[PATCH] Improve OpenMP debug info for threadprivate vars and shared local statics

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

On testcases like:

program foo
  integer :: x, y
  common /blk/ x, y
  !$omp threadprivate (/blk/)
  x = 6
  y = 7
  !$omp parallel
  x = 8
  y = 9
  x = x + 1
  y = y + 1
  !$omp end parallel
end

and

int
main (void)
{
  static int thr;
  static int svar1, svar2;
  int avar1 = 0, avar2 = 0;
#pragma omp threadprivate (thr)
  thr = 18;
  thr++;
  svar1++;
  svar2++;
  avar1++;
  avar2++;
#pragma omp parallel shared(svar2, avar2)
  {
    thr = 16;
    thr++;
    {
      int vv = 6;
      vv++;
      #pragma omp atomic
        svar2++;
    }
    #pragma omp atomic
    avar2++;
  }
  svar1++;
  avar1++;
  return 0;
}

x and y in the first testcase and thr and svar2 aren't visible in the
debugger when in *omp_fn* function.  While in theory it should be possible
for the debugger to look at the containing function in the initial thread
(*omp_fn* is DW_AT_artificial) and find those vars there, that can take a
long time before it is implemented in gdb.

The following patch adds the referenced fn local threadprivate and statics
to the *omp_fn* DW_TAG_subprogram too.

Do you think that is a good idea?

Bootstrapped/regtested on x86_64-linux and i686-linux.

2010-07-22  Jakub Jelinek  <jakub@redhat.com>

	* gimplify.c (enum gimplify_omp_var_data): Add
	GOVD_THREADPRIVATE_WARNED.
	(gimplify_bind_expr): Add GOVD_LOCAL | GOVD_SEEN even for global vars.
	(omp_notice_threadprivate_variable): Note used threadprivate vars
	with current function's context in shared clauses.
	(gimplify_adjust_omp_clauses_1): Allow globals with current function's
	context in taskreg shared clause.
	* omp-low.c (lower_rec_input_clauses): For function-local is_global_var
	VAR_DECLs in shared clauses add a decl copy with DECL_VALUE_EXPR
	pointing to the original.

	* trans-openmp.c (gfc_omp_private_debug_clause): Return false for
	threadprivate decls.

	* gcc.dg/gomp/tls-3.c: New test.

--- gcc/fortran/trans-openmp.c.jj	2010-07-15 14:35:35.000000000 +0200
+++ gcc/fortran/trans-openmp.c	2010-07-22 12:02:26.000000000 +0200
@@ -352,6 +352,18 @@ gfc_omp_disregard_value_expr (tree decl,
 bool
 gfc_omp_private_debug_clause (tree decl, bool shared)
 {
+  if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
+    {
+      if (DECL_THREAD_LOCAL_P (decl))
+	return false;
+      if (DECL_HAS_VALUE_EXPR_P (decl))
+	{
+	  tree value = get_base_address (DECL_VALUE_EXPR (decl));
+	  if (value && DECL_P (value) && DECL_THREAD_LOCAL_P (value))
+	    return false;
+	}
+    }
+
   if (GFC_DECL_CRAY_POINTEE (decl))
     return true;
 
--- gcc/gimplify.c.jj	2010-07-16 17:55:08.000000000 +0200
+++ gcc/gimplify.c	2010-07-22 14:45:08.000000000 +0200
@@ -64,6 +64,7 @@ enum gimplify_omp_var_data
   GOVD_LOCAL = 128,
   GOVD_DEBUG_PRIVATE = 256,
   GOVD_PRIVATE_OUTER_REF = 512,
+  GOVD_THREADPRIVATE_WARNED = 1024,
   GOVD_DATA_SHARE_CLASS = (GOVD_SHARED | GOVD_PRIVATE | GOVD_FIRSTPRIVATE
 			   | GOVD_LASTPRIVATE | GOVD_REDUCTION | GOVD_LOCAL)
 };
@@ -1140,7 +1141,7 @@ gimplify_bind_expr (tree *expr_p, gimple
 	  struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp;
 
