diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Compilation.zig | 10 | ||||
| -rw-r--r-- | src/Module.zig | 60 | ||||
| -rw-r--r-- | src/Sema.zig | 154 | ||||
| -rw-r--r-- | src/codegen.zig | 7 | ||||
| -rw-r--r-- | src/codegen/c.zig | 24 | ||||
| -rw-r--r-- | src/codegen/llvm.zig | 51 | ||||
| -rw-r--r-- | src/codegen/wasm.zig | 1 | ||||
| -rw-r--r-- | src/link/Plan9.zig | 19 | ||||
| -rw-r--r-- | src/value.zig | 45 |
9 files changed, 233 insertions, 138 deletions
diff --git a/src/Compilation.zig b/src/Compilation.zig index 8672a346c3..f8f8cea328 100644 --- a/src/Compilation.zig +++ b/src/Compilation.zig @@ -2061,11 +2061,19 @@ pub fn performAllTheWork(self: *Compilation) error{ TimerUnsupported, OutOfMemor .complete, .codegen_failure_retryable => { if (build_options.omit_stage2) @panic("sadly stage2 is omitted from this build to save memory on the CI server"); + const module = self.bin_file.options.module.?; assert(decl.has_tv); assert(decl.ty.hasCodeGenBits()); - try module.linkerUpdateDecl(decl); + if (decl.alive) { + try module.linkerUpdateDecl(decl); + continue; + } + + // Instead of sending this decl to the linker, we actually will delete it + // because we found out that it in fact was never referenced. + module.deleteUnusedDecl(decl); }, }, .codegen_func => |func| switch (func.owner_decl.analysis) { diff --git a/src/Module.zig b/src/Module.zig index f89f72bc65..909e54ffa2 100644 --- a/src/Module.zig +++ b/src/Module.zig @@ -255,6 +255,15 @@ pub const Decl = struct { has_align: bool, /// Whether the ZIR code provides a linksection instruction. has_linksection: bool, + /// Flag used by garbage collection to mark and sweep. + /// Decls which correspond to an AST node always have this field set to `true`. + /// Anonymous Decls are initialized with this field set to `false` and then it + /// is the responsibility of machine code backends to mark it `true` whenever + /// a `decl_ref` Value is encountered that points to this Decl. + /// When the `codegen_decl` job is encountered in the main work queue, if the + /// Decl is marked alive, then it sends the Decl to the linker. Otherwise it + /// deletes the Decl on the spot. + alive: bool, /// Represents the position of the code in the output file. /// This is populated regardless of semantic analysis and code generation. @@ -2869,6 +2878,7 @@ pub fn semaFile(mod: *Module, file: *Scope.File) SemaError!void { new_decl.val = struct_val; new_decl.has_tv = true; new_decl.owns_tv = true; + new_decl.alive = true; // This Decl corresponds to a File and is therefore always alive. new_decl.analysis = .in_progress; new_decl.generation = mod.generation; @@ -2990,6 +3000,7 @@ fn semaDecl(mod: *Module, decl: *Decl) !bool { if (linksection_ref == .none) break :blk Value.initTag(.null_value); break :blk (try sema.resolveInstConst(&block_scope, src, linksection_ref)).val; }; + try sema.resolveTypeLayout(&block_scope, src, decl_tv.ty); // We need the memory for the Type to go into the arena for the Decl var decl_arena = std.heap.ArenaAllocator.init(gpa); @@ -3027,8 +3038,8 @@ fn semaDecl(mod: *Module, decl: *Decl) !bool { const is_inline = decl_tv.ty.fnCallingConvention() == .Inline; if (!is_inline and decl_tv.ty.hasCodeGenBits()) { // We don't fully codegen the decl until later, but we do need to reserve a global - // offset table index for it. This allows us to codegen decls out of dependency order, - // increasing how many computations can be done in parallel. + // offset table index for it. This allows us to codegen decls out of dependency + // order, increasing how many computations can be done in parallel. try mod.comp.bin_file.allocateDeclIndexes(decl); try mod.comp.work_queue.writeItem(.