>    include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
>       39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
>          |                                     ^
>    include/linux/compiler_types.h:460:2: note: expanded from macro 'compiletime_assert'
>      460 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
>          |         ^
>    include/linux/compiler_types.h:448:2: note: expanded from macro '_compiletime_assert'
>      448 |         __compiletime_assert(condition, msg, prefix, suffix)
>          |         ^
>    include/linux/compiler_types.h:441:4: note: expanded from macro '__compiletime_assert'
>      441 |                         prefix ## suffix();                             \
>          |                         ^
>    <scratch space>:193:1: note: expanded from here
>      193 | __compiletime_assert_127
>          | ^
>    1 error generated.
> 
> 
> vim +1278 lib/test_bitmap.c
> 
> 291f93ca339f5b Barry Song        2021-08-06  1227  
> 2356d198d2b4dd Yury Norov        2023-07-17  1228  /*
> 2356d198d2b4dd Yury Norov        2023-07-17  1229   * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled.
> 2356d198d2b4dd Yury Norov        2023-07-17  1230   * To workaround it, GCOV is force-disabled in Makefile for this configuration.
> 2356d198d2b4dd Yury Norov        2023-07-17  1231   */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1232  static void __init test_bitmap_const_eval(void)
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1233  {
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1234  	DECLARE_BITMAP(bitmap, BITS_PER_LONG);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1235  	unsigned long initvar = BIT(2);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1236  	unsigned long bitopvar = 0;
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1237  	unsigned long var = 0;
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1238  	int res;
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1239  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1240  	/*
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1241  	 * Compilers must be able to optimize all of those to compile-time
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1242  	 * constants on any supported optimization level (-O2, -Os) and any
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1243  	 * architecture. Otherwise, trigger a build bug.
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1244  	 * The whole function gets optimized out then, there's nothing to do
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1245  	 * in runtime.
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1246  	 */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1247  
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1248  	/* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1249  	bitmap_clear(bitmap, 0, BITS_PER_LONG);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1250  	if (!test_bit(7, bitmap))
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1251  		bitmap_set(bitmap, 5, 2);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1252  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1253  	/* Equals to `unsigned long bitopvar = BIT(20)` */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1254  	__change_bit(31, &bitopvar);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1255  	bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1256  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1257  	/* Equals to `unsigned long var = BIT(25)` */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1258  	var |= BIT(25);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1259  	if (var & BIT(0))
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1260  		var ^= GENMASK(9, 6);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1261  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1262  	/* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1263  	res = bitmap_weight(bitmap, 20);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1264  	BUILD_BUG_ON(!__builtin_constant_p(res));
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1265  	BUILD_BUG_ON(res != 2);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1266  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1267  	/* !(BIT(31) & BIT(18)) == 1 */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1268  	res = !test_bit(18, &bitopvar);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1269  	BUILD_BUG_ON(!__builtin_constant_p(res));
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1270  	BUILD_BUG_ON(!res);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1271  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1272  	/* BIT(2) & GENMASK(14, 8) == 0 */
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1273  	res = initvar & GENMASK(14, 8);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1274  	BUILD_BUG_ON(!__builtin_constant_p(res));
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1275  	BUILD_BUG_ON(res);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1276  
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1277  	/* ~BIT(25) */
> dc34d5036692c6 Alexander Lobakin 2022-06-24 @1278  	BUILD_BUG_ON(!__builtin_constant_p(~var));
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1279  	BUILD_BUG_ON(~var != ~BIT(25));
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1280  
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1281  	/* ~BIT(25) | BIT(25) == ~0UL */
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1282  	bitmap_complement(&var, &var, BITS_PER_LONG);
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1283  	__assign_bit(25, &var, true);
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1284  
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1285  	/* !(~(~0UL)) == 1 */
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1286  	res = bitmap_full(&var, BITS_PER_LONG);
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1287  	BUILD_BUG_ON(!__builtin_constant_p(res));
> 7adaf37f7f104a Alexander Lobakin 2024-03-27  1288  	BUILD_BUG_ON(!res);
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1289  }
> dc34d5036692c6 Alexander Lobakin 2022-06-24  1290  
> 
> :::::: The code at line 1278 was first introduced by commit
> :::::: dc34d5036692c614eef23c1130ee42a201c316bf lib: test_bitmap: add compile-time optimization/evaluations assertions
> 
> :::::: TO: Alexander Lobakin <alexandr.lobakin@intel.com>
> :::::: CC: Yury Norov <yury.norov@gmail.com>

+ Cc Clang folks.

clang-dev 20 issue?

