Emit debug info for variables that are used in nested functions

dmd2/declaration.h

@@ -361,6 +361,7 @@ struct VarDeclaration : Declaration
 
     // debug description
     llvm::DIVariable debugVariable;
+    llvm::DISubprogram debugFunc;
 #endif
 };
 

gen/functions.cpp

@@ -729,6 +729,15 @@ void DtoDefineFunction(FuncDeclaration* fd)
     #endif
     }
 
+    // give the 'nestArg' storage
+    if (f->fty.arg_nest)
+    {
+        LLValue *nestArg = irfunction->nestArg;
+        LLValue *val = DtoRawAlloca(nestArg->getType(), 0, "nestedFrame");
+        DtoStore(nestArg, val);
+        irfunction->nestArg = val;
+    }
+
     // give arguments storage
     // and debug info
     if (fd->parameters)

gen/llvmhelpers.cpp

@@ -519,7 +519,7 @@ void DtoAssign(Loc& loc, DValue* lhs, DValue* rhs, int op)
     DVarValue *var = lhs->isVar();
     VarDeclaration *varDecl = var ? var->var : 0;
     if (global.params.symdebug && varDecl && varDecl->debugVariable)
-        DtoDwarfValue(rhs->getRVal(), lhs->isVar()->var);
+        DtoDwarfValue(lhs->getRVal(), varDecl);
     #endif
 }
 

gen/nested.cpp

@@ -6,6 +6,7 @@
 #include "gen/logger.h"
 #include "gen/tollvm.h"
 #include "gen/functions.h"
+#include "gen/todebug.h"
 
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Support/CommandLine.h"
@@ -120,6 +121,10 @@ DValue* DtoNestedVariable(Loc loc, Type* astype, VarDeclaration* vd, bool byref)
         return new DVarValue(astype, vd, val);
     }
 
+    LLValue *dwarfValue = 0;
+    std::vector<LLValue*> dwarfAddr;
+    LLType *int64Ty = LLType::getInt64Ty(gIR->context());
+
     // get the nested context
     LLValue* ctx = 0;
     if (irfunc->decl->isMember2())
@@ -135,10 +140,15 @@ DValue* DtoNestedVariable(Loc loc, Type* astype, VarDeclaration* vd, bool byref)
     #endif
         ctx = DtoLoad(DtoGEPi(val, 0,cd->vthis->ir.irField->index, ".vthis"));
     }
-    else if (irfunc->nestedVar)
+    else if (irfunc->nestedVar) {
         ctx = irfunc->nestedVar;
-    else
-        ctx = irfunc->nestArg;
+        dwarfValue = ctx;
+    } else {
+        ctx = DtoLoad(irfunc->nestArg);
+        dwarfValue = irfunc->nestArg;
+        if (global.params.symdebug)
+            dwarfOpDeref(dwarfAddr);
+    }
     assert(ctx);
 
     DtoCreateNestedContextType(vdparent->isFuncDeclaration());
@@ -174,21 +184,32 @@ DValue* DtoNestedVariable(Loc loc, Type* astype, VarDeclaration* vd, bool byref)
             Logger::println("Same depth");
         } else {
             // Load frame pointer and index that...
+            if (dwarfValue && global.params.symdebug) {
+                dwarfOpOffset(dwarfAddr, val, vd->ir.irLocal->nestedDepth);
+                dwarfOpDeref(dwarfAddr);
+            }
             Logger::println("Lower depth");
             val = DtoGEPi(val, 0, vd->ir.irLocal->nestedDepth);
             Logger::cout() << "Frame index: " << *val << '\n';
             val = DtoAlignedLoad(val, (std::string(".frame.") + vdparent->toChars()).c_str());
             Logger::cout() << "Frame: " << *val << '\n';
         }
+
+        if (dwarfValue && global.params.symdebug)
+            dwarfOpOffset(dwarfAddr, val, vd->ir.irLocal->nestedIndex);
         val = DtoGEPi(val, 0, vd->ir.irLocal->nestedIndex, vd->toChars());
         Logger::cout() << "Addr: " << *val << '\n';
         Logger::cout() << "of type: " << *val->getType() << '\n';
         if (vd->ir.irLocal->byref || byref) {
             val = DtoAlignedLoad(val);
+            //dwarfOpDeref(dwarfAddr);
             Logger::cout() << "Was byref, now: " << *val << '\n';
             Logger::cout() << "of type: " << *val->getType() << '\n';
         }
 
