Merge pull request #2888 from devitocodes/load-so

compiler: load so directly when source is missing (e.g deleted c file)

Author: mloubout

devito/arch/compiler.py

@@ -386,6 +386,14 @@ def jit_compile(self, soname, code):
             # Typically we end up here
             # Make a suite of cache directories based on the soname
             cache_dir.mkdir(parents=True, exist_ok=True)
+
+            # Has the library already been compiled?
+            try:
+                self.load(target)
+                return False, src_file
+            except OSError:
+                # The .so file isn't present, we need to compile it
+                pass
         else:
             # Warning: dropping `code` on the floor in favor to whatever is written
             # within `src_file`

tests/test_cinterface.py

@@ -1,4 +1,6 @@
 import os
+import sys
+from contextlib import suppress
 
 from devito import Eq, Grid, Operator, TimeFunction, configuration
 from devito.types import Timer
@@ -37,3 +39,31 @@ def test_basic():
     assert isinstance(timers, Timer)
     assert 'struct profiler\n{' not in ccode
     assert 'struct profiler\n{' in hcode
+
+
+def test_load_without_source():
+    grid = Grid(shape=(4, 4))
+
+    f = TimeFunction(name='f', grid=grid)
+
+    eq = Eq(f.forward, f + 1.)
+
+    name = "foo"
+    op = Operator(eq, name=name)
+
+    # Make sure the so file is not present
+    dirname = op._compiler.get_jit_dir()
+    soname = op._soname
+    ext = '.dylib' if sys.platform == "darwin" else '.so'
+    with suppress(FileNotFoundError):
+        os.remove(f"{os.path.join(dirname, soname)}{ext}")
+
+    # Trigger compilation
+    recompiled, src_file = op._compiler.jit_compile(op._soname, str(op))
+    assert recompiled
+
+    os.remove(src_file)
+    # Trigger compilation again. It should skip the C part and directly load the .so file
+    recompiled, src_file = op._compiler.jit_compile(op._soname, str(op))
+    assert not recompiled
+    assert not os.path.isfile(src_file)