commit 11f6916f9bd9fbaf81a4bd60fd375eff8db78374 (tree)
parent 66c0fe4f90e5767a608efc77dbcecf2a5c8a5173
Author: Andrew Kelley <andrew@ziglang.org>
Date: Mon, 1 Feb 2021 12:15:52 -0800
Merge pull request #7892 from Vexu/stage2-cbe
Stage2 cbe: more control flow
Diffstat:
8 files changed, 864 insertions(+), 101 deletions(-)
diff --git a/src/Module.zig b/src/Module.zig
@@ -2215,7 +2215,7 @@ pub fn addSwitchBr(
self: *Module,
block: *Scope.Block,
src: usize,
- target_ptr: *Inst,
+ target: *Inst,
cases: []Inst.SwitchBr.Case,
else_body: ir.Body,
) !*Inst {
@@ -2226,7 +2226,7 @@ pub fn addSwitchBr(
.ty = Type.initTag(.noreturn),
.src = src,
},
- .target_ptr = target_ptr,
+ .target = target,
.cases = cases,
.else_body = else_body,
};
diff --git a/src/astgen.zig b/src/astgen.zig
@@ -309,7 +309,7 @@ pub fn expr(mod: *Module, scope: *Scope, rl: ResultLoc, node: *ast.Node) InnerEr
.Catch => return catchExpr(mod, scope, rl, node.castTag(.Catch).?),
.Comptime => return comptimeKeyword(mod, scope, rl, node.castTag(.Comptime).?),
.OrElse => return orelseExpr(mod, scope, rl, node.castTag(.OrElse).?),
- .Switch => return mod.failNode(scope, node, "TODO implement astgen.expr for .Switch", .{}),
+ .Switch => return switchExpr(mod, scope, rl, node.castTag(.Switch).?),
.ContainerDecl => return containerDecl(mod, scope, rl, node.castTag(.ContainerDecl).?),
.Defer => return mod.failNode(scope, node, "TODO implement astgen.expr for .Defer", .{}),
@@ -2246,6 +2246,317 @@ fn forExpr(
);
}
+fn switchCaseUsesRef(node: *ast.Node.Switch) bool {
+ for (node.cases()) |uncasted_case| {
+ const case = uncasted_case.castTag(.SwitchCase).?;
+ const uncasted_payload = case.payload orelse continue;
+ const payload = uncasted_payload.castTag(.PointerPayload).?;
+ if (payload.ptr_token) |_| return true;
+ }
+ return false;
+}
+
+fn getRangeNode(node: *ast.Node) ?*ast.Node.SimpleInfixOp {
+ var cur = node;
+ while (true) {
+ switch (cur.tag) {
+ .Range => return @fieldParentPtr(ast.Node.SimpleInfixOp, "base", cur),
+ .GroupedExpression => cur = @fieldParentPtr(ast.Node.GroupedExpression, "base", cur).expr,
+ else => return null,
+ }
+ }
+}
+
+fn switchExpr(mod: *Module, scope: *Scope, rl: ResultLoc, switch_node: *ast.Node.Switch) InnerError!*zir.Inst {
+ const tree = scope.tree();
+ const switch_src = tree.token_locs[switch_node.switch_token].start;
+ const use_ref = switchCaseUsesRef(switch_node);
+
+ var block_scope: Scope.GenZIR = .{
+ .parent = scope,
+ .decl = scope.ownerDecl().?,
+ .arena = scope.arena(),
+ .force_comptime = scope.isComptime(),
+ .instructions = .{},
+ };
+ setBlockResultLoc(&block_scope, rl);
+ defer block_scope.instructions.deinit(mod.gpa);
+
+ var items = std.ArrayList(*zir.Inst).init(mod.gpa);
+ defer items.deinit();
+
+ // first we gather all the switch items and check else/'_' prongs
+ var else_src: ?usize = null;
+ var underscore_src: ?usize = null;
+ var first_range: ?*zir.Inst = null;
+ var simple_case_count: usize = 0;
+ for (switch_node.cases()) |uncasted_case| {
+ const case = uncasted_case.castTag(.SwitchCase).?;
+ const case_src = tree.token_locs[case.firstToken()].start;
+ assert(case.items_len != 0);
+
+ // Check for else/_ prong, those are handled last.