+        if (dwarfValue && global.params.symdebug)
+            DtoDwarfLocalVariable(dwarfValue, vd, dwarfAddr);
+
         return new DVarValue(astype, vd, val);
     }
     else {
@@ -283,7 +304,7 @@ LLValue* DtoNestedContext(Loc loc, Dsymbol* sym)
     }
     // otherwise, it may have gotten a context from the caller
     else if (irfunc->nestArg)
-        val = irfunc->nestArg;
+        val = DtoLoad(irfunc->nestArg);
     // or just have a this argument
     else if (irfunc->thisArg)
     {
@@ -532,7 +553,7 @@ void DtoCreateNestedContext(FuncDeclaration* fd) {
             // copy parent frame into beginning
             if (nparelems)
             {
-                LLValue* src = irfunction->nestArg;
+                LLValue* src = DtoLoad(irfunction->nestArg);
                 if (!src)
                 {
                     assert(irfunction->thisArg);
@@ -594,7 +615,7 @@ void DtoCreateNestedContext(FuncDeclaration* fd) {
 
             // copy parent frames into beginning
             if (depth != 0) {
-                LLValue* src = irfunction->nestArg;
+                LLValue* src = DtoLoad(irfunction->nestArg);
                 if (!src) {
                     assert(irfunction->thisArg);
                     assert(fd->isMember2());
@@ -669,6 +690,12 @@ void DtoCreateNestedContext(FuncDeclaration* fd) {
                     vd->ir.irLocal->value = gep;
                     vd->ir.irLocal->byref = false;
                 }
+
+                if (global.params.symdebug) {
+                    LLSmallVector<LLValue*, 2> addr;
+                    dwarfOpOffset(addr, frameType, vd->ir.irLocal->nestedIndex);
+                    DtoDwarfLocalVariable(frame, vd, addr);
+                }
             }
         } else if (FuncDeclaration* parFunc = getParentFunc(fd, true)) {
             // Propagate context arg properties if the context arg is passed on unmodified.

gen/todebug.cpp

@@ -361,11 +361,14 @@ static llvm::DIType dwarfTypeDescription(Type* type, const char* c_name)
 
 //////////////////////////////////////////////////////////////////////////////////////////////////
 
-void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd)
+void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd, llvm::ArrayRef<LLValue*> addr)
 {
     Logger::println("D to dwarf local variable");
     LOG_SCOPE;
 
+    if (gIR->func()->diSubprogram == vd->debugFunc) // ensure that the debug variable is created only once
+        return;
+
     // get type description
     llvm::DIType TD = dwarfTypeDescription(vd->type, NULL);
     if ((llvm::MDNode*)TD == 0)
@@ -380,6 +383,7 @@ void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd)
     else
         tag = DW_TAG_auto_variable;
 
+    if (addr.empty()) {
         vd->debugVariable = gIR->dibuilder.createLocalVariable(
             tag, // tag
             gIR->func()->diSubprogram, // context
@@ -389,6 +393,18 @@ void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd)
             TD, // type
             true // preserve
         );
+    } else {
+        vd->debugVariable = gIR->dibuilder.createComplexVariable(
+            tag, // tag
+            gIR->func()->diSubprogram, // context
+            vd->toChars(), // name
+            DtoDwarfFile(vd->loc), // file
+            vd->loc.linnum, // line num
+            TD, // type
+            addr
+        );
+    }
+    vd->debugFunc = gIR->func()->diSubprogram;
 
