calltrace-rs 1.1.4

//! DWARF Debug Information Analysis
//!
//! This module parses DWARF debugging information to extract function signatures,
//! parameter types, and other metadata required for argument capture.

use crate::error::{CallTraceError, Result};
use std::collections::HashMap;
use std::ffi::c_void;
use std::fs;

/// Function information extracted from DWARF
#[derive(Debug, Clone)]
pub struct FunctionInfo {
    pub name: String,
    pub address: u64,
    pub size: Option<u64>,
    pub parameters: Vec<ParameterInfo>,
    pub return_type: Option<TypeInfo>,
    pub source_file: Option<String>,
    pub line_number: Option<u32>,
}

/// Parameter information for function arguments
#[derive(Debug, Clone)]
pub struct ParameterInfo {
    pub name: String,
    pub type_info: TypeInfo,
    pub location: Option<String>, // DW_AT_location if available
}

/// Type information extracted from DWARF
#[derive(Debug, Clone)]
pub struct TypeInfo {
    pub name: String,
    pub size: Option<u64>,
    pub is_pointer: bool,
    pub is_const: bool,
    pub is_struct: bool,
    pub is_array: bool,
    pub array_size: Option<u64>,
    pub base_type: Option<Box<TypeInfo>>,
}

/// DWARF analyzer context that caches parsed information
pub struct DwarfAnalyzer {
    executable_path: String,
    function_cache: HashMap<u64, FunctionInfo>,
    type_cache: HashMap<u64, TypeInfo>,
    symbol_cache: HashMap<u64, String>, // Cache for resolved symbols
    base_address: Option<u64>,          // Program base address
    #[cfg(feature = "dwarf_support")]
    dwarf_data: Option<DwarfData>,
}

/// Cached DWARF data
#[cfg(feature = "dwarf_support")]
struct DwarfData {
    #[allow(dead_code)]
    dwarf: (), // Simplified for now
    #[allow(dead_code)]
    file_data: Vec<u8>, // Keep file data alive
}

impl DwarfAnalyzer {
    /// Create a new DWARF analyzer for the specified executable
    pub fn new(executable_path: &str) -> Result<Self> {
        // Try to get the real executable path
        let real_exe_path = std::fs::read_link("/proc/self/exe")
            .unwrap_or_else(|_| executable_path.into())
            .to_string_lossy()
            .to_string();

        let mut analyzer = DwarfAnalyzer {
            executable_path: real_exe_path,
            function_cache: HashMap::new(),
            type_cache: HashMap::new(),
            symbol_cache: HashMap::new(),
            base_address: None,
            #[cfg(feature = "dwarf_support")]
            dwarf_data: None,
        };

        // Try to load DWARF data
        #[cfg(feature = "dwarf_support")]
        if let Err(e) = analyzer.load_dwarf_data() {
            // Log warning but continue - we can still work with limited functionality
            eprintln!("Warning: Failed to load DWARF data: {}", e);
        }

        // Initialize base address
        analyzer.base_address = analyzer.get_program_base_address();

        Ok(analyzer)
    }

    /// Load DWARF debugging information from the executable
    #[cfg(feature = "dwarf_support")]
    fn load_dwarf_data(&mut self) -> Result<()> {
        let file_data = fs::read(&self.executable_path)
            .map_err(|e| CallTraceError::DwarfError(format!("Failed to read executable: {}", e)))?;

        // TODO: Temporary simplified implementation
        // In the future, this will parse object file and load DWARF sections:
        /*
        let object = object::File::parse(&file_data[..])?;
        let load_section = |id: gimli::SectionId| -> std::result::Result<Cow<[u8]>, gimli::Error> {
            match object.section_by_name(id.name()) {
                Some(ref section) => Ok(section
                    .uncompressed_data()
                    .unwrap_or(Cow::Borrowed(&[][..]))),
                None => Ok(Cow::Borrowed(&[][..])),
            }
        };
        let dwarf_cow = Dwarf::load(&load_section)?;
        */
        // Keep file data alive for future use
        self.dwarf_data = Some(DwarfData {
            dwarf: (),
            file_data,
        });

