feat(show): export target dependency graph as JSON

Add a graph-oriented mode to `xmake show` for exporting target\ndependency relationships as JSON.\n\nThis adds `--target_graph` support for whole-project output and\noptional root-target filtering with `--target`.\n\nAdd a plugin test covering full-graph and single-target graph export.\n\nRefs #7475

3 files changed, 123 insertions, 1 deletions

diff --git a/xmake/plugins/show/info/target_graph.lua b/xmake/plugins/show/info/target_graph.lua
new file mode 100644
index 000000000..30c977fc3
--- /dev/null
+++ b/xmake/plugins/show/info/target_graph.lua
@@ -0,0 +1,120 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-present, Xmake Open Source Community.
+--
+-- @author      ruki
+-- @file        target_graph.lua
+--
+
+-- imports
+import("core.base.option")
+import("core.base.json")
+import("core.project.config")
+import("core.project.project")
+import("private.detect.check_targetname")
+
+local function _collect_target_entry(target)
+    local deps = {}
+    for _, dep in pairs(target:deps() or {}) do
+        table.insert(deps, dep:name())
+    end
+    table.sort(deps)
+
+    local orderdeps = {}
+    for _, dep in ipairs(target:orderdeps() or {}) do
+        table.insert(orderdeps, dep:name())
+    end
+
+    return {
+        name = target:name(),
+        kind = target:kind(),
+        group = target:get("group"),
+        default = target:is_default(),
+        deps = deps,
+        orderdeps = orderdeps
+    }
+end
+
+local function _collect_target_graph(root_target)
+    local targets = {}
+    local selected = {}
+    if root_target then
+        selected[root_target:name()] = true
+        for _, dep in ipairs(root_target:orderdeps() or {}) do
+            selected[dep:name()] = true
+        end
+    end
+
+    for _, target in ipairs(project.ordertargets()) do
+        if not root_target or selected[target:name()] then
+            table.insert(targets, _collect_target_entry(target))
+        end
+    end
+
+    local roots = {}
+    if root_target then
+        table.insert(roots, root_target:name())
+    else
+        local indegrees = {}
+        for _, target in ipairs(targets) do
+            indegrees[target.name] = 0
+        end
+        for _, target in ipairs(targets) do
+            for _, depname in ipairs(target.deps) do
+                if indegrees[depname] ~= nil then
+                    indegrees[depname] = indegrees[depname] + 1
+                end
+            end
+        end
+        for _, target in ipairs(targets) do
+            if indegrees[target.name] == 0 then
+                table.insert(roots, target.name)
+            end
+        end
+    end
+
+    return {
+        root_targets = roots,
+        targets = targets
+    }
+end
+
+local function _print_target_graph(graph)
+    print("The dependency graph of targets:")
+    for _, target in ipairs(graph.targets) do
+        local deps = #target.deps > 0 and table.concat(target.deps, ", ") or "(none)"
+        cprint("    ${color.dump.string}%s${clear}: %s", target.name, deps)
+    end
+end
+
+function main(name)
+    config.load()
+
+    local root_target
+    if name then
+        root_target = assert(check_targetname(name))
+    end
+
+    local graph = _collect_target_graph(root_target)
+    if option.get("json") then
+        local json_opt
+        if option.get("pretty") then
+            json_opt = {pretty = true, orderkeys = true}
+        end
+        print(json.encode(graph, json_opt))
+    else
+        _print_target_graph(graph)
+    end
+end
diff --git a/xmake/plugins/show/main.lua b/xmake/plugins/show/main.lua
index 9dc4f519a..2b337b13e 100644
--- a/xmake/plugins/show/main.lua
+++ b/xmake/plugins/show/main.lua
@@ -32,6 +32,8 @@ function main()
     local listname = option.get("list")
     if listname then
         return _show_list(listname)
+    elseif option.get("target_graph") then
+        return assert(import("info.target_graph", {try = true, anonymous = true}))(option.get("target"))
     else
         -- show the information of the given object
         for _, filepath in ipairs(os.files(path.join(os.scriptdir(), "info", "*.lua"))) do
diff --git a/xmake/plugins/show/xmake.lua b/xmake/plugins/show/xmake.lua
index 331aeb468..3e3709877 100644
--- a/xmake/plugins/show/xmake.lua
+++ b/xmake/plugins/show/xmake.lua
@@ -32,6 +32,7 @@ task("show")
             {'g', "group",  "kv", nil,   "Filter targets by the given group name."},
             {nil, "json",   "k",  false, "Show information with json format."},
             {nil, "pretty", "k",  false, "Enable pretty formatted json output."},
+            {nil, "target_graph", "k", false, "Show the dependency graph of targets."},
             {'t', "target", "kv", nil,   "Show the information of the given target.",
                 values = function (complete, opt)
                     return import("private.utils.complete_helper.targets")(complete, opt)
@@ -40,4 +41,3 @@ task("show")
     }
 
 
-