Wrong "uses" edges for reexported inner modules' types

[regexident]

Wrong "uses" edges for reexported inner modules' types

[regexident]

I'll have to do a more thorough investigation for this, but my guess is that this difference is due to the fact that we make use of rust-analyzer's HIR, rather than it's AST. The HIR might be providing an already resolved dependency graph?

Previously we did depend on an AST (the one from rustc), but that resulted in lots of issues related to path solution,
which eventually lead me to switch to rust-analyzer and it's HIR, which ended up closing about a dozen issues at once.

However I have the feeling that in future we might want to analyze both, the AST, as well as the HIR, since the latter doesn't seem to have any information on inter-type dependencies, either.

[regexident]

I'm closing this

$ cargo modules generate graph --with-uses generates the following graph:

                          ┌───────┐           
                          │ crate │           
                          └───────┘           
                              │               
                              │               
                              ▼               
                        ┌──────────┐          
                       ─│ crate::a │─ ─ ─ ─ ─ 
                      │ └──────────┘         │
                              │               
            ┌─────────┼───────┴────┐         │
            ▼                      ▼          
     ┌─────────────┐  │     ┌─────────────┐  │
┌ ─ ─│ crate::a::b │        │ crate::a::d │◀─ 
     └─────────────┘  │     └─────────────┘   
│           │                      │          
            │         │            │          
│           ▼                      ▼          
   ┌────────────────┐ │   ┌────────────────┐  
└ ▶│ crate::a::b::c │◀    │ crate::a::d::e │  
   └────────────────┘     └────────────────┘  

Where solid lines denote "owns" edges and dashed lines denote "uses" edges.

Corresponding dot code

$ cargo modules generate graph --with-uses:

digraph {

    graph [
        label="github_issue_79",
        labelloc=t,
        pad=0.4,
        layout=neato,
        overlap=false,
        splines="line",
        rankdir=LR,
        fontname="Helvetica", 
        fontsize="36",
    ];

    node [
        fontname="monospace",
        fontsize="10",
        shape="record",
        style="filled",
    ];

    edge [
        fontname="monospace",
        fontsize="10",
    ];

    "github_issue_79" [label="crate|github_issue_79", fillcolor="#5397c8"]; // "crate" node
    "github_issue_79::a" [label="pub mod|a", fillcolor="#81c169"]; // "mod" node
    "github_issue_79::a::b" [label="pub mod|a::b", fillcolor="#81c169"]; // "mod" node
    "github_issue_79::a::b::c" [label="pub(self) mod|a::b::c", fillcolor="#db5367"]; // "mod" node
    "github_issue_79::a::d" [label="pub mod|a::d", fillcolor="#81c169"]; // "mod" node
    "github_issue_79::a::d::e" [label="pub(self) mod|a::d::e", fillcolor="#db5367"]; // "mod" node

    "github_issue_79" -> "github_issue_79::a" [label="owns", color="#000000", style="solid"] [constraint=true]; // "owns" edge
    "github_issue_79::a" -> "github_issue_79::a::b" [label="owns", color="#000000", style="solid"] [constraint=true]; // "owns" edge
    "github_issue_79::a::b" -> "github_issue_79::a::b::c" [label="owns", color="#000000", style="solid"] [constraint=true]; // "owns" edge
    "github_issue_79::a::b" -> "github_issue_79::a::b::c" [label="uses", color="#7f7f7f", style="dashed"] [constraint=false]; // "uses" edge
    "github_issue_79::a" -> "github_issue_79::a::d" [label="owns", color="#000000", style="solid"] [constraint=true]; // "owns" edge
    "github_issue_79::a::d" -> "github_issue_79::a::d::e" [label="owns", color="#000000", style="solid"] [constraint=true]; // "owns" edge
    "github_issue_79::a" -> "github_issue_79::a::b::c" [label="uses", color="#7f7f7f", style="dashed"] [constraint=false]; // "uses" edge
    "github_issue_79::a" -> "github_issue_79::a::d" [label="uses", color="#7f7f7f", style="dashed"] [constraint=false]; // "uses" edge

}

Since rust-analyzer resolves re-exports the edges in the generated graph do not directly correlate to use statements in the code.

As such:

• the use self::b::X; in mod a ends up producing an edge a -> c, since a::b::X is a re-export of a::b::c::X.
• the use self::d::Y; in mod a ends up producing an edge a -> d, since a::d::Y is a type-alias for a::b::c::X and not merely a re-export of it.
• the use self::c; and use self::e; in mod b and mod d on the other hand have no effect whatsoever, since they are superfluous.
• the pub use c::X; in mod b on the other hand does import X from mod c and is thus reflected in the graph as such.