Index: llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
===================================================================
--- llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
+++ llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
@@ -1,4 +1,7 @@
-# RUN: yaml2obj %s | llvm-dwarfdump --statistics - 2>&1 | FileCheck %s
+# RUN: yaml2obj %s -o %t.o
+# RUN: llvm-dwarfdump --statistics %t.o 2>&1 | FileCheck %s
+# RUN: not %llvm-locstats %t.o 2>&1 | FileCheck %s --check-prefix=LOCSTATS
+# RUN: rm %t.o
 
 ## Check that we are covering the situation when a stat field overflows.
 ##
@@ -22,6 +25,7 @@
 ##             [0x0000000000000003, 0x0000000000000005): DW_OP_reg2 RCX)
 
 # CHECK: "sum_all_variables(#bytes in parent scope)": "overflowed"
+# LOCSTATS: error: "sum_all_variables(#bytes in parent scope)" field overflowed.
 
 --- !ELF
 FileHeader:
Index: llvm/utils/llvm-locstats/llvm-locstats.py
===================================================================
--- llvm/utils/llvm-locstats/llvm-locstats.py
+++ llvm/utils/llvm-locstats/llvm-locstats.py
@@ -179,6 +179,8 @@
                   universal_newlines = True)
   cmd_stdout, cmd_stderr = subproc.communicate()
 
+  # TODO: Handle errors that are coming from llvm-dwarfdump.
+
   # Get the JSON and parse it.
   json_parsed = None
 
@@ -190,84 +192,91 @@
 
   # TODO: Parse the statistics Version from JSON.
 
+  def init_field(name):
+    if json_parsed[name] == 'overflowed':
+      print ('error: "' + name + '" field overflowed.')
+      sys.exit(1)
+    return json_parsed[name]
+
   if opts.only_variables:
     # Read the JSON only for local variables.
     variables_total_locstats = \
-      json_parsed['#local vars processed by location statistics']
+      init_field('#local vars processed by location statistics')
     variables_scope_bytes_covered = \
-      json_parsed['sum_all_local_vars(#bytes in parent scope covered' \
-                  ' by DW_AT_location)']
+      init_field('sum_all_local_vars(#bytes in parent scope covered' \
+                  ' by DW_AT_location)')
     variables_scope_bytes = \
-      json_parsed['sum_all_local_vars(#bytes in parent scope)']
+      init_field('sum_all_local_vars(#bytes in parent scope)')
     if not opts.ignore_debug_entry_values:
       for cov_bucket in coverage_buckets():
         cov_category = "#local vars with {} of parent scope covered " \
                        "by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
     else:
       variables_scope_bytes_entry_values = \
-        json_parsed['sum_all_local_vars(#bytes in parent scope ' \
-                    'covered by DW_OP_entry_value)']
+        init_field('sum_all_local_vars(#bytes in parent scope ' \
+                    'covered by DW_OP_entry_value)')
       variables_scope_bytes_covered = variables_scope_bytes_covered \
          - variables_scope_bytes_entry_values
       for cov_bucket in coverage_buckets():
         cov_category = \
           "#local vars - entry values with {} of parent scope " \
           "covered by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
   elif opts.only_formal_parameters:
     # Read the JSON only for formal parameters.
     variables_total_locstats = \
-      json_parsed['#params processed by location statistics']
+      init_field('#params processed by location statistics')
     variables_scope_bytes_covered = \
-      json_parsed['sum_all_params(#bytes in parent scope covered ' \
-                  'by DW_AT_location)']
+      init_field('sum_all_params(#bytes in parent scope covered ' \
+                  'by DW_AT_location)')
     variables_scope_bytes = \
-      json_parsed['sum_all_params(#bytes in parent scope)']
+      init_field('sum_all_params(#bytes in parent scope)')
     if not opts.ignore_debug_entry_values:
       for cov_bucket in coverage_buckets():
         cov_category = "#params with {} of parent scope covered " \
                        "by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
     else:
       variables_scope_bytes_entry_values = \
-        json_parsed['sum_all_params(#bytes in parent scope covered ' \
-                    'by DW_OP_entry_value)']
+        init_field('sum_all_params(#bytes in parent scope covered ' \
+                    'by DW_OP_entry_value)')
       variables_scope_bytes_covered = variables_scope_bytes_covered \
         - variables_scope_bytes_entry_values
       for cov_bucket in coverage_buckets():
         cov_category = \
           "#params - entry values with {} of parent scope covered" \
           " by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
   else:
     # Read the JSON for both local variables and formal parameters.
     variables_total = \
-      json_parsed['#source variables']
-    variables_with_loc = json_parsed['#source variables with location']
+      init_field('#source variables')
+    variables_with_loc = init_field('#source variables with location')
     variables_total_locstats = \
-      json_parsed['#variables processed by location statistics']
+      init_field('#variables processed by location statistics')
     variables_scope_bytes_covered = \
-      json_parsed['sum_all_variables(#bytes in parent scope covered ' \
-                  'by DW_AT_location)']
+      init_field('sum_all_variables(#bytes in parent scope covered ' \
+                  'by DW_AT_location)')
     variables_scope_bytes = \
-      json_parsed['sum_all_variables(#bytes in parent scope)']
+      init_field('sum_all_variables(#bytes in parent scope)')
+
     if not opts.ignore_debug_entry_values:
       for cov_bucket in coverage_buckets():
         cov_category = "#variables with {} of parent scope covered " \
                        "by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
     else:
       variables_scope_bytes_entry_values = \
-        json_parsed['sum_all_variables(#bytes in parent scope covered ' \
-                    'by DW_OP_entry_value)']
+        init_field('sum_all_variables(#bytes in parent scope covered ' \
+                    'by DW_OP_entry_value)')
       variables_scope_bytes_covered = variables_scope_bytes_covered \
         - variables_scope_bytes_entry_values
       for cov_bucket in coverage_buckets():
         cov_category = \
           "#variables - entry values with {} of parent scope covered " \
           "by DW_AT_location".format(cov_bucket)
-        variables_coverage_map[cov_bucket] = json_parsed[cov_category]
+        variables_coverage_map[cov_bucket] = init_field(cov_category)
 
   return LocationStats(binary, variables_total, variables_total_locstats,
                        variables_with_loc, variables_scope_bytes_covered,