+ if (case.items_len == 1 and case.items()[0].tag == .SwitchElse) {
+ if (else_src) |src| {
+ const msg = msg: {
+ const msg = try mod.errMsg(
+ scope,
+ case_src,
+ "multiple else prongs in switch expression",
+ .{},
+ );
+ errdefer msg.destroy(mod.gpa);
+ try mod.errNote(scope, src, msg, "previous else prong is here", .{});
+ break :msg msg;
+ };
+ return mod.failWithOwnedErrorMsg(scope, msg);
+ }
+ else_src = case_src;
+ continue;
+ } else if (case.items_len == 1 and case.items()[0].tag == .Identifier and
+ mem.eql(u8, tree.tokenSlice(case.items()[0].firstToken()), "_"))
+ {
+ if (underscore_src) |src| {
+ const msg = msg: {
+ const msg = try mod.errMsg(
+ scope,
+ case_src,
+ "multiple '_' prongs in switch expression",
+ .{},
+ );
+ errdefer msg.destroy(mod.gpa);
+ try mod.errNote(scope, src, msg, "previous '_' prong is here", .{});
+ break :msg msg;
+ };
+ return mod.failWithOwnedErrorMsg(scope, msg);
+ }
+ underscore_src = case_src;
+ continue;
+ }
+
+ if (else_src) |some_else| {
+ if (underscore_src) |some_underscore| {
+ const msg = msg: {
+ const msg = try mod.errMsg(
+ scope,
+ switch_src,
+ "else and '_' prong in switch expression",
+ .{},
+ );
+ errdefer msg.destroy(mod.gpa);
+ try mod.errNote(scope, some_else, msg, "else prong is here", .{});
+ try mod.errNote(scope, some_underscore, msg, "'_' prong is here", .{});
+ break :msg msg;
+ };
+ return mod.failWithOwnedErrorMsg(scope, msg);
+ }
+ }
+
+ if (case.items_len == 1 and getRangeNode(case.items()[0]) == null) simple_case_count += 1;
+
+ // generate all the switch items as comptime expressions
+ for (case.items()) |item| {
+ if (getRangeNode(item)) |range| {
+ const start = try comptimeExpr(mod, &block_scope.base, .none, range.lhs);
+ const end = try comptimeExpr(mod, &block_scope.base, .none, range.rhs);
+ const range_src = tree.token_locs[range.op_token].start;
+ const range_inst = try addZIRBinOp(mod, &block_scope.base, range_src, .switch_range, start, end);
+ try items.append(range_inst);
+ } else {
+ const item_inst = try comptimeExpr(mod, &block_scope.base, .none, item);
+ try items.append(item_inst);
+ }
+ }
+ }
+
+ var special_prong: zir.Inst.SwitchBr.SpecialProng = .none;
+ if (else_src != null) special_prong = .@"else";
+ if (underscore_src != null) special_prong = .underscore;
+ var cases = try block_scope.arena.alloc(zir.Inst.SwitchBr.Case, simple_case_count);
+
+ const target_ptr = if (use_ref) try expr(mod, &block_scope.base, .ref, switch_node.expr) else null;
+ const target = if (target_ptr) |some|
+ try addZIRUnOp(mod, &block_scope.base, some.src, .deref, some)
+ else
+ try expr(mod, &block_scope.base, .none, switch_node.expr);
+ const switch_inst = try addZIRInst(mod, &block_scope.base, switch_src, zir.Inst.SwitchBr, .{
+ .target = target,
+ .cases = cases,
+ .items = try block_scope.arena.dupe(*zir.Inst, items.items),
+ .else_body = undefined, // populated below
+ }, .{
+ .range = first_range,
+ .special_prong = special_prong,
+ });
+
+ const block = try addZIRInstBlock(mod, scope, switch_src, .block, .{
+ .instructions = try block_scope.arena.dupe(*zir.Inst, block_scope.instructions.items),
+ });
+
+ var case_scope: Scope.GenZIR = .{
+ .parent = scope,
+ .decl = block_scope.decl,
+ .arena = block_scope.arena,
+ .force_comptime = block_scope.force_comptime,
+ .instructions = .{},
+ };
+ defer case_scope.instructions.deinit(mod.gpa);
+
+ var else_scope: Scope.GenZIR = .{
+ .parent = scope,
+ .decl = case_scope.decl,
+ .arena = case_scope.arena,
+ .force_comptime = case_scope.force_comptime,
+ .instructions = .{},
+ };
+ defer else_scope.instructions.deinit(mod.gpa);
+
+ // Now generate all but the special cases
+ var special_case: ?*ast.Node.SwitchCase = null;
+ var items_index: usize = 0;
+ var case_index: usize = 0;
+ for (switch_node.cases()) |uncasted_case| {
+ const case = uncasted_case.castTag(.SwitchCase).?;
+ const case_src = tree.token_locs[case.firstToken()].start;
+ // reset without freeing to reduce allocations.
