Add names to most LLVM Allocas and Calls to make debugging easier

src/codegen_llvm.cpp

@@ -56,7 +56,7 @@ void CodegenLLVM::visit(Builtin &builtin)
   {
     int arg_num = atoi(builtin.ident.substr(3).c_str());
 
-    AllocaInst *dst = b_.CreateAllocaBPF();
+    AllocaInst *dst = b_.CreateAllocaBPF(builtin.ident);
     int offset = arch::arg_offset(arg_num) * sizeof(uintptr_t);
     Value *src = b_.CreateGEP(ctx_, b_.getInt64(offset));
     b_.CreateProbeRead(dst, b_.getInt64(8), src);
@@ -64,7 +64,7 @@ void CodegenLLVM::visit(Builtin &builtin)
   }
   else if (builtin.ident == "retval")
   {
-    AllocaInst *dst = b_.CreateAllocaBPF();
+    AllocaInst *dst = b_.CreateAllocaBPF(builtin.ident);
     int offset = arch::ret_offset() * sizeof(uintptr_t);
     Value *src = b_.CreateGEP(ctx_, b_.getInt64(offset));
     b_.CreateProbeRead(dst, b_.getInt64(8), src);
@@ -126,7 +126,7 @@ void CodegenLLVM::visit(Unop &unop)
     case bpftrace::Parser::token::BNOT: expr_ = b_.CreateNeg(expr_); break;
     case bpftrace::Parser::token::MUL:
     {
-      AllocaInst *dst = b_.CreateAllocaBPF();
+      AllocaInst *dst = b_.CreateAllocaBPF("deref");
       b_.CreateProbeRead(dst, b_.getInt64(8), expr_);
       expr_ = b_.CreateLoad(dst);
       break;
@@ -144,7 +144,7 @@ void CodegenLLVM::visit(AssignMapStatement &assignment)
 {
   Map &map = *assignment.map;
 
-  AllocaInst *val = b_.CreateAllocaBPF();
+  AllocaInst *val = b_.CreateAllocaBPF(map.ident + "_val");
   assignment.expr->accept(*this);
   b_.CreateStore(expr_, val);
 
@@ -162,7 +162,7 @@ void CodegenLLVM::visit(AssignMapCallStatement &assignment)
   {
     AllocaInst *key = getMapKey(map);
     Value *oldval = b_.CreateMapLookupElem(map, key);
-    AllocaInst *newval = b_.CreateAllocaBPF();
+    AllocaInst *newval = b_.CreateAllocaBPF(map.ident + "_val");
     b_.CreateStore(b_.CreateAdd(oldval, b_.getInt64(1)), newval);
     b_.CreateMapUpdateElem(map, key, newval);
   }
@@ -174,7 +174,7 @@ void CodegenLLVM::visit(AssignMapCallStatement &assignment)
     AllocaInst *key = getQuantizeMapKey(map, log2);
 
     Value *oldval = b_.CreateMapLookupElem(map, key);
-    AllocaInst *newval = b_.CreateAllocaBPF();
+    AllocaInst *newval = b_.CreateAllocaBPF(map.ident + "_val");
     b_.CreateStore(b_.CreateAdd(oldval, b_.getInt64(1)), newval);
     b_.CreateMapUpdateElem(map, key, newval);
   }
@@ -246,7 +246,7 @@ AllocaInst *CodegenLLVM::getMapKey(Map &map)
 {
   AllocaInst *key;
   if (map.vargs) {
-    key = b_.CreateAllocaBPF(map.vargs->size());
+    key = b_.CreateAllocaBPF(map.ident + "_key", map.vargs->size());
     int i = 0;
     for (Expression *expr : *map.vargs) {
       expr->accept(*this);
@@ -256,7 +256,7 @@ AllocaInst *CodegenLLVM::getMapKey(Map &map)
   }
   else
   {
-    key = b_.CreateAllocaBPF();
+    key = b_.CreateAllocaBPF(map.ident + "_key");
     b_.CreateStore(b_.getInt64(0), key);
   }
   return key;
@@ -266,7 +266,7 @@ AllocaInst *CodegenLLVM::getQuantizeMapKey(Map &map, Value *log2)
 {
   AllocaInst *key;
   if (map.vargs) {
-    key = b_.CreateAllocaBPF(map.vargs->size() + 1);
+    key = b_.CreateAllocaBPF(map.ident + "_key", map.vargs->size() + 1);
     int i = 0;
     for (Expression *expr : *map.vargs) {
       expr->accept(*this);
@@ -278,7 +278,7 @@ AllocaInst *CodegenLLVM::getQuantizeMapKey(Map &map, Value *log2)
   }
   else
   {
-    key = b_.CreateAllocaBPF();
+    key = b_.CreateAllocaBPF(map.ident + "_key");
     b_.CreateStore(log2, key);
   }
   return key;

src/irbuilderbpf.cpp

@@ -25,22 +25,22 @@ IRBuilderBPF::IRBuilderBPF(LLVMContext &context,
       &module_);
 }
 
-AllocaInst *IRBuilderBPF::CreateAllocaBPF(int num_items, const std::string &name)
+AllocaInst *IRBuilderBPF::CreateAllocaBPF(const std::string &name, int num_items)
 {
   llvm::Type *ty = getInt64Ty();
   Value *array_size = getInt64(num_items);
   Function *parent = GetInsertBlock()->getParent();
   BasicBlock &entry_block = parent->getEntryBlock();
   if (entry_block.empty())
-    return new AllocaInst(ty, array_size, "", &entry_block);
+    return new AllocaInst(ty, array_size, name, &entry_block);
   else
-    return new AllocaInst(ty, array_size, "", &entry_block.front());
+    return new AllocaInst(ty, array_size, name, &entry_block.front());
 }
 
