13 Commits

Author SHA1 Message Date
Sam McCall
d85c233e4b [dataflow] Make SAT solver deterministic
The SAT solver imported its constraints by iterating over an unordered DenseSet.
The path taken, and ultimately the runtime, the specific solution found, and
whether it would time out or complete could depend on the iteration order.

Instead, have the caller specify an ordered collection of constraints.
If this is built in a deterministic way, the system can have deterministic
behavior.
(The main alternative is to sort the constraints by value, but this option
is simpler today).

A lot of nondeterminism still appears to be remain in the framework, so today
the solver's inputs themselves are not deterministic yet.

Differential Revision: https://reviews.llvm.org/D153584
2023-06-26 21:16:25 +02:00
Sam McCall
d630134f1f [dataflow] handle missing case in value debug strings
Differential Revision: https://reviews.llvm.org/D146625
2023-03-25 04:20:06 +01:00
Fangrui Song
1e6adbadc7 [clang] llvm::Optional::value => operator*/operator->
std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
call sites block std::optional migration.

This makes `ninja check-clang` work in the absence of llvm::Optional::value.
2022-12-17 08:10:45 +00:00
Yitzhak Mandelbaum
39b9d4f188 [clang][dataflow] Add support for a Top value in boolean formulas.
Currently, our boolean formulas (`BoolValue`) don't form a lattice, since they
have no Top element. This patch adds such an element, thereby "completing" the
built-in model of bools to be a proper semi-lattice. It still has infinite
height, which is its own problem, but that can be solved separately, through
widening and the like.

Patch 1 for Issue #56931.

Differential Revision: https://reviews.llvm.org/D135397
2022-10-14 17:41:53 +00:00
Wei Yi Tee
dbb95c2a85 [clang][dataflow] Debug string for value kinds.
Differential Revision: https://reviews.llvm.org/D131891
2022-08-19 15:00:01 +00:00
Dmitri Gribenko
b5e3dac33d [clang][dataflow] Add explicit "AST" nodes for implications and iff
Previously we used to desugar implications and biconditionals into
equivalent CNF/DNF as soon as possible. However, this desugaring makes
debug output (Environment::dump()) less readable than it could be.
Therefore, it makes sense to keep the sugared representation of a
boolean formula, and desugar it in the solver.

Reviewed By: sgatev, xazax.hun, wyt

Differential Revision: https://reviews.llvm.org/D130519
2022-07-26 14:19:22 +02:00
Dmitri Gribenko
b5414b566a [clang][dataflow] Add DataflowEnvironment::dump()
Start by dumping the flow condition.

Reviewed By: ymandel

Differential Revision: https://reviews.llvm.org/D130398
2022-07-23 01:31:53 +02:00
Dmitri Gribenko
ee6aba85aa [clang][dataflow] Expose stringification functions for SAT solver enums
Reviewed By: ymandel

Differential Revision: https://reviews.llvm.org/D130399
2022-07-23 01:21:20 +02:00
Dmitri Gribenko
589ddd7fe8 [clang][dataflow] ArrayRef'ize debugString()
Reviewed By: ymandel

Differential Revision: https://reviews.llvm.org/D130400
2022-07-23 01:16:31 +02:00
Fangrui Song
3c849d0aef Modernize Optional::{getValueOr,hasValue} 2022-07-15 01:20:39 -07:00
Kazu Hirata
cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
Wei Yi Tee
b8d83e8004 [clang][dataflow] Generate readable form of input and output of satisfiability checking.
Differential Revision: https://reviews.llvm.org/D129548
2022-07-13 11:58:51 +00:00
Wei Yi Tee
c9666d2339 [clang][dataflow] Generate readable form of boolean values.
Differential Revision: https://reviews.llvm.org/D129547
2022-07-13 10:35:17 +00:00