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Merged
merged 1 commit into from
Sep 26, 2018
Merged

check for side effects in quantifiers #2979

merged 1 commit into from
Sep 26, 2018

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kroening
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@kroening kroening commented Sep 18, 2018 •
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tautschnig
tautschnig requested changes Sep 19, 2018
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src/goto-programs/goto_clean_expr.cpp Outdated
@@ -93,8 +93,6 @@ bool goto_convertt::needs_cleaning(const exprt &expr)
// g1 = (i == 0)
// g2 = (i > 10)
// forall (i : int) (g1 || g2)
if(expr.id()==ID_forall || expr.id()==ID_exists)
return false;
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The comment above this code needs to be moved, it doesn't actually make sense when these lines are removed.

src/goto-programs/goto_clean_expr.cpp Outdated
@@ -409,7 +407,7 @@ void goto_convertt::clean_expr(
// check if there are side-effects
goto_programt tmp;
clean_expr(expr.op1(), tmp, mode, true);
if(tmp.instructions.empty())
if(!tmp.instructions.empty())
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So this was dead code before. It's no longer dead code now - do we have any tests exercising it?

@kroening kroening force-pushed the quantifier-sideeffects branch from cc4fae7 to a887387 Compare September 23, 2018 13:06
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Now with different approach -- the rule is now checked in the front-end

@kroening kroening force-pushed the quantifier-sideeffects branch from a887387 to 0812cc1 Compare September 23, 2018 21:30
allredj
allredj reviewed Sep 23, 2018
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Passed Diffblue compatibility checks (cbmc commit: 0812cc1).
Build URL: https://travis-ci.com/diffblue/test-gen/builds/85673814

smowton
smowton reviewed Sep 24, 2018
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src/goto-programs/goto_clean_expr.cpp Outdated
throw 0;
}
return;
// the front-end checks these for side-effects
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Invariant?

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DATA_INVARIANT(!has_subexpr(expr, ID_side_effect), "the front-end should check quantified expressions for side-effects");

tautschnig
tautschnig requested changes Sep 24, 2018
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I'd suggest to simplify as described below.

src/ansi-c/c_typecheck_expr.cpp Outdated
@@ -166,6 +166,18 @@ bool c_typecheck_baset::gcc_types_compatible_p(
return false;
}

static bool has_side_effect(const exprt &expr)
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No need - see below.

src/ansi-c/c_typecheck_expr.cpp Outdated
@@ -303,6 +315,13 @@ void c_typecheck_baset::typecheck_expr_main(exprt &expr)
throw 0;
}

if(has_side_effect(expr.op1()))
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if(has_subexpr(expr.op1(), ID_side_effect))

src/goto-programs/goto_clean_expr.cpp Outdated
throw 0;
}
return;
// the front-end checks these for side-effects
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DATA_INVARIANT(!has_subexpr(expr, ID_side_effect), "the front-end should check quantified expressions for side-effects");

@kroening kroening force-pushed the quantifier-sideeffects branch from 0812cc1 to f505207 Compare September 26, 2018 09:19
@kroening kroening assigned tautschnig and unassigned kroening Sep 26, 2018
tautschnig
tautschnig approved these changes Sep 26, 2018
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Looks good, except for the line break.

src/goto-programs/goto_clean_expr.cpp Outdated
throw 0;
}
return;
DATA_INVARIANT(!has_subexpr(expr, ID_side_effect), "the front-end should check quantified expressions for side-effects");
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This line got too long.

@tautschnig tautschnig assigned kroening and unassigned tautschnig Sep 26, 2018
allredj
allredj reviewed Sep 26, 2018
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Passed Diffblue compatibility checks (cbmc commit: f505207).
Build URL: https://travis-ci.com/diffblue/test-gen/builds/85988064

@tautschnig
check for side effects in quantifiers in the front-end
a3fa911 
This fixes a failed attempt to check for quantifiers during goto conversion
by checking earlier in the C front-end.
@tautschnig tautschnig force-pushed the quantifier-sideeffects branch from f505207 to a3fa911 Compare September 26, 2018 13:13
@tautschnig tautschnig mentioned this pull request Sep 26, 2018
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@tautschnig tautschnig merged commit 095fb3d into develop Sep 26, 2018
@tautschnig tautschnig deleted the quantifier-sideeffects branch September 26, 2018 14:49
allredj
allredj reviewed Sep 26, 2018
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Passed Diffblue compatibility checks (cbmc commit: a3fa911).
Build URL: https://travis-ci.com/diffblue/test-gen/builds/86019720

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@smowton smowton smowton approved these changes

@allredj allredj allredj left review comments

@tautschnig tautschnig tautschnig approved these changes

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

@pkesseli pkesseli Awaiting requested review from pkesseli

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@kroening @smowton @tautschnig @allredj