Next: Selectors, Up: Test Directives
Test directives appear within comments in a test source file and begin
with dg-. Some of these are defined within DejaGnu and others
are local to the GCC testsuite.
测试指令出现在测试源文件的注释中，并且起始于dg-。
其中一些是在DejaGnu中定义的，其它的是局限于GCC测试包自己的。
The order in which test directives appear in a test can be important: directives local to GCC sometimes override information used by the DejaGnu directives, which know nothing about the GCC directives, so the DejaGnu directives must precede GCC directives. 测试中测试指令出现的顺序很重要： 局限于GCC的指令有时会覆盖DejaGnu的指令使用的信息， 并且其对GCC指令一无所知，所以DejaGnu指令必须在GCC指令之前。
Several test directives include selectors (参见Selectors)
which are usually preceded by the keyword target or xfail.
个别测试指令包含了选择器，
其通常由关键字target或xfail打头。
一个选择器为：一个或多个目标三元组，可能包含通配符；
单个的有效目标关键字；或者一个逻辑表达式。
取决于上下文，选择器指定了是否测试被跳过并报告为不支持，
或者预期为失败。使用‘*-*-*’来匹配任何目标。
有效目标关键字在GCC测试包的target-supports.exp中定义。
选择器表达式出现在大括号中， 并且使用单个的逻辑操作符：‘!’,‘&&’, 或‘||’。 操作数为另一个选择器表达式，一个有效目标关键字， 单个的目标三元组，或者一个双引号或大括号包裹的目标三元组列表。 例如：
{ dg-do do-what-keyword [{ target/xfail selector }] }preprocesscompileassemblelinkrun缺省情况为compile。
可以通过在那些测试的.exp文件中重定义
dg-do-what-default来覆盖这个值。
如果指令包含了可选的‘{ target selector } ’， 则除非目标系统被包含在目标三元组列表中，或者匹配有效目标关键字， 否则测试将被跳过。
如果运行了‘do-what-keyword’并且指令包含了可选的
‘{ xfail selector }’并且选择器匹配，则测试期望为失败。
对于‘do-what-keyword’的其它值，xfail子句会被忽略；
那些测试可以使用指令dg-xfail-if。
{ dg-options options [{ target selector }] }{ dg-add-options feature ... }dg-options指令之后。
支持的feature为：
通常的时间限制，以秒为单位，按照下列顺序来查找：
dg-timeout指令定义
{ dg-timeout n [{target selector }] }{ dg-timeout-factor x [{ target selector }] }{ dg-skip-if comment { selector } [{ include-opts } [{ exclude-opts }]] }For example, to skip a test if option -Os is present:
/* { dg-skip-if "" { *-*-* } { "-Os" } { "" } } */
To skip a test if both options -O2 and -g are present:
/* { dg-skip-if "" { *-*-* } { "-O2 -g" } { "" } } */
To skip a test if either -O2 or -O3 is present:
/* { dg-skip-if "" { *-*-* } { "-O2" "-O3" } { "" } } */
To skip a test unless option -Os is present:
/* { dg-skip-if "" { *-*-* } { "*" } { "-Os" } } */
To skip a test if either -O2 or -O3 is used with -g
but not if -fpic is also present:
/* { dg-skip-if "" { *-*-* } { "-O2 -g" "-O3 -g" } { "-fpic" } } */
{ dg-require-effective-target keyword [{ selector }] }dg-do directive in the test
and before any dg-additional-sources directive.
参见Effective-Target Keywords.
{ dg-require-support args }dg-do directive in the test
and before any dg-additional-sources directive.
They require at least one argument, which can be an empty string if the
specific procedure does not examine the argument.
参见Require Support, for a complete list of these directives.
{ dg-xfail-if comment { selector } [{ include-opts } [{ exclude-opts }]] }dg-skip-if) are met. This does not affect the execute step.
{ dg-xfail-run-if comment { selector } [{ include-opts } [{ exclude-opts }]] }dg-skip-if) are met.
{ dg-shouldfail comment [{ selector } [{ include-opts } [{ exclude-opts }]]] }dg-skip-if) are met.
{ dg-error regexp [comment [{ target/xfail selector } [line] }]] }FAIL message. The check does
not look for the string ‘error’ unless it is part of regexp.
{ dg-warning regexp [comment [{ target/xfail selector } [line] }]] }FAIL message. The check does
not look for the string ‘warning’ unless it is part of regexp.
{ dg-message regexp [comment [{ target/xfail selector } [line] }]] }FAIL message.
{ dg-bogus regexp [comment [{ target/xfail selector } [line] }]] }{ dg-excess-errors comment [{ target/xfail selector }] }{ dg-prune-output regexp }{ dg-output regexp [{ target/xfail selector }] }{ dg-additional-files "filelist" }{ dg-additional-sources "filelist" }{ dg-final { local-directive } }dg-final.