Re: [PATCH] error on missing LTO symbols

[Tom de Vries <tdevries at suse dot de>]

On 14-12-18 14:08, Jakub Jelinek wrote:
> On Fri, Dec 14, 2018 at 02:07:18PM +0100, Tom de Vries wrote:
>> Done, using offload_device_nonshared_as for
>> libgomp.c-c++-common/variable-not-offloaded.c and
>> openacc_nvidia_accel_configured for
>> libgomp.oacc-c-c++-common/function-not-offloaded.c.
>>
>>> Otherwise LGTM.
>>
>> Updated patch OK?
> 
> ENOPATCH

Sorry, here it is.

Thanks,
- Tom

[offloading] Error on missing symbols

When compiling an OpenMP or OpenACC program containing a reference in the
offloaded code to a symbol that has not been included in the offloaded code,
the offloading compiler may ICE in lto1.

Fix this by erroring out instead, mentioning the problematic symbol:
...
error: variable 'var' has been referenced in offloaded code but hasn't
  been marked to be included in the offloaded code
lto1: fatal error: errors during merging of translation units
compilation terminated.
...

Build x86_64 with nvptx accelerator and reg-tested libgomp.

Build x86_64 and reg-tested libgomp.

2018-12-13  Tom de Vries  <tdevries@suse.de>

	* lto-cgraph.c (verify_node_partition): New function.
	(input_overwrite_node, input_varpool_node): Use verify_node_partition.

	* testsuite/libgomp.c-c++-common/function-not-offloaded-aux.c: New test.
	* testsuite/libgomp.c-c++-common/function-not-offloaded.c: New test.
	* testsuite/libgomp.c-c++-common/variable-not-offloaded.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/function-not-offloaded.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/variable-not-offloaded.c: New test.

---
 gcc/lto-cgraph.c                                   | 40 ++++++++++++++++++----
 .../function-not-offloaded-aux.c                   | 12 +++++++
 .../libgomp.c-c++-common/function-not-offloaded.c  | 16 +++++++++
 .../libgomp.c-c++-common/variable-not-offloaded.c  | 19 ++++++++++
 .../function-not-offloaded.c                       | 18 ++++++++++
 .../variable-not-offloaded.c                       | 17 +++++++++
 6 files changed, 115 insertions(+), 7 deletions(-)

diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index 99998cc3c75..546abaeff48 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -1091,6 +1091,37 @@ output_offload_tables (void)
     }
 }
 
+/* Verify the partitioning of a varpool_node or cgraph_node with DECL and NAME,
+   as specified by IN_OTHER_PARTITION and USED_FROM_OTHER_PARTITION.  */
+
+static inline void
+verify_node_partition (symtab_node *node)
+{
+  if (flag_ltrans)
+    return;
+
+#ifdef ACCEL_COMPILER
+  if (node->in_other_partition)
+    {
+      if (TREE_CODE (node->decl) == FUNCTION_DECL)
+	error_at (DECL_SOURCE_LOCATION (node->decl),
+		  "function %qs has been referenced in offloaded code but"
+		  " hasn%'t been marked to be included in the offloaded code",
+		  node->name ());
+      else if (VAR_P (node->decl))
+	error_at (DECL_SOURCE_LOCATION (node->decl),
+		  "variable %qs has been referenced in offloaded code but"
+		  " hasn%'t been marked to be included in the offloaded code",
+		  node->name ());
+      else
+	gcc_unreachable ();
+    }
+#else
+  gcc_assert (!node->in_other_partition
+	      && !node->used_from_other_partition);
+#endif
+}
+
 /* Overwrite the information in NODE based on FILE_DATA, TAG, FLAGS,
    STACK_SIZE, SELF_TIME and SELF_SIZE.  This is called either to initialize
    NODE or to replace the values in it, for instance because the first
@@ -1153,9 +1184,7 @@ input_overwrite_node (struct lto_file_decl_data *file_data,
   node->resolution = bp_unpack_enum (bp, ld_plugin_symbol_resolution,
 				     LDPR_NUM_KNOWN);
   node->split_part = bp_unpack_value (bp, 1);
-  gcc_assert (flag_ltrans
-	      || (!node->in_other_partition
-		  && !node->used_from_other_partition));
+  verify_node_partition (node);
 }
 
