experimental: support for debug info (#118)

Signed-off-by: wpt967 <matt.aw@parity.io>
Signed-off-by: xermicus <cyrill@parity.io>

crates/llvm-context/src/debug_config/mod.rs

@@ -13,41 +13,52 @@ use self::ir_type::IRType;
 #[derive(Debug, Default, Serialize, Deserialize, Clone)]
 pub struct DebugConfig {
     /// The directory to dump the IRs to.
-    pub output_directory: PathBuf,
+    pub output_directory: Option<PathBuf>,
+    /// Whether debug info should be emitted.
+    pub emit_debug_info: bool,
 }
 
 impl DebugConfig {
     /// A shortcut constructor.
-    pub fn new(output_directory: PathBuf) -> Self {
-        Self { output_directory }
+    pub const fn new(output_directory: Option<PathBuf>, emit_debug_info: bool) -> Self {
+        Self {
+            output_directory,
+            emit_debug_info,
+        }
     }
 
     /// Dumps the Yul IR.
     pub fn dump_yul(&self, contract_path: &str, code: &str) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, None, IRType::Yul);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, code)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, None, IRType::Yul);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, code)?;
+        }
 
         Ok(())
     }
 
     /// Dumps the EVM legacy assembly IR.
     pub fn dump_evmla(&self, contract_path: &str, code: &str) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, None, IRType::EVMLA);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, code)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, None, IRType::EVMLA);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, code)?;
+        }
 
         Ok(())
     }
 
     /// Dumps the Ethereal IR.
     pub fn dump_ethir(&self, contract_path: &str, code: &str) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, None, IRType::EthIR);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, code)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, None, IRType::EthIR);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, code)?;
+        }
 
         Ok(())
     }
@@ -58,12 +69,15 @@ impl DebugConfig {
         contract_path: &str,
         module: &inkwell::module::Module,
     ) -> anyhow::Result<()> {
-        let llvm_code = module.print_to_string().to_string();
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let llvm_code = module.print_to_string().to_string();
 
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, Some("unoptimized"), IRType::LLVM);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, llvm_code)?;
+            let mut file_path = output_directory.to_owned();
+            let full_file_name =
+                Self::full_file_name(contract_path, Some("unoptimized"), IRType::LLVM);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, llvm_code)?;
+        }
 
         Ok(())
     }
@@ -74,32 +88,39 @@ impl DebugConfig {
         contract_path: &str,
         module: &inkwell::module::Module,
     ) -> anyhow::Result<()> {
-        let llvm_code = module.print_to_string().to_string();
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let llvm_code = module.print_to_string().to_string();
 
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, Some("optimized"), IRType::LLVM);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, llvm_code)?;
+            let mut file_path = output_directory.to_owned();
+            let full_file_name =
+                Self::full_file_name(contract_path, Some("optimized"), IRType::LLVM);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, llvm_code)?;
+        }
 
         Ok(())
     }
 
     /// Dumps the assembly.
     pub fn dump_assembly(&self, contract_path: &str, code: &str) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, None, IRType::Assembly);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, code)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, None, IRType::Assembly);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, code)?;
+        }
 
         Ok(())
     }
 
     /// Dumps the code object.
     pub fn dump_object(&self, contract_path: &str, code: &[u8]) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, None, IRType::SO);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, code)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, None, IRType::SO);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, code)?;
+        }
 
         Ok(())
     }
@@ -112,10 +133,12 @@ impl DebugConfig {
         contract_suffix: Option<&str>,
         stage_json: &Vec<u8>,
     ) -> anyhow::Result<()> {
-        let mut file_path = self.output_directory.to_owned();
-        let full_file_name = Self::full_file_name(contract_path, contract_suffix, IRType::JSON);
-        file_path.push(full_file_name);
-        std::fs::write(file_path, stage_json)?;
+        if let Some(output_directory) = self.output_directory.as_ref() {
+            let mut file_path = output_directory.to_owned();
+            let full_file_name = Self::full_file_name(contract_path, contract_suffix, IRType::JSON);
+            file_path.push(full_file_name);
+            std::fs::write(file_path, stage_json)?;
+        }
 
