genVar

fn genVar(c: *AsmCodeGen, variable: Node.Variable) !void

File

Code

fn genVar(c: *AsmCodeGen, variable: Node.Variable) !void {
    const comp = c.comp;
    const qt = variable.qt;

    const is_tentative = variable.initializer == null;
    const size = qt.sizeofOrNull(comp) orelse blk: {
        // tentative array definition assumed to have one element
        std.debug.assert(is_tentative and qt.is(c.comp, .array));
        break :blk qt.childType(c.comp).sizeof(comp);
    };

    const name = c.tree.tokSlice(variable.name_tok);
    const nat_align = qt.alignof(comp);
    const alignment = if (qt.is(c.comp, .array) and size >= 16) @max(16, nat_align) else nat_align;

    if (variable.storage_class == .static) {
        try c.data.print("  .local \"{s}\"\n", .{name});
    } else {
        try c.data.print("  .globl \"{s}\"\n", .{name});
    }

    if (is_tentative and comp.code_gen_options.common) {
        try c.data.print("  .comm \"{s}\", {d}, {d}\n", .{ name, size, alignment });
        return;
    }
    if (variable.initializer) |init| {
        if (variable.thread_local and comp.code_gen_options.data_sections) {
            try c.data.print("  .section .tdata.\"{s}\",\"awT\",@progbits\n", .{name});
        } else if (variable.thread_local) {
            try c.data.writeAll("  .section .tdata,\"awT\",@progbits\n");
        } else if (comp.code_gen_options.data_sections) {
            try c.data.print("  .section .data.\"{s}\",\"aw\",@progbits\n", .{name});
        } else {
            try c.data.writeAll("  .data\n");
        }

        try c.data.print("  .type \"{s}\", @object\n", .{name});
        try c.data.print("  .size \"{s}\", {d}\n", .{ name, size });
        try c.data.print("  .align {d}\n", .{alignment});
        try c.data.print("\"{s}\":\n", .{name});
        try c.emitValue(qt, init);
        return;
    }
    if (variable.thread_local and comp.code_gen_options.data_sections) {
        try c.data.print("  .section .tbss.\"{s}\",\"awT\",@nobits\n", .{name});
    } else if (variable.thread_local) {
        try c.data.writeAll("  .section .tbss,\"awT\",@nobits\n");
    } else if (comp.code_gen_options.data_sections) {
        try c.data.print("  .section .bss.\"{s}\",\"aw\",@nobits\n", .{name});
    } else {
        try c.data.writeAll("  .bss\n");
    }
    try c.data.print("  .align {d}\n", .{alignment});
    try c.data.print("\"{s}\":\n", .{name});
    try c.data.print("  .zero {d}\n", .{size});
}