gcc/libstdc++-v3/testsuite

  We're in the process of converting the existing testsuite machinery to 
use the new style DejaGnu framework.  Eventually, we'll abandon
../mkcheck.in in favor of this new testsuite framework. 

Basically, a testcase contains dg-keywords (see dg.exp) indicating
what to do and what kinds of behaviour are to be expected.  New
testcases should be written with the new style DejaGnu framework in
mind.

To ease transition, here is the list of dg-keyword documentation
lifted from dg.exp -- eventuaklly we should improve DejaGnu
documentation, but getting checkin account currently demands Pyrrhic
effort. 

# The currently supported options are:
#
# dg-prms-id N
#	set prms_id to N
#
# dg-options "options ..." [{ target selector }]
#	specify special options to pass to the tool (eg: compiler)
#
# dg-do do-what-keyword [{ target/xfail selector }]
#	`do-what-keyword' is tool specific and is passed unchanged to
#	${tool}-dg-test.  An example is gcc where `keyword' can be any of:
#	preprocess|compile|assemble|link|run
#	and will do one of: produce a .i, produce a .s, produce a .o,
#	produce an a.out, or produce an a.out and run it (the default is
#	compile).
#
# dg-error regexp comment [{ target/xfail selector } [{.|0|linenum}]]
#	indicate an error message <regexp> is expected on this line
#	(the test fails if it doesn't occur)
#	Linenum=0 for general tool messages (eg: -V arg missing).
#	"." means the current line.
#
# dg-warning regexp comment [{ target/xfail selector } [{.|0|linenum}]]
#	indicate a warning message <regexp> is expected on this line
#	(the test fails if it doesn't occur)
#
# dg-bogus regexp comment [{ target/xfail selector } [{.|0|linenum}]]
#	indicate a bogus error message <regexp> use to occur here
#	(the test fails if it does occur)
#
# dg-build regexp comment [{ target/xfail selector }]
#	indicate the build use to fail for some reason
#	(errors covered here include bad assembler generated, tool crashes,
#	and link failures)
#	(the test fails if it does occur)
#
# dg-excess-errors comment [{ target/xfail selector }]
#	indicate excess errors are expected (any line)
#	(this should only be used sparingly and temporarily)
#
# dg-output regexp [{ target selector }]
#	indicate the expected output of the program is <regexp>
#	(there may be multiple occurrences of this, they are concatenated)
#
# dg-final { tcl code }
#	add some tcl code to be run at the end
#	(there may be multiple occurrences of this, they are concatenated)
#	(unbalanced braces must be \-escaped)
#
# "{ target selector }" is a list of expressions that determine whether the
# test succeeds or fails for a particular target, or in some cases whether the
# option applies for a particular target.  If the case of `dg-do' it specifies
# whether the testcase is even attempted on the specified target.
#
# The target selector is always optional.  The format is one of:
#
# { xfail *-*-* ... } - the test is expected to fail for the given targets
# { target *-*-* ... } - the option only applies to the given targets
#
# At least one target must be specified, use *-*-* for "all targets".
# At present it is not possible to specify both `xfail' and `target'.
# "native" may be used in place of "*-*-*".
#
# Example:
#
#       [ ... some complicated code ... ]
#	return a; /* { dg-build "fatal" "ran out of spill regs" { xfail i386-*-* } } */
#
# In this example, the compiler use to crash on the "return a;" for some
# target and that it still does crash on i386-*-*.  Admittedly, this is a
# contrived example.
#
# ??? It might be possible to add additional optional arguments by having
# something like: { dg-error ".*syntax.*" "syntax error" { { foo 1 } ... } }


The V3 testing framework supports additional keywords for the purpose
of easing the job of writing testcases.  All V3-keywords are of the
form @xxx@.  Currently supported keywords include:

  @require@ <files>
      The existence of <files> is essential for the test to complete
      successfully.  For example, a testcase foo.C using bar.baz as
      input file could say
	    // @require@ bar.baz
      The special variable % stands for the rootname, e.g. the
      file-name without its `.C' extension.  Example of use (taken
      verbatim from 27_io/filebuf.cc)
	   // @require@ %-*.tst %-*.txt

  @diff@ <first-list> <second-list>
      After the testcase compiles and ran successfully, diff
      <first-list> against <second-list>, these lists should have the
      same length.  The test fails if diff returns non-zero a pair of
      files.

-- Gaby