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CONTRACTS: make __CPROVER_is_fresh call-local. #6813

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Merged
merged 1 commit into from
Apr 17, 2022
Merged

CONTRACTS: make __CPROVER_is_fresh call-local. #6813

merged 1 commit into from
Apr 17, 2022

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The previous implementation of the __CPROVER_is_fresh predicates used a global static map, which caused different occurrences of a function call from same call site to interfere.

We now use a locally allocated memory map which solves the problem.

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@remi-delmas-3000 remi-delmas-3000 force-pushed the fix-is-fresh-call-local branch from a95cd5c to 5ff1a04 Compare April 15, 2022 20:11
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codecov bot commented Apr 15, 2022 •
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Codecov Report

Merging #6813 (b9290e4) into develop (aed93c8) will increase coverage by 0.00%.
The diff coverage is 98.70%.

@@           Coverage Diff            @@
##           develop    #6813   +/-   ##
========================================
  Coverage    76.99%   77.00%           
========================================
  Files         1594     1594           
  Lines       184263   184348   +85     
========================================
+ Hits        141872   141954   +82     
- Misses       42391    42394    +3
Impacted Files Coverage Δ
src/goto-instrument/contracts/memory_predicates.h 100.00% <ø> (ø)
src/solvers/smt2/smt2_conv.h 100.00% <ø> (ø)
...c/solvers/smt2_incremental/convert_expr_to_smt.cpp 84.53% <0.00%> (-0.35%) ⬇️
src/util/simplify_expr_class.h 90.47% <ø> (ø)
src/util/std_expr.h 93.18% <ø> (ø)
src/ansi-c/c_typecheck_expr.cpp 77.05% <100.00%> (-0.02%) ⬇️
src/ansi-c/goto_check_c.cpp 91.47% <100.00%> (ø)
src/goto-instrument/contracts/contracts.cpp 93.89% <100.00%> (+0.07%) ⬆️
...rc/goto-instrument/contracts/memory_predicates.cpp 85.49% <100.00%> (+1.96%) ⬆️
src/solvers/flattening/bv_pointers.cpp 83.09% <100.00%> (ø)
... and 9 more

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CONTRACTS: make __CPROVER_is_fresh really call-local.
b9290e4 
The previous implementation of the predicates
used a global static map to check for
aliasing between pointers, which caused different
calls to a same function (from a same call site)
to interfere.

We now use locally declared memory maps to track
aliasing seen by the predicates which solves the
problem, since every call will use a freshly
zero-initialised map.

format fixes
@remi-delmas-3000 remi-delmas-3000 force-pushed the fix-is-fresh-call-local branch from 5ff1a04 to b9290e4 Compare April 15, 2022 21:02
@tautschnig tautschnig merged commit abc4e01 into diffblue:develop Apr 17, 2022
@feliperodri feliperodri added aws Bugs or features of importance to AWS CBMC users Code Contracts Function and loop contracts labels Apr 22, 2022
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@tautschnig tautschnig tautschnig approved these changes

@feliperodri feliperodri Awaiting requested review from feliperodri feliperodri is a code owner

@SaswatPadhi SaswatPadhi Awaiting requested review from SaswatPadhi

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