tiny.tldr.formats.elf.addressing.tls

1pub const tls = @import("tls.zig");

1const std = @import("std");2const root = @import("../../../root.zig");3const elf = @import("../root.zig");4const cache = @import("cache.zig");5const contribution_module = @import("contribution.zig");67const model = root.model;8const format = elf.format;9const layout = elf.layout;10const program = elf.program;11const section_state = elf.section_state;1213const Cache = cache.Cache;14const GlobalSymbol = layout.GlobalSymbol;15const ObjectFile = elf.parser.ObjectFile;16const ObjectLayout = layout.ObjectLayout;17const OutputSection = layout.OutputSection;18const Symbol = format.Symbol;19const SymbolRef = layout.SymbolRef;20const symbolSectionDiscarded = section_state.symbolSectionDiscarded;21const tlsSegment = program.tlsSegment;2223pub fn offset(24    objects: []const ObjectFile,25    layouts: []const ObjectLayout,26    output_sections: []const OutputSection,27    globals: *const std.StringHashMapUnmanaged(GlobalSymbol),28    symbol_addresses: *Cache,29    object_index: usize,30    symbol_index: usize,31) model.Error!u64 {32    if (symbol_index >= objects[object_index].symbols.len) return error.UndefinedSymbol;3334    const object = objects[object_index];35    const symbol_record = object.symbols[symbol_index];36    if (symbol_record.isUndefined()) {37        const global = globals.get(symbol_record.name) orelse {38            if (symbol_record.isWeakUndefined()) return 0;39            return error.UndefinedSymbol;40        };41        return offset(objects, layouts, output_sections, globals, symbol_addresses, global.ref.object_index, global.ref.symbol_index);42    }43    if (symbolSectionDiscarded(object, symbol_record) and symbol_record.name.len != 0) {44        const global = globals.get(symbol_record.name) orelse return error.MissingSection;45        const current_ref = SymbolRef{ .object_index = object_index, .symbol_index = symbol_index };46        if (global.ref.eql(current_ref)) return error.MissingSection;47        return offset(objects, layouts, output_sections, globals, symbol_addresses, global.ref.object_index, global.ref.symbol_index);48    }49    if (symbol_record.isCommon() and symbol_record.name.len != 0) {50        const global = globals.get(symbol_record.name) orelse return error.UndefinedSymbol;51        const current_ref = SymbolRef{ .object_index = object_index, .symbol_index = symbol_index };52        if (!global.ref.eql(current_ref)) return offset(objects, layouts, output_sections, globals, symbol_addresses, global.ref.object_index, global.ref.symbol_index);53    }54    if (symbol_record.isAbsolute() or symbol_record.isCommon()) return error.UnsupportedRelocation;55    if (!isSymbol(object, symbol_record)) return error.UnsupportedRelocation;5657    const symbol_contribution = try contribution_module.symbol(objects, layouts, object_index, symbol_index);58    const output = output_sections[symbol_contribution.outputIndex()];59    if (!output.kind.isTls()) return error.UnsupportedRelocation;60    const segment = tlsSegment(output_sections) orelse return error.MissingSection;61    return output.address - segment.address + symbol_contribution.offset + symbol_record.value;62}6364pub fn isSymbol(object: ObjectFile, symbol_record: Symbol) bool {65    if (symbol_record.kind() == std.elf.STT_TLS) return true;66    if (symbol_record.isUndefined() or symbol_record.isCommon() or symbol_record.isAbsolute()) return false;67    if (symbol_record.section_index >= object.sections.len) return false;68    return (object.sections[symbol_record.section_index].flags & std.elf.SHF_TLS) != 0;69}