°C OpenMP C 和 C++ 语法

C.1 表示法
C.2 规则

C.1 表示法

语法规则包括非终端的名称，后跟冒号，后跟单独的行上的替换替代项。

语法表达式术语 _opt 指示该术语在替换中是可选的。

语法表达式术语_optseq 等于带有以下附加规则的 term-seq_opt：

term-seq:
 term
 term-seqterm
 term-seq,term

C.2 规则

C 标准的第 6.1 节介绍了表示法。 此语法附录介绍了 OpenMP C 和 C++ 指令的基本语言语法的扩展。

/* in C++ (ISO/IEC 14882:1998) */

statement-seq:
 语句
 openmp-directive
 statement-seq 语句
 statement-seq openmp-directive

/* in C90 (ISO/IEC 9899:1990) */

statement-list：
 语句
 openmp-directive
 statement-list statement
 statement-list openmp-directive

/* in C99 (ISO/IEC 9899:1999) */

block-item:
 declaration
 语句
 openmp-directive

/* standard statements */

语句：
 openmp-construct

openmp-construct:
 parallel-construct
 for-construct
 sections-construct
 single-construct
 parallel-for-construct
 parallel-sections-construct
 master-construct
 critical-construct
 atomic-construct
 ordered-construct

openmp-directive:
 barrier-directive
 flush-directive

structured-block:
 语句

parallel-construct:
 parallel-directive structured-block

parallel-directive:
  # pragma omp parallelparallel-clause_optseqnew-line

parallel-clause:
 unique-parallel-clause
 data-clause

unique-parallel-clause:
  if (expression)
  num_threads (expression)

for-construct:
 for-directive iteration-statement

for-directive:
  # pragma omp forfor-clause_optseqnew-line

for-clause:
 unique-for-clause
 data-clause
  nowait

unique-for-clause:
  ordered
  schedule (schedule-kind)
  schedule (schedule-kind,expression)

schedule-kind:
  static
  dynamic
  guided
  runtime

sections-construct:
 sections-directive section-scope

sections-directive:
  # pragma omp sectionssections-clause_optseqnew-line

sections-clause:
 data-clause
  nowait

section-scope:
 { section-sequence }

section-sequence:
 section-directive_optstructured-block
 section-sequence section-directive structured-block

section-directive:
  # pragma omp sectionnew-line

single-construct:
 single-directive structured-block

single-directive:
  # pragma omp singlesingle-clause_optseqnew-line

single-clause:
 data-clause
  nowait

parallel-for-construct:
 parallel-for-directive iteration-statement

parallel-for-directive:
  # pragma omp parallel forparallel-for-clause_optseqnew-line

parallel-for-clause:
 unique-parallel-clause
 unique-for-clause
 data-clause

parallel-sections-construct:
 parallel-sections-directive section-scope

parallel-sections-directive:
  # pragma omp parallel sectionsparallel-sections-clause_optseqnew-line

parallel-sections-clause:
 unique-parallel-clause
 data-clause

master-construct:
 master-directive structured-block

master-directive:
  # pragma omp masternew-line

critical-construct:
 critical-directive structured-block

critical-directive:
  # pragma omp criticalregion-phrase_optnew-line

region-phrase:
 (identifier)

barrier-directive:
  # pragma omp barriernew-line

atomic-construct:
 atomic-directive expression-statement

atomic-directive:
  # pragma omp atomicnew-line

flush-directive:
  # pragma omp flushflush-vars_optnew-line

flush-vars:
 (variable-list)

ordered-construct:
 ordered-directive structured-block

ordered-directive:
  # pragma omp orderednew-line

/* standard declarations */

declaration:
 threadprivate-directive

threadprivate-directive:
  # pragma omp threadprivate (variable-list)new-line

data-clause:
  private (variable-list)
  copyprivate (variable-list)
  firstprivate (variable-list)
  lastprivate (variable-list)
  shared (variable-list)
  default ( shared )
  default ( none )
  reduction (reduction-operator:variable-list)
  copyin (variable-list)

reduction-operator:
 以下项之一：+ \* - & ^ | && ||

/* in C */

variable-list:
 identifier
 variable-list,identifier

/* in C++ */

variable-list:
 id-expression
 variable-list,id-expression