{ .codegen_func = func }); if (type_changed and mod.emit_h != null) { @@ -3387,6 +3398,7 @@ fn scanDecl(iter: *ScanDeclIter, decl_sub_index: usize, flags: u4) SemaError!voi new_decl.has_align = has_align; new_decl.has_linksection = has_linksection; new_decl.zir_decl_index = @intCast(u32, decl_sub_index); + new_decl.alive = true; // This Decl corresponds to an AST node and therefore always alive. return; } gpa.free(decl_name); @@ -3526,6 +3538,43 @@ pub fn clearDecl( decl.analysis = .unreferenced; } +pub fn deleteUnusedDecl(mod: *Module, decl: *Decl) void { + log.debug("deleteUnusedDecl {*} ({s})", .{ decl, decl.name }); + + // TODO: remove `allocateDeclIndexes` and make the API that the linker backends + // are required to notice the first time `updateDecl` happens and keep track + // of it themselves. However they can rely on getting a `freeDecl` call if any + // `updateDecl` or `updateFunc` calls happen. This will allow us to avoid any call + // into the linker backend here, since the linker backend will never have been told + // about the Decl in the first place. + // Until then, we did call `allocateDeclIndexes` on this anonymous Decl and so we + // must call `freeDecl` in the linker backend now. + if (decl.has_tv) { + if (decl.ty.hasCodeGenBits()) { + mod.comp.bin_file.freeDecl(decl); + } + } + + const dependants = decl.dependants.keys(); + assert(dependants[0].namespace.anon_decls.swapRemove(decl)); + + for (dependants) |dep| { + dep.removeDependency(decl); + } + + for (decl.dependencies.keys()) |dep| { + dep.removeDependant(decl); + } + decl.destroy(mod); +} + +pub fn deleteAnonDecl(mod: *Module, scope: *Scope, decl: *Decl) void { + log.debug("deleteAnonDecl {*} ({s})", .{ decl, decl.name }); + const scope_decl = scope.ownerDecl().?; + assert(scope_decl.namespace.anon_decls.swapRemove(decl)); + decl.destroy(mod); +} + /// Delete all the Export objects that are caused by this Decl. Re-analysis of /// this Decl will cause them to be re-created (or not). fn deleteDeclExports(mod: *Module, decl: *Decl) void { @@ -3713,6 +3762,7 @@ fn allocateNewDecl(mod: *Module, namespace: *Scope.Namespace, src_node: ast.Node .is_exported = false, .has_linksection = false, .has_align = false, + .alive = false, }; return new_decl; } @@ -3802,12 +3852,6 @@ pub fn analyzeExport( errdefer de_gop.value_ptr.* = mod.gpa.shrink(de_gop.value_ptr.*, de_gop.value_ptr.len - 1); } -pub fn deleteAnonDecl(mod: *Module, scope: *Scope, decl: *Decl) void { - const scope_decl = scope.ownerDecl().?; - assert(scope_decl.namespace.anon_decls.swapRemove(decl)); - decl.destroy(mod); -} - /// Takes ownership of `name` even if it returns an error. pub fn createAnonymousDeclNamed( mod: *Module, diff --git a/src/Sema.zig b/src/Sema.zig index 95baae7e92..0da38d9a76 100644 --- a/src/Sema.zig +++ b/src/Sema.zig @@ -696,7 +696,7 @@ fn resolveMaybeUndefVal( ) CompileError!?Value { const val = (try sema.resolveMaybeUndefValAllowVariables(block, src, inst)) orelse return null; if (val.tag() == .variable) { - return sema.failWithNeededComptime(block, src); + return null; } return val; } @@ -2917,12 +2917,13 @@ fn zirOptionalPayloadPtr( const child_pointer = try Module.simplePtrType(sema.arena, child_type, !optional_ptr_ty.isConstPtr(), .One); if (try sema.resolveDefinedValue(block, src, optional_ptr)) |pointer_val| { - const val = try pointer_val.pointerDeref(sema.arena); - if (val.isNull()) { - return sema.mod.fail(&block.base, src, "unable to unwrap null", .