        Ok(())
    }

    /// Get function information for a given address
    pub fn get_function_info(&mut self, address: u64) -> Result<FunctionInfo> {
        // Check cache first
        if let Some(cached) = self.function_cache.get(&address) {
            return Ok(cached.clone());
        }

        // Try to extract from DWARF data
        #[cfg(feature = "dwarf_support")]
        if let Some(info) = self.extract_function_info_from_dwarf(address)? {
            self.function_cache.insert(address, info.clone());
            return Ok(info);
        }

        // Fallback: create minimal function info using dladdr
        let fallback_info = self.create_fallback_function_info(address)?;
        self.function_cache.insert(address, fallback_info.clone());
        Ok(fallback_info)
    }

    /// Extract function information from DWARF data
    #[cfg(feature = "dwarf_support")]
    fn extract_function_info_from_dwarf(&mut self, _address: u64) -> Result<Option<FunctionInfo>> {
        // TODO: Temporary simplified implementation due to gimli API changes
        // Full implementation will be restored after updating to new gimli API
        Ok(None)
    }

    /*
    // TODO: Restore these functions with updated gimli API

    /// Extract function name from DIE
    #[cfg(feature = "dwarf_support")]
    fn extract_function_name(
        &self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<Option<String>> {
        // Try DW_AT_name first
        if let Some(name_attr) = entry.attr_value(gimli::DW_AT_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = name_attr {
                let name = dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading string: {}", e)))?;
                return Ok(Some(name.to_string_lossy().to_string()));
            }
        }

        // Try DW_AT_linkage_name for mangled names
        if let Some(linkage_attr) = entry.attr_value(gimli::DW_AT_linkage_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading linkage name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = linkage_attr {
                let name = dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading string: {}", e)))?;
                let demangled = demangle_function_name(&name.to_string_lossy());
                return Ok(Some(demangled));
            }
        }

        Ok(None)
    }

    /// Extract function parameters from DIE
    #[cfg(feature = "dwarf_support")]
    fn extract_function_parameters(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<Vec<ParameterInfo>> {
        let mut parameters = Vec::new();
        let mut children = entry.children();

        while let Some(child) = children.next()
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading child: {}", e)))?
        {
            if child.tag() == gimli::DW_TAG_formal_parameter {
                if let Some(param) = self.extract_parameter_info(dwarf, unit, &child)? {
                    parameters.push(param);
                }
            }
        }

        Ok(parameters)
    }

    /// Extract individual parameter information
    #[cfg(feature = "dwarf_support")]
    fn extract_parameter_info(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<Option<ParameterInfo>> {
        // Extract parameter name
        let name = if let Some(name_attr) = entry.attr_value(gimli::DW_AT_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading param name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = name_attr {
                dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading param string: {}", e)))?
                    .to_string_lossy().to_string()
            } else {
                "unnamed".to_string()
            }
        } else {
            "unnamed".to_string()
        };

        // Extract type information
        let type_info = if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading param type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                self.extract_type_info_from_offset(dwarf, unit, type_offset)?
            } else {
                TypeInfo {
                    name: "unknown".to_string(),
                    size: None,
                    is_pointer: false,
                    is_const: false,
                    is_struct: false,
                    is_array: false,
                    array_size: None,
                    base_type: None,
                }
            }
        } else {
            TypeInfo {
                name: "unknown".to_string(),
                size: None,
                is_pointer: false,
                is_const: false,
                is_struct: false,
                is_array: false,
                array_size: None,
                base_type: None,
            }
        };

        // Extract location information (register, stack offset, etc.)
        let location = if let Some(loc_attr) = entry.attr_value(gimli::DW_AT_location)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading param location: {}", e)))?
        {
            // This would parse DWARF location expressions
            // For now, we'll just indicate that location data exists
            Some("dwarf_location".to_string())
        } else {
            None
        };

        Ok(Some(ParameterInfo {
            name,
            type_info,
            location,
        }))
    }

    /// Extract type information from a type offset
    #[cfg(feature = "dwarf_support")]
    fn extract_type_info_from_offset(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        type_offset: gimli::UnitOffset,
    ) -> Result<TypeInfo> {
        // Check cache first
        let cache_key = type_offset.0 as u64;
        if let Some(cached_type) = self.type_cache.get(&cache_key) {
            return Ok(cached_type.clone());
        }