 	  /* Mark variable as local.  */
-	  if (ctx && !is_global_var (t)
+	  if (ctx
 	      && (! DECL_SEEN_IN_BIND_EXPR_P (t)
 		  || splay_tree_lookup (ctx->variables,
 					(splay_tree_key) t) == NULL))
@@ -5520,17 +5521,36 @@ omp_notice_threadprivate_variable (struc
 {
   splay_tree_node n;
 
-  if (ctx->region_type != ORT_UNTIED_TASK)
+  while (ctx && ctx->region_type == ORT_WORKSHARE)
+    {
+      n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
+      if (n != NULL)
+	{
+	  gcc_assert (n->value & GOVD_LOCAL);
+	  return false;
+	}
+      ctx = ctx->outer_context;
+    }
+  if (ctx == NULL)
     return false;
+
   n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
   if (n == NULL)
+    n = splay_tree_insert (ctx->variables, (splay_tree_key)decl,
+			   DECL_CONTEXT (decl) == current_function_decl
+			   ? GOVD_SHARED | GOVD_SEEN : 0);
+  if (ctx->region_type == ORT_UNTIED_TASK
+      && (n->value & GOVD_THREADPRIVATE_WARNED) == 0)
     {
-      error ("threadprivate variable %qE used in untied task", DECL_NAME (decl));
+      error ("threadprivate variable %qE used in untied task",
+	     DECL_NAME (decl));
       error_at (ctx->location, "enclosing task");
-      splay_tree_insert (ctx->variables, (splay_tree_key)decl, 0);
+      n->value |= GOVD_THREADPRIVATE_WARNED;
     }
   if (decl2)
-    splay_tree_insert (ctx->variables, (splay_tree_key)decl2, 0);
+    splay_tree_insert (ctx->variables, (splay_tree_key)decl2,
+		       DECL_CONTEXT (decl2) == current_function_decl
+		       ? GOVD_SHARED | GOVD_SEEN : 0);
   return false;
 }
 
@@ -5958,7 +5978,9 @@ gimplify_adjust_omp_clauses_1 (splay_tre
 		break;
 	      ctx = ctx->outer_context;
 	    }
-	  if (ctx == NULL)
+	  if (ctx == NULL
+	      && (DECL_CONTEXT (decl) != current_function_decl
+		  || gimplify_omp_ctxp->region_type == ORT_WORKSHARE))
 	    return 0;
 	}
       code = OMP_CLAUSE_SHARED;
--- gcc/omp-low.c.jj	2010-07-16 17:55:08.000000000 +0200
+++ gcc/omp-low.c	2010-07-22 14:09:33.000000000 +0200
@@ -2248,6 +2248,17 @@ lower_rec_input_clauses (tree clauses, g
 		continue;
 	      break;
 	    case OMP_CLAUSE_SHARED:
+	      if (pass == 0
+		  && is_global_var (OMP_CLAUSE_DECL (c))
+		  && (DECL_CONTEXT (OMP_CLAUSE_DECL (c))
+		      == current_function_decl)
+		  && is_taskreg_ctx (ctx)
+		  && !DECL_IGNORED_P (OMP_CLAUSE_DECL (c)))
+		{
+		  new_var = omp_copy_decl_1 (OMP_CLAUSE_DECL (c), ctx);
+		  SET_DECL_VALUE_EXPR (new_var, OMP_CLAUSE_DECL (c));
+		  DECL_HAS_VALUE_EXPR_P (new_var) = 1;
+		}
 	      if (maybe_lookup_decl (OMP_CLAUSE_DECL (c), ctx) == NULL)
 		{
 		  gcc_assert (is_global_var (OMP_CLAUSE_DECL (c)));
--- gcc/testsuite/gcc.dg/gomp/tls-3.c.jj	2010-07-22 15:48:41.000000000 +0200
+++ gcc/testsuite/gcc.dg/gomp/tls-3.c	2010-07-22 15:48:47.000000000 +0200
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+
+int thr;
+#pragma omp threadprivate(thr)
+
+void
+foo (void)
+{
+  #pragma omp task untied	/* { dg-error "enclosing task" } */
+  {
+    static int thr2;
+    #pragma omp threadprivate(thr2)
+    static int thr3;
+    #pragma omp threadprivate(thr3)
+    thr++;	/* { dg-error "used in untied task" } */
+    thr2++;	/* { dg-error "used in untied task" } */
+    thr++;
+    thr2++;
+  }
+}

	Jakub