On certain databases, the evaluation of this predicate was running out
of memory due to the way the `count` aggregate was being used. Here's
an example of the tuple counts involved:
```
Tuple counts for PointsToContext::syntactic_call_count#cf3039a0#ff#antijoin_rhs/1@d2199bb8 after 1m27s:
595518502 ~521250% {1} r1 = JOIN PointsToContext::syntactic_call_count#cf3039a0#ff#shared#3 WITH Flow::CallNode::getFunction#dispred#f0820431#ff_1#join_rhs ON FIRST 1 OUTPUT Lhs.1 'arg0'
26518709 ~111513% {1} r2 = JOIN PointsToContext::syntactic_call_count#cf3039a0#ff#shared#2 WITH Flow::CallNode::getFunction#dispred#f0820431#ff_1#join_rhs ON FIRST 1 OUTPUT Lhs.1 'arg0'
622037211 ~498045% {1} r3 = r1 UNION r2
return r3
```
and a timing report that looked like this:
```
time | evals | max @ iter | predicate
------|-------|--------------|----------
5m8s | | | PointsToContext::syntactic_call_count#cf3039a0#ff#shared#2@6d98d1nd
4m38s | | | PointsToContext::syntactic_call_count#cf3039a0#ff#count_range@f5df1do4
3m51s | | | PointsToContext::syntactic_call_count#cf3039a0#ff#shared#3@da3b4abf
1m58s | 7613 | 37ms @ 4609 | MRO::ClassListList::removedClassParts#f0820431#fffff#reorder_2_3_4_0_1@8155axyi
1m37s | 7613 | 33ms @ 3904 | MRO::ClassListList::bestMergeCandidate#f0820431#2#fff@8155a83w
1m27s | | | PointsToContext::syntactic_call_count#cf3039a0#ff#antijoin_rhs@d2199bb8
1m8s | 1825 | 63ms @ 404 | PointsTo::Expressions::equalityEvaluatesTo#741b54e2#fffff@8155aw7w
37.6s | | | PointsToContext::syntactic_call_count#cf3039a0#ff#join_rhs@e348fc1p
...
```
To make optimising this easier for the compiler, I moved the bodies of
the `count` aggregate into their own helper predicates (with size
linear in the number of `CallNode`s), and also factored out the many
calls to `f.getName()`.
The astute reader will notice that in writing this as a sum of `count`s
rather than a count of a disjunction, the intersection (if it exists)
will be counted twice, and so the semantics may be different. However,
since `method_call` and `function_call` require `AttrNode` and
`NameNode` functions respectively, and as these two types are disjoint,
there is no intersection, and so the semantics should be preserved.
After the change, the evaluation of `syntactic_call_count` now looks as
follows:
```
Tuple counts for PointsToContext::syntactic_call_count#cf3039a0#ff/2@662dd8s0 after 216ms:
23960 ~0% {1} r1 = @py_scope#f AND NOT py_Functions_0#antijoin_rhs(Lhs.0 's')
23960 ~0% {2} r2 = SCAN r1 OUTPUT In.0 's', 0
276309 ~7% {2} r3 = SCAN @py_scope#f OUTPUT In.0 's', "__init__"
11763 ~0% {2} r4 = JOIN r3 WITH Scope::Scope::getName#dispred#f0820431#fb ON FIRST 2 OUTPUT Lhs.0 's', 1
35723 ~0% {2} r5 = r2 UNION r4
252349 ~0% {2} r6 = JOIN @py_scope#f WITH Function::Function::getName#dispred#f0820431#ff ON FIRST 1 OUTPUT Lhs.0 's', Rhs.1
240586 ~0% {2} r7 = SELECT r6 ON In.1 != "__init__"
131727 ~4% {2} r8 = r7 AND NOT project#PointsToContext::method_call#cf3039a0#ff(Lhs.1)
131727 ~0% {3} r9 = SCAN r8 OUTPUT In.1, In.0 's', 0
240586 ~0% {2} r10 = SCAN r7 OUTPUT In.1, In.0 's'
108859 ~0% {3} r11 = JOIN r10 WITH PointsToContext::syntactic_call_count#cf3039a0#ff#join_rhs ON FIRST 1 OUTPUT Lhs.0, Lhs.1 's', Rhs.1
240586 ~0% {3} r12 = r9 UNION r11
24100 ~0% {2} r13 = JOIN r12 WITH PointsToContext::syntactic_call_count#cf3039a0#ff#join_rhs#1 ON FIRST 1 OUTPUT Lhs.1 's', (Rhs.1 + Lhs.2)
240586 ~0% {2} r14 = SELECT r6 ON In.1 != "__init__"
131727 ~4% {2} r15 = r14 AND NOT project#PointsToContext::method_call#cf3039a0#ff(Lhs.1)
131727 ~0% {3} r16 = SCAN r15 OUTPUT In.0 's', In.1, 0
108859 ~4% {3} r17 = JOIN r10 WITH PointsToContext::syntactic_call_count#cf3039a0#ff#join_rhs ON FIRST 1 OUTPUT Lhs.1 's', Lhs.0, Rhs.1
240586 ~4% {3} r18 = r16 UNION r17
216486 ~2% {3} r19 = r18 AND NOT project#PointsToContext::function_call#cf3039a0#ff(Lhs.1)
216486 ~0% {2} r20 = SCAN r19 OUTPUT In.0 's', (0 + In.2)
240586 ~0% {2} r21 = r13 UNION r20
276309 ~0% {2} r22 = r5 UNION r21
return r22
```
- "Normal" instead of "NonSpecial"
- "NonLibrary" instead of "2"
I could not find a good replacement for "NonLibrary", nor for "Source",
but I added QLDocs in a few places to help the reading.
With this change, users are now able to run View AST command in
vscode within vscode workspaces that do not include the core libraries.
The relevant core library only needs to be installed in the package
cache.