        // Get the type DIE
        let mut entries = unit.entries_at_offset(type_offset)
            .map_err(|e| CallTraceError::DwarfError(format!("Error getting type entry: {}", e)))?;

        let (_, type_entry) = entries.next_entry()
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading type entry: {}", e)))?
            .ok_or_else(|| CallTraceError::DwarfError("Type entry not found".to_string()))?;

        let type_info = self.extract_type_info_from_die(dwarf, unit, &type_entry)?;

        // Cache the result
        self.type_cache.insert(cache_key, type_info.clone());

        Ok(type_info)
    }

    /// Extract detailed type information from a type DIE
    #[cfg(feature = "dwarf_support")]
    fn extract_type_info_from_die(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        let tag = entry.tag();

        match tag {
            gimli::DW_TAG_base_type => {
                self.extract_base_type_info(dwarf, unit, entry)
            }
            gimli::DW_TAG_pointer_type => {
                self.extract_pointer_type_info(dwarf, unit, entry)
            }
            gimli::DW_TAG_array_type => {
                self.extract_array_type_info(dwarf, unit, entry)
            }
            gimli::DW_TAG_structure_type | gimli::DW_TAG_class_type => {
                self.extract_struct_type_info(dwarf, unit, entry)
            }
            gimli::DW_TAG_const_type => {
                self.extract_const_type_info(dwarf, unit, entry)
            }
            gimli::DW_TAG_typedef => {
                self.extract_typedef_info(dwarf, unit, entry)
            }
            _ => {
                // Fallback for unknown types
                Ok(TypeInfo {
                    name: format!("unknown_type_{:?}", tag),
                    size: entry.attr_value(gimli::DW_AT_byte_size)
                        .ok()
                        .flatten()
                        .and_then(|v| {
                            if let gimli::AttributeValue::Udata(size) = v {
                                Some(size)
                            } else {
                                None
                            }
                        }),
                    is_pointer: false,
                    is_const: false,
                    is_struct: false,
                    is_array: false,
                    array_size: None,
                    base_type: None,
                })
            }
        }
    }

    /// Extract return type information
    #[cfg(feature = "dwarf_support")]
    fn extract_return_type(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<Option<TypeInfo>> {
        if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading return type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                let type_info = self.extract_type_info_from_offset(dwarf, unit, type_offset)?;
                return Ok(Some(type_info));
            }
        }

        // No return type means void
        Ok(None)
    }

    /// Extract source file and line number information
    #[cfg(feature = "dwarf_support")]
    fn extract_source_location(
        &self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<(Option<String>, Option<u32>)> {
        let mut source_file = None;
        let mut line_number = None;

        // Extract line number
        if let Some(line_attr) = entry.attr_value(gimli::DW_AT_decl_line)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading line: {}", e)))?
        {
            if let gimli::AttributeValue::Udata(line) = line_attr {
                line_number = Some(line as u32);
            }
        }

        // Extract source file
        if let Some(file_attr) = entry.attr_value(gimli::DW_AT_decl_file)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading file: {}", e)))?
        {
            if let gimli::AttributeValue::Udata(file_index) = file_attr {
                // This would require parsing the line number table to get the actual filename
                // For now, we'll just use the file index
                source_file = Some(format!("file_{}", file_index));
            }
        }

        Ok((source_file, line_number))
    }

    /// Extract base type information (int, char, float, etc.)
    #[cfg(feature = "dwarf_support")]
    fn extract_base_type_info(
        &self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        _unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Extract type name
        let name = if let Some(name_attr) = entry.attr_value(gimli::DW_AT_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading base type name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = name_attr {
                dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading base type string: {}", e)))?
                    .to_string_lossy().to_string()
            } else {
                "unknown_base_type".to_string()
            }
        } else {
            "unknown_base_type".to_string()
        };

        // Extract size
        let size = entry.attr_value(gimli::DW_AT_byte_size)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading base type size: {}", e)))?
            .and_then(|v| {
                if let gimli::AttributeValue::Udata(size) = v {
                    Some(size)
                } else {
                    None
                }
            });

