brokk-bifrost-cpp 0.8.24

//! C++ type-hierarchy resolution: the include-visible class table and the
//! namespace/alias search that turns a written base specifier into a `CodeUnit`.
//!
//! `analyzer/cpp/hierarchy.rs` in `brokk-bifrost-analysis` keeps the
//! `TypeHierarchyProvider` impl, the two moka caches it reads through and the
//! `test-support` build counter; every decision they memoize is a function here.

use crate::declarations::normalize_cpp_whitespace;
use crate::graph_support::CppSource;
use crate::imports::{include_paths, resolve_include_targets_with_index};
use brokk_bifrost_core::analyzer::{CodeUnit, ProjectFile};
use brokk_bifrost_core::hash::HashSet;
use brokk_bifrost_core::path_utils::rel_path_string;
use brokk_bifrost_core::profiling;

/// Every class-like or alias declaration reachable from `file` through its
/// transitive `#include` closure, sorted and deduplicated.
///
/// This is the builder behind [`CppSource::visible_type_units`]; the
/// analyzer memoizes the result per file and records the build for the
/// `visible_type_units_build_count_for_test` counter before calling in.
pub fn build_cpp_visible_type_units(cpp: &dyn CppSource, file: &ProjectFile) -> Vec<CodeUnit> {
    let _scope =
        profiling::scope_with(|| format!("cpp.visible_types.build[{}]", rel_path_string(file)));
    let include_targets = cpp.include_target_index();
    let mut visited = HashSet::default();
    let mut declarations = Vec::new();
    let mut pending = vec![file.clone()];
    visited.insert(file.clone());

    while let Some(current) = pending.pop() {
        {
            let _decls = profiling::scope("cpp.visible_types.decls");
            declarations.extend(
                cpp.declarations(&current)
                    .into_iter()
                    .filter(|unit| unit.is_class() || cpp.is_type_alias(unit)),
            );
        }

        let imports = {
            let _imports = profiling::scope("cpp.visible_types.imports");
            cpp.import_statements(&current)
        };
        for include in include_paths(&imports) {
            for target in resolve_include_targets_with_index(&current, &include, include_targets) {
                if visited.insert(target.clone()) {
                    pending.push(target);
                }
            }
        }
    }

    declarations.sort();
    declarations.dedup();
    profiling::note_with(|| {
        format!(
            "cpp.visible_types.done[{}] visited={} declarations={}",
            rel_path_string(file),
            visited.len(),
            declarations.len()
        )
    });
    declarations
}

/// The direct base classes of `code_unit`, resolved through the include-visible
/// class table and canonicalized past any type-alias hops.
pub fn cpp_resolve_direct_ancestors(cpp: &dyn CppSource, code_unit: &CodeUnit) -> Vec<CodeUnit> {
    if !code_unit.is_class() || cpp.is_type_alias(code_unit) {
        return Vec::new();
    }

    let visible = cpp.visible_type_units(code_unit.source());
    let mut ancestors = Vec::new();
    for raw in cpp.raw_supertypes_of(code_unit) {
        if let Some(ancestor) = resolve_base_type(cpp, code_unit, &raw, &visible)
            && !ancestors.iter().any(|existing| existing == &ancestor)
        {
            ancestors.push(ancestor);
        }
    }
    ancestors
}

fn resolve_base_type(
    cpp: &dyn CppSource,
    code_unit: &CodeUnit,
    raw: &str,
    visible: &[CodeUnit],
) -> Option<CodeUnit> {
    let normalized = normalize_cpp_type_reference(raw)?;
    let resolved = if normalized.name.contains("::") || normalized.global {
        resolve_qualified_type(
            code_unit.package_name(),
            &normalized.name,
            normalized.global,
            visible,
        )
    } else {
        resolve_unqualified_base(code_unit, &normalized.name, visible)
    }?;
    canonicalize_alias(cpp, resolved, visible, &mut HashSet::default())
}

