Merge pull request #11062 from ziglang/dwarf-more-types

5 files changed, 158 insertions, 68 deletions

diff --git a/src/arch/x86_64/Emit.zig b/src/arch/x86_64/Emit.zig
index f4d365dc4f..86cdf8dcdb 100644
--- a/src/arch/x86_64/Emit.zig
+++ b/src/arch/x86_64/Emit.zig
@@ -1019,7 +1019,14 @@ fn genArgDbgInfo(emit: *Emit, inst: Air.Inst.Index, mcv: MCValue, max_stack: u32
             switch (emit.debug_output) {
                 .dwarf => |dbg_out| {
                     try dbg_out.dbg_info.ensureUnusedCapacity(3);
-                    dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
+
+                    // TODO this will go away once we pull DWARF into a cross-platform module.
+                    if (emit.bin_file.cast(link.File.MachO)) |_| {
+                        dbg_out.dbg_info.appendAssumeCapacity(link.File.MachO.DebugSymbols.abbrev_parameter);
+                    } else if (emit.bin_file.cast(link.File.Elf)) |_| {
+                        dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
+                    } else return emit.fail("TODO DWARF in non-MachO and non-ELF backend", .{});
+
                     dbg_out.dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
                         1, // ULEB128 dwarf expression length
                         reg.dwarfLocOp(),
@@ -1042,7 +1049,14 @@ fn genArgDbgInfo(emit: *Emit, inst: Air.Inst.Index, mcv: MCValue, max_stack: u32
                     // for example when -fomit-frame-pointer is set.
                     const disp = @intCast(i32, max_stack) - off + 16;
                     try dbg_out.dbg_info.ensureUnusedCapacity(8);
-                    dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
+
+                    // TODO this will go away once we pull DWARF into a cross-platform module.
+                    if (emit.bin_file.cast(link.File.MachO)) |_| {
+                        dbg_out.dbg_info.appendAssumeCapacity(link.File.MachO.DebugSymbols.abbrev_parameter);
+                    } else if (emit.bin_file.cast(link.File.Elf)) |_| {
+                        dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
+                    } else return emit.fail("TODO DWARF in non-MachO and non-ELF backend", .{});
+
                     const fixup = dbg_out.dbg_info.items.len;
                     dbg_out.dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
                         1, // we will backpatch it after we encode the displacement in LEB128
diff --git a/src/codegen.zig b/src/codegen.zig
index 265c205f2f..299a808447 100644
--- a/src/codegen.zig
+++ b/src/codegen.zig
@@ -639,7 +639,6 @@ pub fn generateSymbol(
             return Result{ .appended = {} };
         },
         .Optional => {
-            // TODO generate debug info for optionals
             var opt_buf: Type.Payload.ElemType = undefined;
             const payload_type = typed_value.ty.optionalChild(&opt_buf);
             const is_pl = !typed_value.val.isNull();
diff --git a/src/link/Elf.zig b/src/link/Elf.zig
index 1424a521b9..810bef2f9b 100644
--- a/src/link/Elf.zig
+++ b/src/link/Elf.zig
@@ -983,10 +983,9 @@ pub const abbrev_subprogram_retvoid = 3;
 pub const abbrev_base_type = 4;
 pub const abbrev_ptr_type = 5;
 pub const abbrev_struct_type = 6;
-pub const abbrev_anon_struct_type = 7;
-pub const abbrev_struct_member = 8;
-pub const abbrev_pad1 = 9;
-pub const abbrev_parameter = 10;
+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) {
@@ -1127,13 +1126,6 @@ pub fn flushModule(self: *Elf, comp: *Compilation) !void {
             DW.FORM.string,
             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
@@ -3186,6 +3178,7 @@ fn addDbgInfoType(
     dbg_info_buffer: *std.ArrayList(u8),
     dbg_info_type_relocs: *File.DbgInfoTypeRelocsTable,
 ) error{OutOfMemory}!void {
+    const target = self.base.options.target;
     var relocs = std.ArrayList(struct { ty: Type, reloc: u32 }).init(arena);
 