        Ok(TypeInfo {
            name,
            size,
            is_pointer: false,
            is_const: false,
            is_struct: false,
            is_array: false,
            array_size: None,
            base_type: None,
        })
    }

    /// Extract pointer type information
    #[cfg(feature = "dwarf_support")]
    fn extract_pointer_type_info(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Get the pointed-to type
        let base_type = if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading pointer target type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                Some(Box::new(self.extract_type_info_from_offset(dwarf, unit, type_offset)?))
            } else {
                None
            }
        } else {
            // Void pointer
            None
        };

        // Construct pointer type name
        let name = if let Some(ref base) = base_type {
            format!("{}*", base.name)
        } else {
            "void*".to_string()
        };

        // Pointer size (typically 8 bytes on 64-bit systems)
        let size = entry.attr_value(gimli::DW_AT_byte_size)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading pointer size: {}", e)))?
            .and_then(|v| {
                if let gimli::AttributeValue::Udata(size) = v {
                    Some(size)
                } else {
                    None
                }
            })
            .or(Some(8)); // Default to 8 bytes

        Ok(TypeInfo {
            name,
            size,
            is_pointer: true,
            is_const: false,
            is_struct: false,
            is_array: false,
            array_size: None,
            base_type,
        })
    }

    /// Extract array type information
    #[cfg(feature = "dwarf_support")]
    fn extract_array_type_info(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Get the element type
        let base_type = if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading array element type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                Some(Box::new(self.extract_type_info_from_offset(dwarf, unit, type_offset)?))
            } else {
                None
            }
        } else {
            None
        };

        // Extract array dimensions by looking at subrange_type children
        let mut array_size = None;
        let mut children = entry.children();

        while let Some(child) = children.next()
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading array child: {}", e)))?
        {
            if child.tag() == gimli::DW_TAG_subrange_type {
                // Try to get the count or upper bound
                if let Some(count_attr) = child.attr_value(gimli::DW_AT_count)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading array count: {}", e)))?
                {
                    if let gimli::AttributeValue::Udata(count) = count_attr {
                        array_size = Some(count);
                        break;
                    }
                } else if let Some(upper_attr) = child.attr_value(gimli::DW_AT_upper_bound)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading array upper bound: {}", e)))?
                {
                    if let gimli::AttributeValue::Udata(upper) = upper_attr {
                        // Upper bound is typically count - 1 for zero-based arrays
                        array_size = Some(upper + 1);
                        break;
                    }
                }
            }
        }

        // Construct array type name
        let name = if let Some(ref base) = base_type {
            if let Some(size) = array_size {
                format!("{}[{}]", base.name, size)
            } else {
                format!("{}[]", base.name)
            }
        } else {
            "unknown_array".to_string()
        };

        // Calculate total size
        let total_size = if let (Some(ref base), Some(count)) = (&base_type, array_size) {
            base.size.map(|element_size| element_size * count)
        } else {
            None
        };

        Ok(TypeInfo {
            name,
            size: total_size,
            is_pointer: false,
            is_const: false,
            is_struct: false,
            is_array: true,
            array_size,
            base_type,
        })
    }

    /// Extract structure/class type information
    #[cfg(feature = "dwarf_support")]
    fn extract_struct_type_info(
        &self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        _unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Extract struct name
        let name = if let Some(name_attr) = entry.attr_value(gimli::DW_AT_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading struct name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = name_attr {
                dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading struct string: {}", e)))?
                    .to_string_lossy().to_string()
            } else {
                "anonymous_struct".to_string()
            }
        } else {
            "anonymous_struct".to_string()
        };

        // Extract size
        let size = entry.attr_value(gimli::DW_AT_byte_size)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading struct size: {}", e)))?
            .and_then(|v| {
                if let gimli::AttributeValue::Udata(size) = v {
                    Some(size)
                } else {
                    None
                }
            });

        // Note: In a complete implementation, we would also extract member information
        // This would involve iterating through DW_TAG_member children

        Ok(TypeInfo {
            name,
            size,
            is_pointer: false,
            is_const: false,
            is_struct: true,
            is_array: false,
            array_size: None,
            base_type: None,
        })
    }