Thanks,
Olek

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
  2024-08-13 14:38 ` Alexander Lobakin
@ 2024-08-13 19:47   ` Yury Norov
  2024-08-13 22:12     ` Nathan Chancellor
  0 siblings, 1 reply; 4+ messages in thread
From: Yury Norov @ 2024-08-13 19:47 UTC (permalink / raw)
  To: Alexander Lobakin
  Cc: Kees Cook, Nick Desaulniers, oe-kbuild-all, linux-kernel,
	Przemek Kitszel, kernel test robot, llvm, llvm-bugs

On Tue, Aug 13, 2024 at 04:38:10PM +0200, Alexander Lobakin wrote:
> From: Kernel Test Robot <lkp@intel.com>
> Date: Tue, 13 Aug 2024 17:00:56 +0800
> 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   d74da846046aeec9333e802f5918bd3261fb5509
> > commit: 7adaf37f7f104a7ee5f150af491674ccbbfc4114 lib/bitmap: add compile-time test for __assign_bit() optimization
> > date:   4 months ago
> > config: um-randconfig-r132-20240812 (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/config)
> > compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202408131601.Aj9JmK7K-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>):
> > 
> >>> lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
> >     1278 |         BUILD_BUG_ON(!__builtin_constant_p(~var));
> >          |         ^
> >    include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
> >       50 |         BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> >          |         ^
> >    include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
> >       39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> >          |                                     ^
> >    include/linux/compiler_types.h:460:2: note: expanded from macro 'compiletime_assert'
> >      460 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> >          |         ^
> >    include/linux/compiler_types.h:448:2: note: expanded from macro '_compiletime_assert'
> >      448 |         __compiletime_assert(condition, msg, prefix, suffix)
> >          |         ^
> >    include/linux/compiler_types.h:441:4: note: expanded from macro '__compiletime_assert'
> >      441 |                         prefix ## suffix();                             \
> >          |                         ^
> >    <scratch space>:193:1: note: expanded from here
> >      193 | __compiletime_assert_127
> >          | ^
> >    1 error generated.
> > 
> > 
> > vim +1278 lib/test_bitmap.c
> > 
> > 291f93ca339f5b Barry Song        2021-08-06  1227  
> > 2356d198d2b4dd Yury Norov        2023-07-17  1228  /*
> > 2356d198d2b4dd Yury Norov        2023-07-17  1229   * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled.
> > 2356d198d2b4dd Yury Norov        2023-07-17  1230   * To workaround it, GCOV is force-disabled in Makefile for this configuration.
> > 2356d198d2b4dd Yury Norov        2023-07-17  1231   */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1232  static void __init test_bitmap_const_eval(void)
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1233  {
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1234  	DECLARE_BITMAP(bitmap, BITS_PER_LONG);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1235  	unsigned long initvar = BIT(2);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1236  	unsigned long bitopvar = 0;
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1237  	unsigned long var = 0;
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1238  	int res;
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1239  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1240  	/*
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1241  	 * Compilers must be able to optimize all of those to compile-time
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1242  	 * constants on any supported optimization level (-O2, -Os) and any
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1243  	 * architecture. Otherwise, trigger a build bug.
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1244  	 * The whole function gets optimized out then, there's nothing to do
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1245  	 * in runtime.
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1246  	 */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1247  
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1248  	/* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1249  	bitmap_clear(bitmap, 0, BITS_PER_LONG);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1250  	if (!test_bit(7, bitmap))
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1251  		bitmap_set(bitmap, 5, 2);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1252  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1253  	/* Equals to `unsigned long bitopvar = BIT(20)` */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1254  	__change_bit(31, &bitopvar);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1255  	bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1256  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1257  	/* Equals to `unsigned long var = BIT(25)` */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1258  	var |= BIT(25);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1259  	if (var & BIT(0))
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1260  		var ^= GENMASK(9, 6);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1261  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1262  	/* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1263  	res = bitmap_weight(bitmap, 20);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1264  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1265  	BUILD_BUG_ON(res != 2);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1266  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1267  	/* !(BIT(31) & BIT(18)) == 1 */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1268  	res = !test_bit(18, &bitopvar);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1269  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1270  	BUILD_BUG_ON(!res);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1271  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1272  	/* BIT(2) & GENMASK(14, 8) == 0 */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1273  	res = initvar & GENMASK(14, 8);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1274  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1275  	BUILD_BUG_ON(res);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1276  
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1277  	/* ~BIT(25) */
> > dc34d5036692c6 Alexander Lobakin 2022-06-24 @1278  	BUILD_BUG_ON(!__builtin_constant_p(~var));
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1279  	BUILD_BUG_ON(~var != ~BIT(25));
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1280  
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1281  	/* ~BIT(25) | BIT(25) == ~0UL */
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1282  	bitmap_complement(&var, &var, BITS_PER_LONG);
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1283  	__assign_bit(25, &var, true);
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1284  
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1285  	/* !(~(~0UL)) == 1 */
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1286  	res = bitmap_full(&var, BITS_PER_LONG);
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1287  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1288  	BUILD_BUG_ON(!res);
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1289  }
> > dc34d5036692c6 Alexander Lobakin 2022-06-24  1290  
> > 
> > :::::: The code at line 1278 was first introduced by commit
> > :::::: dc34d5036692c614eef23c1130ee42a201c316bf lib: test_bitmap: add compile-time optimization/evaluations assertions
> > 
> > :::::: TO: Alexander Lobakin <alexandr.lobakin@intel.com>
> > :::::: CC: Yury Norov <yury.norov@gmail.com>
> 
> + Cc Clang folks.
> 
> clang-dev 20 issue?
> 
> Thanks,
> Olek