+ case_scope.instructions.items.len = 0;
+
+ // Check for else/_ prong, those are handled last.
+ if (case.items_len == 1 and case.items()[0].tag == .SwitchElse) {
+ special_case = case;
+ continue;
+ } else if (case.items_len == 1 and case.items()[0].tag == .Identifier and
+ mem.eql(u8, tree.tokenSlice(case.items()[0].firstToken()), "_"))
+ {
+ special_case = case;
+ continue;
+ }
+
+ // If this is a simple one item prong then it is handled by the switchbr.
+ if (case.items_len == 1 and getRangeNode(case.items()[0]) == null) {
+ const item = items.items[items_index];
+ items_index += 1;
+ try switchCaseExpr(mod, &case_scope.base, block_scope.break_result_loc, block, case, target, target_ptr);
+
+ cases[case_index] = .{
+ .item = item,
+ .body = .{ .instructions = try scope.arena().dupe(*zir.Inst, case_scope.instructions.items) },
+ };
+ case_index += 1;
+ continue;
+ }
+
+ // TODO if the case has few items and no ranges it might be better
+ // to just handle them as switch prongs.
+
+ // Check if the target matches any of the items.
+ // 1, 2, 3..6 will result in
+ // target == 1 or target == 2 or (target >= 3 and target <= 6)
+ var any_ok: ?*zir.Inst = null;
+ for (case.items()) |item| {
+ if (getRangeNode(item)) |range| {
+ const range_src = tree.token_locs[range.op_token].start;
+ const range_inst = items.items[items_index].castTag(.switch_range).?;
+ items_index += 1;
+
+ // target >= start and target <= end
+ const range_start_ok = try addZIRBinOp(mod, &else_scope.base, range_src, .cmp_gte, target, range_inst.positionals.lhs);
+ const range_end_ok = try addZIRBinOp(mod, &else_scope.base, range_src, .cmp_lte, target, range_inst.positionals.rhs);
+ const range_ok = try addZIRBinOp(mod, &else_scope.base, range_src, .bool_and, range_start_ok, range_end_ok);
+
+ if (any_ok) |some| {
+ any_ok = try addZIRBinOp(mod, &else_scope.base, range_src, .bool_or, some, range_ok);
+ } else {
+ any_ok = range_ok;
+ }
+ continue;
+ }
+
+ const item_inst = items.items[items_index];
+ items_index += 1;
+ const cpm_ok = try addZIRBinOp(mod, &else_scope.base, item_inst.src, .cmp_eq, target, item_inst);
+
+ if (any_ok) |some| {
+ any_ok = try addZIRBinOp(mod, &else_scope.base, item_inst.src, .bool_or, some, cpm_ok);
+ } else {
+ any_ok = cpm_ok;
+ }
+ }
+
+ const condbr = try addZIRInstSpecial(mod, &case_scope.base, case_src, zir.Inst.CondBr, .{
+ .condition = any_ok.?,
+ .then_body = undefined, // populated below
+ .else_body = undefined, // populated below
+ }, .{});
+ const cond_block = try addZIRInstBlock(mod, &else_scope.base, case_src, .block, .{
+ .instructions = try scope.arena().dupe(*zir.Inst, case_scope.instructions.items),
+ });
+
+ // reset cond_scope for then_body
+ case_scope.instructions.items.len = 0;
+ try switchCaseExpr(mod, &case_scope.base, block_scope.break_result_loc, block, case, target, target_ptr);
+ condbr.positionals.then_body = .{
+ .instructions = try scope.arena().dupe(*zir.Inst, case_scope.instructions.items),
+ };
+
+ // reset cond_scope for else_body
+ case_scope.instructions.items.len = 0;
+ _ = try addZIRInst(mod, &case_scope.base, case_src, zir.Inst.BreakVoid, .{
+ .block = cond_block,
+ }, .{});
+ condbr.positionals.else_body = .{
+ .instructions = try scope.arena().dupe(*zir.Inst, case_scope.instructions.items),
+ };
+ }
+
+ // Finally generate else block or a break.