    /// Extract const type information
    #[cfg(feature = "dwarf_support")]
    fn extract_const_type_info(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Get the underlying type
        let mut base_type_info = if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading const target type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                self.extract_type_info_from_offset(dwarf, unit, type_offset)?
            } else {
                TypeInfo {
                    name: "unknown".to_string(),
                    size: None,
                    is_pointer: false,
                    is_const: false,
                    is_struct: false,
                    is_array: false,
                    array_size: None,
                    base_type: None,
                }
            }
        } else {
            TypeInfo {
                name: "unknown".to_string(),
                size: None,
                is_pointer: false,
                is_const: false,
                is_struct: false,
                is_array: false,
                array_size: None,
                base_type: None,
            }
        };

        // Mark as const and update name
        base_type_info.is_const = true;
        base_type_info.name = format!("const {}", base_type_info.name);

        Ok(base_type_info)
    }

    /// Extract typedef information
    #[cfg(feature = "dwarf_support")]
    fn extract_typedef_info(
        &mut self,
        dwarf: &Dwarf<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        unit: &gimli::Unit<gimli::EndianSlice<'static, gimli::LittleEndian>>,
        entry: &gimli::DebuggingInformationEntry<gimli::EndianSlice<'static, gimli::LittleEndian>>,
    ) -> Result<TypeInfo> {
        // Extract typedef name
        let typedef_name = if let Some(name_attr) = entry.attr_value(gimli::DW_AT_name)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading typedef name: {}", e)))?
        {
            if let gimli::AttributeValue::DebugStrRef(offset) = name_attr {
                dwarf.debug_str.get_str(offset)
                    .map_err(|e| CallTraceError::DwarfError(format!("Error reading typedef string: {}", e)))?
                    .to_string_lossy().to_string()
            } else {
                "unknown_typedef".to_string()
            }
        } else {
            "unknown_typedef".to_string()
        };

        // Get the underlying type
        let mut base_type_info = if let Some(type_attr) = entry.attr_value(gimli::DW_AT_type)
            .map_err(|e| CallTraceError::DwarfError(format!("Error reading typedef target type: {}", e)))?
        {
            if let gimli::AttributeValue::UnitRef(type_offset) = type_attr {
                self.extract_type_info_from_offset(dwarf, unit, type_offset)?
            } else {
                TypeInfo {
                    name: "unknown".to_string(),
                    size: None,
                    is_pointer: false,
                    is_const: false,
                    is_struct: false,
                    is_array: false,
                    array_size: None,
                    base_type: None,
                }
            }
        } else {
            TypeInfo {
                name: "unknown".to_string(),
                size: None,
                is_pointer: false,
                is_const: false,
                is_struct: false,
                is_array: false,
                array_size: None,
                base_type: None,
            }
        };

        // Use the typedef name but preserve other type information
        base_type_info.name = typedef_name;

        Ok(base_type_info)
    }
    */

    /// Get program base address from /proc/self/maps
    fn get_program_base_address(&self) -> Option<u64> {
        use std::fs;

        let maps = fs::read_to_string("/proc/self/maps").ok()?;
        for line in maps.lines() {
            if line.contains(&self.executable_path) && line.contains("r-xp") {
                let parts: Vec<&str> = line.split('-').collect();
                if let Some(base_str) = parts.first() {
                    return u64::from_str_radix(base_str, 16).ok();
                }
            }
        }
        None
    }

    /// Create fallback function info using dladdr
    fn create_fallback_function_info(&self, address: u64) -> Result<FunctionInfo> {
        use libc::{dladdr, Dl_info};
        use std::ffi::CStr;

        let mut info: Dl_info = unsafe { std::mem::zeroed() };
        let result = unsafe { dladdr(address as *const c_void, &mut info) };

        let name = if result != 0 && !info.dli_sname.is_null() {
            let raw_name = unsafe {
                CStr::from_ptr(info.dli_sname)
                    .to_string_lossy()
                    .into_owned()
            };

            // Try to demangle C++ function names
            demangle_function_name(&raw_name)
        } else {
            format!("0x{:x}", address)
        };