{}); + if (try pointer_val.pointerDeref(sema.arena)) |val| { + if (val.isNull()) { + return sema.mod.fail(&block.base, src, "unable to unwrap null", .{}); + } + // The same Value represents the pointer to the optional and the payload. + return sema.addConstant(child_pointer, pointer_val); } - // The same Value represents the pointer to the optional and the payload. - return sema.addConstant(child_pointer, pointer_val); } try sema.requireRuntimeBlock(block, src); @@ -3027,14 +3028,15 @@ fn zirErrUnionPayloadPtr( const operand_pointer_ty = try Module.simplePtrType(sema.arena, payload_ty, !operand_ty.isConstPtr(), .One); if (try sema.resolveDefinedValue(block, src, operand)) |pointer_val| { - const val = try pointer_val.pointerDeref(sema.arena); - if (val.getError()) |name| { - return sema.mod.fail(&block.base, src, "caught unexpected error '{s}'", .{name}); + if (try pointer_val.pointerDeref(sema.arena)) |val| { + if (val.getError()) |name| { + return sema.mod.fail(&block.base, src, "caught unexpected error '{s}'", .{name}); + } + return sema.addConstant( + operand_pointer_ty, + try Value.Tag.eu_payload_ptr.create(sema.arena, pointer_val), + ); } - return sema.addConstant( - operand_pointer_ty, - try Value.Tag.eu_payload_ptr.create(sema.arena, pointer_val), - ); } try sema.requireRuntimeBlock(block, src); @@ -3086,10 +3088,11 @@ fn zirErrUnionCodePtr(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) Co const result_ty = operand_ty.elemType().errorUnionSet(); if (try sema.resolveDefinedValue(block, src, operand)) |pointer_val| { - const val = try pointer_val.pointerDeref(sema.arena); - assert(val.getError() != null); - const data = val.castTag(.error_union).?.data; - return sema.addConstant(result_ty, data); + if (try pointer_val.pointerDeref(sema.arena)) |val| { + assert(val.getError() != null); + const data = val.castTag(.error_union).?.data; + return sema.addConstant(result_ty, data); + } } try sema.requireRuntimeBlock(block, src); @@ -4920,10 +4923,13 @@ fn analyzeArithmetic( log.debug("{s}({}, {}) result: {}", .{ @tagName(zir_tag), lhs_val, rhs_val, value }); return sema.addConstant(scalar_type, value); + } else { + try sema.requireRuntimeBlock(block, rhs_src); } + } else { + try sema.requireRuntimeBlock(block, lhs_src); } - try sema.requireRuntimeBlock(block, src); const air_tag: Air.Inst.Tag = switch (zir_tag) { .add => .add, .addwrap => .addwrap, @@ -6811,16 +6817,10 @@ fn fieldPtr( if (mem.eql(u8, field_name, "len")) { var anon_decl = try block.startAnonDecl(); defer anon_decl.deinit(); - return sema.addConstant( - Type.initTag(.single_const_pointer_to_comptime_int), - try Value.Tag.decl_ref.create( - arena, - try anon_decl.finish( - Type.initTag(.comptime_int), - try Value.Tag.int_u64.create(anon_decl.arena(), object_ty.arrayLen()), - ), - ), - ); + return sema.analyzeDeclRef(try anon_decl.finish( + Type.initTag(.comptime_int), + try Value.Tag.int_u64.create(anon_decl.arena(), object_ty.arrayLen()), + )); } else { return mod.fail( &block.base, @@ -6867,16 +6867,10 @@ fn fieldPtr( if (mem.eql(u8, field_name, "len")) { var anon_decl = try block.startAnonDecl(); defer anon_decl.deinit(); - return sema.addConstant( - Type.initTag(.single_const_pointer_to_comptime_int), - try Value.Tag.decl_ref.create( - arena, - try anon_decl.finish( - Type.initTag(.comptime_int), - try Value.Tag.int_u64.create(anon_decl.arena(), ptr_child.arrayLen()), - ), - ), - ); + return sema.analyzeDeclRef(try anon_decl.finish( + Type.initTag(.comptime_int), + try Value.Tag.int_u64.create(anon_decl.arena(), ptr_child.arrayLen()), + )); } else { return mod.fail( &block.base, @@ -6915,16 +6909,10 @@ fn fieldPtr( var anon_decl = try block.startAnonDecl(); defer anon_decl.deinit(); - return sema.addConstant( - try Module.simplePtrType(arena, child_type, false, .One), - try Value.Tag.decl_ref.create( - arena, - try anon_decl.finish( - child_type, - try Value.Tag.@"error".create(anon_decl.arena(), .{ .name = name }), - ), - ), - ); + return sema.analyzeDeclRef(try anon_decl.finish( + child_type, + try Value.Tag.@"error".create(anon_decl.arena(), .{ .name = name }), + )); }, .Struct, .Opaque, .Union => { if (child_type.getNamespace()) |namespace| { @@ -6971,16 +6959,10 @@ fn fieldPtr( const field_index_u32 = @intCast(u32, field_index); var anon_decl = try block.startAnonDecl(); defer anon_decl.deinit(); - return sema.addConstant( - try Module.simplePtrType(arena, child_type, false, .One), - try Value.Tag.decl_ref.create( - arena, - try anon_decl.finish( - child_type, - try Value.Tag.enum_field_index.create(anon_decl.arena(), field_index_u32), - ), - ), - ); + return sema.analyzeDeclRef(try anon_decl.finish( + child_type, + try Value.Tag.enum_field_index.create(anon_decl.arena(), field_index_u32), + )); }, else => return mod.fail(&block.base, src, "type '{}' has no members", .{child_type}), } @@ -7671,21 +7653,18 @@ fn analyzeRef( operand: Air.Inst.Ref, ) CompileError!Air.Inst.Ref { const operand_ty = sema.typeOf(operand); - const ptr_type = try Module.simplePtrType(sema.arena, operand_ty, false, .One); if (try sema.resolveMaybeUndefVal(block, src, operand)) |val| { var anon_decl = try block.startAnonDecl(); defer anon_decl.deinit(); - return sema.addConstant( - ptr_type, - try Value.Tag.decl_ref.create( - sema.arena, - try anon_decl.finish(operand_ty, try val.copy(anon_decl.arena())), - ), - ); + return sema.analyzeDeclRef(try anon_decl.finish( + operand_ty, + try val.copy(anon_decl.arena()), + )); } try sema.requireRuntimeBlock(block, src); + const ptr_type = try Module.simplePtrType(sema.arena, operand_ty, false, .One); const alloc = try block.addTy(.alloc, ptr_type); try sema.storePtr(block, src, alloc, operand); return alloc; @@ -7703,11 +7682,10 @@ fn analyzeLoad( .Pointer => ptr_ty.elemType(), else => return sema.mod.fail(&block.base, ptr_src, "expected pointer, found '{}'", .{ptr_ty}), }; - if (try sema.resolveDefinedValue(block, ptr_src, ptr)) |ptr_val| blk: { - if (ptr_val.tag() == .int_u64) - break :blk; // do it at runtime - - return sema.addConstant(elem_ty, try ptr_val.pointerDeref(sema.arena)); + if (try sema.resolveDefinedValue(block, ptr_src, ptr)) |ptr_val| { + if (try ptr_val.pointerDeref(sema.arena)) |elem_val| { + return sema.addConstant(elem_ty, elem_val); + } } try sema.requireRuntimeBlock(block, src); @@ -8215,6 +8193,36 @@ fn resolvePeerTypes( return sema.typeOf(chosen); } +pub fn resolveTypeLayout( + sema: *Sema, + block: *Scope.Block, + src: LazySrcLoc, + ty: Type, +) CompileError!void { + switch (ty.zigTypeTag()) { + .Pointer => { + return sema.resolveTypeLayout(block, src, ty.elemType()); + }, + .Struct => { + const resolved_ty = try sema.resolveTypeFields(block, src, ty); + const struct_obj = resolved_ty.castTag(.