tests: provide check-examples and check-tests

[Akim Demaille]

commit 77a8b84fc8bbe39dc231a1f657fd56a50fac5855
Author: Akim Demaille <akim.demaille@gmail.com>
Date:   Tue Jan 26 07:11:32 2021 +0100

    tests: provide check-examples and check-tests
    
    * examples/local.mk (check-examples): New.
    * tests/local.mk (check-tests): New.
    * README-hacking.md: Document them.

diff --git a/README-hacking.md b/README-hacking.md
index 61c3a47cb..a50e18b20 100644
--- a/README-hacking.md
+++ b/README-hacking.md
@@ -388,6 +388,11 @@ In examples/, there is a number of ready-to-use examples 
(see
 suites run by `make check`.  The test results are in local `*.log` files
 (e.g., `$build/examples/c/calc/calc.log`).
 
+To check only the examples, run `make check-examples`.  To check just one
+example,
+
+    make check-examples TESTS='examples/c/bistromathic/bistromathic.test'
+
 ### The Main Test Suite
 The main test suite, in tests/, is written on top of GNU Autotest, which is
 part of Autoconf.  Run `info autoconf 'Using Autotest'` to read the
@@ -401,28 +406,23 @@ contains lots of details that should help diagnosing 
issues, including build
 issues.  The per-test logs are more convenient when working locally.
 
 #### TESTSUITEFLAGS
-To run just the main test suite, run `make check-local`.
+To run just the main test suite, run `make check-tests`.
 
-The default is for make check-local to run all tests sequentially.  This can
-be very time consuming when checking repeatedly or on slower setups.  This
-can be sped up in two ways:
+The default is for `make check-tests` to run all tests sequentially.  This
+can be very time consuming when checking repeatedly or on slower setups.
+This can be sped up in two ways.
 
-Using -j, in a make-like fashion, for example:
+1. Using -j, in a make-like fashion, for example:
 
-    $ make check-local TESTSUITEFLAGS='-j8'
+    $ make check-tests TESTSUITEFLAGS='-j8'
 
-Actually, when using GNU Make, TESTSUITEFLAGS defaults to the -jN passed to
-it, so you may simply run
+When using GNU Make, TESTSUITEFLAGS defaults to the -jN passed to it, so you
+may simply run
 
-    $ make check-local -j8
+    $ make check-tests -j8
 
-Running only the tests of a certain category, as specified in the AT files
-with AT_KEYWORDS([[category]]). Categories include:
-- c++, for c++ parsers
-- deprec, for tests concerning deprecated constructs.
-- glr, for glr parsers
-- java, for java parsers
-- report, for automaton dumps
+2. Running only the tests of a certain category. See
+[tests/README.md](tests/README.md#keywords) for the list of categories.
 
 To get a list of all the tests (and their keywords for -k), run
 
@@ -430,11 +430,11 @@ To get a list of all the tests (and their keywords for 
-k), run
 
 To run a specific set of tests, use -k (for "keyword"). For example:
 
-    $ make check-local TESTSUITEFLAGS='-k c++'
+    $ make check-tests TESTSUITEFLAGS='-k c++'
 
 Both can be combined.
 
-    $ make check-local TESTSUITEFLAGS='-j8 -k c++'
+    $ make check-tests TESTSUITEFLAGS='-j8 -k c++'
 
 To rerun the tests that failed:
 
@@ -488,7 +488,7 @@ useful.  Here's one way to set them up with GCC 10 on Mac 
Ports
 4. Run the tests with leak detection enabled
    (`ASAN_OPTIONS=detect_leaks=1`).  E.g. for counterexamples:
    ```
-   $ make check-local TESTSUITEFLAGS='-j5 -k cex' ASAN_OPTIONS=detect_leaks=1
+   $ make check-tests TESTSUITEFLAGS='-j5 -k cex' ASAN_OPTIONS=detect_leaks=1
    ```
 
 5. You might need a suppression file.  See
diff --git a/examples/local.mk b/examples/local.mk
index 09e1747bb..318df0dc9 100644
--- a/examples/local.mk
+++ b/examples/local.mk
@@ -93,6 +93,9 @@ dist_examples_DATA = %D%/README.md
 
 CLEANDIRS += %D%/*.dSYM
 
+.PHONY: check-examples
+check-examples: check-TESTS
+
 include %D%/c/local.mk
 include %D%/c++/local.mk
 include %D%/d/local.mk
diff --git a/tests/README.md b/tests/README.md
index 53d1a2bfc..aa409a54f 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -7,11 +7,12 @@ define a number of other macros to:
 - what skeleton is used
 
 # Keywords
-The following keywords are used to label tests.  Please follow them
-and avoid creating synonyms.
+The following keywords are used to label tests (with
+AT_KEYWORDS([[category]])).  Please follow them and avoid creating
+synonyms.
 - action
 - api.value.type
-- c++
+- c++: c++ language
 - cex: counterexamples.
 - d: d language
 - deprec: deprecated features.
@@ -23,7 +24,7 @@ and avoid creating synonyms.
 - %merge
 - multistart
 - push
-- report
+- report: for automaton dumps
 - %union
 - variant
 
diff --git a/tests/local.mk b/tests/local.mk
index 37c542ad8..9896d9126 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -114,7 +114,8 @@ recheck: $(RUN_TESTSUITE_deps)
             -e 'eof && /^(\d+).*: FAILED/ && print "$$1 "'     \
                %D%/testsuite.dir/*/testsuite.log)
 
-check-local: $(RUN_TESTSUITE_deps)
+.PHONY: check-tests
+check-local check-tests: $(RUN_TESTSUITE_deps)
        $(RUN_TESTSUITE)
 
 # Run the test suite on the *installed* tree.