         Ok(())
     }

crates/llvm-context/src/lib.rs

@@ -16,6 +16,7 @@ pub use self::polkavm::context::argument::Argument as PolkaVMArgument;
 pub use self::polkavm::context::attribute::Attribute as PolkaVMAttribute;
 pub use self::polkavm::context::build::Build as PolkaVMBuild;
 pub use self::polkavm::context::code_type::CodeType as PolkaVMCodeType;
+pub use self::polkavm::context::debug_info::DebugInfo;
 pub use self::polkavm::context::evmla_data::EVMLAData as PolkaVMContextEVMLAData;
 pub use self::polkavm::context::function::block::evmla_data::key::Key as PolkaVMFunctionBlockKey;
 pub use self::polkavm::context::function::block::evmla_data::EVMLAData as PolkaVMFunctionBlockEVMLAData;

crates/llvm-context/src/optimizer/settings/mod.rs

@@ -9,7 +9,7 @@ use itertools::Itertools;
 
 use self::size_level::SizeLevel;
 
-/// The LLVM optimizer settings.
+/// The LLVM optimizer and code-gen settings.
 #[derive(Debug, Serialize, Deserialize, Clone, Eq)]
 pub struct Settings {
     /// The middle-end optimization level.

crates/llvm-context/src/polkavm/context/debug_info.rs

@@ -1,7 +1,43 @@
 //! The LLVM debug information.
 
+use std::cell::RefCell;
+
 use inkwell::debug_info::AsDIScope;
-use num::Zero;
+use inkwell::debug_info::DIScope;
+
+/// Debug info scope stack
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct ScopeStack<'ctx> {
+    stack: Vec<DIScope<'ctx>>,
+}
+
+// Abstract the type of the DIScope stack.
+impl<'ctx> ScopeStack<'ctx> {
+    pub fn from(item: DIScope<'ctx>) -> Self {
+        Self { stack: vec![item] }
+    }
+
+    /// Return the top of the scope stack, or None if the stack is empty.
+    pub fn top(&self) -> Option<DIScope<'ctx>> {
+        self.stack.last().copied()
+    }
+
+    /// Push a scope onto the stack.
+    pub fn push(&mut self, scope: DIScope<'ctx>) {
+        self.stack.push(scope)
+    }
+
+    /// Pop the scope at the top of the stack and return it.
+    /// Return None if the stack is empty.
+    pub fn pop(&mut self) -> Option<DIScope<'ctx>> {
+        self.stack.pop()
+    }
+
+    /// Return the number of scopes on the stack.
+    pub fn len(&self) -> usize {
+        self.stack.len()
+    }
+}
 
 /// The LLVM debug information.
 pub struct DebugInfo<'ctx> {
@@ -9,6 +45,8 @@ pub struct DebugInfo<'ctx> {
     compile_unit: inkwell::debug_info::DICompileUnit<'ctx>,
     /// The debug info builder.
     builder: inkwell::debug_info::DebugInfoBuilder<'ctx>,
+    /// Enclosing debug info scopes.
+    scope_stack: RefCell<ScopeStack<'ctx>>,
 }
 
 impl<'ctx> DebugInfo<'ctx> {
@@ -35,19 +73,43 @@ impl<'ctx> DebugInfo<'ctx> {
         Self {
             compile_unit,
             builder,
+            scope_stack: RefCell::new(ScopeStack::from(compile_unit.as_debug_info_scope())),
         }
     }
 
