re PR c++/60228 (ICE using lambda in #pragma omp declare reduction)

	PR c++/60228
	* parser.c (cp_parser_omp_declare_reduction_exprs): If
	processing_template_decl, wrap the combiner or initializer
	into EXPR_STMT.
	* decl.c (start_preparsed_function): Don't start a lambda scope
	for DECL_OMP_DECLARE_REDUCTION_P functions.
	(finish_function): Don't finish a lambda scope for
	DECL_OMP_DECLARE_REDUCTION_P functions, nor cp_fold_function
	them nor cp_genericize them.
	* mangle.c (decl_mangling_context): Look through
	DECL_OMP_DECLARE_REDUCTION_P functions.
	* semantics.c (expand_or_defer_fn_1): For DECL_OMP_DECLARE_REDUCTION_P
	functions, use tentative linkage, don't keep their bodies with
	-fkeep-inline-functions and return false at the end.

	* g++.dg/gomp/openmp-simd-2.C: Don't expect bodies for
	DECL_OMP_DECLARE_REDUCTION_P functions.

	* testsuite/libgomp.c++/udr-20.C: New test.
	* testsuite/libgomp.c++/udr-21.C: New test.

From-SVN: r278831

5 files changed, 48 insertions, 6 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8b71f02..3a6bf05 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,20 @@
+2019-11-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/60228
+	* parser.c (cp_parser_omp_declare_reduction_exprs): If
+	processing_template_decl, wrap the combiner or initializer
+	into EXPR_STMT.
+	* decl.c (start_preparsed_function): Don't start a lambda scope
+	for DECL_OMP_DECLARE_REDUCTION_P functions.
+	(finish_function): Don't finish a lambda scope for
+	DECL_OMP_DECLARE_REDUCTION_P functions, nor cp_fold_function
+	them nor cp_genericize them.
+	* mangle.c (decl_mangling_context): Look through
+	DECL_OMP_DECLARE_REDUCTION_P functions.
+	* semantics.c (expand_or_defer_fn_1): For DECL_OMP_DECLARE_REDUCTION_P
+	functions, use tentative linkage, don't keep their bodies with
+	-fkeep-inline-functions and return false at the end.
+
 2019-11-28  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/92695
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 7d5bc91..81d7343 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -16318,7 +16318,8 @@ start_preparsed_function (tree decl1, tree attrs, int flags)
       && !implicit_default_ctor_p (decl1))
     cp_ubsan_maybe_initialize_vtbl_ptrs (current_class_ptr);
 
-  start_lambda_scope (decl1);
+  if (!DECL_OMP_DECLARE_REDUCTION_P (decl1))
+    start_lambda_scope (decl1);
 
   return true;
 }
@@ -16703,7 +16704,8 @@ finish_function (bool inline_p)
   if (fndecl == NULL_TREE)
     return error_mark_node;
 
-  finish_lambda_scope ();
+  if (!DECL_OMP_DECLARE_REDUCTION_P (fndecl))
+    finish_lambda_scope ();
 
   if (c_dialect_objc ())
     objc_finish_function ();
@@ -16845,7 +16847,9 @@ finish_function (bool inline_p)
     invoke_plugin_callbacks (PLUGIN_PRE_GENERICIZE, fndecl);
 
   /* Perform delayed folding before NRV transformation.  */
-  if (!processing_template_decl && !DECL_IMMEDIATE_FUNCTION_P (fndecl))
+  if (!processing_template_decl
+      && !DECL_IMMEDIATE_FUNCTION_P (fndecl)
+      && !DECL_OMP_DECLARE_REDUCTION_P (fndecl))
     cp_fold_function (fndecl);
 
   /* Set up the named return value optimization, if we can.  Candidate
@@ -16958,7 +16962,9 @@ finish_function (bool inline_p)
     do_warn_unused_parameter (fndecl);
 
   /* Genericize before inlining.  */
-  if (!processing_template_decl && !DECL_IMMEDIATE_FUNCTION_P (fndecl))
+  if (!processing_template_decl
+      && !DECL_IMMEDIATE_FUNCTION_P (fndecl)
+      && !DECL_OMP_DECLARE_REDUCTION_P (fndecl))
     cp_genericize (fndecl);
 
  cleanup:
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index 0ac0451..88c5fa2 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -873,7 +873,16 @@ decl_mangling_context (tree decl)
   else if (template_type_parameter_p (decl))
      /* template type parms have no mangling context.  */
       return NULL_TREE;
-  return CP_DECL_CONTEXT (decl);
+
+  tcontext = CP_DECL_CONTEXT (decl);
+
+  /* Ignore the artificial declare reduction functions.  */
+  if (tcontext
+      && TREE_CODE (tcontext) == FUNCTION_DECL
+      && DECL_OMP_DECLARE_REDUCTION_P (tcontext))
+    return decl_mangling_context (tcontext);
+
+  return tcontext;
 }
 
 /* <name> ::= <unscoped-name>
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index ed24416..fb03002 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -41244,6 +41244,8 @@ cp_parser_omp_declare_reduction_exprs (tree fndecl, cp_parser *parser)
   combiner = cp_parser_expression (parser);
   finish_expr_stmt (combiner);
   block = finish_omp_structured_block (block);
+  if (processing_template_decl)
+    block = build_stmt (input_location, EXPR_STMT, block);
   add_stmt (block);
 
   if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN))
@@ -41348,6 +41350,8 @@ cp_parser_omp_declare_reduction_exprs (tree fndecl, cp_parser *parser)
 
       block = finish_omp_structured_block (block);
       cp_walk_tree (&block, cp_remove_omp_priv_cleanup_stmt, omp_priv, NULL);
+      if (processing_template_decl)
+	block = build_stmt (input_location, EXPR_STMT, block);
       add_stmt (block);
 
       if (ctor)
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 4a5479c..17de39e 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -4417,7 +4417,9 @@ expand_or_defer_fn_1 (tree fn)
       if (DECL_INTERFACE_KNOWN (fn))
 	/* We've already made a decision as to how this function will
 	   be handled.  */;
-      else if (!at_eof || DECL_IMMEDIATE_FUNCTION_P (fn))
+      else if (!at_eof
+	       || DECL_IMMEDIATE_FUNCTION_P (fn)
+	       || DECL_OMP_DECLARE_REDUCTION_P (fn))
 	tentative_decl_linkage (fn);
       else
 	import_export_decl (fn);
@@ -4429,6 +4431,7 @@ expand_or_defer_fn_1 (tree fn)
       if (DECL_DECLARED_INLINE_P (fn)
 	  && !DECL_REALLY_EXTERN (fn)
 	  && !DECL_IMMEDIATE_FUNCTION_P (fn)
+	  && !DECL_OMP_DECLARE_REDUCTION_P (fn)
 	  && (flag_keep_inline_functions
 	      || (flag_keep_inline_dllexport
 		  && lookup_attribute ("dllexport", DECL_ATTRIBUTES (fn)))))
@@ -4461,6 +4464,9 @@ expand_or_defer_fn_1 (tree fn)
       return false;
     }
 
+  if (DECL_OMP_DECLARE_REDUCTION_P (fn))
+    return false;
+
   return true;
 }