FIR CFA: properly visit subgraphs in checkers

Interpretation: a graph A is a subgraph of B if information available at
nodes of A depends on the paths taken in B. For example, local classes
are subgraphs of a graph in which they are declared, and members of
those classes are subgraphs of the local class itself - because these
members can reference captured values.

Consequences:

 * if graph G is a subgraph of node N, then G is a subgraph of N's
   owner;
 * `ControlFlowAnalysisDiagnosticComponent` will only visit root graphs;
 * `graph.traverse` will ignore subgraph boundaries, as if all subgraphs
   are inlined into one huge root graph;
 * if a control flow checker needs information from a declaration to
   which a graph is attached, it must look at subgraphs explicitly.

For example, consider the `callsInPlace` checker. When a function
has a `callsInPlace` contract and a local declaration, the checker must
visit that local declaration to ensure it does not capture the allegedly
called-in-place argument - hence `graph.traverse` will look at the
nodes. However, the local declaration can also be a function with its
own `callsInPlace` contracts, so the checker should also run for it in
isolation. If that sounds quadratic, that's because unfortunately it is.
This commit is contained in:
pyos
2022-12-09 12:32:46 +01:00
committed by Dmitriy Novozhilov
parent 5180e1f4a4
commit aadea0e26f
35 changed files with 1191 additions and 1325 deletions
@@ -13,34 +13,33 @@ digraph initBlock_kt {
1 -> {2};
subgraph cluster_1 {
color=red
3 [label="Enter init block" style="filled" fillcolor=red];
subgraph cluster_2 {
color=blue
4 [label="Enter block"];
5 [label="Const: Int(1)"];
6 [label="Variable declaration: lval x: R|kotlin/Int|"];
7 [label="Exit block"];
}
8 [label="Exit init block" style="filled" fillcolor=red];
}
3 -> {4};
4 -> {5};
5 -> {6};
6 -> {7};
7 -> {8};
8 -> {11} [color=green];
subgraph cluster_3 {
color=red
9 [label="Enter class Foo" style="filled" fillcolor=red];
10 [label="Part of class initialization"];
subgraph cluster_2 {
color=blue
3 [label="Enter init block" style="filled" fillcolor=red];
subgraph cluster_3 {
color=blue
4 [label="Enter block"];
5 [label="Const: Int(1)"];
6 [label="Variable declaration: lval x: R|kotlin/Int|"];
7 [label="Exit block"];
}
8 [label="Exit init block" style="filled" fillcolor=red];
}
11 [label="Exit class Foo" style="filled" fillcolor=red];
}
9 -> {10} [color=green];
10 -> {3} [color=green];
10 -> {11} [style=dotted];
10 -> {3} [style=dashed];
3 -> {4};
4 -> {5};
5 -> {6};
6 -> {7};
7 -> {8};
8 -> {11} [color=green];
subgraph cluster_4 {
color=red
@@ -53,21 +52,31 @@ digraph initBlock_kt {
subgraph cluster_5 {
color=red
15 [label="Enter init block" style="filled" fillcolor=red];
26 [label="Enter class Bar" style="filled" fillcolor=red];
27 [label="Part of class initialization"];
subgraph cluster_6 {
color=blue
16 [label="Enter block"];
17 [label="Const: Int(1)"];
18 [label="Variable declaration: lval x: R|kotlin/Int|"];
19 [label="Function call: R|java/lang/Exception.Exception|()" style="filled" fillcolor=yellow];
20 [label="Throw: throw R|java/lang/Exception.Exception|()"];
21 [label="Stub" style="filled" fillcolor=gray];
22 [label="Const: Int(2)" style="filled" fillcolor=gray];
23 [label="Variable declaration: lval y: R|kotlin/Int|" style="filled" fillcolor=gray];
24 [label="Exit block" style="filled" fillcolor=gray];
15 [label="Enter init block" style="filled" fillcolor=red];
subgraph cluster_7 {
color=blue
16 [label="Enter block"];
17 [label="Const: Int(1)"];
18 [label="Variable declaration: lval x: R|kotlin/Int|"];
19 [label="Function call: R|java/lang/Exception.Exception|()" style="filled" fillcolor=yellow];
20 [label="Throw: throw R|java/lang/Exception.Exception|()"];
21 [label="Stub" style="filled" fillcolor=gray];
22 [label="Const: Int(2)" style="filled" fillcolor=gray];
23 [label="Variable declaration: lval y: R|kotlin/Int|" style="filled" fillcolor=gray];
24 [label="Exit block" style="filled" fillcolor=gray];
}
25 [label="Exit init block" style="filled" fillcolor=red style="filled" fillcolor=gray];
}
25 [label="Exit init block" style="filled" fillcolor=red style="filled" fillcolor=gray];
28 [label="Exit class Bar" style="filled" fillcolor=red style="filled" fillcolor=gray];
}
26 -> {27} [color=green];
27 -> {15} [color=green];
27 -> {28} [style=dotted];
27 -> {15} [style=dashed];
15 -> {16};
16 -> {17};
17 -> {18};
@@ -80,15 +89,4 @@ digraph initBlock_kt {
24 -> {25} [style=dotted];
25 -> {28} [style=dotted];
subgraph cluster_7 {
color=red
26 [label="Enter class Bar" style="filled" fillcolor=red];
27 [label="Part of class initialization"];
28 [label="Exit class Bar" style="filled" fillcolor=red style="filled" fillcolor=gray];
}
26 -> {27} [color=green];
27 -> {15} [color=green];
27 -> {28} [style=dotted];
27 -> {15} [style=dashed];
}