 CallInst *IRBuilderBPF::CreateBpfPseudoCall(int mapfd)
 {
   Function *pseudo_func = module_.getFunction("llvm.bpf.pseudo");
-  return CreateCall(pseudo_func, {getInt64(BPF_PSEUDO_MAP_FD), getInt64(mapfd)});
+  return CreateCall(pseudo_func, {getInt64(BPF_PSEUDO_MAP_FD), getInt64(mapfd)}, "pseudo");
 }
 
 CallInst *IRBuilderBPF::CreateBpfPseudoCall(Map &map)
@@ -64,7 +64,7 @@ LoadInst *IRBuilderBPF::CreateMapLookupElem(Map &map, AllocaInst *key)
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_map_lookup_elem),
       lookup_func_ptr_type);
-  CallInst *call = CreateCall(lookup_func, {map_ptr, key});
+  CallInst *call = CreateCall(lookup_func, {map_ptr, key}, "lookup_elem");
 
   // Check if result == 0
   Function *parent = GetInsertBlock()->getParent();
@@ -72,7 +72,7 @@ LoadInst *IRBuilderBPF::CreateMapLookupElem(Map &map, AllocaInst *key)
   BasicBlock *lookup_failure_block = BasicBlock::Create(module_.getContext(), "lookup_failure", parent);
   BasicBlock *lookup_merge_block = BasicBlock::Create(module_.getContext(), "lookup_merge", parent);
 
-  Value *value = CreateAllocaBPF();
+  Value *value = CreateAllocaBPF("lookup_elem_val");
   Value *condition = CreateICmpNE(
       CreateIntCast(call, getInt8PtrTy(), true),
       ConstantExpr::getCast(Instruction::IntToPtr, getInt64(0), getInt8PtrTy()),
@@ -105,7 +105,7 @@ void IRBuilderBPF::CreateMapUpdateElem(Map &map, AllocaInst *key, Value *val)
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_map_update_elem),
       update_func_ptr_type);
-  CallInst *call = CreateCall(update_func, {map_ptr, key, val, flags});
+  CallInst *call = CreateCall(update_func, {map_ptr, key, val, flags}, "update_elem");
 }
 
 void IRBuilderBPF::CreateMapDeleteElem(Map &map, AllocaInst *key)
@@ -124,7 +124,7 @@ void IRBuilderBPF::CreateMapDeleteElem(Map &map, AllocaInst *key)
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_map_delete_elem),
       delete_func_ptr_type);
-  CallInst *call = CreateCall(delete_func, {map_ptr, key});
+  CallInst *call = CreateCall(delete_func, {map_ptr, key}, "delete_elem");
 }
 
 void IRBuilderBPF::CreateProbeRead(AllocaInst *dst, Value *size, Value *src)
@@ -140,7 +140,7 @@ void IRBuilderBPF::CreateProbeRead(AllocaInst *dst, Value *size, Value *src)
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_probe_read),
       proberead_func_ptr_type);
-  CallInst *call = CreateCall(proberead_func, {dst, size, src});
+  CallInst *call = CreateCall(proberead_func, {dst, size, src}, "probe_read");
 }
 
 CallInst *IRBuilderBPF::CreateGetNs()
@@ -153,7 +153,7 @@ CallInst *IRBuilderBPF::CreateGetNs()
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_ktime_get_ns),
       gettime_func_ptr_type);
-  return CreateCall(gettime_func);
+  return CreateCall(gettime_func, {}, "get_ns");
 }
 
 CallInst *IRBuilderBPF::CreateGetPidTgid()
@@ -166,7 +166,7 @@ CallInst *IRBuilderBPF::CreateGetPidTgid()
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_get_current_pid_tgid),
       getpidtgid_func_ptr_type);
-  return CreateCall(getpidtgid_func);
+  return CreateCall(getpidtgid_func, {}, "get_pid_tgid");
 }
 
 CallInst *IRBuilderBPF::CreateGetUidGid()
@@ -179,7 +179,7 @@ CallInst *IRBuilderBPF::CreateGetUidGid()
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_get_current_uid_gid),
       getuidgid_func_ptr_type);
-  return CreateCall(getuidgid_func);
+  return CreateCall(getuidgid_func, {}, "get_uid_gid");
 }
 
 CallInst *IRBuilderBPF::CreateGetStackId(Value *ctx, bool ustack)
@@ -202,7 +202,7 @@ CallInst *IRBuilderBPF::CreateGetStackId(Value *ctx, bool ustack)
       Instruction::IntToPtr,
       getInt64(BPF_FUNC_get_stackid),
       getstackid_func_ptr_type);
-  return CreateCall(getstackid_func, {ctx, map_ptr, flags_val});
+  return CreateCall(getstackid_func, {ctx, map_ptr, flags_val}, "get_stackid");
 }
 
 } // namespace ast

src/irbuilderbpf.h

@@ -17,7 +17,7 @@ public:
                Module &module,
                BPFtrace &bpftrace);
 
-  AllocaInst *CreateAllocaBPF(int array_size=1, const std::string &name="");
+  AllocaInst *CreateAllocaBPF(const std::string &name="", int num_items=1);
   CallInst   *CreateBpfPseudoCall(int mapfd);
   CallInst   *CreateBpfPseudoCall(Map &map);
   LoadInst   *CreateMapLookupElem(Map &map, AllocaInst *key);