[llvm-dwarfdump] Fix statistics for "vars"

[vsk]

Summary

In llvm-dwwarfdump --statistics output, "vars" refers to parameters and
local variables. Fix an issue where the scope bytes covered metric for
"vars" is unexpectedly low because parameter coverage isn't included.

[djtodoro]

I think that it was intentional. The "vars" fields refer only to local variables, and I agree we should try renaming this...

[aprantl]

This is one of those things where I am fine either way, we just should document what exactly the fields mean. (Could we even sneak the field description into the JSON output in a meaningful way?)

[vsk]

Sorry for the noise, this patch isn't correct for the reason @djtodoro pointed out.

[djtodoro]

I will just add that we should try renaming the JSON fields (with a meaningful name) as well as the variables used to compute this numbers, since I am also always confused what the fields refers to :)

( at least, we can add a TODO marker there, and address that when we get a chance)

[aprantl]

I think it would be reasonable to bump the version number and move to a coherent naming scheme. I came up with the original names in hurry while preparing for a dev meeting talk, I'm not wed to them :-)

[djtodoro]

OK then :)
I'll try to find some time to rename that in the following days (if you do not have time to do that).

[vsk]

I think it'd be nice if the stats fields were a little shorter and clearer. Unfortunately I'm not sure I'll be able to revisit this soon.

[djtodoro]

Please take a look: D77789.

llvm/test/tools/llvm-dwarfdump/X86/locstats.ll

 ; RUN: llc -debug-entry-values %s -o - -filetype=obj \
 ; RUN:   | llvm-dwarfdump -statistics - | FileCheck %s
 ;
 ; CHECK: "entry value scope bytes covered":5
 ; CHECK: "formal params scope bytes total":20
 ; CHECK: "formal params scope bytes covered":20
 ; CHECK: "formal params entry value scope bytes covered":5
-; CHECK: "vars scope bytes total":90
-; CHECK: "vars scope bytes covered":60
-; CHECK: "vars entry value scope bytes covered":0
+; CHECK: "vars scope bytes total":110
+; CHECK: "vars scope bytes covered":80
+; CHECK: "vars entry value scope bytes covered":5
 ; CHECK: "total variables procesed by location statistics":6
 ; CHECK: "variables with 0% of its scope covered":1
 ; CHECK: "variables with (0%,10%) of its scope covered":0
 ; CHECK: "variables with [10%,20%) of its scope covered":0
 ; CHECK: "variables with [20%,30%) of its scope covered":0
 ; CHECK: "variables with [30%,40%) of its scope covered":0
 ; CHECK: "variables with [40%,50%) of its scope covered":0
 ; CHECK: "variables with [50%,60%) of its scope covered":1

llvm/test/tools/llvm-dwarfdump/X86/statistics-dwo.test

 #   printf ("fibonacci(9) = %d\n", result);
 #   result = fib(10);
 #   printf ("fibonacci(10) = %d\n", result);
 # 
 #   return 0;
 # }
 #
 
-CHECK: "version":4
+CHECK: "version":5
 CHECK: "source functions":3
 CHECK: "source functions with location":3
 CHECK: "inlined functions":7
 CHECK: "inlined funcs with abstract origins":7
 CHECK: "unique source variables":9
 CHECK: "source variables":30
 
 # Ideally the value below would be 33 but currently it's not.

llvm/test/tools/llvm-dwarfdump/X86/statistics-v3.test

 #   printf ("fibonacci(9) = %d\n", result);
 #   result = fib(10);
 #   printf ("fibonacci(10) = %d\n", result);
 # 
 #   return 0;
 # }
 #
 
-CHECK: "version":4
+CHECK: "version":5
 CHECK: "source functions":3
 CHECK: "source functions with location":3
 CHECK: "inlined functions":8
 CHECK: "inlined funcs with abstract origins":8
 CHECK: "unique source variables":9
 CHECK: "source variables":33
 
 # Ideally the value below would be 33 but currently it's not.

llvm/test/tools/llvm-dwarfdump/X86/statistics.ll

 ; RUN: llc -O0 %s -o - -filetype=obj \
 ; RUN:   | llvm-dwarfdump -statistics - | FileCheck %s
-; CHECK: "version":4
+; CHECK: "version":5
 
 ; namespace test {
 ;  extern int a;
 ; }
 ; using test::a;
 ;
 ; int GlobalConst = 42;
 ; int Global;

llvm/tools/llvm-dwarfdump/Statistics.cpp

 //===-- Statistics.cpp - Debug Info quality metrics -----------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
if (BytesInScope) {
     GlobalStats.ScopeBytesCovered += std::min(BytesInScope, BytesCovered);
     GlobalStats.ScopeBytes += BytesInScope;
     GlobalStats.ScopeEntryValueBytesCovered += BytesEntryValuesCovered;
     if (IsParam) {
       GlobalStats.ParamScopeBytesCovered +=
           std::min(BytesInScope, BytesCovered);
       GlobalStats.ParamScopeBytes += BytesInScope;
       GlobalStats.ParamScopeEntryValueBytesCovered += BytesEntryValuesCovered;
-    } else if (IsVariable) {
+    }
+    if (IsParam || IsVariable) {
       GlobalStats.VarScopeBytesCovered += std::min(BytesInScope, BytesCovered);
       GlobalStats.VarScopeBytes += BytesInScope;
       GlobalStats.VarScopeEntryValueBytesCovered += BytesEntryValuesCovered;
     }
     assert(GlobalStats.ScopeBytesCovered <= GlobalStats.ScopeBytes);
   }
 
   if (IsConstantMember) {
bool collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
 
   /// Collect the sizes of debug sections.
   SectionSizes Sizes;
   calculateSectionSizes(Obj, Sizes, Filename);
 
   /// The version number should be increased every time the algorithm is changed
   /// (including bug fixes). New metrics may be added without increasing the
   /// version.
-  unsigned Version = 4;
+  unsigned Version = 5;
   unsigned VarParamTotal = 0;
   unsigned VarParamUnique = 0;
   unsigned VarParamWithLoc = 0;
   unsigned NumFunctions = 0;
   unsigned NumInlinedFunctions = 0;
   unsigned NumFuncsWithSrcLoc = 0;
   unsigned NumAbstractOrigins = 0;
   unsigned ParamTotal = 0;