+    /// Prepare an LLVM-IR module for debug-info generation
+    pub fn initialize_module(
+        &self,
+        llvm: &'ctx inkwell::context::Context,
+        module: &inkwell::module::Module<'ctx>,
+    ) {
+        let debug_metadata_value = llvm
+            .i32_type()
+            .const_int(inkwell::debug_info::debug_metadata_version() as u64, false);
+        module.add_basic_value_flag(
+            "Debug Info Version",
+            inkwell::module::FlagBehavior::Warning,
+            debug_metadata_value,
+        );
+        self.push_scope(self.compilation_unit().get_file().as_debug_info_scope());
+    }
+
+    /// Finalize debug-info for an LLVM-IR module.
+    pub fn finalize_module(&self) {
+        self.builder().finalize()
+    }
+
     /// Creates a function info.
     pub fn create_function(
         &self,
         name: &str,
     ) -> anyhow::Result<inkwell::debug_info::DISubprogram<'ctx>> {
+        let flags = inkwell::debug_info::DIFlagsConstants::ZERO;
         let subroutine_type = self.builder.create_subroutine_type(
             self.compile_unit.get_file(),
-            Some(self.create_type(revive_common::BIT_LENGTH_FIELD)?),
+            Some(self.create_word_type(Some(flags))?.as_type()),
             &[],
-            inkwell::debug_info::DIFlags::zero(),
+            flags,
         );
 
         let function = self.builder.create_function(
@@ -60,7 +122,7 @@ impl<'ctx> DebugInfo<'ctx> {
             true,
             false,
             1,
-            inkwell::debug_info::DIFlags::zero(),
+            flags,
             false,
         );
 
@@ -74,24 +136,55 @@ impl<'ctx> DebugInfo<'ctx> {
         Ok(function)
     }
 
-    /// Creates a primitive type info.
-    pub fn create_type(
+    /// Creates primitive integer type debug-info.
+    pub fn create_primitive_type(
         &self,
         bit_length: usize,
-    ) -> anyhow::Result<inkwell::debug_info::DIType<'ctx>> {
+        flags: Option<inkwell::debug_info::DIFlags>,
+    ) -> anyhow::Result<inkwell::debug_info::DIBasicType<'ctx>> {
+        let di_flags = flags.unwrap_or(inkwell::debug_info::DIFlagsConstants::ZERO);
+        let di_encoding: u32 = 0;
+        let type_name = String::from("U") + bit_length.to_string().as_str();
         self.builder
-            .create_basic_type(
-                "U256",
-                bit_length as u64,
-                0,
-                inkwell::debug_info::DIFlags::zero(),
-            )
-            .map(|basic_type| basic_type.as_type())
+            .create_basic_type(type_name.as_str(), bit_length as u64, di_encoding, di_flags)
             .map_err(|error| anyhow::anyhow!("Debug info error: {}", error))
     }
 
-    /// Finalizes the builder.
-    pub fn finalize(&self) {
-        self.builder.finalize();
+    /// Returns the debug-info model of word-sized integer types.
+    pub fn create_word_type(
+        &self,
+        flags: Option<inkwell::debug_info::DIFlags>,
+    ) -> anyhow::Result<inkwell::debug_info::DIBasicType<'ctx>> {
+        self.create_primitive_type(revive_common::BIT_LENGTH_WORD, flags)
+    }
+
+    /// Return the DIBuilder.
+    pub fn builder(&self) -> &inkwell::debug_info::DebugInfoBuilder<'ctx> {
+        &self.builder
+    }
+
+    /// Return the compilation unit. {
+    pub fn compilation_unit(&self) -> &inkwell::debug_info::DICompileUnit<'ctx> {
+        &self.compile_unit
+    }
+
+    /// Push a debug-info scope onto the stack.
+    pub fn push_scope(&self, scope: DIScope<'ctx>) {
+        self.scope_stack.borrow_mut().push(scope)
+    }
+
+    /// Pop the top of the debug-info scope stack and return it.
+    pub fn pop_scope(&self) -> Option<DIScope<'ctx>> {
+        self.scope_stack.borrow_mut().pop()
+    }
+
+    /// Return the top of the debug-info scope stack.
+    pub fn top_scope(&self) -> Option<DIScope<'ctx>> {
+        self.scope_stack.borrow().top()
+    }
+
+    /// Return the number of debug-info scopes on the scope stack.
+    pub fn num_scopes(&self) -> usize {
+        self.scope_stack.borrow().len()
     }
 }

crates/llvm-context/src/polkavm/context/function/declaration.rs

@@ -17,4 +17,8 @@ impl<'ctx> Declaration<'ctx> {
     ) -> Self {
         Self { r#type, value }
     }
+
+    pub fn function_value(&self) -> inkwell::values::FunctionValue<'ctx> {
+        self.value
+    }
 }

crates/llvm-context/src/polkavm/context/function/mod.rs

@@ -11,6 +11,8 @@ pub mod yul_data;
 
 use std::collections::HashMap;
 
