[PATCH 24/25] Ignore LLVM's blank lines.

[<ams at codesourcery dot com>]

The GCN toolchain must use the LLVM assembler and linker because there's no
binutils port.  The LLVM tools do not have the same diagnostic style as
binutils, so the "blank line(s) in output" tests are inappropriate (and very
noisy).

The LLVM tools also have different command line options, so it's not possible
to autodetect object formats in the same way.

This patch addresses both issues.

2018-09-05  Andrew Stubbs  <ams@codesourcery.com>

	gcc/testsuite/
	* lib/file-format.exp (gcc_target_object_format): Handle AMD GCN.
	* lib/gcc-dg.exp (gcc-dg-prune): Ignore blank lines from the LLVM
	linker.
	* lib/target-supports.exp (check_effective_target_llvm_binutils): New.
---
 gcc/testsuite/lib/file-format.exp     |  3 +++
 gcc/testsuite/lib/gcc-dg.exp          |  2 +-
 gcc/testsuite/lib/target-supports.exp | 14 ++++++++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/lib/file-format.exp b/gcc/testsuite/lib/file-format.exp
index 5c47246..c595fe2 100644
--- a/gcc/testsuite/lib/file-format.exp
+++ b/gcc/testsuite/lib/file-format.exp
@@ -41,6 +41,9 @@ proc gcc_target_object_format { } {
     } elseif { [istarget *-*-aix*] } {
 	# AIX doesn't necessarily have objdump, so hand-code it.
 	set gcc_target_object_format_saved coff
+    } elseif { [istarget *-*-amdhsa*] } {
+	# AMD GCN uses LLVM objdump which is not CLI-compatible
+	set gcc_target_object_format_saved elf
     } else {
         set objdump_name [find_binutils_prog objdump]
         set open_file [open objfmtst.c w]
diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
index f5e6bef..7df348e 100644
--- a/gcc/testsuite/lib/gcc-dg.exp
+++ b/gcc/testsuite/lib/gcc-dg.exp
@@ -361,7 +361,7 @@ proc gcc-dg-prune { system text } {
 
     # Complain about blank lines in the output (PR other/69006)
     global allow_blank_lines
-    if { !$allow_blank_lines } {
+    if { !$allow_blank_lines && ![check_effective_target_llvm_binutils]} {
 	set num_blank_lines [llength [regexp -all -inline "\n\n" $text]]
 	if { $num_blank_lines } {
 	    global testname_with_flags
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 61442bd..1e627fa 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -9129,6 +9129,14 @@ proc check_effective_target_offload_hsa { } {
     } "-foffload=hsa" ]
 }
 
+# Return 1 if the compiler has been configured with hsa offloading.
+
+proc check_effective_target_offload_gcn { } {
+    return [check_no_compiler_messages offload_gcn assembly {
+	int main () {return 0;}
+    } "-foffload=amdgcn-unknown-amdhsa" ]
+}
+
 # Return 1 if the target support -fprofile-update=atomic
 proc check_effective_target_profile_update_atomic {} {
     return [check_no_compiler_messages profile_update_atomic assembly {
@@ -9427,3 +9435,9 @@ proc check_effective_target_cet { } {
 	}
     } "-O2" ]
 }
+
+# Return 1 if this target uses an LLVM assembler and/or linker
+proc check_effective_target_llvm_binutils { } {
+    return [expr { [istarget amdgcn*-*-*]
+		   || [check_effective_target_offload_gcn] } ]
+}