        Ok(FunctionInfo {
            name,
            address,
            size: None,
            parameters: Vec::new(), // No parameter info available
            return_type: None,
            source_file: None,
            line_number: None,
        })
    }

    /// Get the number of cached functions
    pub fn cache_size(&self) -> usize {
        self.function_cache.len()
    }

    /// Clear the function cache
    pub fn clear_cache(&mut self) {
        self.function_cache.clear();
        self.type_cache.clear();
        self.symbol_cache.clear();
    }
}

impl Drop for DwarfAnalyzer {
    fn drop(&mut self) {
        // Clean up any resources
        self.clear_cache();
    }
}

/// Helper function to demangle C++ function names
pub fn demangle_function_name(mangled: &str) -> String {
    // Try multiple demangling approaches

    // First try: Use cxa_demangle from libc++abi
    if let Some(demangled) = try_cxa_demangle(mangled) {
        return demangled;
    }

    // Second try: Use external c++filt tool
    if let Some(demangled) = try_cppfilt_demangle(mangled) {
        return demangled;
    }

    // Fallback: Return original mangled name
    mangled.to_string()
}

/// Try to demangle using libc++abi's cxa_demangle function
fn try_cxa_demangle(mangled: &str) -> Option<String> {
    use std::ffi::{CStr, CString};
    use std::ptr;

    // Only process names that look like C++ mangled names
    if !mangled.starts_with("_Z") && !mangled.starts_with("__Z") {
        return None;
    }

    let c_mangled = CString::new(mangled).ok()?;
    let mut status: libc::c_int = 0;

    unsafe {
        // Try to get __cxa_demangle dynamically to avoid linking issues
        let cxa_demangle_fn = libc::dlsym(libc::RTLD_DEFAULT, c"__cxa_demangle".as_ptr());
        if cxa_demangle_fn.is_null() {
            // __cxa_demangle not available (e.g., in C programs without libstdc++)
            return None;
        }

        // Cast to the correct function pointer type
        type CxaDemangleFn = extern "C" fn(
            *const libc::c_char,
            *mut libc::c_char,
            *mut libc::size_t,
            *mut libc::c_int,
        ) -> *mut libc::c_char;

        let demangle_fn: CxaDemangleFn = std::mem::transmute(cxa_demangle_fn);

        let result = demangle_fn(
            c_mangled.as_ptr(),
            ptr::null_mut(),
            ptr::null_mut(),
            &mut status,
        );

        if status == 0 && !result.is_null() {
            let demangled_cstr = CStr::from_ptr(result);
            let demangled = demangled_cstr.to_string_lossy().into_owned();

            // Free the memory allocated by __cxa_demangle
            libc::free(result as *mut libc::c_void);

            Some(demangled)
        } else {
            None
        }
    }
}

/// Try to demangle using external c++filt tool
fn try_cppfilt_demangle(mangled: &str) -> Option<String> {
    use std::process::Command;

    // Only process names that look like C++ mangled names
    if !mangled.starts_with("_Z") && !mangled.starts_with("__Z") {
        return None;
    }

    // Try to run c++filt command
    let output = Command::new("c++filt").arg(mangled).output().ok()?;

    if output.status.success() {
        let demangled = String::from_utf8(output.stdout).ok()?;
        let trimmed = demangled.trim();

        // If c++filt actually demangled something, it should be different from input
        if trimmed != mangled && !trimmed.is_empty() {
            Some(trimmed.to_string())
        } else {
            None
        }
    } else {
        None
    }
}

/*
/// Extract type information from a DWARF DIE
#[cfg(feature = "dwarf_support")]
#[allow(dead_code)]
fn extract_type_info<R: Reader>(
    _dwarf: &Dwarf<R>,
    _unit: &gimli::Unit<R>,
    _entry: &DebuggingInformationEntry<R>,
) -> Result<TypeInfo> {
    // This would extract detailed type information from DWARF
    // Including struct layouts, array sizes, pointer levels, etc.

    Ok(TypeInfo {
        name: "unknown".to_string(),
        size: None,
        is_pointer: false,
        is_const: false,
        is_struct: false,
        is_array: false,
        array_size: None,
        base_type: None,
    })
}
*/