Commit 4192be8403
Changed files (1)
src
link
src/link/Elf.zig
@@ -784,8 +784,10 @@ pub const abbrev_subprogram = 2;
pub const abbrev_subprogram_retvoid = 3;
pub const abbrev_base_type = 4;
pub const abbrev_ptr_type = 5;
-pub const abbrev_pad1 = 6;
-pub const abbrev_parameter = 7;
+pub const abbrev_anon_struct_type = 6;
+pub const abbrev_struct_member = 7;
+pub const abbrev_pad1 = 8;
+pub const abbrev_parameter = 9;
pub fn flush(self: *Elf, comp: *Compilation) !void {
if (self.base.options.emit == null) {
@@ -882,6 +884,24 @@ pub fn flushModule(self: *Elf, comp: *Compilation) !void {
DW.FORM.ref4,
0,
0, // table sentinel
+ abbrev_anon_struct_type,
+ DW.TAG.structure_type,
+ DW.CHILDREN.yes, // header
+ DW.AT.byte_size,
+ DW.FORM.sdata,
+ 0,
+ 0, // table sentinel
+ abbrev_struct_member,
+ DW.TAG.member,
+ DW.CHILDREN.no, // header
+ DW.AT.name,
+ DW.FORM.string,
+ DW.AT.type,
+ DW.FORM.ref4,
+ DW.AT.data_member_location,
+ DW.FORM.sdata,
+ 0,
+ 0, // table sentinel
abbrev_pad1,
DW.TAG.unspecified_type,
DW.CHILDREN.no, // header
@@ -2395,6 +2415,16 @@ fn finishUpdateDecl(
dbg_info_type_relocs: *File.DbgInfoTypeRelocsTable,
dbg_info_buffer: *std.ArrayList(u8),
) !void {
+ // We need this for the duration of this function only so that for composite
+ // types such as []const u32, if the type *u32 is non-existent, we create
+ // it synthetically and store the backing bytes in this arena. After we are
+ // done with the relocations, we can safely deinit the entire memory slab.
+ // TODO currently, we do not store the relocations for future use, however,
+ // if that is the case, we should move memory management to a higher scope,
+ // such as linker scope, or whatnot.
+ var dbg_type_arena = std.heap.ArenaAllocator.init(self.base.allocator);
+ defer dbg_type_arena.deinit();
+
// Now we emit the .debug_info types of the Decl. These will count towards the size of
// the buffer, so we have to do it before computing the offset, and we can't perform the actual
// relocations yet.
@@ -2404,7 +2434,7 @@ fn finishUpdateDecl(
const ty = dbg_info_type_relocs.keys()[it];
const value_ptr = dbg_info_type_relocs.getPtr(ty).?;
value_ptr.off = @intCast(u32, dbg_info_buffer.items.len);
- try self.addDbgInfoType(ty, dbg_info_buffer, dbg_info_type_relocs);
+ try self.addDbgInfoType(dbg_type_arena.allocator(), ty, dbg_info_buffer, dbg_info_type_relocs);
}
}
@@ -2721,11 +2751,12 @@ pub fn updateDecl(self: *Elf, module: *Module, decl: *Module.Decl) !void {
/// Asserts the type has codegen bits.
fn addDbgInfoType(
self: *Elf,
+ arena: Allocator,
ty: Type,
dbg_info_buffer: *std.ArrayList(u8),
dbg_info_type_relocs: *File.DbgInfoTypeRelocsTable,
) error{OutOfMemory}!void {
- var reloc: ?struct { ty: Type, reloc: u32 } = null;
+ var relocs = std.ArrayList(struct { ty: Type, reloc: u32 }).init(arena);
switch (ty.zigTypeTag()) {
.Void => unreachable,
@@ -2767,17 +2798,48 @@ fn addDbgInfoType(
try dbg_info_buffer.append(abbrev_pad1);
}
},
- .Pointer => blk: {
+ .Pointer => {
if (ty.isSlice()) {
- log.debug("TODO implement .debug_info for type '{}'", .{ty});
- try dbg_info_buffer.append(abbrev_pad1);
- break :blk;
+ // Slices are anonymous structs: struct { .ptr = *, .len = N }
+ try dbg_info_buffer.ensureUnusedCapacity(23);
+ // DW.AT.structure_type
+ dbg_info_buffer.appendAssumeCapacity(abbrev_anon_struct_type);
+ // DW.AT.byte_size, DW.FORM.sdata
+ dbg_info_buffer.appendAssumeCapacity(16);
+ // DW.AT.member
+ dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
+ // DW.AT.name, DW.FORM.string
+ dbg_info_buffer.appendSliceAssumeCapacity("ptr");
+ dbg_info_buffer.appendAssumeCapacity(0);
+ // DW.AT.type, DW.FORM.ref4
+ var index = dbg_info_buffer.items.len;
+ try dbg_info_buffer.resize(index + 4);
+ var buf = try arena.create(Type.SlicePtrFieldTypeBuffer);
+ const ptr_ty = ty.slicePtrFieldType(buf);
+ try relocs.append(.{ .ty = ptr_ty, .reloc = @intCast(u32, index) });
+ // DW.AT.data_member_location, DW.FORM.sdata
+ dbg_info_buffer.appendAssumeCapacity(0);
+ // DW.AT.member
+ dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
+ // DW.AT.name, DW.FORM.string
+ dbg_info_buffer.appendSliceAssumeCapacity("len");
+ dbg_info_buffer.appendAssumeCapacity(0);
+ // DW.AT.type, DW.FORM.ref4
+ index = dbg_info_buffer.items.len;
+ try dbg_info_buffer.resize(index + 4);
+ try relocs.append(.{ .ty = Type.initTag(.usize), .reloc = @intCast(u32, index) });
+ // DW.AT.data_member_location, DW.FORM.sdata
+ dbg_info_buffer.appendAssumeCapacity(8);
+ // DW.AT.structure_type delimit children
+ dbg_info_buffer.appendAssumeCapacity(0);
+ } else {
+ try dbg_info_buffer.ensureUnusedCapacity(5);
+ dbg_info_buffer.appendAssumeCapacity(abbrev_ptr_type);
+ // DW.AT.type, DW.FORM.ref4
+ const index = dbg_info_buffer.items.len;
+ try dbg_info_buffer.resize(index + 4);
+ try relocs.append(.{ .ty = ty.childType(), .reloc = @intCast(u32, index) });
}
- try dbg_info_buffer.ensureUnusedCapacity(5);
- dbg_info_buffer.appendAssumeCapacity(abbrev_ptr_type);
- const index = dbg_info_buffer.items.len;
- try dbg_info_buffer.resize(index + 4); // DW.AT.type, DW.FORM.ref4
- reloc = .{ .ty = ty.childType(), .reloc = @intCast(u32, index) };
},
else => {
log.debug("TODO implement .debug_info for type '{}'", .{ty});
@@ -2785,7 +2847,7 @@ fn addDbgInfoType(
},
}
- if (reloc) |rel| {
+ for (relocs.items) |rel| {
const gop = try dbg_info_type_relocs.getOrPut(self.base.allocator, rel.ty);
if (!gop.found_existing) {
gop.value_ptr.* = .{