[llvm-dwarfdump][Statistics] Distinguish parameters with same name or w/o a name

chbessonova · chbessonova · commit 5499e2f455ca · 2020-01-28T20:52:20.000+02:00
A few DW_TAG_formal_parameter's of the same function may have the same name (e.g. variadic (template) functions) or don't have a name at all (if the parameter isn't used inside the function body), but we still need to be able to distinguish between them to get correct number of 'total vars' and 'availability' metric. Reviewed by: aprantl Differential Revision: https://reviews.llvm.org/D73003
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/statistics.ll b/llvm/test/tools/llvm-dwarfdump/X86/statistics.ll
@@ -20,23 +20,26 @@
 ;   int squared = square(i);
 ;   return squared*i;
 ; }
+;
+; int boo(int, int) {}
 
 ; Following variables/arguments/members should be counted:
 ;     - GlobalConst,
 ;     - Global,
 ;     - s, s.constant,
 ;     - square::i,
 ;     - cube::i, cube::squared
+;     - boo::1, boo::2
 ; Skipped entities:
 ;     - declaration of test::a,
 ;     - non-constant member S:fn,
 ;     - arguments of S:fn.
 
-; CHECK: "unique source variables":7
+; CHECK: "unique source variables":9
 ; +1 extra inline i.
-; CHECK: "source variables":8
+; CHECK: "source variables":10
 ; -1 square::i
-; CHECK: "variables with location":7
+; CHECK: "variables with location":9
 ; CHECK: "scope bytes total":[[BYTES:[0-9]+]]
 ; Because of the dbg.value in the middle of the function, the pc range coverage
 ; must be below 100%.
@@ -99,6 +102,18 @@ entry:
   ret i32 %mul, !dbg !44
 }
 
+; Function Attrs: noinline optnone uwtable
+define dso_local i32 @_Z3booii(i32 %0, i32 %1) !dbg !52 {
+entry:
+  %.addr = alloca i32, align 4
+  %.addr1 = alloca i32, align 4
+  store i32 %0, i32* %.addr, align 4
+  call void @llvm.dbg.declare(metadata i32* %.addr, metadata !55, metadata !DIExpression()), !dbg !56
+  store i32 %1, i32* %.addr1, align 4
+  call void @llvm.dbg.declare(metadata i32* %.addr1, metadata !57, metadata !DIExpression()), !dbg !58
+  ret i32 0, !dbg !58
+}
+
 attributes #0 = { alwaysinline nounwind ssp uwtable }
 attributes #1 = { nounwind readnone speculatable }
 attributes #2 = { noinline nounwind optnone ssp uwtable }
@@ -159,3 +174,10 @@ attributes #2 = { noinline nounwind optnone ssp uwtable }
 !49 = !DIImportedEntity(tag: DW_TAG_imported_declaration, scope: !2, entity: !50, file: !3, line: 2)
 !50 = !DIGlobalVariable(name: "a", linkageName: "_ZN4test1aE", scope: !51, file: !3, line: 2, type: !8, isLocal: false, isDefinition: false)
 !51 = !DINamespace(name: "test", scope: !2)
+!52 = distinct !DISubprogram(name: "boo", linkageName: "_Z3booii", scope: !3, file: !3, line: 10, type: !53, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !2, retainedNodes: !4)
+!53 = !DISubroutineType(types: !54)
+!54 = !{!8, !8, !8}
+!55 = !DILocalVariable(arg: 1, scope: !52, file: !3, line: 10, type: !8)
+!56 = !DILocation(line: 10, column: 12, scope: !52)
+!57 = !DILocalVariable(arg: 2, scope: !52, file: !3, line: 10, type: !8)
+!58 = !DILocation(line: 10, column: 17, scope: !52)
diff --git a/llvm/tools/llvm-dwarfdump/Statistics.cpp b/llvm/tools/llvm-dwarfdump/Statistics.cpp
@@ -436,11 +436,14 @@ static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
 
   // Traverse children.
   unsigned LexicalBlockIndex = 0;
+  unsigned FormalParameterIndex = 0;
   DWARFDie Child = Die.getFirstChild();
   while (Child) {
     std::string ChildVarPrefix = VarPrefix;
     if (Child.getTag() == dwarf::DW_TAG_lexical_block)
       ChildVarPrefix += toHex(LexicalBlockIndex++) + '.';
+    if (Child.getTag() == dwarf::DW_TAG_formal_parameter)
+      ChildVarPrefix += 'p' + toHex(FormalParameterIndex++) + '.';
 
     collectStatsRecursive(Child, FnPrefix, ChildVarPrefix, BytesInScope,
                           InlineDepth, FnStatMap, GlobalStats, LocStats);