     switch (ty.zigTypeTag()) {
@@ -3202,7 +3195,7 @@ fn addDbgInfoType(
             });
         },
         .Int => {
-            const info = ty.intInfo(self.base.options.target);
+            const info = ty.intInfo(target);
             try dbg_info_buffer.ensureUnusedCapacity(12);
             dbg_info_buffer.appendAssumeCapacity(abbrev_base_type);
             // DW.AT.encoding, DW.FORM.data1
@@ -3211,7 +3204,7 @@ fn addDbgInfoType(
                 .unsigned => DW.ATE.unsigned,
             });
             // DW.AT.byte_size,  DW.FORM.data1
-            dbg_info_buffer.appendAssumeCapacity(@intCast(u8, ty.abiSize(self.base.options.target)));
+            dbg_info_buffer.appendAssumeCapacity(@intCast(u8, ty.abiSize(target)));
             // DW.AT.name,  DW.FORM.string
             try dbg_info_buffer.writer().print("{}\x00", .{ty});
         },
@@ -3222,23 +3215,61 @@ fn addDbgInfoType(
                 // DW.AT.encoding, DW.FORM.data1
                 dbg_info_buffer.appendAssumeCapacity(DW.ATE.address);
                 // DW.AT.byte_size,  DW.FORM.data1
-                dbg_info_buffer.appendAssumeCapacity(@intCast(u8, ty.abiSize(self.base.options.target)));
+                dbg_info_buffer.appendAssumeCapacity(@intCast(u8, ty.abiSize(target)));
                 // DW.AT.name,  DW.FORM.string
                 try dbg_info_buffer.writer().print("{}\x00", .{ty});
             } else {
-                log.debug("TODO implement .debug_info for type '{}'", .{ty});
-                try dbg_info_buffer.append(abbrev_pad1);
+                // Non-pointer optionals are structs: struct { .maybe = *, .val = * }
+                var buf = try arena.create(Type.Payload.ElemType);
+                const payload_ty = ty.optionalChild(buf);
+                // DW.AT.structure_type
+                try dbg_info_buffer.append(abbrev_struct_type);
+                // DW.AT.byte_size, DW.FORM.sdata
+                const abi_size = ty.abiSize(target);
+                try leb128.writeULEB128(dbg_info_buffer.writer(), abi_size);
+                // DW.AT.name, DW.FORM.string
+                try dbg_info_buffer.writer().print("{}\x00", .{ty});
+                // DW.AT.member
+                try dbg_info_buffer.ensureUnusedCapacity(7);
+                dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
+                // DW.AT.name, DW.FORM.string
+                dbg_info_buffer.appendSliceAssumeCapacity("maybe");
+                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);
+                try relocs.append(.{ .ty = Type.bool, .reloc = @intCast(u32, index) });
+                // DW.AT.data_member_location, DW.FORM.sdata
+                try dbg_info_buffer.ensureUnusedCapacity(6);
+                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("val");
+                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 = payload_ty, .reloc = @intCast(u32, index) });
+                // DW.AT.data_member_location, DW.FORM.sdata
+                const offset = abi_size - payload_ty.abiSize(target);
+                try leb128.writeULEB128(dbg_info_buffer.writer(), offset);