Seems like that. Looping LLVM-bugs <llvm-bugs@lists.llvm.org>.

Thanks,
Yury

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
  2024-08-13 19:47   ` Yury Norov
@ 2024-08-13 22:12     ` Nathan Chancellor
  0 siblings, 0 replies; 4+ messages in thread
From: Nathan Chancellor @ 2024-08-13 22:12 UTC (permalink / raw)
  To: Yury Norov
  Cc: Alexander Lobakin, Kees Cook, Nick Desaulniers, oe-kbuild-all,
	linux-kernel, Przemek Kitszel, kernel test robot, llvm, llvm-bugs

On Tue, Aug 13, 2024 at 12:47:27PM -0700, Yury Norov wrote:
> On Tue, Aug 13, 2024 at 04:38:10PM +0200, Alexander Lobakin wrote:
> > From: Kernel Test Robot <lkp@intel.com>
> > Date: Tue, 13 Aug 2024 17:00:56 +0800
> > 
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > head:   d74da846046aeec9333e802f5918bd3261fb5509
> > > commit: 7adaf37f7f104a7ee5f150af491674ccbbfc4114 lib/bitmap: add compile-time test for __assign_bit() optimization
> > > date:   4 months ago
> > > config: um-randconfig-r132-20240812 (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/config)
> > > compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18)
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240813/202408131601.Aj9JmK7K-lkp@intel.com/reproduce)
> > > 
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202408131601.Aj9JmK7K-lkp@intel.com/
> > > 
> > > All errors (new ones prefixed by >>):
> > > 
> > >>> lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var)
> > >     1278 |         BUILD_BUG_ON(!__builtin_constant_p(~var));
> > >          |         ^
> > >    include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
> > >       50 |         BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> > >          |         ^
> > >    include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
> > >       39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> > >          |                                     ^
> > >    include/linux/compiler_types.h:460:2: note: expanded from macro 'compiletime_assert'
> > >      460 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> > >          |         ^
> > >    include/linux/compiler_types.h:448:2: note: expanded from macro '_compiletime_assert'
> > >      448 |         __compiletime_assert(condition, msg, prefix, suffix)
> > >          |         ^
> > >    include/linux/compiler_types.h:441:4: note: expanded from macro '__compiletime_assert'
> > >      441 |                         prefix ## suffix();                             \
> > >          |                         ^
> > >    <scratch space>:193:1: note: expanded from here
> > >      193 | __compiletime_assert_127
> > >          | ^
> > >    1 error generated.
> > > 
> > > 
> > > vim +1278 lib/test_bitmap.c
> > > 
> > > 291f93ca339f5b Barry Song        2021-08-06  1227  
> > > 2356d198d2b4dd Yury Norov        2023-07-17  1228  /*
> > > 2356d198d2b4dd Yury Norov        2023-07-17  1229   * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled.
> > > 2356d198d2b4dd Yury Norov        2023-07-17  1230   * To workaround it, GCOV is force-disabled in Makefile for this configuration.
> > > 2356d198d2b4dd Yury Norov        2023-07-17  1231   */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1232  static void __init test_bitmap_const_eval(void)
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1233  {
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1234  	DECLARE_BITMAP(bitmap, BITS_PER_LONG);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1235  	unsigned long initvar = BIT(2);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1236  	unsigned long bitopvar = 0;
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1237  	unsigned long var = 0;
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1238  	int res;
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1239  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1240  	/*
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1241  	 * Compilers must be able to optimize all of those to compile-time
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1242  	 * constants on any supported optimization level (-O2, -Os) and any
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1243  	 * architecture. Otherwise, trigger a build bug.
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1244  	 * The whole function gets optimized out then, there's nothing to do
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1245  	 * in runtime.
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1246  	 */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1247  
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1248  	/* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1249  	bitmap_clear(bitmap, 0, BITS_PER_LONG);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1250  	if (!test_bit(7, bitmap))
