From: Andrew Stubbs <ams@codesourcery.com>
Date: Sun, 6 Dec 2020 19:23:55 +0000 (+0000)
Subject: Fix offload dwarf info
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=27a14054a8a21b994bb91c624f3306dc24a3888b;p=thirdparty%2Fgcc.git

Fix offload dwarf info

Add a notional code range to the notional parent function of offload kernel
functions.  This is enough to prevent GDB discarding them.

gcc/ChangeLog:

	* dwarf2out.cc (gen_subprogram_die): Add high/low_pc attributes for
	parents of offload kernels.
---

diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index 444d008139dd..4346ea0411c2 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,8 @@
+2020-12-06  Andrew Stubbs  <ams@codesourcery.com>
+
+	* dwarf2out.cc (gen_subprogram_die): Add high/low_pc attributes for
+	parents of offload kernels.
+
 2021-01-13  Julian Brown  <julian@codesourcery.com>
 
 	* doc/tm.texi.in (TARGET_VECTORIZE_PREFER_GATHER_SCATTER): Add
diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
index d7a39944424b..dfdc0426cf1f 100644
--- a/gcc/dwarf2out.cc
+++ b/gcc/dwarf2out.cc
@@ -23755,6 +23755,20 @@ gen_subprogram_die (tree decl, dw_die_ref context_die)
 	      /* We have already generated the labels.  */
              add_AT_low_high_pc (subr_die, fde->dw_fde_begin,
                                  fde->dw_fde_end, false);
+
+	     /* Offload kernel functions are nested within a parent function
+	        that doesn't actually exist within the offload object.  GDB
+		will ignore the function and everything nested within unless
+		we give it a notional code range (the values aren't
+		important, as long as they are valid).  */
+	     if (flag_generate_offload
+		 && lookup_attribute ("omp target entrypoint",
+				      DECL_ATTRIBUTES (decl))
+		 && subr_die->die_parent
+		 && subr_die->die_parent->die_tag == DW_TAG_subprogram
+		 && !get_AT_low_pc (subr_die->die_parent))
+	       add_AT_low_high_pc (subr_die->die_parent, fde->dw_fde_begin,
+				   fde->dw_fde_end, false);
 	    }
 	  else
 	    {