+                // DW.AT.structure_type delimit children
+                try dbg_info_buffer.append(0);
             }
         },
         .Pointer => {
             if (ty.isSlice()) {
-                // Slices are anonymous structs: struct { .ptr = *, .len = N }
-                try dbg_info_buffer.ensureUnusedCapacity(23);
+                // Slices are structs: struct { .ptr = *, .len = N }
                 // DW.AT.structure_type
-                dbg_info_buffer.appendAssumeCapacity(abbrev_anon_struct_type);
+                try dbg_info_buffer.ensureUnusedCapacity(2);
+                dbg_info_buffer.appendAssumeCapacity(abbrev_struct_type);
                 // DW.AT.byte_size, DW.FORM.sdata
-                dbg_info_buffer.appendAssumeCapacity(16);
+                dbg_info_buffer.appendAssumeCapacity(@sizeOf(usize) * 2);
+                // DW.AT.name, DW.FORM.string
+                try dbg_info_buffer.writer().print("{}\x00", .{ty});
                 // DW.AT.member
+                try dbg_info_buffer.ensureUnusedCapacity(5);
                 dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
                 // DW.AT.name, DW.FORM.string
                 dbg_info_buffer.appendSliceAssumeCapacity("ptr");
@@ -3250,6 +3281,7 @@ fn addDbgInfoType(
                 const ptr_ty = ty.slicePtrFieldType(buf);
                 try relocs.append(.{ .ty = ptr_ty, .reloc = @intCast(u32, index) });
                 // DW.AT.data_member_location, DW.FORM.sdata
+                try dbg_info_buffer.ensureUnusedCapacity(6);
                 dbg_info_buffer.appendAssumeCapacity(0);
                 // DW.AT.member
                 dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
@@ -3261,7 +3293,8 @@ fn addDbgInfoType(
                 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);
+                try dbg_info_buffer.ensureUnusedCapacity(2);
+                dbg_info_buffer.appendAssumeCapacity(@sizeOf(usize));
                 // DW.AT.structure_type delimit children
                 dbg_info_buffer.appendAssumeCapacity(0);
             } else {
@@ -3278,7 +3311,7 @@ fn addDbgInfoType(
             // DW.AT.structure_type
             try dbg_info_buffer.append(abbrev_struct_type);
             // DW.AT.byte_size, DW.FORM.sdata
-            const abi_size = ty.abiSize(self.base.options.target);
+            const abi_size = ty.abiSize(target);
             try leb128.writeULEB128(dbg_info_buffer.writer(), abi_size);
             // DW.AT.name, DW.FORM.string
             const struct_name = try ty.nameAlloc(arena);
@@ -3306,7 +3339,7 @@ fn addDbgInfoType(
                 try dbg_info_buffer.resize(index + 4);
                 try relocs.append(.{ .ty = field.ty, .reloc = @intCast(u32, index) });
                 // DW.AT.data_member_location, DW.FORM.sdata
-                const field_off = ty.structFieldOffset(field_index, self.base.options.target);
+                const field_off = ty.structFieldOffset(field_index, target);
                 try leb128.writeULEB128(dbg_info_buffer.writer(), field_off);
             }
 