 /* Return string alias is alias of.  */
@@ -1366,10 +1395,7 @@ input_varpool_node (struct lto_file_decl_data *file_data,
     node->set_section_for_node (section);
   node->resolution = streamer_read_enum (ib, ld_plugin_symbol_resolution,
 					        LDPR_NUM_KNOWN);
-  gcc_assert (flag_ltrans
-	      || (!node->in_other_partition
-		  && !node->used_from_other_partition));
-
+  verify_node_partition (node);
   return node;
 }
 
diff --git a/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded-aux.c b/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded-aux.c
new file mode 100644
index 00000000000..b8aa3da48a1
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded-aux.c
@@ -0,0 +1,12 @@
+/* { dg-skip-if "" { *-*-* } } */
+
+#pragma omp declare target
+extern int var;
+#pragma omp end declare target
+
+void __attribute__((noinline, noclone))
+foo (void)
+{
+  var++;
+}
+
diff --git a/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded.c b/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded.c
new file mode 100644
index 00000000000..9e59ef8864e
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c-c++-common/function-not-offloaded.c
@@ -0,0 +1,16 @@
+/* { dg-do link } */
+/* { dg-excess-errors "unresolved symbol foo, lto1, mkoffload and lto-wrapper fatal errors" { target offload_device_nonshared_as } } */
+/* { dg-additional-sources "function-not-offloaded-aux.c" } */
+
+#pragma omp declare target
+int var;
+#pragma omp end declare target
+
+extern void foo ();
+
+int
+main ()
+{
+#pragma omp target
+  foo ();
+}
diff --git a/libgomp/testsuite/libgomp.c-c++-common/variable-not-offloaded.c b/libgomp/testsuite/libgomp.c-c++-common/variable-not-offloaded.c
new file mode 100644
index 00000000000..bc4b916e9a4
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c-c++-common/variable-not-offloaded.c
@@ -0,0 +1,19 @@
+/* { dg-do link } */
+/* { dg-excess-errors "lto1, mkoffload and lto-wrapper fatal errors" { target offload_device_nonshared_as } } */
+
+int var; /* { dg-error "variable 'var' has been referenced in offloaded code but hasn't been marked to be included in the offloaded code" "" { target offload_device_nonshared_as } } */
+
+#pragma omp declare target
+void  __attribute__((noinline, noclone))
+foo (void)
+{
+  var++;
+}
+#pragma omp end declare target
+
+int
+main ()
+{
+#pragma omp target
+  foo ();
+}
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/function-not-offloaded.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/function-not-offloaded.c
new file mode 100644
index 00000000000..c94f268462f
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/function-not-offloaded.c
@@ -0,0 +1,18 @@
+/* { dg-do link } */
+/* { dg-excess-errors "lto1, mkoffload and lto-wrapper fatal errors" { target openacc_nvidia_accel_configured } } */
+
+int var;
+#pragma acc declare create (var)
+
+void __attribute__((noinline, noclone))
+foo () /* { dg-error "function 'foo' has been referenced in offloaded code but hasn't been marked to be included in the offloaded code" "" { target openacc_nvidia_accel_configured } } */
+{
+  var++;
+}
+
+int
+main ()
+{
+#pragma acc parallel
+  foo ();
+}
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/variable-not-offloaded.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/variable-not-offloaded.c
new file mode 100644
index 00000000000..8e10271b97f
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/variable-not-offloaded.c
@@ -0,0 +1,17 @@
+/* { dg-do link } */
+
+int var; /* { dg-error "'var' requires a 'declare' directive for use in a 'routine' function" } */
+
+#pragma acc routine
+void  __attribute__((noinline, noclone))
+foo (void)
+{
+  var++;
+}
+
+int
+main ()
+{
+#pragma acc parallel
+  foo ();
+}