fn resolve_unqualified_base<'a>(
    code_unit: &CodeUnit,
    name: &str,
    visible: &'a [CodeUnit],
) -> Option<&'a CodeUnit> {
    for namespace in namespace_search_order(code_unit.package_name()) {
        if let Some(candidate) = visible.iter().find(|candidate| {
            candidate.identifier() == name && candidate.package_name() == namespace
        }) {
            return Some(candidate);
        }
    }

    visible
        .iter()
        .find(|candidate| candidate.identifier() == name)
}

fn canonicalize_alias(
    cpp: &dyn CppSource,
    unit: &CodeUnit,
    visible: &[CodeUnit],
    seen: &mut HashSet<String>,
) -> Option<CodeUnit> {
    if !cpp.is_type_alias(unit) {
        return Some(unit.clone());
    }
    if !seen.insert(unit.fq_name()) {
        return None;
    }
    let target = alias_target_text(unit)?;
    let resolved = if target.name.contains("::") || target.global {
        resolve_qualified_type(unit.package_name(), &target.name, target.global, visible)
    } else {
        visible
            .iter()
            .find(|candidate| {
                candidate.identifier() == target.name
                    && candidate.package_name() == unit.package_name()
            })
            .or_else(|| {
                visible
                    .iter()
                    .find(|candidate| candidate.identifier() == target.name)
            })
    }?;
    canonicalize_alias(cpp, resolved, visible, seen)
}

fn resolve_qualified_type<'a>(
    lexical_namespace: &str,
    name: &str,
    global: bool,
    visible: &'a [CodeUnit],
) -> Option<&'a CodeUnit> {
    let namespaces = if global {
        vec![""]
    } else {
        namespace_search_order(lexical_namespace)
    };
    namespaces.into_iter().find_map(|namespace| {
        let qualified = if namespace.is_empty() {
            name.to_string()
        } else {
            format!("{namespace}::{name}")
        };
        visible
            .iter()
            .find(|candidate| cpp_name_for(candidate) == qualified)
    })
}

fn namespace_search_order(package_name: &str) -> Vec<&str> {
    let mut namespaces = Vec::new();
    let mut current = package_name;
    loop {
        namespaces.push(current);
        let Some((parent, _)) = current.rsplit_once("::") else {
            if !current.is_empty() {
                namespaces.push("");
            }
            return namespaces;
        };
        current = parent;
    }
}

fn alias_target_text(alias: &CodeUnit) -> Option<NormalizedCppTypeReference> {
    let signature = alias.signature()?.trim();
    let target = signature
        .strip_prefix("using ")
        .and_then(|rest| rest.split_once('=').map(|(_, rhs)| rhs))
        .or_else(|| {
            signature
                .strip_prefix("typedef ")
                .and_then(|rest| rest.rsplit_once(' ').map(|(lhs, _)| lhs))
        })?
        .trim()
        .trim_end_matches(';');
    normalize_cpp_type_reference(target)
}

struct NormalizedCppTypeReference {
    name: String,
    global: bool,
}

fn normalize_cpp_type_reference(value: &str) -> Option<NormalizedCppTypeReference> {
    let mut text = normalize_cpp_whitespace(value)
        .trim_start_matches("new ")
        .trim()
        .to_string();
    if let Some(index) = text.find(['(', '{']) {
        text.truncate(index);
    }
    if let Some(index) = text.find('<') {
        text.truncate(index);
    }
    let normalized = text
        .trim()
        .trim_start_matches("const ")
        .trim_end_matches(|ch: char| ch == '*' || ch == '&' || ch.is_whitespace())
        .trim();
    let global = normalized.starts_with("::");
    let normalized = normalized.trim_matches(':').trim();
    let normalized = normalized
        .strip_prefix("struct ")
        .or_else(|| normalized.strip_prefix("class "))
        .or_else(|| normalized.strip_prefix("enum "))
        .unwrap_or(normalized)
        .trim();
    (!normalized.is_empty()).then(|| NormalizedCppTypeReference {
        name: normalized.to_string(),
        global,
    })
}

fn cpp_name_for(unit: &CodeUnit) -> String {
    let short = unit.short_name().replace(['.', '$'], "::");
    if unit.package_name().is_empty() {
        short
    } else {
        format!("{}::{}", unit.package_name(), short)
    }
}