@"struct").?.data; + switch (struct_obj.status) { + .none, .have_field_types => {}, + .field_types_wip, .layout_wip => { + return sema.mod.fail(&block.base, src, "struct {} depends on itself", .{ty}); + }, + .have_layout => return, + } + struct_obj.status = .layout_wip; + for (struct_obj.fields.values()) |field| { + try sema.resolveTypeLayout(block, src, field.ty); + } + struct_obj.status = .have_layout; + }, + else => {}, + } +} + fn resolveTypeFields(sema: *Sema, block: *Scope.Block, src: LazySrcLoc, ty: Type) CompileError!Type { switch (ty.tag()) { .@"struct" => { @@ -8222,9 +8230,7 @@ fn resolveTypeFields(sema: *Sema, block: *Scope.Block, src: LazySrcLoc, ty: Type switch (struct_obj.status) { .none => {}, .field_types_wip => { - return sema.mod.fail(&block.base, src, "struct {} depends on itself", .{ - ty, - }); + return sema.mod.fail(&block.base, src, "struct {} depends on itself", .{ty}); }, .have_field_types, .have_layout, .layout_wip => return ty, } diff --git a/src/codegen.zig b/src/codegen.zig index b7ba367d54..d16a87adca 100644 --- a/src/codegen.zig +++ b/src/codegen.zig @@ -184,6 +184,7 @@ pub fn generateSymbol( if (typed_value.val.castTag(.decl_ref)) |payload| { const decl = payload.data; if (decl.analysis != .complete) return error.AnalysisFail; + decl.alive = true; // TODO handle the dependency of this symbol on the decl's vaddr. // If the decl changes vaddr, then this symbol needs to get regenerated. const vaddr = bin_file.getDeclVAddr(decl); @@ -4680,13 +4681,13 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { }, else => { if (typed_value.val.castTag(.decl_ref)) |payload| { + const decl = payload.data; + decl.alive = true; if (self.bin_file.cast(link.File.Elf)) |elf_file| { - const decl = payload.data; const got = &elf_file.program_headers.items[elf_file.phdr_got_index.?]; const got_addr = got.p_vaddr + decl.link.elf.offset_table_index * ptr_bytes; return MCValue{ .memory = got_addr }; } else if (self.bin_file.cast(link.File.MachO)) |macho_file| { - const decl = payload.data; const got_addr = blk: { const seg = macho_file.load_commands.items[macho_file.data_const_segment_cmd_index.?].Segment; const got = seg.sections.items[macho_file.got_section_index.?]; @@ -4698,11 +4699,9 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { }; return MCValue{ .memory = got_addr }; } else if (self.bin_file.cast(link.File.Coff)) |coff_file| { - const decl = payload.data; const got_addr = coff_file.offset_table_virtual_address + decl.link.coff.offset_table_index * ptr_bytes; return MCValue{ .memory = got_addr }; } else if (self.bin_file.cast(link.File.Plan9)) |p9| { - const decl = payload.data; const got_addr = p9.bases.data + decl.link.plan9.got_index.? * ptr_bytes; return MCValue{ .memory = got_addr }; } else { diff --git a/src/codegen/c.zig b/src/codegen/c.zig index a8ec677753..826b73317c 100644 --- a/src/codegen/c.zig +++ b/src/codegen/c.zig @@ -262,6 +262,7 @@ pub const DeclGen = struct { .one => try writer.writeAll("1"), .decl_ref => { const decl = val.castTag(.decl_ref).?.data; + decl.alive = true; // Determine if we must pointer cast. assert(decl.has_tv); @@ -281,21 +282,7 @@ pub const DeclGen = struct { const decl = val.castTag(.extern_fn).?.data; try writer.print("{s}", .