+ if (special_case) |case| {
+ try switchCaseExpr(mod, &else_scope.base, block_scope.break_result_loc, block, case, target, target_ptr);
+ } else {
+ // Not handling all possible cases is a compile error.
+ _ = try addZIRNoOp(mod, &else_scope.base, switch_src, .unreachable_unsafe);
+ }
+ switch_inst.castTag(.switchbr).?.positionals.else_body = .{
+ .instructions = try block_scope.arena.dupe(*zir.Inst, else_scope.instructions.items),
+ };
+
+ return &block.base;
+}
+
+fn switchCaseExpr(
+ mod: *Module,
+ scope: *Scope,
+ rl: ResultLoc,
+ block: *zir.Inst.Block,
+ case: *ast.Node.SwitchCase,
+ target: *zir.Inst,
+ target_ptr: ?*zir.Inst,
+) !void {
+ const tree = scope.tree();
+ const case_src = tree.token_locs[case.firstToken()].start;
+ const sub_scope = blk: {
+ const uncasted_payload = case.payload orelse break :blk scope;
+ const payload = uncasted_payload.castTag(.PointerPayload).?;
+ const is_ptr = payload.ptr_token != null;
+ const value_name = tree.tokenSlice(payload.value_symbol.firstToken());
+ if (mem.eql(u8, value_name, "_")) {
+ if (is_ptr) {
+ return mod.failTok(scope, payload.ptr_token.?, "pointer modifier invalid on discard", .{});
+ }
+ break :blk scope;
+ }
+ return mod.failNode(scope, payload.value_symbol, "TODO implement switch value payload", .{});
+ };
+
+ const case_body = try expr(mod, sub_scope, rl, case.expr);
+ if (!case_body.tag.isNoReturn()) {
+ _ = try addZIRInst(mod, sub_scope, case_src, zir.Inst.Break, .{
+ .block = block,
+ .operand = case_body,
+ }, .{});
+ }
+}
+
fn ret(mod: *Module, scope: *Scope, cfe: *ast.Node.ControlFlowExpression) InnerError!*zir.Inst {
const tree = scope.tree();
const src = tree.token_locs[cfe.ltoken].start;
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
@@ -1,12 +1,12 @@
const std = @import("std");
const mem = std.mem;
const log = std.log.scoped(.c);
-const Writer = std.ArrayList(u8).Writer;
const link = @import("../link.zig");
const Module = @import("../Module.zig");
const Compilation = @import("../Compilation.zig");
-const Inst = @import("../ir.zig").Inst;
+const ir = @import("../ir.zig");
+const Inst = ir.Inst;
const Value = @import("../value.zig").Value;
const Type = @import("../type.zig").Type;
const TypedValue = @import("../TypedValue.zig");
@@ -41,6 +41,8 @@ pub const Object = struct {
value_map: CValueMap,
next_arg_index: usize = 0,
next_local_index: usize = 0,
+ next_block_index: usize = 0,
+ indent_writer: std.io.AutoIndentingStream(std.ArrayList(u8).Writer),
fn resolveInst(o: *Object, inst: *Inst) !CValue {
if (inst.value()) |_| {
@@ -57,31 +59,28 @@ pub const Object = struct {
fn allocLocal(o: *Object, ty: Type, mutability: Mutability) !CValue {
const local_value = o.allocLocalValue();
- try o.renderTypeAndName(o.code.writer(), ty, local_value, mutability);
+ try o.renderTypeAndName(o.writer(), ty, local_value, mutability);
return local_value;
}
- fn indent(o: *Object) !void {
