InstallGraph.reduce

conan/cli/commands/graph.py

@@ -62,6 +62,8 @@ def graph_build_order(conan_api, parser, subparser, *args):
     common_graph_args(subparser)
     subparser.add_argument("--order", choices=['recipe', 'configuration'], default="recipe",
                            help='Select how to order the output, "recipe" by default if not set.')
+    subparser.add_argument("--reduce", action='store_true', default=False,
+                           help='Reduce the build order, output only those to build')
     args = parser.parse_args(*args)
 
     # parameter validation
@@ -100,6 +102,8 @@ def graph_build_order(conan_api, parser, subparser, *args):
     out = ConanOutput()
     out.title("Computing the build order")
     install_graph = InstallGraph(deps_graph, order=args.order)
+    if args.reduce:
+        install_graph.reduce()
     install_order_serialized = install_graph.install_build_order()
 
     lockfile = conan_api.lockfile.update_lockfile(lockfile, deps_graph, args.lockfile_packages,

conans/client/graph/install_graph.py

@@ -4,7 +4,7 @@
 
 from conan.api.output import ConanOutput
 from conans.client.graph.graph import RECIPE_CONSUMER, RECIPE_VIRTUAL, BINARY_SKIP, \
-    BINARY_MISSING, BINARY_INVALID, Overrides, BINARY_BUILD
+    BINARY_MISSING, BINARY_INVALID, Overrides, BINARY_BUILD, BINARY_EDITABLE_BUILD
 from conans.errors import ConanInvalidConfiguration, ConanException
 from conans.model.package_ref import PkgReference
 from conans.model.recipe_ref import RecipeReference
@@ -111,6 +111,13 @@ def __init__(self):
         self.packages = {}  # {package_id: _InstallPackageReference}
         self.depends = []  # Other REFs, defines the graph topology and operation ordering
 
+    @property
+    def need_build(self):
+        for package in self.packages.values():
+            if package.binary in (BINARY_BUILD, BINARY_EDITABLE_BUILD):
+                return True
+        return False
+
     @property
     def node(self):
         return self._node
@@ -212,6 +219,10 @@ def __init__(self):
         self.depends = []  # List of full prefs
         self.overrides = Overrides()
 
+    @property
+    def need_build(self):
+        return self.binary in (BINARY_BUILD, BINARY_EDITABLE_BUILD)
+
     @property
     def pref(self):
         return PkgReference(self.ref, self.package_id, self.prev)
@@ -363,6 +374,19 @@ def _initialize_deps_graph(self, deps_graph):
             else:
                 existing.add(node)
 
+    def reduce(self):
+        result = {}
+        for k, node in self._nodes.items():
+            if node.need_build:
+                result[k] = node
+            else:  # Eliminate this element from the graph
+                dependencies = node.depends
+                # Find all consumers
+                for n in self._nodes.values():
+                    if k in n.depends:
+                        n.depends = [d for d in n.depends if d != k] + dependencies
+        self._nodes = result
+
     def install_order(self, flat=False):
         # a topological order by levels, returns a list of list, in order of processing
         levels = []

conans/test/integration/command_v2/test_info_build_order.py

@@ -60,6 +60,9 @@ def test_info_build_order():
     ]
 
     assert bo_json == result
+    c.run("graph build-order consumer --build=missing --reduce --format=json")
+    bo_json = json.loads(c.stdout)
+    assert bo_json == result
 
 
 def test_info_build_order_configuration():
@@ -109,6 +112,9 @@ def test_info_build_order_configuration():
     ]
 
     assert bo_json == result
+    c.run("graph build-order consumer --build=missing --order=configuration --reduce --format=json")
+    bo_json = json.loads(c.stdout)
+    assert bo_json == result
 
 
 def test_info_build_order_configuration_text_formatter():
@@ -526,3 +532,26 @@ def export(self):
     c.run("graph build-order --requires=dep/0.1 --format=json", assert_error=True)
     assert "ImportError" in c.out
     assert "It is possible that this recipe is not Conan 2.0 ready" in c.out
+
+
+class TestBuildOrderReduce:
+    def test_reduce(self):
+        c = TestClient()
+        c.save({"liba/conanfile.py": GenConanfile("liba", "0.1"),
+                "libb/conanfile.py": GenConanfile("libb", "0.1").with_requires("liba/0.1"),
+                "libc/conanfile.py": GenConanfile("libc", "0.1").with_requires("libb/0.1"),
+                "consumer/conanfile.txt": "[requires]\nlibc/0.1"})
+        c.run("create liba")
+        c.run("create libb")
+        c.run("create libc")
+        c.run("remove liba:* -c")
+        c.run("remove libc:* -c")
+        c.run("graph build-order consumer --build=missing --reduce --format=json")
+        bo_json = json.loads(c.stdout)
+        assert len(bo_json) == 2  # 2 levels
+        level0 = bo_json[0]
+        assert len(level0) == 1
+        assert level0[0]["ref"] == "liba/0.1#a658e7beaaae5d6be0b6f67dcc9859e2"
+        level1 = bo_json[1]
+        assert len(level1) == 1
+        assert level1[0]["depends"] == ["liba/0.1#a658e7beaaae5d6be0b6f67dcc9859e2"]