DebugInfo: Sure up subprogram variable list handling with more assertions and fewer conditionals.

Many old tests using prior schemas still had some brokenness here (both
indirect arrays and arrays with single bogus elements). Fixed those up
so they don't hit the new assertions.

Also reduced nesting in some places, etc.

llvm-svn: 208817

1 files changed, 31 insertions, 33 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 902bc3a4a5d..2b445977750 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -325,30 +325,27 @@ DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
     // Pick up abstract subprogram DIE.
     SPDie = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
     SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
-  } else {
-    DISubprogram SPDecl = SP.getFunctionDeclaration();
-    if (!SPDecl.isSubprogram()) {
-      // There is not any need to generate specification DIE for a function
-      // defined at compile unit level. If a function is defined inside another
-      // function then gdb prefers the definition at top level and but does not
-      // expect specification DIE in parent function. So avoid creating
-      // specification DIE for a function defined inside a function.
-      DIScope SPContext = resolve(SP.getContext());
-      if (SP.isDefinition() && !SPContext.isCompileUnit() &&
-          !SPContext.isFile() && !isSubprogramContext(SPContext)) {
-        SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
-
-        // Add arguments.
-        DICompositeType SPTy = SP.getType();
-        DIArray Args = SPTy.getTypeArray();
-        uint16_t SPTag = SPTy.getTag();
-        if (SPTag == dwarf::DW_TAG_subroutine_type)
-          SPCU.constructSubprogramArguments(*SPDie, Args);
-        DIE *SPDeclDie = SPDie;
-        SPDie =
-            &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
-        SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
-      }
+  } else if (!SP.getFunctionDeclaration()) {
+    // There is not any need to generate specification DIE for a function
+    // defined at compile unit level. If a function is defined inside another
+    // function then gdb prefers the definition at top level and but does not
+    // expect specification DIE in parent function. So avoid creating
+    // specification DIE for a function defined inside a function.
+    DIScope SPContext = resolve(SP.getContext());
+    if (SP.isDefinition() && !SPContext.isCompileUnit() &&
+        !SPContext.isFile() && !isSubprogramContext(SPContext)) {
+      SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
+
+      // Add arguments.
+      DICompositeType SPTy = SP.getType();
+      DIArray Args = SPTy.getTypeArray();
+      uint16_t SPTag = SPTy.getTag();
+      if (SPTag == dwarf::DW_TAG_subroutine_type)
+        SPCU.constructSubprogramArguments(*SPDie, Args);
+      DIE *SPDeclDie = SPDie;
+      SPDie =
+          &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
+      SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
     }
   }
 
@@ -594,10 +591,10 @@ DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
   assert(Scope && Scope->getScopeNode());
   assert(!Scope->getInlinedAt());
   assert(!Scope->isAbstractScope());
-  assert(DIScope(Scope->getScopeNode()).isSubprogram());
-
   DISubprogram Sub(Scope->getScopeNode());
 
+  assert(Sub.isSubprogram());
+
   ProcessedSPNodes.insert(Sub);
 
   DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
@@ -747,6 +744,7 @@ void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
   CURef = &TheCU;
 
   DISubprogram SP(N);
+  assert(SP.isSubprogram());
   if (!SP.isDefinition())
     // This is a method declaration which will be handled while constructing
     // class type.
@@ -866,6 +864,10 @@ void DwarfDebug::collectDeadVariables() {
   if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
     for (MDNode *N : CU_Nodes->operands()) {
       DICompileUnit TheCU(N);
+      // Construct subprogram DIE and add variables DIEs.
+      DwarfCompileUnit *SPCU =
+          static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
+      assert(SPCU && "Unable to find Compile Unit!");
       DIArray Subprograms = TheCU.getSubprograms();
       for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
         DISubprogram SP(Subprograms.getElement(i));
@@ -879,18 +881,13 @@ void DwarfDebug::collectDeadVariables() {
         if (Variables.getNumElements() == 0)
           continue;
 
-        // Construct subprogram DIE and add variables DIEs.
-        DwarfCompileUnit *SPCU =
-            static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
-        assert(SPCU && "Unable to find Compile Unit!");
         // FIXME: See the comment in constructSubprogramDIE about duplicate
         // subprogram DIEs.
         constructSubprogramDIE(*SPCU, SP);
         DIE *SPDIE = SPCU->getDIE(SP);
         for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
           DIVariable DV(Variables.getElement(vi));
-          if (!DV.isVariable())
-            continue;
+          assert(DV.isVariable());
           DbgVariable NewVar(DV, nullptr, this);
           SPDIE->addChild(SPCU->constructVariableDIE(NewVar));
         }
@@ -1279,7 +1276,8 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
   DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
   for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
     DIVariable DV(Variables.getElement(i));
-    if (!DV || !DV.isVariable() || !Processed.insert(DV))
+    assert(DV.isVariable());
+    if (!Processed.insert(DV))
       continue;
     if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
       addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));