- const indent_size = 4;
- const indent_level = 1;
- const indent_amt = indent_size * indent_level;
- try o.code.writer().writeByteNTimes(' ', indent_amt);
+ fn writer(o: *Object) std.io.AutoIndentingStream(std.ArrayList(u8).Writer).Writer {
+ return o.indent_writer.writer();
}
- fn writeCValue(o: *Object, writer: Writer, c_value: CValue) !void {
+ fn writeCValue(o: *Object, w: anytype, c_value: CValue) !void {
switch (c_value) {
.none => unreachable,
- .local => |i| return writer.print("t{d}", .{i}),
- .local_ref => |i| return writer.print("&t{d}", .{i}),
- .constant => |inst| return o.dg.renderValue(writer, inst.ty, inst.value().?),
- .arg => |i| return writer.print("a{d}", .{i}),
- .decl => |decl| return writer.writeAll(mem.span(decl.name)),
+ .local => |i| return w.print("t{d}", .{i}),
+ .local_ref => |i| return w.print("&t{d}", .{i}),
+ .constant => |inst| return o.dg.renderValue(w, inst.ty, inst.value().?),
+ .arg => |i| return w.print("a{d}", .{i}),
+ .decl => |decl| return w.writeAll(mem.span(decl.name)),
}
}
fn renderTypeAndName(
o: *Object,
- writer: Writer,
+ w: anytype,
ty: Type,
name: CValue,
mutability: Mutability,
@@ -97,15 +96,15 @@ pub const Object = struct {
render_ty = render_ty.elemType();
}
- try o.dg.renderType(writer, render_ty);
+ try o.dg.renderType(w, render_ty);
const const_prefix = switch (mutability) {
.Const => "const ",
.Mut => "",
};
- try writer.print(" {s}", .{const_prefix});
- try o.writeCValue(writer, name);
- try writer.writeAll(suffix.items);
+ try w.print(" {s}", .{const_prefix});
+ try o.writeCValue(w, name);
+ try w.writeAll(suffix.items);
}
};
@@ -126,10 +125,13 @@ pub const DeclGen = struct {
fn renderValue(
dg: *DeclGen,
- writer: Writer,
+ writer: anytype,
t: Type,
val: Value,
) error{ OutOfMemory, AnalysisFail }!void {
+ if (val.isUndef()) {
+ return dg.fail(dg.decl.src(), "TODO: C backend: properly handle undefined in all cases (with debug safety?)", .{});
+ }
switch (t.zigTypeTag()) {
.Int => {
if (t.isSignedInt())
@@ -197,13 +199,14 @@ pub const DeclGen = struct {
},
}
},
+ .Bool => return writer.print("{}", .{val.toBool()}),
else => |e| return dg.fail(dg.decl.src(), "TODO: C backend: implement value {s}", .{
@tagName(e),
}),
}
}
- fn renderFunctionSignature(dg: *DeclGen, w: Writer, is_global: bool) !void {
+ fn renderFunctionSignature(dg: *DeclGen, w: anytype, is_global: bool) !void {
if (!is_global) {
try w.writeAll("static ");
}
@@ -227,7 +230,7 @@ pub const DeclGen = struct {
try w.writeByte(')');
}
- fn renderType(dg: *DeclGen, w: Writer, t: Type) error{ OutOfMemory, AnalysisFail }!void {
+ fn renderType(dg: *DeclGen, w: anytype, t: Type) error{ OutOfMemory, AnalysisFail }!void {
switch (t.zigTypeTag()) {
.NoReturn => {
try w.writeAll("zig_noreturn void");
@@ -257,8 +260,8 @@ pub const DeclGen = struct {
.int_signed, .int_unsigned => {
const info = t.intInfo(dg.module.getTarget());
const sign_prefix = switch (info.signedness) {