{decl.name}); }, - else => switch (t.ptrSize()) { - .Slice => unreachable, - .Many => unreachable, - .One => { - var arena = std.heap.ArenaAllocator.init(dg.module.gpa); - defer arena.deinit(); - - const elem_ty = t.elemType(); - const elem_val = try val.pointerDeref(&arena.allocator); - - try writer.writeAll("&"); - try dg.renderValue(writer, elem_ty, elem_val); - }, - .C => unreachable, - }, + else => unreachable, }, }, .Array => { @@ -421,6 +408,7 @@ pub const DeclGen = struct { .one => try writer.writeAll("1"), .decl_ref => { const decl = val.castTag(.decl_ref).?.data; + decl.alive = true; // Determine if we must pointer cast. assert(decl.has_tv); @@ -433,11 +421,13 @@ pub const DeclGen = struct { } }, .function => { - const func = val.castTag(.function).?.data; - try writer.print("{s}", .{func.owner_decl.name}); + const decl = val.castTag(.function).?.data.owner_decl; + decl.alive = true; + try writer.print("{s}", .{decl.name}); }, .extern_fn => { const decl = val.castTag(.extern_fn).?.data; + decl.alive = true; try writer.print("{s}", .{decl.name}); }, else => unreachable, diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig index 0e9a572bea..961ed7ee99 100644 --- a/src/codegen/llvm.zig +++ b/src/codegen/llvm.zig @@ -673,17 +673,21 @@ pub const DeclGen = struct { } fn genTypedValue(self: *DeclGen, tv: TypedValue) error{ OutOfMemory, CodegenFail }!*const llvm.Value { - const llvm_type = try self.llvmType(tv.ty); - - if (tv.val.isUndef()) + if (tv.val.isUndef()) { + const llvm_type = try self.llvmType(tv.ty); return llvm_type.getUndef(); + } switch (tv.ty.zigTypeTag()) { - .Bool => return if (tv.val.toBool()) llvm_type.constAllOnes() else llvm_type.constNull(), + .Bool => { + const llvm_type = try self.llvmType(tv.ty); + return if (tv.val.toBool()) llvm_type.constAllOnes() else llvm_type.constNull(); + }, .Int => { var bigint_space: Value.BigIntSpace = undefined; const bigint = tv.val.toBigInt(&bigint_space); + const llvm_type = try self.llvmType(tv.ty); if (bigint.eqZero()) return llvm_type.constNull(); if (bigint.limbs.len != 1) { @@ -698,12 +702,17 @@ pub const DeclGen = struct { .Pointer => switch (tv.val.tag()) { .decl_ref => { const decl = tv.val.castTag(.decl_ref).?.data; + decl.alive = true; const val = try self.resolveGlobalDecl(decl); + const llvm_type = try self.llvmType(tv.ty); return val.constBitCast(llvm_type); }, .variable => { - const variable = tv.val.castTag(.variable).?.data; - const val = try self.resolveGlobalDecl(variable.owner_decl); + const decl = tv.val.castTag(.variable).?.data.owner_decl; + decl.alive = true; + const val = try self.resolveGlobalDecl(decl); + const llvm_var_type = try self.llvmType(tv.ty); + const llvm_type = llvm_var_type.pointerType(0); return val.constBitCast(llvm_type); }, .slice => { @@ -783,6 +792,7 @@ pub const DeclGen = struct { .decl_ref => tv.val.castTag(.decl_ref).?.data, else => unreachable, }; + fn_decl.alive = true; return self.resolveLlvmFunction(fn_decl); }, .ErrorSet => { @@ -903,9 +913,7 @@ pub const FuncGen = struct { return self.dg.genTypedValue(.