mago-analyzer 1.25.0

A PHP static analyzer that can detect type errors in PHP code, and provide suggestions for fixing them.
Documentation
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use mago_atom::Atom;
use mago_atom::atom;

use mago_codex::metadata::function_like::FunctionLikeMetadata;

use mago_codex::visibility::Visibility;
use mago_php_version::feature::Feature;
use mago_reporting::Annotation;
use mago_reporting::Issue;
use mago_span::Span;

use crate::code::IssueCode;
use crate::context::Context;
use crate::context::block::BlockContext;

/// Checks if a method is visible from the current scope and reports a detailed
/// error if it is not.
///
/// # Arguments
///
/// * `context` - The global analysis context.
/// * `block_context` - The context of the current code block, providing scope information.
/// * `fqcn` - The fully-qualified class name on which the method is being called.
/// * `method_name` - The method name.
/// * `access_span` - The span of the entire method call/access expression (e.g., `$obj->method()`).
/// * `method_name_span` - The span of just the method name identifier (e.g., `method`).
///
/// # Returns
///
/// `true` if the method is visible, `false` otherwise. An error is reported to the
/// context buffer if the method is not visible.
pub fn check_method_visibility<'ctx>(
    context: &mut Context<'ctx, '_>,
    block_context: &BlockContext<'ctx>,
    fqcn: &str,
    method_name: &str,
    access_span: Span,
    member_span: Option<Span>,
) -> bool {
    let declaring_class = context.codebase.get_declaring_method_class(fqcn, method_name).unwrap_or_else(|| atom(fqcn));

    let Some(method_metadata) = context.codebase.get_declaring_method(fqcn, method_name) else {
        return true;
    };

    // Get the effective visibility, checking trait alias visibility overrides
    let Some(visibility) = context.codebase.get_method_visibility(fqcn, method_name) else {
        return true;
    };

    if visibility == Visibility::Public {
        return true;
    }

    let is_visible =
        is_visible_from_scope(context, visibility, &declaring_class, block_context.scope.get_class_like_name());

    if !is_visible {
        let declaring_class_name = context
            .codebase
            .get_class_like(&declaring_class)
            .map_or_else(|| declaring_class, |metadata| metadata.original_name);

        let issue_title =
            format!("Cannot access {} method `{}::{}`.", visibility.as_str(), declaring_class_name, method_name);
        let help_text =
            format!("Change the visibility of method `{method_name}` to `public`, or call it from an allowed scope.");

        report_visibility_issue(
            context,
            block_context,
            IssueCode::InvalidMethodAccess,
            issue_title,
            visibility,
            access_span,
            member_span,
            Some(method_metadata.span),
            help_text,
        );
    }

    is_visible
}

/// Checks if a property is readable from the current scope and reports a detailed
/// error if it is not.
pub fn check_property_read_visibility<'ctx>(
    context: &mut Context<'ctx, '_>,
    block_context: &BlockContext<'ctx>,
    fqcn: &str,
    property_name: &str,
    access_span: Span,
    member_span: Option<Span>,
) -> bool {
    let property_name = atom(property_name);

    let Some(class_metadata) = context.codebase.get_class_like(fqcn) else {
        return true;
    };

    let Some(declaring_class_id) = class_metadata.declaring_property_ids.get(&property_name) else {
        return true;
    };

    let Some(declaring_class_metadata) = context.codebase.get_class_like(declaring_class_id) else {
        return true;
    };

    let Some(property_metadata) = declaring_class_metadata.properties.get(&property_name) else {
        return true;
    };

    if property_metadata.flags.is_magic_property() && property_metadata.flags.is_writeonly() {
        let class_name = &declaring_class_metadata.original_name;

        context.collector.report_with_code(
            IssueCode::InvalidPropertyRead,
            Issue::error(format!(
                "Cannot read from write-only property `{class_name}::{property_name}`."
            ))
            .with_annotation(
                Annotation::primary(member_span.unwrap_or(access_span))
                    .with_message("Attempt to read from a write-only property"),
            )
            .with_annotation(
                Annotation::secondary(declaring_class_metadata.name_span.unwrap_or(declaring_class_metadata.span))
                    .with_message(format!("Property is defined as write-only via a `@property-write` tag on class `{class_name}`")),
            )
            .with_note("Properties defined with `@property-write` are 'magic' properties that can be assigned to, but not read from.")
            .with_help("If this property should be readable, change its docblock definition from `@property-write` to `@property`."),
        );

        return false;
    }

    if !property_metadata.hooks.is_empty()
        && property_metadata.hooks.contains_key(&atom("set"))
        && !property_metadata.hooks.contains_key(&atom("get"))
        && property_metadata.flags.is_virtual_property()
    {
        let class_name = &declaring_class_metadata.original_name;