+use inkwell::debug_info::AsDIScope;
+
 use crate::optimizer::settings::size_level::SizeLevel;
 use crate::optimizer::Optimizer;
 use crate::polkavm::context::attribute::Attribute;
@@ -94,6 +96,14 @@ impl<'ctx> Function<'ctx> {
         self.declaration
     }
 
+    /// Returns the debug-info scope.
+    pub fn get_debug_scope(&self) -> Option<inkwell::debug_info::DIScope<'ctx>> {
+        self.declaration()
+            .function_value()
+            .get_subprogram()
+            .map(|scp| scp.as_debug_info_scope())
+    }
+
     /// Returns the N-th parameter of the function.
     pub fn get_nth_param(&self, index: usize) -> inkwell::values::BasicValueEnum<'ctx> {
         self.declaration()

crates/llvm-context/src/polkavm/context/function/runtime/deploy_code.rs

@@ -54,12 +54,14 @@ where
     }
 
     fn into_llvm(self, context: &mut Context<D>) -> anyhow::Result<()> {
-        context.set_current_function(runtime::FUNCTION_DEPLOY_CODE)?;
+        context.set_current_function(runtime::FUNCTION_DEPLOY_CODE, None)?;
 
         context.set_basic_block(context.current_function().borrow().entry_block());
         context.set_code_type(CodeType::Deploy);
 
         self.inner.into_llvm(context)?;
+        context.set_debug_location(0, 0, None)?;
+
         match context
             .basic_block()
             .get_last_instruction()
@@ -72,8 +74,11 @@ where
         }
 
         context.set_basic_block(context.current_function().borrow().return_block());
+        context.set_debug_location(0, 0, None)?;
         context.build_return(None);
 
+        context.pop_debug_scope();
+
         Ok(())
     }
 }

crates/llvm-context/src/polkavm/context/function/runtime/entry.rs

@@ -125,6 +125,8 @@ impl Entry {
     where
         D: Dependency + Clone,
     {
+        context.set_debug_location(0, 0, None)?;
+
         let is_deploy = context
             .current_function()
             .borrow()
@@ -214,7 +216,7 @@ where
             true,
         );
 
-        context.set_current_function(runtime::FUNCTION_ENTRY)?;
+        context.set_current_function(runtime::FUNCTION_ENTRY, None)?;
         context.set_basic_block(context.current_function().borrow().entry_block());
 
         Self::initialize_globals(context)?;
@@ -225,6 +227,8 @@ where
         context.set_basic_block(context.current_function().borrow().return_block());
         context.build_unreachable();
 
+        context.pop_debug_scope();
+
         Ok(())
     }
 }

crates/llvm-context/src/polkavm/context/function/runtime/immutable_data_load.rs

@@ -34,7 +34,7 @@ where
     }
 
     fn into_llvm(self, context: &mut Context<D>) -> anyhow::Result<()> {
-        context.set_current_function(runtime::FUNCTION_LOAD_IMMUTABLE_DATA)?;
+        context.set_current_function(runtime::FUNCTION_LOAD_IMMUTABLE_DATA, None)?;
         context.set_basic_block(context.current_function().borrow().entry_block());
 
         let immutable_data_size_pointer = context
@@ -111,6 +111,8 @@ where
         context.set_basic_block(return_block);
         context.build_return(None);
 
