Purge intermediate relations, but not input/output

[adamjseitz]

In #2066, a new option was added to the C++ interface to allow purging intermediate relations. However, the current implementation purges input and output relations, which makes it impractical to use with performIO disabled (since the output relations would be purged before there is an opportunity for user code to read the output relation). By excluding input and output relations from those that are purged, the C++ interface can be used with pruneImdtRels enabled but performIO disabled.

[aeflores]

@adamjseitz maybe we should add a test? I see there are some C++ tests in https://github.com/souffle-lang/souffle/tree/master/tests/interface

[b-scholz]

Can you run clang-format? I.e.,

diff --git a/src/synthesiser/Synthesiser.cpp b/src/synthesiser/Synthesiser.cpp
[11](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:12)
index 58b7ead..487f340 100644
[12](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:13)
--- a/src/synthesiser/Synthesiser.cpp
[13](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:14)
+++ b/src/synthesiser/Synthesiser.cpp
[14](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:15)
@@ -466,7 +466,8 @@void Synthesiser::emitCode(std::ostream& out, const Statement& stmt) {
[15](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:16)
[16](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:17)
            auto Relation = synthesiser.lookup(clear.getRelation());
[17](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:18)
            bool isIntermediate = !contains(synthesiser.loadRelations, Relation->getName()) &&
[18](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:19)
-                !contains(synthesiser.storeRelations, Relation->getName()) && !Relation->isTemp();
[19](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:20)
+                                  !contains(synthesiser.storeRelations, Relation->getName()) &&
[20](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:21)
+                                  !Relation->isTemp();
[21](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:22)
[22](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:23)
            if (isIntermediate) {
[23](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:24)
                out << "if (pruneImdtRels) ";
[24](https://github.com/souffle-lang/souffle/runs/6947156929?check_suite_focus=true#step:3:25)

[codecov]

Codecov Report

Merging #2286 (dc76fd6) into master (8979bdf) will increase coverage by 0.24%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2286      +/-   ##
==========================================
+ Coverage   77.17%   77.41%   +0.24%     
==========================================
  Files         458      461       +3     
  Lines       29159    28998     -161     
==========================================
- Hits        22504    22450      -54     
+ Misses       6655     6548     -107     

Impacted Files	Coverage Δ
src/synthesiser/Synthesiser.h	100.00% <ø> (ø)
src/synthesiser/Synthesiser.cpp	83.85% <100.00%> (+0.01%)	⬆️
src/include/souffle/profile/ProfileEvent.h	92.85% <0.00%> (-5.11%)	⬇️
src/ast2ram/seminaive/ClauseTranslator.cpp	97.84% <0.00%> (-0.12%)	⬇️
src/ast/utility/SipsMetric.cpp
src/ast/utility/SipsMetric.h
src/ast2ram/utility/SipGraph.h	100.00% <0.00%> (ø)
src/ast2ram/utility/SipsMetric.cpp	55.19% <0.00%> (ø)
src/include/souffle/utility/SubsetCache.h	88.23% <0.00%> (ø)
src/ast2ram/utility/SipsMetric.h	30.00% <0.00%> (ø)
... and 5 more

[adamjseitz]

@adamjseitz maybe we should add a test? I see there are some C++ tests in https://github.com/souffle-lang/souffle/tree/master/tests/interface

I modified the existing insert_print test to utilize pruneImdtRels to verify that it's working - it didn't seem worth adding a near-duplicate test.

Can you run clang-format? I.e.,

Sorry! I think the formatting is fixed now.

[b-scholz]

Thanks for the refactoring!