Add option to disable */shcomp test variants

We always expect the ksh */shcomp unit test variants to behave like the
non-shcomp variants. So there is normally no reason to run the shcomp
variants. Provide an option to disable those tests in order to reduce
the cost of testing ksh script behavior.

CONTRIBUTING.md

@@ -284,12 +284,42 @@ The `--setup=malloc` will enable malloc integrity features provided by your
 system's malloc implementation if it supports such things via environment
 variables. That flag can be omitted but its use is recommended.
 
+### Disabling some tests.
+
+You can minimize total test time by changing some build time defaults. This
+can be useful to minimize test run time on your local system(s) since:
+
+a) We expect API tests to never fail since the core APIs (e.g., SFIO) rarely
+  change and thus should never fail their unit tests.
+
+b) We expect shcomp and non-shcomp variants to pass/fail in lock step. So
+  normally there is no reason to run the `*/shcomp` variants.
+
+That is done by configuring the build thusly:
+
+```
+  meson -Dbuild-api-tests=false -Dbuild-shcomp-tests=false
+```
+
+Obviously, all CI environments should enable both sets of tests, at least
+some, if not all, of the time, and it would be a good idea for everyone
+else to occassionally enable both sets of tests. Which is why the default
+is for both sets to be enabled. You have to deliberately disable those
+sets of tests if you care about the overhead they add.
+
+You can also enable just the API tests, thus skipping all the ksh script
+tests, by doing
+
+```
+  meson -Dbuild-api-tests-only=true
+```
+
 ### Testing with ASAN -- AddressSanitizer
 
 At the moment this only works on Linux using gcc.
 
-Configure with `meson -DASAN=true -Dbuild-api-tests=false`. Then build with
-`ninja` as usual. Run the tests with `meson test --setup=asan`.
+Configure with `meson -DASAN=true`. Then build with `ninja` as usual. Run
+the tests with `meson test --setup=asan`.
 
 You will need to install the `llvm-symbolizer` tool if the gcc version is less
 than 4.9.3. For example, on OpenSuse 42.3 you'll need to run `sudo zypper

meson.build

@@ -297,7 +297,7 @@ run_command('scripts/libast_prereq.sh')
 subdir('src/lib/libast')
 subdir('src/lib/libdll')
 
-# Check if api tests should be built
+# Check if API tests should be built.
 if get_option('build-api-tests') == true
     subdir('src/lib/libast/tests/')
 endif

meson_options.txt

@@ -15,7 +15,7 @@ option('unittest', type : 'boolean', value : false)
 # TODO: Use the following definition when we can count on Meson 0.45 being
 # available on the platforms we care about. For the moment we're stuck with
 # Meson 0.44.
-# option('read-timeout', type : 'integer', min : 0, value : 0)
+#   option('read-timeout', type : 'integer', min : 0, value : 0)
 #
 option('read-timeout', type : 'string', value : '0')
 
@@ -25,14 +25,18 @@ option('read-timeout', type : 'string', value : '0')
 #
 option('audit-file', type : 'string', value : '/etc/ksh_audit')
 
-# To disable building api tests, set build-api-tests option to false:
-#   meson -Dbuild-api-tests=false
-option('build-api-tests', type : 'boolean', value : true)
-
 # To build api tests only, set build-api-tests-only option to true:
 #   meson -Dbuild-api-tests-only=true
 option('build-api-tests-only', type : 'boolean', value : false)
 
+# To disable running API tests, set build-api-tests option to false:
+#   meson -Dbuild-api-tests=false
+option('build-api-tests', type : 'boolean', value : true)
+
+# To disable running */shcomp tests, set build-shcomp-tests option to false:
+#   meson -Dbuild-shcomp-tests=false
+option('build-shcomp-tests', type : 'boolean', value : true)
+
 # This number is used when git is not available
 #   meson -Dfallback-version-number='x.y.z'
 option('fallback-version-number', type : 'string', value : '2020.99.99')

src/cmd/ksh93/meson.build

@@ -61,8 +61,12 @@ ld_library_path = 'LD_LIBRARY_PATH=' + ':'.join(
 # Sample loadable builtin will be loaded from this path in builtins test cases
 libsample_path = 'LIBSAMPLE_PATH=' + libsample.full_path()
 
-subdir('tests/api')
-# Check if only api tests should be built
+# Check if API tests should be built.
+if get_option('build-api-tests') == true
+    subdir('tests/api')
+endif
+
+# Check if only API tests should be built.
 if get_option('build-api-tests-only') == false
     subdir('tests')
 endif

src/cmd/ksh93/tests/meson.build

@@ -139,7 +139,7 @@ foreach testspec : all_tests
               system_var, timeout_var])
 
     # The shcomp variants are only applicable to the non-interactive tests.
-    if not test_name.endswith('.exp')
+    if get_option('build-shcomp-tests') == true and not test_name.endswith('.exp')
         # Run the test after compiling the script with `shcomp`.
         test(test_name + '/shcomp', ksh93_exe, timeout: timeout, is_parallel: parallel,
             args: ['-p', test_driver, 'shcomp', test_name],