- .signed => "i",
- .unsigned => "",
+ .signed => "",
+ .unsigned => "u",
};
inline for (.{ 8, 16, 32, 64, 128 }) |nbits| {
if (info.bits <= nbits) {
@@ -290,6 +293,7 @@ pub const DeclGen = struct {
try dg.renderType(w, t.elemType());
try w.writeAll(" *");
},
+ .Null, .Undefined => unreachable, // must be const or comptime
else => |e| return dg.fail(dg.decl.src(), "TODO: C backend: implement type {s}", .{
@tagName(e),
}),
@@ -324,58 +328,20 @@ pub fn genDecl(o: *Object) !void {
try fwd_decl_writer.writeAll(";\n");
const func: *Module.Fn = func_payload.data;
- const instructions = func.body.instructions;
- const writer = o.code.writer();
- try writer.writeAll("\n");
- try o.dg.renderFunctionSignature(writer, is_global);
- if (instructions.len == 0) {
- try writer.writeAll(" {}\n");
- return;
- }
+ try o.indent_writer.insertNewline();
+ try o.dg.renderFunctionSignature(o.writer(), is_global);
- try writer.writeAll(" {");
-
- try writer.writeAll("\n");
- for (instructions) |inst| {
- const result_value = switch (inst.tag) {
- .add => try genBinOp(o, inst.castTag(.add).?, " + "),
- .alloc => try genAlloc(o, inst.castTag(.alloc).?),
- .arg => genArg(o),
- .assembly => try genAsm(o, inst.castTag(.assembly).?),
- .block => try genBlock(o, inst.castTag(.block).?),
- .bitcast => try genBitcast(o, inst.castTag(.bitcast).?),
- .breakpoint => try genBreakpoint(o, inst.castTag(.breakpoint).?),
- .call => try genCall(o, inst.castTag(.call).?),
- .cmp_eq => try genBinOp(o, inst.castTag(.cmp_eq).?, " == "),
- .cmp_gt => try genBinOp(o, inst.castTag(.cmp_gt).?, " > "),
- .cmp_gte => try genBinOp(o, inst.castTag(.cmp_gte).?, " >= "),
- .cmp_lt => try genBinOp(o, inst.castTag(.cmp_lt).?, " < "),
- .cmp_lte => try genBinOp(o, inst.castTag(.cmp_lte).?, " <= "),
- .cmp_neq => try genBinOp(o, inst.castTag(.cmp_neq).?, " != "),
- .dbg_stmt => try genDbgStmt(o, inst.castTag(.dbg_stmt).?),
- .intcast => try genIntCast(o, inst.castTag(.intcast).?),
- .load => try genLoad(o, inst.castTag(.load).?),
- .ret => try genRet(o, inst.castTag(.ret).?),
- .retvoid => try genRetVoid(o),
- .store => try genStore(o, inst.castTag(.store).?),
- .sub => try genBinOp(o, inst.castTag(.sub).?, " - "),
- .unreach => try genUnreach(o, inst.castTag(.unreach).?),
- else => |e| return o.dg.fail(o.dg.decl.src(), "TODO: C backend: implement codegen for {}", .{e}),
- };
- switch (result_value) {
- .none => {},
- else => try o.value_map.putNoClobber(inst, result_value),
- }
- }
+ try o.writer().writeByte(' ');
+ try genBody(o, func.body);
- try writer.writeAll("}\n");
+ try o.indent_writer.insertNewline();
} else if (tv.val.tag() == .extern_fn) {
- const writer = o.code.writer();
+ const writer = o.writer();
try writer.writeAll("ZIG_EXTERN_C ");
try o.dg.renderFunctionSignature(writer, true);
try writer.writeAll(";\n");
} else {
- const writer = o.code.writer();
+ const writer = o.writer();