diff --git a/src/link/MachO.zig b/src/link/MachO.zig
index 2f55c69b3a..6bf7d183df 100644
--- a/src/link/MachO.zig
+++ b/src/link/MachO.zig
@@ -27,7 +27,6 @@ const Atom = @import("MachO/Atom.zig");
 const Cache = @import("../Cache.zig");
 const CodeSignature = @import("MachO/CodeSignature.zig");
 const Compilation = @import("../Compilation.zig");
-const DebugSymbols = @import("MachO/DebugSymbols.zig");
 const Dylib = @import("MachO/Dylib.zig");
 const File = link.File;
 const Object = @import("MachO/Object.zig");
@@ -43,6 +42,7 @@ const TypedValue = @import("../TypedValue.zig");
 const Value = @import("../value.zig").Value;
 
 pub const TextBlock = Atom;
+pub const DebugSymbols = @import("MachO/DebugSymbols.zig");
 
 pub const base_tag: File.Tag = File.Tag.macho;
 
@@ -2178,6 +2178,34 @@ fn writeAllAtoms(self: *MachO) !void {
     }
 }
 
+fn writePadding(self: *MachO, match: MatchingSection, size: usize, writer: anytype) !void {
+    const is_code = match.seg == self.text_segment_cmd_index.? and match.sect == self.text_section_index.?;
+    const min_alignment: u3 = if (!is_code)
+        1
+    else switch (self.base.options.target.cpu.arch) {
+        .aarch64 => @sizeOf(u32),
+        .x86_64 => @as(u3, 1),
+        else => unreachable,
+    };
+
+    const len = @divExact(size, min_alignment);
+    var i: usize = 0;
+    while (i < len) : (i += 1) {
+        if (!is_code) {
+            try writer.writeByte(0);
+        } else switch (self.base.options.target.cpu.arch) {
+            .aarch64 => {
+                const inst = aarch64.Instruction.nop();
+                try writer.writeIntLittle(u32, inst.toU32());
+            },
+            .x86_64 => {
+                try writer.writeByte(0x90);
+            },
+            else => unreachable,
+        }
+    }
+}
+
 fn writeAtoms(self: *MachO) !void {
     var buffer = std.ArrayList(u8).init(self.base.allocator);
     defer buffer.deinit();
@@ -2213,11 +2241,7 @@ fn writeAtoms(self: *MachO) !void {
                 try atom.resolveRelocs(self);
                 try buffer.appendSlice(atom.code.items);
                 try buffer.ensureUnusedCapacity(padding_size);
-
-                var i: usize = 0;
-                while (i < padding_size) : (i += 1) {
-                    buffer.appendAssumeCapacity(0);
-                }
+                try self.writePadding(match, padding_size, buffer.writer());
 
                 if (file_offset == null) {
                     file_offset = sect.offset + atom_sym.n_value - sect.addr;
diff --git a/src/link/MachO/DebugSymbols.zig b/src/link/MachO/DebugSymbols.zig
index b3eb5cd5a7..f9393476dc 100644
--- a/src/link/MachO/DebugSymbols.zig
+++ b/src/link/MachO/DebugSymbols.zig
@@ -78,16 +78,15 @@ debug_aranges_section_dirty: bool = false,
 debug_info_header_dirty: bool = false,
 debug_line_header_dirty: bool = false,
 
-const abbrev_compile_unit = 1;
-const abbrev_subprogram = 2;
-const abbrev_subprogram_retvoid = 3;
-const abbrev_base_type = 4;
-const abbrev_ptr_type = 5;
-const abbrev_struct_type = 6;
-const abbrev_anon_struct_type = 7;
-const abbrev_struct_member = 8;
-const abbrev_pad1 = 9;
-const abbrev_parameter = 10;
+pub const abbrev_compile_unit = 1;
+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_struct_type = 6;
+pub const abbrev_struct_member = 7;
+pub const abbrev_pad1 = 8;
+pub const abbrev_parameter = 9;
 
 /// The reloc offset for the virtual address of a function in its Line Number Program.
 /// Size is a virtual address integer.
@@ -353,13 +352,6 @@ pub fn flushModule(self: *DebugSymbols, allocator: Allocator, options: link.Opti
             DW.FORM.string,
             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
@@ -1134,18 +1126,6 @@ pub fn commitDeclDebugInfo(
                 mem.writeIntLittle(u32, ptr, @intCast(u32, text_block.size));
             }
 
-            {
-                // Advance line and PC.
-                // TODO encapsulate logic in a helper function.
-                try dbg_line_buffer.append(DW.LNS.advance_pc);
-                try leb.writeULEB128(dbg_line_buffer.writer(), text_block.size);
-
-                try dbg_line_buffer.append(DW.LNS.advance_line);
-                const func = decl.val.castTag(.function).?.data;
-                const line_off = @intCast(u28, func.rbrace_line - func.lbrace_line);
-                try leb.writeULEB128(dbg_line_buffer.writer(), line_off);
-            }
-
             try dbg_line_buffer.appendSlice(&[_]u8{ DW.LNS.extended_op, 1, DW.LNE.end_sequence });
 
