Modify dwarf verification JSON to include detailed counts by sub-category (#128018)

To help make better use of dwarfdump verification for identifying and
fixing issues with debug information, the JSON will now emit details
(sub-categories) where relevant. First modification concerns missing
tags as those were recently missing for BOLT debug names.

Test:
test files for JSON output were previously added, so modify here to
expect the new JSON keys. One test has sub-categories and another is
empty.
  ninja check-llvm-tools-llvm-dwarfdump
Also build the tool and run with a local executable to verify.
  ninja llvm-dwarfdump

Author: youngd007

llvm/include/llvm/DebugInfo/DWARF/DWARFVerifier.h

@@ -30,18 +30,28 @@ class DWARFDebugAbbrev;
 class DataExtractor;
 struct DWARFSection;
 
+struct AggregationData {
+  unsigned OverallCount;
+  std::map<std::string, unsigned> DetailedCounts;
+};
+
 class OutputCategoryAggregator {
 private:
-  std::map<std::string, unsigned> Aggregation;
+  std::map<std::string, AggregationData> Aggregation;
   bool IncludeDetail;
 
 public:
   OutputCategoryAggregator(bool includeDetail = false)
       : IncludeDetail(includeDetail) {}
   void ShowDetail(bool showDetail) { IncludeDetail = showDetail; }
   size_t GetNumCategories() const { return Aggregation.size(); }
-  void Report(StringRef s, std::function<void()> detailCallback);
+  void Report(StringRef category, std::function<void()> detailCallback);
+  void Report(StringRef category, StringRef sub_category,
+              std::function<void()> detailCallback);
   void EnumerateResults(std::function<void(StringRef, unsigned)> handleCounts);
+  void EnumerateDetailedResultsFor(
+      StringRef category,
+      std::function<void(StringRef, unsigned)> handleCounts);
 };
 
 /// A class that verifies DWARF debug information given a DWARF Context.

llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp

@@ -1941,12 +1941,14 @@ unsigned DWARFVerifier::verifyNameIndexCompleteness(
     if (none_of(NI.equal_range(Name), [&](const DWARFDebugNames::Entry &E) {
           return E.getDIEUnitOffset() == DieUnitOffset;
         })) {
-      ErrorCategory.Report("Name Index DIE entry missing name", [&]() {
-        error() << formatv(
-            "Name Index @ {0:x}: Entry for DIE @ {1:x} ({2}) with "
-            "name {3} missing.\n",
-            NI.getUnitOffset(), Die.getOffset(), Die.getTag(), Name);
-      });
+      ErrorCategory.Report(
+          "Name Index DIE entry missing name",
+          llvm::dwarf::TagString(Die.getTag()), [&]() {
+            error() << formatv(
+                "Name Index @ {0:x}: Entry for DIE @ {1:x} ({2}) with "
+                "name {3} missing.\n",
+                NI.getUnitOffset(), Die.getOffset(), Die.getTag(), Name);
+          });
       ++NumErrors;
     }
   }
@@ -2168,15 +2170,35 @@ bool DWARFVerifier::verifyDebugStrOffsets(
 
 void OutputCategoryAggregator::Report(
     StringRef s, std::function<void(void)> detailCallback) {
-  Aggregation[std::string(s)]++;
+  this->Report(s, "", detailCallback);
+}
+
+void OutputCategoryAggregator::Report(
+    StringRef category, StringRef sub_category,
+    std::function<void(void)> detailCallback) {
+  std::string category_str = std::string(category);
+  AggregationData &Agg = Aggregation[category_str];
+  Agg.OverallCount++;
+  if (!sub_category.empty()) {
+    Agg.DetailedCounts[std::string(sub_category)]++;
+  }
   if (IncludeDetail)
     detailCallback();
 }
 
 void OutputCategoryAggregator::EnumerateResults(
     std::function<void(StringRef, unsigned)> handleCounts) {
-  for (auto &&[name, count] : Aggregation) {
-    handleCounts(name, count);
+  for (const auto &[name, aggData] : Aggregation) {
+    handleCounts(name, aggData.OverallCount);
+  }
+}
+void OutputCategoryAggregator::EnumerateDetailedResultsFor(
+    StringRef category, std::function<void(StringRef, unsigned)> handleCounts) {
+  const auto Agg = Aggregation.find(std::string(category));
+  if (Agg != Aggregation.end()) {
+    for (const auto &[name, aggData] : Agg->second.DetailedCounts) {
+      handleCounts(name, aggData);
+    }
   }
 }
 
@@ -2203,6 +2225,12 @@ void DWARFVerifier::summarize() {
     ErrorCategory.EnumerateResults([&](StringRef Category, unsigned Count) {
       llvm::json::Object Val;
       Val.try_emplace("count", Count);
+      llvm::json::Object Details;
+      ErrorCategory.EnumerateDetailedResultsFor(
+          Category, [&](StringRef SubCategory, unsigned SubCount) {
+            Details.try_emplace(SubCategory, SubCount);
+          });
+      Val.try_emplace("details", std::move(Details));
       Categories.try_emplace(Category, std::move(Val));
       ErrorCount += Count;
     });

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

@@ -1,7 +1,7 @@
 # RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj -o - | not llvm-dwarfdump -verify --verify-json=%t.json -
 # RUN: FileCheck %s --input-file %t.json
 
-# CHECK: {"error-categories":{"Name Index DIE entry missing name":{"count":10}},"error-count":10}
+# CHECK: {"error-categories":{"Name Index DIE entry missing name":{"count":10,"details":{"DW_TAG_inlined_subroutine":1,"DW_TAG_label":1,"DW_TAG_namespace":2,"DW_TAG_subprogram":2,"DW_TAG_variable":4}}},"error-count":10}
 # CHECK-NOT: error: Name Index @ 0x0: Entry for DIE @ {{.*}} (DW_TAG_variable) with name var_block_addr missing.
 
         .section        .debug_loc,"",@progbits

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

@@ -2,7 +2,7 @@
 # RUN:   not llvm-dwarfdump -verify -verify-json=%t.json -
 # RUN: FileCheck %s --input-file %t.json
 
-# CHECK: {"error-categories":{"Duplicate Name Index":{"count":1},"Name Index doesn't index any CU":{"count":1},"Name Index references non-existing CU":{"count":1}},"error-count":3}
+# CHECK: {"error-categories":{"Duplicate Name Index":{"count":1,"details":{}},"Name Index doesn't index any CU":{"count":1,"details":{}},"Name Index references non-existing CU":{"count":1,"details":{}}},"error-count":3}
 # CHECK-NOT : error: Name Index @ 0x58 references a CU @ 0x0, but this CU is already indexed by Name Index @ 0x28
 # CHECK-NOT: warning: CU @ 0x13 not covered by any Name Index