+        context.pop_debug_scope();
+
         Ok(())
     }
 }

crates/llvm-context/src/polkavm/context/function/runtime/runtime_code.rs

@@ -54,11 +54,14 @@ where
     }
 
     fn into_llvm(self, context: &mut Context<D>) -> anyhow::Result<()> {
-        context.set_current_function(runtime::FUNCTION_RUNTIME_CODE)?;
+        context.set_current_function(runtime::FUNCTION_RUNTIME_CODE, None)?;
 
         context.set_basic_block(context.current_function().borrow().entry_block());
         context.set_code_type(CodeType::Runtime);
+
         self.inner.into_llvm(context)?;
+        context.set_debug_location(0, 0, None)?;
+
         match context
             .basic_block()
             .get_last_instruction()
@@ -73,6 +76,8 @@ where
         context.set_basic_block(context.current_function().borrow().return_block());
         context.build_unreachable();
 
+        context.pop_debug_scope();
+
         Ok(())
     }
 }

crates/llvm-context/src/polkavm/context/mod.rs

@@ -5,7 +5,7 @@ pub mod argument;
 pub mod attribute;
 pub mod build;
 pub mod code_type;
-// pub mod debug_info;
+pub mod debug_info;
 pub mod evmla_data;
 pub mod function;
 pub mod global;
@@ -21,6 +21,8 @@ use std::cell::RefCell;
 use std::collections::HashMap;
 use std::rc::Rc;
 
+use inkwell::debug_info::AsDIScope;
+use inkwell::debug_info::DIScope;
 use inkwell::types::BasicType;
 use inkwell::values::BasicValue;
 
@@ -35,7 +37,7 @@ use self::address_space::AddressSpace;
 use self::attribute::Attribute;
 use self::build::Build;
 use self::code_type::CodeType;
-// use self::debug_info::DebugInfo;
+use self::debug_info::DebugInfo;
 use self::evmla_data::EVMLAData;
 use self::function::declaration::Declaration as FunctionDeclaration;
 use self::function::intrinsics::Intrinsics;
@@ -85,9 +87,9 @@ where
     /// Whether to append the metadata hash at the end of bytecode.
     include_metadata_hash: bool,
     /// The debug info of the current module.
-    // debug_info: DebugInfo<'ctx>,
+    debug_info: Option<DebugInfo<'ctx>>,
     /// The debug configuration telling whether to dump the needed IRs.
-    debug_config: Option<DebugConfig>,
+    debug_config: DebugConfig,
 
     /// The Solidity data.
     solidity_data: Option<SolidityData>,
@@ -207,7 +209,7 @@ where
         optimizer: Optimizer,
         dependency_manager: Option<D>,
         include_metadata_hash: bool,
-        debug_config: Option<DebugConfig>,
+        debug_config: DebugConfig,
     ) -> Self {
         Self::link_stdlib_module(llvm, &module);
         Self::link_polkavm_imports(llvm, &module);
@@ -216,6 +218,11 @@ where
 
         let intrinsics = Intrinsics::new(llvm, &module);
         let llvm_runtime = LLVMRuntime::new(llvm, &module, &optimizer);
+        let debug_info = debug_config.emit_debug_info.then(|| {
+            let debug_info = DebugInfo::new(&module);
+            debug_info.initialize_module(llvm, &module);
+            debug_info
+        });
 
         Self {
             llvm,
@@ -232,7 +239,8 @@ where
 
             dependency_manager,
             include_metadata_hash,
-            // debug_info,
+
+            debug_info,
             debug_config,
 
             solidity_data: None,
@@ -255,9 +263,9 @@ where
         let target_machine = TargetMachine::new(Target::PVM, self.optimizer.settings())?;
         target_machine.set_target_data(self.module());
 
-        if let Some(ref debug_config) = self.debug_config {
-            debug_config.dump_llvm_ir_unoptimized(contract_path, self.module())?;
-        }
+        self.debug_config
+            .dump_llvm_ir_unoptimized(contract_path, self.module())?;
+
         self.verify().map_err(|error| {
             anyhow::anyhow!(
                 "The contract `{}` unoptimized LLVM IR verification error: {}",
@@ -275,9 +283,10 @@ where
                     error
                 )
             })?;
-        if let Some(ref debug_config) = self.debug_config {
-            debug_config.dump_llvm_ir_optimized(contract_path, self.module())?;
-        }
+
+        self.debug_config
+            .dump_llvm_ir_optimized(contract_path, self.module())?;
+
         self.verify().map_err(|error| {
             anyhow::anyhow!(
                 "The contract `{}` optimized LLVM IR verification error: {}",
@@ -298,11 +307,11 @@ where
 
         let shared_object = revive_linker::link(buffer.as_slice())?;
 