        context.collector.report_with_code(
            IssueCode::InvalidPropertyRead,
            Issue::error(format!(
                "Cannot read from write-only property `{class_name}::{property_name}` - property only has a set hook."
            ))
            .with_annotation(Annotation::primary(member_span.unwrap_or(access_span)).with_message("Read access here"))
            .with_annotation(
                Annotation::secondary(property_metadata.span.or(property_metadata.name_span).unwrap_or(access_span))
                    .with_message("Property defined here with only a set hook"),
            )
            .with_help("Add a get hook to make this property readable."),
        );

        return false;
    }

    let visibility = property_metadata.read_visibility;
    let is_visible =
        is_visible_from_scope(context, visibility, declaring_class_id, block_context.scope.get_class_like_name());

    if !is_visible {
        let issue_title = format!(
            "Cannot read {} property `{}` from class `{}`.",
            visibility.as_str(),
            property_name,
            declaring_class_metadata.original_name
        );

        let help_text =
            format!("Make the property `{property_name}` readable (e.g., `public`), or add a public getter method.");

        report_visibility_issue(
            context,
            block_context,
            IssueCode::InvalidPropertyRead,
            issue_title,
            visibility,
            access_span,
            member_span,
            property_metadata.span.or(property_metadata.name_span),
            help_text,
        );
    }

    is_visible
}

pub fn check_property_write_visibility<'ctx>(
    context: &mut Context<'ctx, '_>,
    block_context: &BlockContext<'ctx>,
    fqcn: &str,
    property_name: &str,
    access_span: Span,
    member_span: Option<Span>,
) -> bool {
    let property_name = atom(property_name);

    let Some(class_metadata) = context.codebase.get_class_like(fqcn) else {
        return true;
    };

    let Some(declaring_class_name) = class_metadata.declaring_property_ids.get(&property_name) else {
        return true;
    };

    let Some(declaring_class_metadata) = context.codebase.get_class_like(declaring_class_name) else {
        return true;
    };

    let Some(property_metadata) = declaring_class_metadata.properties.get(&property_name) else {
        return true;
    };

    if !property_metadata.hooks.is_empty()
        && property_metadata.hooks.contains_key(&atom("get"))
        && !property_metadata.hooks.contains_key(&atom("set"))
        && property_metadata.flags.is_virtual_property()
    {
        let class_name = &declaring_class_metadata.original_name;

        context.collector.report_with_code(
            IssueCode::InvalidPropertyWrite,
            Issue::error(format!(
                "Cannot write to read-only property `{class_name}::{property_name}` - property only has a get hook."
            ))
            .with_annotation(Annotation::primary(member_span.unwrap_or(access_span)).with_message("Write access here"))
            .with_annotation(
                Annotation::secondary(property_metadata.span.or(property_metadata.name_span).unwrap_or(access_span))
                    .with_message("Property defined here with only a get hook"),
            )
            .with_help("Add a set hook to make this property writable."),
        );

        return false;
    }

    let visibility = property_metadata.write_visibility;
    let is_visible =
        is_visible_from_scope(context, visibility, declaring_class_name, block_context.scope.get_class_like_name());

    if !is_visible {
        let issue_title = format!(
            "Cannot write to {} property `{}` on class `{}`.",
            visibility.as_str(),
            property_name,
            declaring_class_metadata.original_name
        );

        let help_text = format!(
            "Make the property `{property_name}` writable (e.g., `public` or `public(set)`), or add a public setter method."
        );

        report_visibility_issue(
            context,
            block_context,
            IssueCode::InvalidPropertyWrite,
            issue_title,
            visibility,
            access_span,
            member_span,
            property_metadata.span.or(property_metadata.name_span),
            help_text,
        );
    } else if property_metadata.flags.is_readonly()
        && !can_initialize_readonly_property(
            context,
            declaring_class_name,
            block_context.scope.get_class_like_name(),
            block_context.scope.get_function_like(),
        )
    {
        report_readonly_issue(
            context,
            block_context,
            IssueCode::InvalidPropertyWrite,
            access_span,
            member_span,
            property_metadata.span.or(property_metadata.name_span),
        );
    }

    is_visible
}

fn is_visible_from_scope(
    context: &Context<'_, '_>,
    visibility: Visibility,
    declaring_class_id: &str,
    current_class_opt: Option<Atom>,
) -> bool {
    match visibility {
        Visibility::Public => true,
        Visibility::Protected => {
            if let Some(current_class_id) = current_class_opt {
                current_class_id.eq_ignore_ascii_case(declaring_class_id)
                    || context.codebase.is_instance_of(&current_class_id, declaring_class_id)
                    || context.codebase.is_instance_of(declaring_class_id, &current_class_id)
                    || is_visible_via_required_extends(context, &current_class_id, declaring_class_id)
            } else {
                false
            }
        }
        Visibility::Private => {
            if let Some(current_class_id) = current_class_opt {
                current_class_id.eq_ignore_ascii_case(declaring_class_id)
                    || context.codebase.class_uses_trait(&current_class_id, declaring_class_id)
                    || context.codebase.class_uses_trait(declaring_class_id, &current_class_id)
            } else {
                false
            }
        }
    }
}