             // Now we have the full contents and may allocate a region to store it.
@@ -1332,19 +1312,57 @@ fn addDbgInfoType(
                 // DW.AT.name,  DW.FORM.string
                 try dbg_info_buffer.writer().print("{}\x00", .{ty});
             } else {
-                log.debug("TODO implement .debug_info for type '{}'", .{ty});
-                try dbg_info_buffer.append(abbrev_pad1);
+                // Non-pointer optionals are structs: struct { .maybe = *, .val = * }
+                var buf = try arena.create(Type.Payload.ElemType);
+                const payload_ty = ty.optionalChild(buf);
+                // DW.AT.structure_type
+                try dbg_info_buffer.append(abbrev_struct_type);
+                // DW.AT.byte_size, DW.FORM.sdata
+                const abi_size = ty.abiSize(target);
+                try leb128.writeULEB128(dbg_info_buffer.writer(), abi_size);
+                // DW.AT.name, DW.FORM.string
+                try dbg_info_buffer.writer().print("{}\x00", .{ty});
+                // DW.AT.member
+                try dbg_info_buffer.ensureUnusedCapacity(7);
+                dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
+                // DW.AT.name, DW.FORM.string
+                dbg_info_buffer.appendSliceAssumeCapacity("maybe");
+                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);
+                try relocs.append(.{ .ty = Type.bool, .reloc = @intCast(u32, index) });
+                // DW.AT.data_member_location, DW.FORM.sdata
+                try dbg_info_buffer.ensureUnusedCapacity(6);
+                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("val");
+                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 = payload_ty, .reloc = @intCast(u32, index) });
+                // DW.AT.data_member_location, DW.FORM.sdata
+                const offset = abi_size - payload_ty.abiSize(target);
+                try leb128.writeULEB128(dbg_info_buffer.writer(), offset);
+                // DW.AT.structure_type delimit children
+                try dbg_info_buffer.append(0);
             }
         },
         .Pointer => {
             if (ty.isSlice()) {
-                // Slices are anonymous structs: struct { .ptr = *, .len = N }
-                try dbg_info_buffer.ensureUnusedCapacity(23);
+                // Slices are structs: struct { .ptr = *, .len = N }
                 // DW.AT.structure_type
-                dbg_info_buffer.appendAssumeCapacity(abbrev_anon_struct_type);
+                try dbg_info_buffer.ensureUnusedCapacity(2);
+                dbg_info_buffer.appendAssumeCapacity(abbrev_struct_type);
                 // DW.AT.byte_size, DW.FORM.sdata
-                dbg_info_buffer.appendAssumeCapacity(16);
+                dbg_info_buffer.appendAssumeCapacity(@sizeOf(usize) * 2);
+                // DW.AT.name, DW.FORM.string
+                try dbg_info_buffer.writer().print("{}\x00", .{ty});
                 // DW.AT.member
+                try dbg_info_buffer.ensureUnusedCapacity(5);
                 dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
                 // DW.AT.name, DW.FORM.string
                 dbg_info_buffer.appendSliceAssumeCapacity("ptr");
@@ -1356,6 +1374,7 @@ fn addDbgInfoType(
                 const ptr_ty = ty.slicePtrFieldType(buf);
                 try relocs.append(.{ .ty = ptr_ty, .reloc = @intCast(u32, index) });
                 // DW.AT.data_member_location, DW.FORM.sdata
+                try dbg_info_buffer.ensureUnusedCapacity(6);
                 dbg_info_buffer.appendAssumeCapacity(0);
                 // DW.AT.member
                 dbg_info_buffer.appendAssumeCapacity(abbrev_struct_member);
@@ -1367,7 +1386,8 @@ fn addDbgInfoType(
                 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);
+                try dbg_info_buffer.ensureUnusedCapacity(2);
+                dbg_info_buffer.appendAssumeCapacity(@sizeOf(usize));
                 // DW.AT.structure_type delimit children
                 dbg_info_buffer.appendAssumeCapacity(0);
             } else {