{ .ty = self.air.typeOf(inst), .val = val }); } const inst_index = Air.refToIndex(inst).?; - if (self.func_inst_table.get(inst_index)) |value| return value; - - return self.todo("implement global llvm values (or the value is not in the func_inst_table table)", .{}); + return self.func_inst_table.get(inst_index).?; } fn genBody(self: *FuncGen, body: []const Air.Inst.Index) error{ OutOfMemory, CodegenFail }!void { @@ -966,8 +974,8 @@ pub const FuncGen = struct { .struct_field_ptr => try self.airStructFieldPtr(inst), .struct_field_val => try self.airStructFieldVal(inst), - .slice_elem_val => try self.airSliceElemVal(inst, false), - .ptr_slice_elem_val => try self.airSliceElemVal(inst, true), + .slice_elem_val => try self.airSliceElemVal(inst), + .ptr_slice_elem_val => try self.airPtrSliceElemVal(inst), .optional_payload => try self.airOptionalPayload(inst, false), .optional_payload_ptr => try self.airOptionalPayload(inst, true), @@ -1170,11 +1178,20 @@ pub const FuncGen = struct { return self.builder.buildExtractValue(operand, index, ""); } - fn airSliceElemVal( - self: *FuncGen, - inst: Air.Inst.Index, - operand_is_ptr: bool, - ) !?*const llvm.Value { + fn airSliceElemVal(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value { + if (self.liveness.isUnused(inst)) + return null; + + const bin_op = self.air.instructions.items(.data)[inst].bin_op; + const lhs = try self.resolveInst(bin_op.lhs); + const rhs = try self.resolveInst(bin_op.rhs); + const base_ptr = self.builder.buildExtractValue(lhs, 0, ""); + const indices: [1]*const llvm.Value = .{rhs}; + const ptr = self.builder.buildInBoundsGEP(base_ptr, &indices, indices.len, ""); + return self.builder.buildLoad(ptr, ""); + } + + fn airPtrSliceElemVal(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value { if (self.liveness.isUnused(inst)) return null; @@ -1182,7 +1199,7 @@ pub const FuncGen = struct { const lhs = try self.resolveInst(bin_op.lhs); const rhs = try self.resolveInst(bin_op.rhs); - const base_ptr = if (!operand_is_ptr) lhs else ptr: { + const base_ptr = ptr: { const index_type = self.context.intType(32); const indices: [2]*const llvm.Value = .{ index_type.constNull(), diff --git a/src/codegen/wasm.zig b/src/codegen/wasm.zig index 37cc6bc59c..2f1632e0fc 100644 --- a/src/codegen/wasm.zig +++ b/src/codegen/wasm.zig @@ -1016,6 +1016,7 @@ pub const Context = struct { .Pointer => { if (val.castTag(.decl_ref)) |payload| { const decl = payload.data; + decl.alive = true; // offset into the offset table within the 'data' section const ptr_width = self.target.cpu.arch.ptrBitWidth() / 8; diff --git a/src/link/Plan9.zig b/src/link/Plan9.zig index 135b59f82b..3b2aae85bc 100644 --- a/src/link/Plan9.zig +++ b/src/link/Plan9.zig @@ -224,7 +224,9 @@ pub fn flushModule(self: *Plan9, comp: *Compilation) !void { const mod = self.base.options.module orelse return error.LinkingWithoutZigSourceUnimplemented; - assert(self.got_len == self.fn_decl_table.count() + self.data_decl_table.count()); + // TODO I changed this assert from == to >= but this code all needs to be audited; see + // the comment in `freeDecl`. + assert(self.got_len >= self.fn_decl_table.count() + self.data_decl_table.count()); const got_size = self.got_len * if (!self.sixtyfour_bit) @as(u32, 4) else 8; var got_table = try self.base.allocator.alloc(u8, got_size); defer self.base.allocator.free(got_table); @@ -358,11 +360,18 @@ fn addDeclExports( } pub fn freeDecl(self: *Plan9, decl: *Module.Decl) void { + // TODO this is not the correct check for being function body, + // it could just be a function pointer. + // TODO audit the lifetimes of decls table entries. It's possible to get + // allocateDeclIndexes and then freeDecl without any updateDecl in between. + // However that is planned to change, see the TODO comment in Module.zig + // in the deleteUnusedDecl function. const is_fn = (decl.ty.zigTypeTag() == .Fn); - if (is_fn) - assert(self.fn_decl_table.swapRemove(decl)) - else - assert(self.data_decl_table.swapRemove(decl)); + if (is_fn) { + _ = self.fn_decl_table.swapRemove(decl); + } else { + _ = self.data_decl_table.swapRemove(decl); + } } pub fn updateDeclExports( diff --git a/src/value.zig b/src/value.zig index d3317ef31d..32be34ee2c 100644 --- a/src/value.zig +++ b/src/value.zig @@ -103,6 +103,7 @@ pub const Value = extern union { /// Represents a comptime variables storage. comptime_alloc, /// Represents a pointer to a decl, not the value of the decl. + /// When machine codegen backend sees this, it must set the Decl's `alive` field to true. decl_ref, elem_ptr, field_ptr, @@ -1346,28 +1347,48 @@ pub const Value = extern union { /// Asserts the value is a pointer and dereferences it. /// Returns error.AnalysisFail if the pointer points to a Decl that failed semantic analysis. - pub fn pointerDeref(self: Value, allocator: *Allocator) error{ AnalysisFail, OutOfMemory }!Value { - return switch (self.tag()) { + pub fn pointerDeref( + self: Value, + allocator: *Allocator, + ) error{ AnalysisFail, OutOfMemory }!?Value { + const sub_val: Value = switch (self.tag()) { .comptime_alloc => self.castTag(.comptime_alloc).?.data.val, - .decl_ref => self.castTag(.decl_ref).?.data.value(), - .elem_ptr => { + .decl_ref => try self.castTag(.decl_ref).?.data.value(), + .elem_ptr => blk: { const elem_ptr = self.castTag(.elem_ptr).?.data; - const array_val = try elem_ptr.array_ptr.pointerDeref(allocator); - return array_val.elemValue(allocator, elem_ptr.index); + const array_val = (try elem_ptr.array_ptr.pointerDeref(allocator)) orelse return null; + break :blk try array_val.elemValue(allocator, elem_ptr.index); }, - .field_ptr => { + .field_ptr => blk: { const field_ptr = self.castTag(.field_ptr).?.data; - const container_val = try field_ptr.container_ptr.pointerDeref(allocator); - return container_val.fieldValue(allocator, field_ptr.field_index); + const container_val = (try field_ptr.container_ptr.pointerDeref(allocator)) orelse return null; + break :blk try container_val.fieldValue(allocator, field_ptr.field_index); }, - .eu_payload_ptr => { + .eu_payload_ptr => blk: { const err_union_ptr = self.castTag(.eu_payload_ptr).?.data; - const err_union_val = try err_union_ptr.pointerDeref(allocator); - return err_union_val.castTag(.error_union).?.data; + const err_union_val = (try err_union_ptr.pointerDeref(allocator)) orelse return null; + break :blk err_union_val.castTag(.error_union).?.data; }, + .zero, + .one, + .int_u64, + .int_i64, + .int_big_positive, + .int_big_negative, + .variable, + .extern_fn, + .function, + => return null, + else => unreachable, }; + if (sub_val.tag() == .variable) { + // This would be loading a runtime value at compile-time so we return + // the indicator that this pointer dereference requires being done at runtime. + return null; + } + return sub_val; } pub fn sliceLen(val: Value) u64 { |