try writer.writeAll("static ");
// TODO ask the Decl if it is const
@@ -410,11 +376,69 @@ pub fn genHeader(dg: *DeclGen) error{ AnalysisFail, OutOfMemory }!void {
}
}
+pub fn genBody(o: *Object, body: ir.Body) error{ AnalysisFail, OutOfMemory }!void {
+ const writer = o.writer();
+ if (body.instructions.len == 0) {
+ try writer.writeAll("{}");
+ return;
+ }
+
+ try writer.writeAll("{\n");
+ o.indent_writer.pushIndent();
+
+ for (body.instructions) |inst| {
+ const result_value = switch (inst.tag) {
+ .constant => unreachable, // excluded from function bodies
+ .add => try genBinOp(o, inst.castTag(.add).?, " + "),
+ .alloc => try genAlloc(o, inst.castTag(.alloc).?),
+ .arg => genArg(o),
+ .assembly => try genAsm(o, inst.castTag(.assembly).?),
+ .block => try genBlock(o, inst.castTag(.block).?),
+ .bitcast => try genBitcast(o, inst.castTag(.bitcast).?),
+ .breakpoint => try genBreakpoint(o, inst.castTag(.breakpoint).?),
+ .call => try genCall(o, inst.castTag(.call).?),
+ .cmp_eq => try genBinOp(o, inst.castTag(.cmp_eq).?, " == "),
+ .cmp_gt => try genBinOp(o, inst.castTag(.cmp_gt).?, " > "),
+ .cmp_gte => try genBinOp(o, inst.castTag(.cmp_gte).?, " >= "),
+ .cmp_lt => try genBinOp(o, inst.castTag(.cmp_lt).?, " < "),
+ .cmp_lte => try genBinOp(o, inst.castTag(.cmp_lte).?, " <= "),
+ .cmp_neq => try genBinOp(o, inst.castTag(.cmp_neq).?, " != "),
+ .dbg_stmt => try genDbgStmt(o, inst.castTag(.dbg_stmt).?),
+ .intcast => try genIntCast(o, inst.castTag(.intcast).?),
+ .load => try genLoad(o, inst.castTag(.load).?),
+ .ret => try genRet(o, inst.castTag(.ret).?),
+ .retvoid => try genRetVoid(o),
+ .store => try genStore(o, inst.castTag(.store).?),
+ .sub => try genBinOp(o, inst.castTag(.sub).?, " - "),
+ .unreach => try genUnreach(o, inst.castTag(.unreach).?),
+ .loop => try genLoop(o, inst.castTag(.loop).?),
+ .condbr => try genCondBr(o, inst.castTag(.condbr).?),
+ .br => try genBr(o, inst.castTag(.br).?),
+ .br_void => try genBrVoid(o, inst.castTag(.br_void).?.block),
+ .switchbr => try genSwitchBr(o, inst.castTag(.switchbr).?),
+ // bool_and and bool_or are non-short-circuit operations
+ .bool_and => try genBinOp(o, inst.castTag(.bool_and).?, " & "),
+ .bool_or => try genBinOp(o, inst.castTag(.bool_or).?, " | "),
+ .bit_and => try genBinOp(o, inst.castTag(.bit_and).?, " & "),
+ .bit_or => try genBinOp(o, inst.castTag(.bit_or).?, " | "),
+ .xor => try genBinOp(o, inst.castTag(.xor).?, " ^ "),
+ .not => try genUnOp(o, inst.castTag(.not).?, "!"),
+ else => |e| return o.dg.fail(o.dg.decl.src(), "TODO: C backend: implement codegen for {}", .{e}),
+ };
+ switch (result_value) {
+ .none => {},
+ else => try o.value_map.putNoClobber(inst, result_value),
+ }
+ }
+
+ o.indent_writer.popIndent();
+ try writer.writeAll("}");
+}
+
fn genAlloc(o: *Object, alloc: *Inst.NoOp) !CValue {
- const writer = o.code.writer();
+ const writer = o.writer();
// First line: the variable used as data storage.
