Auto merge of rust-lang#9499 - weihanglo:tree-depth, r=ehuss

Add `--depth` option for `cargo-tree`

Part of rust-lang#8105

Note that the `--depth` option only regards the "tree" depth but not dependency depth.

## To resolve

Bike-shedding naming problem: `-L,--level`  or `--depth`?

src/bin/cargo/commands/tree.rs

@@ -56,6 +56,7 @@ pub fn cli() -> App {
             )
             .short("i"),
         )
+        .arg(opt("depth", "Maximum display depth of the dependency tree").value_name("DEPTH"))
         // Deprecated, use --prefix=none instead.
         .arg(Arg::with_name("no-indent").long("no-indent").hidden(true))
         // Deprecated, use --prefix=depth instead.
@@ -202,6 +203,7 @@ subtree of the package given to -p.\n\
         charset,
         format: args.value_of("format").unwrap().to_string(),
         graph_features,
+        max_display_depth: args.value_of_u32("depth")?.unwrap_or(u32::MAX),
         no_proc_macro,
     };
 

src/cargo/ops/tree/mod.rs

@@ -43,6 +43,8 @@ pub struct TreeOptions {
     pub format: String,
     /// Includes features in the tree as separate nodes.
     pub graph_features: bool,
+    /// Maximum display depth of the dependency tree.
+    pub max_display_depth: u32,
     /// Exculdes proc-macro dependencies.
     pub no_proc_macro: bool,
 }
@@ -240,6 +242,7 @@ fn print(
             symbols,
             opts.prefix,
             opts.no_dedupe,
+            opts.max_display_depth,
             opts.no_proc_macro,
             &mut visited_deps,
             &mut levels_continue,
@@ -259,6 +262,7 @@ fn print_node<'a>(
     symbols: &Symbols,
     prefix: Prefix,
     no_dedupe: bool,
+    max_display_depth: u32,
     no_proc_macro: bool,
     visited_deps: &mut HashSet<usize>,
     levels_continue: &mut Vec<bool>,
@@ -317,6 +321,7 @@ fn print_node<'a>(
             symbols,
             prefix,
             no_dedupe,
+            max_display_depth,
             no_proc_macro,
             visited_deps,
             levels_continue,
@@ -336,6 +341,7 @@ fn print_dependencies<'a>(
     symbols: &Symbols,
     prefix: Prefix,
     no_dedupe: bool,
+    max_display_depth: u32,
     no_proc_macro: bool,
     visited_deps: &mut HashSet<usize>,
     levels_continue: &mut Vec<bool>,
@@ -383,20 +389,23 @@ fn print_dependencies<'a>(
         .peekable();
 
     while let Some(dependency) = it.next() {
-        levels_continue.push(it.peek().is_some());
-        print_node(
-            config,
-            graph,
-            *dependency,
-            format,
-            symbols,
-            prefix,
-            no_dedupe,
-            no_proc_macro,
-            visited_deps,
-            levels_continue,
-            print_stack,
-        );
-        levels_continue.pop();
+        if levels_continue.len() + 1 <= max_display_depth as usize {
+            levels_continue.push(it.peek().is_some());
+            print_node(
+                config,
+                graph,
+                *dependency,
+                format,
+                symbols,
+                prefix,
+                no_dedupe,
+                max_display_depth,
+                no_proc_macro,
+                visited_deps,
+                levels_continue,
+                print_stack,
+            );
+            levels_continue.pop();
+        }
     }
 }

src/doc/man/cargo-tree.md

@@ -71,6 +71,11 @@ flag can be used to display the package's reverse dependencies only with the
 subtree of the package given to `-p`.
 {{/option}}
 
+{{#option "`--depth` _depth_" }}
+Maximum display depth of the dependency tree. A depth of 1 displays the direct
+dependencies, for example.
+{{/option}}
+
 {{#option "`--no-dedupe`" }}
 Do not de-duplicate repeated dependencies. Usually, when a package has already
 displayed its dependencies, further occurrences will not re-display its

src/doc/man/generated_txt/cargo-tree.txt

@@ -59,6 +59,10 @@ OPTIONS
            package's reverse dependencies only with the subtree of the package
            given to -p.
 
