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Simplify. The condition on line 1223 is always true.

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Here's why:

The condition

 if (VG_(brk_limit) > VG_(brk_base))   line 1223

is reachable iff 

  newbrk < VG_(brk_base)  on line 1201  is false  AND
  newbrk < VG_(brk_limit) on line 1205  is true

Rewrite as

  newbrk >= VG_(brk_base)    is true  AND
  newbrk <  VG_(brk_limit)   is true

Rewrite as

  newbrk >= VG_(brk_base)        is true  AND
  newbrk <= VG_(brk_limit) - 1   is true

Combine

  VG_(brk_base) <= newbrk <= VG_(brk_limit) - 1

Therefore

  VG_(brk_base) <= VG_(brk_limit) - 1

Or

  VG_(brk_base) < VG_(brk_limit)

Which is the same as

  VG_(brk_limit) > VG_(brk_base)

qed.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15181
This commit is contained in:
Florian Krohm 2015-05-05 06:14:10 +00:00
parent d31115a1d4
commit fa0d7aa5c6
1 changed files with 1 additions and 4 deletions
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5
coregrind/m_syswrap/syswrap-generic.c
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@ -1220,10 +1220,7 @@ static Addr do_brk ( Addr newbrk, ThreadId tid )
and that segment is writable. */
NSegment const * seg2;
if (VG_(brk_limit) > VG_(brk_base))
seg2 = VG_(am_find_nsegment)( VG_(brk_limit)-1 );
else
seg2 = VG_(am_find_nsegment)( VG_(brk_limit) );
seg2 = VG_(am_find_nsegment)( VG_(brk_limit) - 1 );
vg_assert(seg2);
if (seg == seg2 && seg->hasW)