backend/ninja: add generated sources to depscan order deps

Since we changed to using a json file to avoid over long command lines
we created a situation where the generated files may not be ready when
the depscan happens. To avoid that, we need to add all of the generated
sources as order deps.

Fixes: #9258

mesonbuild/backend/ninjabackend.py

@@ -887,7 +887,7 @@ class NinjaBackend(backends.Backend):
         else:
             final_obj_list = obj_list
         elem = self.generate_link(target, outname, final_obj_list, linker, pch_objects, stdlib_args=stdlib_args)
-        self.generate_dependency_scan_target(target, compiled_sources, source2object)
+        self.generate_dependency_scan_target(target, compiled_sources, source2object, generated_source_files)
         self.generate_shlib_aliases(target, self.get_target_dir(target))
         self.add_build(elem)
 
@@ -911,7 +911,7 @@ class NinjaBackend(backends.Backend):
             return False
         return True
 
-    def generate_dependency_scan_target(self, target, compiled_sources, source2object):
+    def generate_dependency_scan_target(self, target, compiled_sources, source2object, generated_source_files: T.List[mesonlib.File]):
         if not self.should_use_dyndeps_for_target(target):
             return
         depscan_file = self.get_dep_scan_file_for(target)
@@ -929,6 +929,10 @@ class NinjaBackend(backends.Backend):
             json.dump(scan_sources, f)
         elem = NinjaBuildElement(self.all_outputs, depscan_file, rule_name, json_abs)
         elem.add_item('picklefile', pickle_file)
+        # Add any generated outputs to the order deps of the scan target, so
+        # that those sources are present
+        for g in generated_source_files:
+            elem.orderdeps.add(g.relative_name())
         scaninfo = TargetDependencyScannerInfo(self.get_target_private_dir(target), source2object)
         with open(pickle_abs, 'wb') as p:
             pickle.dump(scaninfo, p)

test cases/fortran/7 generated/meson.build

@@ -7,9 +7,21 @@ project('generated', 'fortran',
 conf_data = configuration_data()
 conf_data.set('ONE', 1)
 conf_data.set('TWO', 2)
-conf_data.set('THREE', 3)
 
-mod3_f = configure_file(input : 'mod3.fpp', output : 'mod3.f90', configuration : conf_data)
+mod3_f = custom_target(
+  'mod3.f',
+  input : 'mod3.f90',
+  output : 'mod3.f90',
+  # We need a platform agnostic way to do a copy a file, using a custom_target
+  # and we need to use the @OUTDIR@, not @OUTPUT@ in order to exercise
+  # https://github.com/mesonbuild/meson/issues/9258
+  command : [
+    find_program('python', 'python3'), '-c',
+    'import sys, shutil; shutil.copy(sys.argv[1], sys.argv[2])',
+    '@INPUT@', '@OUTDIR@',
+  ],
+)
+
 three = library('mod3', mod3_f)
 
 templates_basenames = ['mod2', 'mod1']

test cases/fortran/7 generated/mod3.f90

@@ -1,6 +1,6 @@
 module mod3
 implicit none
 
-integer, parameter :: modval3 = @THREE@
+integer, parameter :: modval3 = 3
 
 end module mod3