+       --depth depth
+           Maximum display depth of the dependency tree. A depth of 1 displays
+           the direct dependencies, for example.
+
        --no-dedupe
            Do not de-duplicate repeated dependencies. Usually, when a package
            has already displayed its dependencies, further occurrences will not

src/doc/src/commands/cargo-tree.md

@@ -71,6 +71,11 @@ flag can be used to display the package's reverse dependencies only with the
 subtree of the package given to <code>-p</code>.</dd>
 
 
+<dt class="option-term" id="option-cargo-tree---depth"><a class="option-anchor" href="#option-cargo-tree---depth"></a><code>--depth</code> <em>depth</em></dt>
+<dd class="option-desc">Maximum display depth of the dependency tree. A depth of 1 displays the direct
+dependencies, for example.</dd>
+
+
 <dt class="option-term" id="option-cargo-tree---no-dedupe"><a class="option-anchor" href="#option-cargo-tree---no-dedupe"></a><code>--no-dedupe</code></dt>
 <dd class="option-desc">Do not de-duplicate repeated dependencies. Usually, when a package has already
 displayed its dependencies, further occurrences will not re-display its

src/etc/man/cargo-tree.1

@@ -69,6 +69,12 @@ flag can be used to display the package's reverse dependencies only with the
 subtree of the package given to \fB\-p\fR\&.
 .RE
 .sp
+\fB\-\-depth\fR \fIdepth\fR
+.RS 4
+Maximum display depth of the dependency tree. A depth of 1 displays the direct
+dependencies, for example.
+.RE
+.sp
 \fB\-\-no\-dedupe\fR
 .RS 4
 Do not de\-duplicate repeated dependencies. Usually, when a package has already

tests/testsuite/tree.rs

@@ -1627,3 +1627,96 @@ foo v0.1.0 ([..]/foo)
         )
         .run();
 }
+
+#[cargo_test]
+fn depth_limit() {
+    let p = make_simple_proj();
+
+    p.cargo("tree --depth 0")
+        .with_stdout(
+            "\
+foo v0.1.0 ([..]/foo)
+[build-dependencies]
+[dev-dependencies]
+",
+        )
+        .run();
+
+    p.cargo("tree --depth 1")
+        .with_stdout(
+            "\
+foo v0.1.0 ([..]/foo)
+├── a v1.0.0
+└── c v1.0.0
+[build-dependencies]
+└── bdep v1.0.0
+[dev-dependencies]
+└── devdep v1.0.0
+",
+        )
+        .run();
+
+    p.cargo("tree --depth 2")
+        .with_stdout(
+            "\
+foo v0.1.0 ([..]/foo)
+├── a v1.0.0
+│   └── b v1.0.0
+└── c v1.0.0
+[build-dependencies]
+└── bdep v1.0.0
+    └── b v1.0.0 (*)
+[dev-dependencies]
+└── devdep v1.0.0
+    └── b v1.0.0 (*)
+",
+        )
+        .run();
+
+    // specify a package
+    p.cargo("tree -p bdep --depth 1")
+        .with_stdout(
+            "\
+bdep v1.0.0
+└── b v1.0.0
+",
+        )
+        .run();
+
+    // different prefix
+    p.cargo("tree --depth 1 --prefix depth")
+        .with_stdout(
+            "\
+0foo v0.1.0 ([..]/foo)
+1a v1.0.0
+1c v1.0.0
+1bdep v1.0.0
+1devdep v1.0.0
+",
+        )
+        .run();
+
+    // with edge-kinds
+    p.cargo("tree --depth 1 -e no-dev")
+        .with_stdout(
+            "\
+foo v0.1.0 ([..]/foo)
+├── a v1.0.0
+└── c v1.0.0
+[build-dependencies]
+└── bdep v1.0.0
+",
+        )
+        .run();
+
+    // invert
+    p.cargo("tree --depth 1 --invert c")
+        .with_stdout(
+            "\
+c v1.0.0
+├── b v1.0.0
+└── foo v0.1.0 ([..]/foo)
+",
+        )
+        .run();
+}