7 files changed, 50 insertions, 4 deletions

diff --git a/docs/markdown/IDE-integration.md b/docs/markdown/IDE-integration.md
index 816225f..5188359 100644
--- a/docs/markdown/IDE-integration.md
+++ b/docs/markdown/IDE-integration.md
@@ -247,6 +247,7 @@ line arguments, environment variable settings and how to process the output.
     "is_parallel": true / false,
     "protocol": "exitcode" / "tap",
     "cmd": ["command", "to", "run"],
+    "depends": ["target1-id", "target2-id"],
     "env": {
         "VARIABLE1": "value 1",
         "VARIABLE2": "value 2"
@@ -254,6 +255,11 @@ line arguments, environment variable settings and how to process the output.
 }
 ```
 
+The `depends` entry *(since 0.56.0)* contains target ids; they can be
+looked up in the targets introspection data.  The executable
+pointed to by `cmd` is also included in the entry, as are any
+arguments to the test that are build products.
+
 ## Build system files
 
 It is also possible to get Meson build files used in your current project. This
diff --git a/docs/markdown/snippets/introspect_test_deps.md b/docs/markdown/snippets/introspect_test_deps.md
new file mode 100644
index 0000000..a29ea09
--- /dev/null
+++ b/docs/markdown/snippets/introspect_test_deps.md
@@ -0,0 +1,5 @@
+## Dependencies listed in test and benchmark introspection
+
+The introspection data for tests and benchmarks now includes the target
+ids for executables and built files that are needed by the test.  IDEs can
+use this feature to update the build more quickly before running a test.
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 7bdccbf..6c5b75a 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -120,7 +120,8 @@ class TestSerialisation:
                  env: build.EnvironmentVariables, should_fail: bool,
                  timeout: T.Optional[int], workdir: T.Optional[str],
                  extra_paths: T.List[str], protocol: TestProtocol, priority: int,
-                 cmd_is_built: bool):
+                 cmd_is_built: bool,
+                 depends: T.List[str]):
         self.name = name
         self.project_name = project
         self.suite = suite
@@ -140,6 +141,7 @@ class TestSerialisation:
         self.priority = priority
         self.needs_exe_wrapper = needs_exe_wrapper
         self.cmd_is_built = cmd_is_built
+        self.depends = depends
 
 
 def get_backend_from_name(backend: str, build: T.Optional[build.Build] = None, interpreter: T.Optional['Interpreter'] = None) -> T.Optional['Backend']:
@@ -830,7 +832,12 @@ class Backend:
                 extra_paths = []
 
             cmd_args = []
+            depends = set(t.depends)
+            if isinstance(exe, build.Target):
+                depends.add(exe)
             for a in unholder(t.cmd_args):
+                if isinstance(a, build.Target):
+                    depends.add(a)
                 if isinstance(a, build.BuildTarget):
                     extra_paths += self.determine_windows_extra_paths(a, [])
                 if isinstance(a, mesonlib.File):
@@ -852,7 +859,8 @@ class Backend:
                                    t.is_parallel, cmd_args, t.env,
                                    t.should_fail, t.timeout, t.workdir,
                                    extra_paths, t.protocol, t.priority,
-                                   isinstance(exe, build.Executable))
+                                   isinstance(exe, build.Executable),
+                                   [x.get_id() for x in depends])
             arr.append(ts)
         return arr
 
diff --git a/mesonbuild/mintro.py b/mesonbuild/mintro.py
index 0049bbd..d55227a 100644
--- a/mesonbuild/mintro.py
+++ b/mesonbuild/mintro.py
@@ -325,6 +325,7 @@ def get_test_list(testdata) -> T.List[T.Dict[str, T.Union[str, int, T.List[str],
         to['is_parallel'] = t.is_parallel
