Avoid building an ISL AST for illegal schedules

.github/workflows/python-package.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install ruff
+        python -m pip install "ruff==0.15.22"
     - name: Check formating with ruff
       run: |
         ruff format --check
@@ -33,7 +33,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install ruff
+        python -m pip install "ruff==0.15.22"
     - name: Lint with ruff
       run: |
         # stop the build if there are Python syntax errors or undefined names
@@ -59,7 +59,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install ruff pytest pytest-cov coverage
+        python -m pip install "ruff==0.15.22" pytest pytest-cov coverage
         if [ -f requirements.txt ]; then python -m pip install --user -r requirements.txt; fi
 
     - name: Install TiraLibCPP

pyproject.toml

@@ -14,7 +14,7 @@ pyyaml = "^6.0.1"
 [tool.poetry.group.dev.dependencies]
 pytest-cov = "^4.1.0"
 coverage = "^7.2.7"
-ruff = "^0.9"
+ruff = "0.15.22"
 
 [build-system]
 requires = ["poetry-core"]

tests/tiramisu/test_schedule.py

@@ -1,11 +1,13 @@
+from types import SimpleNamespace
+
 import pytest
 
 import tests.utils as test_utils
+from tests.utils import benchmark_program_test_sample
+from tiralib.config import BaseConfig
 from tiralib.tiramisu import tiramisu_actions
 from tiralib.tiramisu.schedule import Schedule
 from tiralib.tiramisu.tiramisu_actions.parallelization import Parallelization
-from tiralib.config import BaseConfig
-from tests.utils import benchmark_program_test_sample
 
 
 def test_execute():
@@ -105,6 +107,58 @@ def test_is_legal():
     assert legality is True
 
 
+def test_illegal_server_result_keeps_last_valid_tree():
+    BaseConfig.init()
+    test_program = benchmark_program_test_sample()
+
+    class FakeServer:
+        def run(self, *args, **kwargs):
+            return SimpleNamespace(
+                legality=False,
+                isl_ast="",
+                additional_info="",
+            )
+
+    test_program.server = FakeServer()
+    schedule = Schedule(test_program)
+    original_tree = schedule.tree
+    schedule.add_optimizations([Parallelization(params=[("comp02", 0)])])
+
+    assert schedule.is_legal() is False
+    assert schedule.tree is original_tree
+
+
+def test_legal_server_result_updates_tree_for_follow_up_actions():
+    BaseConfig.init()
+    test_program = benchmark_program_test_sample()
+
+    class FakeServer:
+        def run(self, *args, **kwargs):
+            return SimpleNamespace(
+                legality=True,
+                isl_ast=(
+                    "0|iterator|i|0|i <= 3|\n"
+                    "1|iterator|j|0|j <= 7|\n"
+                    "2|computation|comp02\n"
+                ),
+                additional_info="",
+            )
+
+    test_program.server = FakeServer()
+    schedule = Schedule(test_program)
+    schedule.add_optimizations([Parallelization(params=[("comp02", 0)])])
+
+    assert schedule.is_legal() is True
+    unrolling = tiramisu_actions.Unrolling(
+        params=[("comp02", -1), 4],
+        comps=["comp02"],
+    )
+    schedule.add_optimizations([unrolling])
+
+    assert unrolling.iterator_id == ("comp02", 1)
+    assert str(unrolling) == "U(L1,4,comps=['comp02'])"
+
+
 def test_copy():
     BaseConfig.init()
     original = Schedule(benchmark_program_test_sample())

tests/tiramisu/test_tiramisu_tree.py

@@ -1,6 +1,6 @@
 import tests.utils as test_utils
-from tiralib.tiramisu.tiramisu_tree import TiramisuTree
 from tiralib.config import BaseConfig
+from tiralib.tiramisu.tiramisu_tree import TiramisuTree
 
 
 def test_from_annotations():
@@ -58,6 +58,21 @@ def test_get_candidate_computations():
     ]
 
 
+def test_repeated_isl_ast_computations_are_unique():
+    t_tree = TiramisuTree.from_isl_ast_string_list(
+        [
+            "0|iterator|i|0|i <= 3|",
+            "1|computation|comp00",
+            "0|iterator|i|0|i <= 3|",
+            "1|computation|comp00",
+        ]
+    )
+
+    assert t_tree.computations == ["comp00"]
+    assert t_tree.computations_absolute_order == {"comp00": 1}
+    assert t_tree.get_iterator_subtree_computations(("comp00", 0)) == ["comp00"]
+
+
 def test_get_root_of_node():
     t_tree = test_utils.tree_test_sample()
 

tiralib/tiramisu/compiling_service.py

@@ -55,10 +55,12 @@ def compile_legality(cls, schedule: Schedule, with_ast: bool = False):
             legality_result = legality_result.strip()
             if legality_result not in ["0", "1"]:
                 raise Exception(f"Error in legality check: {legality_result}")
+            if legality_result == "0":
+                return False, None
             ast = TiramisuTree.from_isl_ast_string_list(
                 isl_ast_string_list=result_lines[1:]
             )
-            return legality_result == "1", ast
+            return True, ast
 
         else:
             result = result.strip()
@@ -100,11 +102,14 @@ def get_legality_code(cls, schedule: Schedule, with_ast: bool = False):
 
         if with_ast:
             legality_check_lines += """
-    auto fct = tiramisu::global::get_implicit_function();
-
-    fct->gen_time_space_domain();
-    fct->gen_isl_ast();
-    fct->print_isl_ast_representation();
+    if (is_legal)
+    {
+        auto fct = tiramisu::global::get_implicit_function();
+
+        fct->gen_time_space_domain();
+        fct->gen_isl_ast();
+        fct->print_isl_ast_representation();
+    }
 """
 
         cpp_code = schedule.tiramisu_program.cpp_code.replace(