From acafab9b5fea6f00701d82174fcf678c8caee420 Mon Sep 17 00:00:00 2001
From: Christoph Reiter <reiter.christoph@gmail.com>
Date: Sat, 26 Oct 2024 14:18:19 +0200
Subject: [PATCH] queue: fix missing cycles with build-only deps of deps

We only looked at the dependencies of a package that are needed for building,
but for detecting build cycles we also have to look at all transitive deps.

Unless the dependency is already finished, then we can ignore its build deps,
even if they are not finished yet.

The test shows such a case where things indirectly create a cycle via cmake.

Fixes #91
---
 msys2_autobuild/queue.py | 45 +++++++++++++++++-----
 tests/main_test.py       | 83 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+), 9 deletions(-)

diff --git a/msys2_autobuild/queue.py b/msys2_autobuild/queue.py
index 4abb877..d699ce1 100644
--- a/msys2_autobuild/queue.py
+++ b/msys2_autobuild/queue.py
@@ -137,12 +137,16 @@ class Package(dict):
 
 
 def get_buildqueue() -> List[Package]:
-    pkgs = []
     session = get_requests_session()
     r = session.get("https://packages.msys2.org/api/buildqueue2", timeout=REQUESTS_TIMEOUT)
     r.raise_for_status()
 
-    for received in r.json():
+    return parse_buildqueue(r.text)
+
+
+def parse_buildqueue(payload: str) -> List[Package]:
+    pkgs = []
+    for received in json.loads(payload):
         pkg = Package(received)
         pkg['repo'] = pkg['repo_url'].split('/')[-1]
         pkgs.append(pkg)
@@ -188,23 +192,46 @@ def get_cycles(pkgs: List[Package]) -> Set[Tuple[Package, Package]]:
             PackageStatus.FINISHED_BUT_INCOMPLETE,
         ]
 
+    # Transitive dependencies of a package. Excluding branches where a root is finished
+    def get_buildqueue_deps(pkg: Package, build_type: ArchType) -> "Dict[ArchType, Set[Package]]":
+        start = (build_type, pkg)
+        todo = set([start])
+        done = set()
+        result = set()
+
+        while todo:
+            build_type, pkg = todo.pop()
+            item = (build_type, pkg)
+            done.add(item)
+            if pkg_is_finished(pkg, build_type):
+                continue
+            result.add(item)
+            for dep_build_type, deps in pkg.get_depends(build_type).items():
+                for dep in deps:
+                    dep_item = (dep_build_type, dep)
+                    if dep_item not in done:
+                        todo.add(dep_item)
+        result.discard(start)
+
+        d: Dict[ArchType, Set[Package]] = {}
+        for build_type, pkg in result:
+            d.setdefault(build_type, set()).add(pkg)
+        return d
+
     for pkg in pkgs:
         for build_type in pkg.get_build_types():
             if build_type_is_src(build_type):
                 continue
-            if pkg_is_finished(pkg, build_type):
-                continue
             build_type = cast(ArchType, build_type)
-            for dep_type, deps in pkg.get_depends(build_type).items():
+            for dep_build_type, deps in get_buildqueue_deps(pkg, build_type).items():
                 for dep in deps:
-                    if pkg_is_finished(dep, dep_type):
-                        continue
                     # manually broken cycle
-                    if pkg.is_optional_dep(dep, dep_type) or dep.is_optional_dep(pkg, build_type):
+                    if pkg.is_optional_dep(dep, dep_build_type) or dep.is_optional_dep(pkg, build_type):
                         continue
-                    dep_deps = dep.get_depends(dep_type)
+                    dep_deps = get_buildqueue_deps(dep, dep_build_type)
                     if pkg in dep_deps.get(build_type, set()):
                         cycles.add(tuple(sorted([pkg, dep], key=lambda p: p["name"])))  # type: ignore
+
     return cycles
 
 
diff --git a/tests/main_test.py b/tests/main_test.py
index d0f3caa..7b24583 100644
--- a/tests/main_test.py
+++ b/tests/main_test.py
@@ -1,7 +1,90 @@
 # type: ignore
 
 from msys2_autobuild.utils import parse_optional_deps
+from msys2_autobuild.queue import parse_buildqueue, get_cycles
 
 
 def test_parse_optional_deps():
     assert parse_optional_deps("a:b,c:d,a:x") == {'a': ['b', 'x'], 'c': ['d']}
+
+
+def test_get_cycles():
+    buildqueue = """
+[
+  {
+    "name": "c-ares",
+    "version": "1.34.2-1",
+    "version_repo": "1.33.1-1",
+    "repo_url": "https://github.com/msys2/MSYS2-packages",
+    "repo_path": "c-ares",
+    "source": true,
+    "builds": {
+      "msys": {
+        "packages": [
+          "libcares",
+          "libcares-devel"
+        ],
+        "depends": {
+          "msys": [
+            "libnghttp2",
+            "libuv"
+          ]
+        },
+        "new": false
+      }
+    }
+  },
+  {
+    "name": "nghttp2",
+    "version": "1.64.0-1",
+    "version_repo": "1.63.0-1",
+    "repo_url": "https://github.com/msys2/MSYS2-packages",
+    "repo_path": "nghttp2",
+    "source": true,
+    "builds": {
+      "msys": {
+        "packages": [
+          "libnghttp2",
+          "libnghttp2-devel",
+          "nghttp2"
+        ],
+        "depends": {
+          "msys": [
+            "libcares",
+            "libcares-devel"
+          ]
+        },
+        "new": false
+      }
+    }
+  },
+  {
+    "name": "libuv",
+    "version": "1.49.2-1",
+    "version_repo": "1.49.1-1",
+    "repo_url": "https://github.com/msys2/MSYS2-packages",
+    "repo_path": "libuv",
+    "source": true,
+    "builds": {
+      "msys": {
+        "packages": [
+          "libuv",
+          "libuv-devel"
+        ],
+        "depends": {
+          "msys": [
+            "libnghttp2"
+          ]
+        },
+        "new": false
+      }
+    }
+  }
+]"""
+
+    pkgs = parse_buildqueue(buildqueue)
+    cycles = get_cycles(pkgs)
+    assert len(cycles) == 3
+    assert (pkgs[0], pkgs[2]) in cycles
+    assert (pkgs[0], pkgs[1]) in cycles
+    assert (pkgs[2], pkgs[1]) in cycles