         to['priority'] = t.priority
         to['protocol'] = str(t.protocol)
+        to['depends'] = t.depends
         result.append(to)
     return result
 
diff --git a/run_unittests.py b/run_unittests.py
index 8c03693..2ff2af5 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -4281,6 +4281,7 @@ recommended as it is not supported on some platforms''')
             ('suite', list),
             ('is_parallel', bool),
             ('protocol', str),
+            ('depends', list),
         ]
 
         buildoptions_keylist = [
@@ -4338,12 +4339,28 @@ recommended as it is not supported on some platforms''')
 
         assertKeyTypes(root_keylist, res)
 
+        # Match target ids to input and output files for ease of reference
+        src_to_id = {}
+        out_to_id = {}
+        for i in res['targets']:
+            print(json.dump(i, sys.stdout))
+            out_to_id.update({os.path.relpath(out, self.builddir): i['id']
+                              for out in i['filename']})
+            for group in i['target_sources']:
+                src_to_id.update({os.path.relpath(src, testdir): i['id']
+                                  for src in group['sources']})
+
         # Check Tests and benchmarks
         tests_to_find = ['test case 1', 'test case 2', 'benchmark 1']
+        deps_to_find = {'test case 1': [src_to_id['t1.cpp']],
+                        'test case 2': [src_to_id['t2.cpp'], src_to_id['t3.cpp']],
+                        'benchmark 1': [out_to_id['file2'], src_to_id['t3.cpp']]}
         for i in res['benchmarks'] + res['tests']:
             assertKeyTypes(test_keylist, i)
             if i['name'] in tests_to_find:
                 tests_to_find.remove(i['name'])
+            self.assertEqual(sorted(i['depends']),
+                             sorted(deps_to_find[i['name']]))
         self.assertListEqual(tests_to_find, [])
 
         # Check buildoptions
@@ -4484,6 +4501,7 @@ recommended as it is not supported on some platforms''')
         res_nb = self.introspect_directory(testfile, ['--targets'] + self.meson_args)
 
         # Account for differences in output
+        res_wb = [i for i in res_wb if i['type'] != 'custom']
         for i in res_wb:
             i['filename'] = [os.path.relpath(x, self.builddir) for x in i['filename']]
             if 'install_filename' in i:
diff --git a/test cases/unit/57 introspection/cp.py b/test cases/unit/57 introspection/cp.py
new file mode 100644
index 0000000..cb09cf3
--- /dev/null
+++ b/test cases/unit/57 introspection/cp.py
@@ -0,0 +1,5 @@
+#! /usr/bin/env python3
+
+import sys
+from shutil import copyfile
+copyfile(*sys.argv[1:])
diff --git a/test cases/unit/57 introspection/meson.build b/test cases/unit/57 introspection/meson.build
index 5d4dd02..3a3db10 100644
--- a/test cases/unit/57 introspection/meson.build
+++ b/test cases/unit/57 introspection/meson.build
@@ -26,6 +26,9 @@ var1 = '1'
 var2 = 2.to_string()
 var3 = 'test3'
 
+cus = custom_target('custom target test', output: 'file2', input: 'cp.py',
+                    command: [find_program('cp.py'), '@INPUT@', '@OUTPUT@'])
+
 t1 = executable('test' + var1, ['t1.cpp'], link_with: [sharedlib], install: not false, build_by_default: get_option('test_opt2'))
 t2 = executable('test@0@'.format('@0@'.format(var2)), sources: ['t2.cpp'], link_with: [staticlib])
 t3 = executable(var3, 't3.cpp', link_with: [sharedlib, staticlib], dependencies: [dep1])
@@ -44,8 +47,8 @@ osmesa_lib_name = osmesa_lib_name + osmesa_bits
 message(osmesa_lib_name) # Infinite recursion gets triggered here when the parameter osmesa_lib_name is resolved
 
 test('test case 1', t1)
-test('test case 2', t2)
-benchmark('benchmark 1', t3)
+test('test case 2', t2, depends: t3)
+benchmark('benchmark 1', t3, args: cus)
 
 ### Stuff to test the AST JSON printer
 foreach x : ['a', 'b', 'c']