-        if let Some(ref debug_config) = self.debug_config {
-            debug_config.dump_object(contract_path, &shared_object)?;
-        }
+        self.debug_config
+            .dump_object(contract_path, &shared_object)?;
 
-        let polkavm_bytecode = revive_linker::polkavm_linker(shared_object)?;
+        let polkavm_bytecode =
+            revive_linker::polkavm_linker(shared_object, !self.debug_config().emit_debug_info)?;
 
         let build = match crate::polkavm::build_assembly_text(
             contract_path,
@@ -428,6 +437,21 @@ where
     ) -> anyhow::Result<Rc<RefCell<Function<'ctx>>>> {
         let value = self.module().add_function(name, r#type, linkage);
 
+        if self.debug_info().is_some() {
+            self.builder().unset_current_debug_location();
+            let func_scope = match value.get_subprogram() {
+                None => {
+                    let fn_name = value.get_name().to_str()?;
+                    let scp = self.build_function_debug_info(fn_name, 0)?;
+                    value.set_subprogram(scp);
+                    scp
+                }
+                Some(scp) => scp,
+            };
+            self.push_debug_scope(func_scope.as_debug_info_scope());
+            self.set_debug_location(0, 0, Some(func_scope.as_debug_info_scope()))?;
+        }
+
         let entry_block = self.llvm.append_basic_block(value, "entry");
         let return_block = self.llvm.append_basic_block(value, "return");
 
@@ -461,6 +485,8 @@ where
         let function = Rc::new(RefCell::new(function));
         self.functions.insert(name.to_string(), function.clone());
 
+        self.pop_debug_scope();
+
         Ok(function)
     }
 
@@ -476,15 +502,95 @@ where
             .expect("Must be declared before use")
     }
 
-    /// Sets the current active function.
-    pub fn set_current_function(&mut self, name: &str) -> anyhow::Result<()> {
+    /// Sets the current active function. If debug-info generation is enabled,
+    /// constructs a debug-scope and pushes in on the scope-stack.
+    pub fn set_current_function(&mut self, name: &str, line: Option<u32>) -> anyhow::Result<()> {
         let function = self.functions.get(name).cloned().ok_or_else(|| {
             anyhow::anyhow!("Failed to activate an undeclared function `{}`", name)
         })?;
         self.current_function = Some(function);
+
+        if let Some(scope) = self.current_function().borrow().get_debug_scope() {
+            self.push_debug_scope(scope);
+        }
+        self.set_debug_location(line.unwrap_or_default(), 0, None)?;
+
         Ok(())
     }
 
