[llvm] 30a3652 - [llvm-locstats] Report a warning if overflow was detected by llvm-dwarfdump

via llvm-commits llvm-commits at lists.llvm.org
Wed Oct 27 05:35:52 PDT 2021


Author: djtodoro
Date: 2021-10-27T14:35:29+02:00
New Revision: 30a3652b6ade43504087f6e3acd8dc879055f501

URL: https://github.com/llvm/llvm-project/commit/30a3652b6ade43504087f6e3acd8dc879055f501
DIFF: https://github.com/llvm/llvm-project/commit/30a3652b6ade43504087f6e3acd8dc879055f501.diff

LOG: [llvm-locstats] Report a warning if overflow was detected by llvm-dwarfdump

Catch that llvm-dwarfdump detected an overflow in statistics.

Differential Revision: https://reviews.llvm.org/D110621

Added: 
    

Modified: 
    llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
    llvm/utils/llvm-locstats/llvm-locstats.py

Removed: 
    


################################################################################
diff  --git a/llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml b/llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
index 0fb82404c72fb..c19d54cafcaca 100644
--- a/llvm/test/tools/llvm-dwarfdump/X86/locstats-bytes-overflow.yaml
+++ b/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: %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 +25,8 @@
 ##             [0x0000000000000003, 0x0000000000000005): DW_OP_reg2 RCX)
 
 # CHECK: "sum_all_variables(#bytes in parent scope)": "overflowed"
+# LOCSTATS: warning: "sum_all_variables(#bytes in parent scope)" field overflowed.
+# LOCSTATS: PC ranges covered: tainted
 
 --- !ELF
 FileHeader:

diff  --git a/llvm/utils/llvm-locstats/llvm-locstats.py b/llvm/utils/llvm-locstats/llvm-locstats.py
index 7114661e70fe9..e86cf13df8c1d 100755
--- a/llvm/utils/llvm-locstats/llvm-locstats.py
+++ b/llvm/utils/llvm-locstats/llvm-locstats.py
@@ -14,6 +14,9 @@
 from collections import OrderedDict
 from subprocess import Popen, PIPE
 
+# This special value has been used to mark statistics that overflowed.
+TAINT_VALUE = "tainted"
+
 # Initialize the plot.
 def init_plot(plt):
   plt.title('Debug Location Statistics', fontweight='bold')
@@ -44,6 +47,9 @@ def __init__(self, file_name, variables_total, variables_total_locstats,
 
   # Get the PC ranges coverage.
   def get_pc_coverage(self):
+    if self.scope_bytes_covered == TAINT_VALUE or \
+       self.scope_bytes == TAINT_VALUE:
+      return TAINT_VALUE
     pc_ranges_covered = int(ceil(self.scope_bytes_covered * 100.0) \
                 / self.scope_bytes)
     return pc_ranges_covered
@@ -57,9 +63,14 @@ def pretty_print(self):
     pc_ranges_covered = self.get_pc_coverage()
     variables_coverage_per_map = {}
     for cov_bucket in coverage_buckets():
-      variables_coverage_per_map[cov_bucket] = \
-        int(ceil(self.variables_coverage_map[cov_bucket] * 100.0) \
-                 / self.variables_total_locstats)
+      variables_coverage_per_map[cov_bucket] = None
+      if self.variables_coverage_map[cov_bucket] == TAINT_VALUE or \
+         self.variables_total_locstats == TAINT_VALUE:
+        variables_coverage_per_map[cov_bucket] = TAINT_VALUE
+      else:
+        variables_coverage_per_map[cov_bucket] = \
+          int(ceil(self.variables_coverage_map[cov_bucket] * 100.0) \
+                   / self.variables_total_locstats)
 
     print (' =================================================')
     print ('            Debug Location Statistics       ')
@@ -67,9 +78,15 @@ def pretty_print(self):
     print ('     cov%           samples         percentage(~)  ')
     print (' -------------------------------------------------')
     for cov_bucket in coverage_buckets():
-      print ('   {0:10}     {1:8d}              {2:3d}%'. \
-        format(cov_bucket, self.variables_coverage_map[cov_bucket], \
-               variables_coverage_per_map[cov_bucket]))
+      if self.variables_coverage_map[cov_bucket] or \
+         self.variables_total_locstats == TAINT_VALUE:
+        print ('   {0:10}     {1:8}              {2:3}%'. \
+          format(cov_bucket, self.variables_coverage_map[cov_bucket], \
+                 variables_coverage_per_map[cov_bucket]))
+      else:
+        print ('   {0:10}     {1:8d}              {2:3d}%'. \
+          format(cov_bucket, self.variables_coverage_map[cov_bucket], \
+                 variables_coverage_per_map[cov_bucket]))
     print (' =================================================')
     print (' -the number of debug variables processed: ' \
       + str(self.variables_total_locstats))
@@ -78,8 +95,13 @@ def pretty_print(self):
     # Only if we are processing all the variables output the total
     # availability.
     if self.variables_total and self.variables_with_loc:
-      total_availability = int(ceil(self.variables_with_loc * 100.0) \
-                                    / self.variables_total)
+      total_availability = None
+      if self.variables_total == TAINT_VALUE or \
+         self.variables_with_loc == TAINT_VALUE:
+        total_availability = TAINT_VALUE
+      else:
+        total_availability = int(ceil(self.variables_with_loc * 100.0) \
+                                      / self.variables_total)
       print (' -------------------------------------------------')
       print (' -total availability: ' + str(total_availability) + '%')
     print (' =================================================')
@@ -179,6 +201,8 @@ def parse_locstats(opts, binary):
                   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 +214,97 @@ def parse_locstats(opts, binary):
 
   # TODO: Parse the statistics Version from JSON.
 
+  def init_field(name):
+    if json_parsed[name] == 'overflowed':
+      print ('warning: "' + name + '" field overflowed.')
+      return TAINT_VALUE
+    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)']
-      variables_scope_bytes_covered = variables_scope_bytes_covered \
-         - variables_scope_bytes_entry_values
+        init_field('sum_all_local_vars(#bytes in parent scope ' \
+                    'covered by DW_OP_entry_value)')
+      if variables_scope_bytes_covered != TAINT_VALUE and \
+         variables_scope_bytes_entry_values != TAINT_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)']
-      variables_scope_bytes_covered = variables_scope_bytes_covered \
-        - variables_scope_bytes_entry_values
+        init_field('sum_all_params(#bytes in parent scope covered ' \
+                    'by DW_OP_entry_value)')
+      if variables_scope_bytes_covered != TAINT_VALUE and \
+         variables_scope_bytes_entry_values != TAINT_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)']
-      variables_scope_bytes_covered = variables_scope_bytes_covered \
-        - variables_scope_bytes_entry_values
+        init_field('sum_all_variables(#bytes in parent scope covered ' \
+                    'by DW_OP_entry_value)')
+      if variables_scope_bytes_covered != TAINT_VALUE and \
+         variables_scope_bytes_entry_values != TAINT_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,


        


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