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1251  		bitmap_set(bitmap, 5, 2);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1252  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1253  	/* Equals to `unsigned long bitopvar = BIT(20)` */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1254  	__change_bit(31, &bitopvar);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1255  	bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1256  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1257  	/* Equals to `unsigned long var = BIT(25)` */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1258  	var |= BIT(25);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1259  	if (var & BIT(0))
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1260  		var ^= GENMASK(9, 6);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1261  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1262  	/* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1263  	res = bitmap_weight(bitmap, 20);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1264  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1265  	BUILD_BUG_ON(res != 2);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1266  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1267  	/* !(BIT(31) & BIT(18)) == 1 */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1268  	res = !test_bit(18, &bitopvar);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1269  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1270  	BUILD_BUG_ON(!res);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1271  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1272  	/* BIT(2) & GENMASK(14, 8) == 0 */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1273  	res = initvar & GENMASK(14, 8);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1274  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1275  	BUILD_BUG_ON(res);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1276  
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1277  	/* ~BIT(25) */
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24 @1278  	BUILD_BUG_ON(!__builtin_constant_p(~var));
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1279  	BUILD_BUG_ON(~var != ~BIT(25));
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1280  
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1281  	/* ~BIT(25) | BIT(25) == ~0UL */
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1282  	bitmap_complement(&var, &var, BITS_PER_LONG);
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1283  	__assign_bit(25, &var, true);
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1284  
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1285  	/* !(~(~0UL)) == 1 */
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1286  	res = bitmap_full(&var, BITS_PER_LONG);
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1287  	BUILD_BUG_ON(!__builtin_constant_p(res));
> > > 7adaf37f7f104a Alexander Lobakin 2024-03-27  1288  	BUILD_BUG_ON(!res);
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1289  }
> > > dc34d5036692c6 Alexander Lobakin 2022-06-24  1290  
> > > 
> > > :::::: The code at line 1278 was first introduced by commit
> > > :::::: dc34d5036692c614eef23c1130ee42a201c316bf lib: test_bitmap: add compile-time optimization/evaluations assertions
> > > 
> > > :::::: TO: Alexander Lobakin <alexandr.lobakin@intel.com>
> > > :::::: CC: Yury Norov <yury.norov@gmail.com>
> > 
> > + Cc Clang folks.
> > 
> > clang-dev 20 issue?
> > 
> > Thanks,
> > Olek
> 
> Seems like that. Looping LLVM-bugs <llvm-bugs@lists.llvm.org>.

It's not, I bisected it to a change in the 17 release. I think this only
shows up with this change because of '-fprofile-instr-generate', which
ARCH=um uses for GCOV, which was only added in commit 32a84cfc6caf
("arch: um: Add Clang coverage support") from 6.8.

I reported this upstream (I don't think llvm-bugs is really monitored
for traffic like this) and cc'd the author of the change that broke
this:

https://github.com/llvm/llvm-project/issues/103479

I think there is a tangential issue with ARCH=um doing its own thing
with the GCOV flags (such that it does not appear to respect
GCOV_PROFILE_... := n) but that just results in not being able to remove
the flags from test_bitmap.o's command.

Cheers,
Nathan

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-08-13 22:12 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2024-08-13  9:00 lib/test_bitmap.c:1278:2: error: call to '__compiletime_assert_127' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(~var) kernel test robot
2024-08-13 14:38 ` Alexander Lobakin
2024-08-13 19:47   ` Yury Norov
2024-08-13 22:12     ` Nathan Chancellor

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