changed to default 1 thread, updated tests

Author: ayermolo

llvm/test/tools/llvm-dwarfdump/X86/debug-names-verify-abbrev-forms.s

@@ -1,5 +1,5 @@
 # RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj | \
-# RUN:   not llvm-dwarfdump -verify --verify-num-threads 1 - | FileCheck %s
+# RUN:   not llvm-dwarfdump -verify - | FileCheck %s
 
 # CHECK: error: NameIndex @ 0x0: Abbreviation 0x2: DW_IDX_compile_unit uses an unexpected form DW_FORM_ref1 (expected form class constant).
 # CHECK: error: NameIndex @ 0x0: Abbreviation 0x2: DW_IDX_type_unit uses an unexpected form DW_FORM_ref1 (expected form class constant).

llvm/test/tools/llvm-dwarfdump/X86/debug-names-verify-completeness.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj -o - | not llvm-dwarfdump -verify --verify-num-threads 1  - | FileCheck %s
+# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj -o - | not llvm-dwarfdump -verify - | FileCheck %s
 
 # CHECK: error: Name Index @ 0x0: Entry for DIE @ {{.*}} (DW_TAG_namespace) with name namesp missing.
 # CHECK: error: Name Index @ 0x0: Entry for DIE @ {{.*}} (DW_TAG_variable) with name var_block_addr missing.

llvm/test/tools/llvm-dwarfdump/X86/debug-names-verify-cu-lists.s

@@ -1,5 +1,5 @@
 # RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj | \
-# RUN:   not llvm-dwarfdump -verify --verify-num-threads 1 - | FileCheck %s
+# RUN:   not llvm-dwarfdump -verify - | FileCheck %s
 
 # CHECK: error: Name Index @ 0x0 does not index any CU
 # CHECK: error: Name Index @ 0x28 references a non-existing CU @ 0x1

llvm/test/tools/llvm-dwarfdump/X86/debug-names-verify-entries.s

@@ -1,4 +1,4 @@
-# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj -o - | not llvm-dwarfdump -verify --verify-num-threads 1 - | FileCheck %s
+# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj -o - | not llvm-dwarfdump -verify - | FileCheck %s
 
 # CHECK: error: Name Index @ 0x0: Unable to get string associated with name 1.
 # CHECK: error: Name Index @ 0x0: Entry @ 0x73 contains an invalid CU index (47).

llvm/test/tools/llvm-dwarfdump/verify_split_dwarf_debug_names.test

@@ -5,7 +5,7 @@
 # RUN: yaml2obj %p/Inputs/verify_split_dwarf_debug_names_exe.yaml > %t1/a.out
 # RUN: yaml2obj %p/Inputs/verify_split_dwarf_debug_names_main_dwo.yaml > %t1/main.dwo
 # RUN: cd %t1
-# RUN: llvm-dwarfdump --verify --verify-num-threads 1 %t1/a.out | FileCheck %s
+# RUN: llvm-dwarfdump --verify %t1/a.out | FileCheck %s
 
 # CHECK: Verifying unit: 1 / 1
 # CHECK: Verifying dwo Units...
@@ -17,7 +17,7 @@
 # Now verify if we remove the "main.dwo" file that we get an error letting us
 # know that the .dwo file was not able to be found.
 # RUN: rm %t1/main.dwo
-# RUN: not llvm-dwarfdump --verify --verify-num-threads 1 %t1/a.out | FileCheck --check-prefix=NODWO %s
+# RUN: not llvm-dwarfdump --verify %t1/a.out | FileCheck --check-prefix=NODWO %s
 
 # NODWO: Verifying unit: 1 / 1
 # NODWO: Verifying dwo Units...

llvm/test/tools/llvm-dwarfdump/verify_split_dwarf_debug_names_ftus.test

@@ -5,7 +5,7 @@
 # RUN: yaml2obj %p/Inputs/verify_split_dwarf_debug_names_ftus_exe.yaml > %t1/a.out
 # RUN: yaml2obj %p/Inputs/verify_split_dwarf_debug_names_ftus_dwo.yaml > %t1/main.dwo
 # RUN: cd %t1
-# RUN: llvm-dwarfdump --verify --verify-num-threads 1 %t1/a.out | FileCheck %s
+# RUN: llvm-dwarfdump --verify %t1/a.out | FileCheck %s
 
 # CHECK: Verifying unit: 1 / 1
 # CHECK: Verifying dwo Units...
@@ -17,7 +17,7 @@
 # Now verify if we remove the "main.dwo" file that we get an error letting us
 # know that the .dwo file was not able to be found.
 # RUN: rm %t1/main.dwo
-# RUN: not llvm-dwarfdump --verify --verify-num-threads 1 %t1/a.out | FileCheck --check-prefix=NODWO %s
+# RUN: not llvm-dwarfdump --verify %t1/a.out | FileCheck --check-prefix=NODWO %s
 
 # NODWO: Verifying unit: 1 / 1
 # NODWO: Verifying dwo Units...

llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp

@@ -287,8 +287,12 @@ static cl::opt<bool>
 static opt<bool> Verify("verify", desc("Verify the DWARF debug info."),
                         cat(DwarfDumpCategory));
 static opt<unsigned> VerifyNumThreads(
-    "verify-num-threads", init(hardware_concurrency().compute_thread_count()),
-    desc("Number of threads to use for --verify."), cat(DwarfDumpCategory));
+    "verify-num-threads", init(1),
+    desc("Number of threads to use for --verify. Single threaded verification "
+         "is the default unless this option is specified. This can cause the "
+         "output to be non determinisitic, but can speed up verification and "
+         "is useful when running with the summary only or JSON summary modes."),
+    cat(DwarfDumpCategory));
 static opt<ErrorDetailLevel> ErrorDetails(
     "error-display", init(Unspecified),
     desc("Set the level of detail and summary to display when verifying "