openmp: Add support for OpenMP 5.1 structured-block-sequences

Related to this is the addition of structured-block-sequence in OpenMP 5.1,
which doesn't change anything for Fortran, but for C/C++ allows multiple
statements instead of just one possibly compound around the separating
directives (section and scan).

I've also made some updates to the OpenMP 5.1 support list in libgomp.texi.

2021-10-09  Jakub Jelinek  <jakub@redhat.com>

gcc/c/
	* c-parser.c (c_parser_omp_structured_block_sequence): New function.
	(c_parser_omp_scan_loop_body): Use it.
	(c_parser_omp_sections_scope): Likewise.
gcc/cp/
	* parser.c (cp_parser_omp_structured_block): Remove disallow_omp_attrs
	argument.
	(cp_parser_omp_structured_block_sequence): New function.
	(cp_parser_omp_scan_loop_body): Use it.
	(cp_parser_omp_sections_scope): Likewise.
gcc/testsuite/
	* c-c++-common/gomp/sections1.c (foo): Don't expect errors on
	multiple statements in between section directive(s).  Add testcases
	for invalid no statements in between section directive(s).
	* gcc.dg/gomp/sections-2.c (foo): Don't expect errors on
	multiple statements in between section directive(s).
	* g++.dg/gomp/sections-2.C (foo): Likewise.
	* g++.dg/gomp/attrs-6.C (foo): Add testcases for multiple
	statements in between section directive(s).
	(bar): Add testcases for multiple statements in between scan
	directive.
	* g++.dg/gomp/attrs-7.C (bar): Adjust expected error recovery.
libgomp/
	* libgomp.texi (OpenMP 5.1): Mention implemented support for
	structured block sequences in C/C++.  Mention support for
	unconstrained/reproducible modifiers on order clause.
	Mention partial (C/C++ only) support of extentensions to atomics
	construct.  Mention partial (C/C++ on clause only) support of
	align/allocator modifiers on allocate clause.

1 files changed, 45 insertions, 9 deletions

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index c7005eb..0818d66 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -40136,14 +40136,12 @@ cp_parser_end_omp_structured_block (cp_parser *parser, unsigned save)
 }
 
 static tree
-cp_parser_omp_structured_block (cp_parser *parser, bool *if_p,
-				bool disallow_omp_attrs = true)
+cp_parser_omp_structured_block (cp_parser *parser, bool *if_p)
 {
   tree stmt = begin_omp_structured_block ();
   unsigned int save = cp_parser_begin_omp_structured_block (parser);
 
-  if (disallow_omp_attrs)
-    parser->omp_attrs_forbidden_p = true;
+  parser->omp_attrs_forbidden_p = true;
   cp_parser_statement (parser, NULL_TREE, false, if_p);
 
   cp_parser_end_omp_structured_block (parser, save);
@@ -42001,6 +41999,43 @@ cp_parser_omp_section_scan (cp_parser *parser, const char *directive,
   return true;
 }
 
+/* Parse an OpenMP structured block sequence.  KIND is the corresponding
+   separating directive.  */
+
+static tree
+cp_parser_omp_structured_block_sequence (cp_parser *parser,
+					 enum pragma_kind kind)
+{
+  tree stmt = begin_omp_structured_block ();
+  unsigned int save = cp_parser_begin_omp_structured_block (parser);
+
+  cp_parser_statement (parser, NULL_TREE, false, NULL);
+  while (true)
+    {
+      cp_token *token = cp_lexer_peek_token (parser->lexer);
+
+      if (token->type == CPP_CLOSE_BRACE
+	  || token->type == CPP_EOF
+	  || token->type == CPP_PRAGMA_EOL
+	  || (token->type == CPP_KEYWORD && token->keyword == RID_AT_END)
+	  || (kind != PRAGMA_NONE
+	      && cp_parser_pragma_kind (token) == kind))
+	break;
+
+      if (kind != PRAGMA_NONE
+	  && cp_parser_omp_section_scan (parser,
+					 kind == PRAGMA_OMP_SCAN
+					 ? "scan" : "section", false))
+	break;
+
+      cp_parser_statement (parser, NULL_TREE, false, NULL);
+    }
+
+  cp_parser_end_omp_structured_block (parser, save);
+  return finish_omp_structured_block (stmt);
+}
+
+
 /* OpenMP 5.0:
 
    scan-loop-body:
@@ -42015,11 +42050,10 @@ cp_parser_omp_scan_loop_body (cp_parser *parser)
   if (!braces.require_open (parser))
     return;
 
-  substmt = cp_parser_omp_structured_block (parser, NULL, false);
+  substmt = cp_parser_omp_structured_block_sequence (parser, PRAGMA_OMP_SCAN);
   substmt = build2 (OMP_SCAN, void_type_node, substmt, NULL_TREE);
   add_stmt (substmt);
 
-  cp_parser_omp_section_scan (parser, "scan", false);
   cp_token *tok = cp_lexer_peek_token (parser->lexer);
   if (cp_parser_pragma_kind (tok) == PRAGMA_OMP_SCAN)
     {
@@ -42055,7 +42089,7 @@ cp_parser_omp_scan_loop_body (cp_parser *parser)
     error ("expected %<#pragma omp scan%>");
 
   clauses = finish_omp_clauses (clauses, C_ORT_OMP);
-  substmt = cp_parser_omp_structured_block (parser, NULL, false);
+  substmt = cp_parser_omp_structured_block_sequence (parser, PRAGMA_NONE);
   substmt = build2_loc (tok->location, OMP_SCAN, void_type_node, substmt,
 			clauses);
   add_stmt (substmt);
@@ -42924,7 +42958,8 @@ cp_parser_omp_sections_scope (cp_parser *parser)
       != PRAGMA_OMP_SECTION
       && !cp_parser_omp_section_scan (parser, "section", true))
     {
-      substmt = cp_parser_omp_structured_block (parser, NULL, false);
+      substmt = cp_parser_omp_structured_block_sequence (parser,
+							 PRAGMA_OMP_SECTION);
       substmt = build1 (OMP_SECTION, void_type_node, substmt);
       add_stmt (substmt);
     }
@@ -42951,7 +42986,8 @@ cp_parser_omp_sections_scope (cp_parser *parser)
 	  error_suppress = true;
 	}
 
-      substmt = cp_parser_omp_structured_block (parser, NULL, false);
+      substmt = cp_parser_omp_structured_block_sequence (parser,
+							 PRAGMA_OMP_SECTION);
       substmt = build1 (OMP_SECTION, void_type_node, substmt);
       add_stmt (substmt);
     }