/// Checks if a protected member declared in `declaring_class_id` is accessible from
/// `current_class_id` via `@require-extends`. This handles the case where a trait has
/// `@require-extends BaseClass` and `BaseClass` uses another trait that declares the method.
fn is_visible_via_required_extends(
    context: &Context<'_, '_>,
    current_class_id: &str,
    declaring_class_id: &str,
) -> bool {
    let current_class_id_lc = mago_atom::ascii_lowercase_atom(current_class_id);

    let Some(current_metadata) = context.codebase.get_class_like(&current_class_id_lc) else {
        return false;
    };

    if current_metadata.require_extends.is_empty() {
        return false;
    }

    for required_class in current_metadata.require_extends.iter() {
        if context.codebase.is_instance_of(required_class, declaring_class_id)
            || context.codebase.class_uses_trait(required_class, declaring_class_id)
        {
            return true;
        }
    }

    false
}

fn can_initialize_readonly_property(
    context: &Context<'_, '_>,
    declaring_class_id: &str,
    current_class_opt: Option<Atom>,
    current_function_opt: Option<&FunctionLikeMetadata>,
) -> bool {
    let is_allowed_method = current_function_opt.is_some_and(|func| {
        // Constructor is always allowed
        if func.method_metadata.as_ref().is_some_and(|m| m.is_constructor) {
            return true;
        }

        // __clone is allowed in PHP 8.3+
        if context.settings.version.is_supported(Feature::ReadonlyPropertyReinitializationInClone)
            && func.name.is_some_and(|name| name.eq_ignore_ascii_case("__clone"))
        {
            return true;
        }

        false
    });

    is_allowed_method
        && current_class_opt.is_some_and(|current_class_id| {
            current_class_id.eq_ignore_ascii_case(declaring_class_id)
                || context.codebase.is_instance_of(&current_class_id, declaring_class_id)
                || context.codebase.is_instance_of(declaring_class_id, &current_class_id)
        })
}

fn report_visibility_issue<'ctx>(
    context: &mut Context<'ctx, '_>,
    block_context: &BlockContext<'ctx>,
    code: IssueCode,
    title: String,
    visibility: Visibility,
    access_span: Span,
    member_span: Option<Span>,
    definition_span: Option<Span>,
    help_text: String,
) {
    let current_scope_str = if let Some(current_class) = block_context.scope.get_class_like_name() {
        format!("from within `{current_class}`")
    } else {
        "from the global scope".to_string()
    };

    let primary_annotation_span = member_span.unwrap_or(access_span);

    let mut issue = Issue::error(title)
        .with_annotation(
            Annotation::primary(primary_annotation_span)
                .with_message(format!("This member is {} and cannot be accessed here", visibility.as_str())),
        )
        .with_annotation(
            Annotation::secondary(access_span).with_message(format!("Invalid access occurs here, {current_scope_str}")),
        );

    if let Some(definition_span) = definition_span
        && definition_span != primary_annotation_span
    {
        issue = issue.with_annotation(
            Annotation::secondary(definition_span)
                .with_message(format!("Member is defined as `{}` here", visibility.as_str())),
        );
    }

    issue = issue.with_help(help_text);

    context.collector.report_with_code(code, issue);
}

fn report_readonly_issue<'ctx>(
    context: &mut Context<'ctx, '_>,
    block_context: &BlockContext<'ctx>,
    code: IssueCode,
    access_span: Span,
    member_span: Option<Span>,
    definition_span: Option<Span>,
) {
    let current_scope_str = if let Some(current_class) = block_context.scope.get_class_like_name() {
        format!("from within `{current_class}`")
    } else {
        "from the global scope".to_string()
    };

    let primary_annotation_span = member_span.unwrap_or(access_span);

    let (note, help) = if context.settings.version.is_supported(Feature::ReadonlyPropertyReinitializationInClone) {
        (
            "Readonly properties can only be initialized once, within `__construct` or `__clone` methods of the declaring class or its descendants.",
            "Move this initialization to `__construct` or `__clone`.",
        )
    } else {
        (
            "Readonly properties can only be initialized once within `__construct`. Since PHP 8.3, re-initialization is also allowed in `__clone`.",
            "Move this initialization to the constructor, or upgrade to PHP 8.3+ to use `__clone` for re-initialization.",
        )
    };

    let mut issue = Issue::error("Cannot modify a readonly property after initialization.")
        .with_annotation(
            Annotation::primary(primary_annotation_span).with_message("Illegal write to readonly property"),
        )
        .with_annotation(
            Annotation::secondary(access_span).with_message(format!("Write attempt occurs here, {current_scope_str}")),
        )
        .with_note(note)
        .with_help(help);

    if let Some(definition_span) = definition_span {
        issue = issue.with_annotation(
            Annotation::secondary(definition_span).with_message("Property is defined as `readonly` here"),
        );
    }

    context.collector.report_with_code(code, issue);
}