+    /// Builds a debug-info scope for a function.
+    pub fn build_function_debug_info(
+        &self,
+        name: &str,
+        line_no: u32,
+    ) -> anyhow::Result<inkwell::debug_info::DISubprogram<'ctx>> {
+        let Some(debug_info) = self.debug_info() else {
+            anyhow::bail!("expected debug-info builders");
+        };
+        let builder = debug_info.builder();
+        let file = debug_info.compilation_unit().get_file();
+        let scope = file.as_debug_info_scope();
+        let flags = inkwell::debug_info::DIFlagsConstants::PUBLIC;
+        let return_type = debug_info.create_word_type(Some(flags))?.as_type();
+        let subroutine_type = builder.create_subroutine_type(file, Some(return_type), &[], flags);
+
+        Ok(builder.create_function(
+            scope,
+            name,
+            None,
+            file,
+            line_no,
+            subroutine_type,
+            false,
+            true,
+            1,
+            flags,
+            false,
+        ))
+    }
+
+    /// Set the debug info location.
+    ///
+    /// No-op if the emitting debug info is disabled.
+    ///
+    /// If `scope` is `None` the top scope will be used.
+    pub fn set_debug_location(
+        &self,
+        line: u32,
+        column: u32,
+        scope: Option<DIScope<'ctx>>,
+    ) -> anyhow::Result<()> {
+        let Some(debug_info) = self.debug_info() else {
+            return Ok(());
+        };
+        let scope = match scope {
+            Some(scp) => scp,
+            None => debug_info.top_scope().expect("expected a debug-info scope"),
+        };
+        let location =
+            debug_info
+                .builder()
+                .create_debug_location(self.llvm(), line, column, scope, None);
+
+        self.builder().set_current_debug_location(location);
+
+        Ok(())
+    }
+
+    /// Pushes a debug-info scope to the stack.
+    pub fn push_debug_scope(&self, scope: DIScope<'ctx>) {
+        if let Some(debug_info) = self.debug_info() {
+            debug_info.push_scope(scope);
+        }
+    }
+
+    /// Pops the top of the debug-info scope stack.
+    pub fn pop_debug_scope(&self) {
+        if let Some(debug_info) = self.debug_info() {
+            debug_info.pop_scope();
+        }
+    }
+
     /// Pushes a new loop context to the stack.
     pub fn push_loop(
         &mut self,
@@ -554,9 +660,14 @@ where
             .expect("The dependency manager is unset")
     }
 
+    /// Returns the debug info.
+    pub fn debug_info(&self) -> Option<&DebugInfo<'ctx>> {
+        self.debug_info.as_ref()
+    }
+
     /// Returns the debug config reference.
-    pub fn debug_config(&self) -> Option<&DebugConfig> {
-        self.debug_config.as_ref()
+    pub fn debug_config(&self) -> &DebugConfig {
+        &self.debug_config
     }
 
     /// Appends a new basic block to the current function.

crates/llvm-context/src/polkavm/context/tests.rs

@@ -15,7 +15,7 @@ pub fn create_context(
     let module = llvm.create_module("test");
     let optimizer = Optimizer::new(optimizer_settings);
 
-    Context::<DummyDependency>::new(llvm, module, optimizer, None, true, None)
+    Context::<DummyDependency>::new(llvm, module, optimizer, None, true, Default::default())
 }
 
 #[test]

crates/llvm-context/src/polkavm/mod.rs

@@ -29,7 +29,7 @@ pub fn build_assembly_text(
     contract_path: &str,
     bytecode: &[u8],
     metadata_hash: Option<[u8; revive_common::BYTE_LENGTH_WORD]>,
-    debug_config: Option<&DebugConfig>,
+    debug_config: &DebugConfig,
 ) -> anyhow::Result<Build> {
     let program_blob = ProgramBlob::parse(bytecode.into())
         .map_err(anyhow::Error::msg)
@@ -49,9 +49,7 @@ pub fn build_assembly_text(
         format!("Failed to convert disassembled code to string for contract: {contract_path}")
     })?;
 
-    if let Some(debug_config) = debug_config {
-        debug_config.dump_assembly(contract_path, &assembly_text)?;
-    }
+    debug_config.dump_assembly(contract_path, &assembly_text)?;
 
     Ok(Build::new(
         assembly_text.to_owned(),
@@ -98,7 +96,7 @@ pub trait Dependency {
         path: &str,
         optimizer_settings: OptimizerSettings,
         include_metadata_hash: bool,
-        debug_config: Option<DebugConfig>,
+        debug_config: DebugConfig,
     ) -> anyhow::Result<String>;
 
     /// Resolves a full contract path.
@@ -118,7 +116,7 @@ impl Dependency for DummyDependency {
         _path: &str,
         _optimizer_settings: OptimizerSettings,
         _include_metadata_hash: bool,
-        _debug_config: Option<DebugConfig>,
+        _debug_config: DebugConfig,
     ) -> anyhow::Result<String> {
         Ok(String::new())
     }