#### 7.2.5 Variants of `dg-require-`support

A few of the `dg-require` directives take arguments.

`dg-require-iconv` codeset
  Skip the test if the target does not support iconv. codeset is the codeset to convert to.
`dg-require-profiling` profopt
  Skip the test if the target does not support profiling with option profopt.
`dg-require-visibility` vis
  Skip the test if the target does not support the `visibility` attribute. If vis is `""`, support for `visibility("hidden")` is checked, for `visibility("`vis`")` otherwise.

The original `dg-require` directives were defined before there was support for effective-target keywords. The directives that do not take arguments could be replaced with effective-target keywords.

`dg-require-alias ""`
  Skip the test if the target does not support the ``alias`' attribute.
`dg-require-ascii-locale ""`
  Skip the test if the host does not support an ASCII locale.
`dg-require-compat-dfp ""`
  Skip this test unless both compilers in a `compat` testsuite support decimal floating point.
`dg-require-cxa-atexit ""`
  Skip the test if the target does not support `__cxa_atexit`. This is equivalent to `dg-require-effective-target cxa_atexit`.
`dg-require-dll ""`
  Skip the test if the target does not support DLL attributes.
`dg-require-fork ""`
  Skip the test if the target does not support `fork`.
`dg-require-gc-sections ""`
  Skip the test if the target's linker does not support the `--gc-sections` flags. This is equivalent to `dg-require-effective-target gc-sections`.
`dg-require-host-local ""`
  Skip the test if the host is remote, rather than the same as the build system. Some tests are incompatible with DejaGnu's handling of remote hosts, which involves copying the source file to the host and compiling it with a relative path and "`-o a.out`".
`dg-require-mkfifo ""`
  Skip the test if the target does not support `mkfifo`.
`dg-require-named-sections ""`
  Skip the test is the target does not support named sections. This is equivalent to `dg-require-effective-target named_sections`.
`dg-require-weak ""`
  Skip the test if the target does not support weak symbols.
`dg-require-weak-override ""`
  Skip the test if the target does not support overriding weak symbols.