Working with the testsuite

Running just one test (or just a few)

1) Find the pertinent Tcl script that runs the test: a .exp script in the same directory, or one of the ancestors directories. The significant part is the filename.

For example, for test case gcc/testsuite/gcc.dg/pragma-diag-1.c, it’s gcc/testsuite/gcc.dg/dg.exp, where the filename is dg.exp.

2) Figure out the appropriate “make” target, normally based on the source language for the test. For the above example, it’s check-gcc.

3) Run make in your BUILDDIR/gcc, passing in a suitable value for RUNTESTFLAGS based on the filename found in step 1 above. For this case, giving it a couple of -v flags for verbosity (so that we can see the command-line of the compiler invocation) it would be:

$ make -jN && make check-gcc RUNTESTFLAGS="-v -v dg.exp=pragma-diag-1.c"

for some N; I like the make && make check-FOO construction to ensure that the compiler is rebuilt before running the tests.

You can also use wildcards e.g.:

make -j64 && make check-gcc RUNTESTFLAGS="-v -v dg.exp=pragma-diag-*.c"

(and can use -jN for some N on the make check-FOO invocation if there are a lot of tests; I tend not to use it for a small number of tests, to avoid interleaving of output in the logs).

Testcases that apply to both C and C++ should live in c-c++-common. You can run them by making both the check-gcc and check-g++ Makefile targets. Adapting the idea from above, here’s an invocation I used whilst working on a patch:

make -k -j64 \
  && make check-gcc check-g++ \
       RUNTESTFLAGS="-v -v dg.exp=Wformat-pr88257.c"

Here’s a yet more complicated example, which runs various tests from both dg.exp and tree-ssa.exp (with multiple wildcards), and runs them for both 32-bit and 64-bit ABIs:

make check-gcc \
  RUNTESTFLAGS="--target_board=unix\{-m32,-m64\} dg.exp='pr10474.c pr15698*.c' tree-ssa.exp=20030530-2.c"

“test for excess errors”

If a DejaGnu test is failing with “test for excess errors” you can go into gcc/testsuite/lib/prune.exp and uncomment this line within proc prune_gcc_output:

#send_user "After:$text\n"

to:

send_user "After:$text\n"

This will print any messages that weren’t pruned by dg- directives.