     // declare
     dwarfDeclare(ll, vd->debugVariable);
@@ -522,12 +538,9 @@ void DtoDwarfStopPoint(unsigned ln)
 
 //////////////////////////////////////////////////////////////////////////////////////////////////
 
-void DtoDwarfValue(LLValue* var, VarDeclaration* vd)
+void DtoDwarfValue(LLValue *val, VarDeclaration* vd)
 {
-    if (llvm::isa<llvm::AllocaInst>(vd->ir.irLocal->value) == 0)
-        return;
-    
-    llvm::Instruction *instr = gIR->dibuilder.insertDbgValueIntrinsic(vd->ir.irLocal->value, 0, vd->debugVariable, gIR->scopebb());
+    llvm::Instruction *instr = gIR->dibuilder.insertDbgValueIntrinsic(val, 0, vd->debugVariable, gIR->scopebb());
     instr->setDebugLoc(gIR->ir->getCurrentDebugLocation());
 }
 

gen/todebug.h

@@ -3,6 +3,9 @@
 
 #ifndef DISABLE_DEBUG_INFO
 
+#include "gen/tollvm.h"
+#include "gen/irstate.h"
+
 void RegisterDwarfSymbols(llvm::Module* mod);
 
 /**
@@ -31,14 +34,15 @@ void DtoDwarfFuncEnd(FuncDeclaration* fd);
 
 void DtoDwarfStopPoint(unsigned ln);
 
-void DtoDwarfValue(LLValue* var, VarDeclaration* vd);
+void DtoDwarfValue(LLValue *val, VarDeclaration* vd);
 
 /**
  * Emits all things necessary for making debug info for a local variable vd.
  * @param ll LLVM Value of the variable.
  * @param vd Variable declaration to emit debug info for.
  */
-void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd);
+void DtoDwarfLocalVariable(LLValue* ll, VarDeclaration* vd,
+                           llvm::ArrayRef<LLValue*> addr = llvm::ArrayRef<LLValue*>());
 
 /**
  * Emits all things necessary for making debug info for a global variable vd.
@@ -50,6 +54,30 @@ llvm::DIGlobalVariable DtoDwarfGlobalVariable(LLGlobalVariable* ll, VarDeclarati
 
 void DtoDwarfModuleEnd();
 
+template<typename T>
+void dwarfOpOffset(T &addr, LLStructType *type, int index)
+{
+    uint64_t offset = gTargetData->getStructLayout(type)->getElementOffset(index);
+    LLType *int64Ty = LLType::getInt64Ty(gIR->context());
+    addr.push_back(LLConstantInt::get(int64Ty, llvm::DIBuilder::OpPlus));
+    addr.push_back(LLConstantInt::get(int64Ty, offset));
+}
+
+template<typename T>
+void dwarfOpOffset(T &addr, LLValue *val, int index)
+{
+   LLStructType *type = isaStruct(val->getType()->getContainedType(0));
+   assert(type);
+   dwarfOpOffset(addr, type, index);
+}
+
+template<typename T>
+void dwarfOpDeref(T &addr)
+{
+    LLType *int64Ty = LLType::getInt64Ty(gIR->context());
+    addr.push_back(LLConstantInt::get(int64Ty, llvm::DIBuilder::OpDeref));
+}
+
 
 #endif // DISABLE_DEBUG_INFO
 

gen/toir.cpp

@@ -2553,7 +2553,7 @@ DValue* FuncExp::toElem(IRState* p)
             )
             cval = irfn->nestedVar;
         else if (irfn->nestArg)
-            cval = irfn->nestArg;
+            cval = DtoLoad(irfn->nestArg);
 #if DMDV2
         // TODO: should we enable that for D1 as well?
         else if (irfn->thisArg)