tests/tcg: introduce meson.build

Every target declare its tests, and add them in global tcg_tests
dictionary, indexed by target name. See comment for full description.

We make sure that if a user repeats a test several time it won't result
in duplicated executables or tests. In next commits, we'll introduce
what's needed to deal with that.

A test is compiled from a single source file (and later, a single set of
compile flags). We make sure dependencies are correctly handled by
generating a depfile.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Aniket Sahu <asahu1x@linux.ibm.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
Message-ID: <20260827221506.91574-6-pierrick.bouvier@oss.qualcomm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

tests/meson.build

@@ -74,7 +74,7 @@ subdir('decode')
 
 if 'CONFIG_TCG' in config_all_accel
   subdir('fp')
-  subdir('tcg/plugins')
+  subdir('tcg')
 endif
 
 subdir('audio')

tests/tcg/meson.build

@@ -0,0 +1,96 @@
+env = find_program('env')
+
+tcg_tests = {}
+# tcg_tests is a dictionary with following structure:
+#
+# {
+#   'name_of_target': {
+#     'cc': cross_compiler,
+#     'folder': 'folder_for_test_src_files',
+#     'qemu': emulators['qemu-...'],
+#     'tests': [
+#       {
+#         'src_file': {
+#         }
+#       },
+#       ...
+#     ]
+#   }
+# }
+#
+# Every test executable, is built only once.
+# Tests for a given src use the same executable by default, and their definition
+# is guaranteed to be unique also.
+# Default name is derived from src.
+
+# plugins come first, as we need to build the list
+subdir('plugins')
+
+# Finally, we can create all test executables and test targets
+foreach target, plan: tcg_tests
+  # Detect duplicated executables/tests, and report an error to force user to
+  # choose how to deal with it.
+  built_tests = {}
+  added_tests = {}
+
+  # return a clear error if user misspell a target entry
+  foreach key, _ : plan
+    allowed = ['cc', 'folder', 'qemu', 'tests']
+    if key not in allowed
+      error('unknown tcg test plan entry \'' + key + '\' for target ' + target +
+            ' (possible: [' + ', '.join(allowed) + '])')
+    endif
+  endforeach
+
+  cc = plan['cc']
+  folder = plan['folder']
+  qemu = plan['qemu']
+  tests = plan['tests']
+
+  foreach t : tests
+    foreach src, setup: t
+      # meson '/' operator drops left operand if right is an absolute path
+      src = folder / src
+      file = files(src)
+      exe_name = fs.stem(src)
+
+      exe_name = target + '-' + exe_name
+      test_name = exe_name
+
+      if test_name in added_tests
+        error('test ' + test_name + ' was already added: ' +
+              'specify a different \'test_name\'')
+      endif
+
+      # build executable if needed
+      if exe_name not in built_tests
+        exe = custom_target(exe_name,
+                            input: file,
+                            command: [cc, '@INPUT@',
+                                      '-o', '@OUTPUT@', '-static',
+                                      '-MMD', '-MF', '@DEPFILE@',
+                                      '-Wall', '-Werror',
+                                      '-O0', '-g', '-fno-strict-aliasing',
+                                      ],
+                            depfile: exe_name + '.d',
+                            output: exe_name + '.test',
+                            build_by_default: false)
+        built_tests += {exe_name: exe}
+      endif
+
+      depends = []
+
+      exe = built_tests[exe_name]
+      cmd = [qemu, exe]
+
+      # some tests expect QEMU env var to be set
+      cmd = ['QEMU=' + qemu.full_path(), cmd]
+
+      test(test_name, env, args: cmd,
+           depends: depends,
+           timeout: 120,
+           suite: ['tcg', 'tcg-' + target])
+      added_tests += {test_name: true}
+    endforeach
+  endforeach
+endforeach