- try o.indent();
const elem_type = alloc.base.ty.elemType();
const mutability: Mutability = if (alloc.base.ty.isConstPtr()) .Const else .Mut;
const local = try o.allocLocal(elem_type, mutability);
@@ -430,15 +454,13 @@ fn genArg(o: *Object) CValue {
}
fn genRetVoid(o: *Object) !CValue {
- try o.indent();
- try o.code.writer().print("return;\n", .{});
+ try o.writer().print("return;\n", .{});
return CValue.none;
}
fn genLoad(o: *Object, inst: *Inst.UnOp) !CValue {
const operand = try o.resolveInst(inst.operand);
- const writer = o.code.writer();
- try o.indent();
+ const writer = o.writer();
const local = try o.allocLocal(inst.base.ty, .Const);
switch (operand) {
.local_ref => |i| {
@@ -458,8 +480,7 @@ fn genLoad(o: *Object, inst: *Inst.UnOp) !CValue {
fn genRet(o: *Object, inst: *Inst.UnOp) !CValue {
const operand = try o.resolveInst(inst.operand);
- try o.indent();
- const writer = o.code.writer();
+ const writer = o.writer();
try writer.writeAll("return ");
try o.writeCValue(writer, operand);
try writer.writeAll(";\n");
@@ -472,8 +493,7 @@ fn genIntCast(o: *Object, inst: *Inst.UnOp) !CValue {
const from = try o.resolveInst(inst.operand);
- try o.indent();
- const writer = o.code.writer();
+ const writer = o.writer();
const local = try o.allocLocal(inst.base.ty, .Const);
try writer.writeAll(" = (");
try o.dg.renderType(writer, inst.base.ty);
@@ -488,8 +508,7 @@ fn genStore(o: *Object, inst: *Inst.BinOp) !CValue {
const dest_ptr = try o.resolveInst(inst.lhs);
const src_val = try o.resolveInst(inst.rhs);
- try o.indent();
- const writer = o.code.writer();
+ const writer = o.writer();
switch (dest_ptr) {
.local_ref => |i| {
const dest: CValue = .{ .local = i };
@@ -516,8 +535,7 @@ fn genBinOp(o: *Object, inst: *Inst.BinOp, operator: []const u8) !CValue {
const lhs = try o.resolveInst(inst.lhs);
const rhs = try o.resolveInst(inst.rhs);
- try o.indent();
- const writer = o.code.writer();
+ const writer = o.writer();
const local = try o.allocLocal(inst.base.ty, .Const);
try writer.writeAll(" = ");
@@ -529,6 +547,22 @@ fn genBinOp(o: *Object, inst: *Inst.BinOp, operator: []const u8) !CValue {
return local;
}
+fn genUnOp(o: *Object, inst: *Inst.UnOp, operator: []const u8) !CValue {
+ if (inst.base.isUnused())
+ return CValue.none;
+
+ const operand = try o.resolveInst(inst.operand);
+
+ const writer = o.writer();
+ const local = try o.allocLocal(inst.base.ty, .Const);
+
+ try writer.print(" = {s}", .{operator});
+ try o.writeCValue(writer, operand);
+ try writer.writeAll(";\n");
+
+ return local;
+}
+
fn genCall(o: *Object, inst: *Inst.Call) !CValue {
if (inst.func.castTag(.constant)) |func_inst| {
const fn_decl = if (func_inst.val.castTag(.extern_fn)) |extern_fn|
@@ -543,8 +577,7 @@ fn genCall(o: *Object, inst: *Inst.Call) !CValue {
const unused_result = inst.base.isUnused();
var result_local: CValue = .none;
- try o.indent();
- const writer = o.code.writer();
+ const writer = o.writer();
if (unused_result) {
if (ret_ty.hasCodeGenBits()) {
try writer.print("(void)", .{});
@@ -581,14 +614,53 @@ fn genDbgStmt(o: *Object, inst: *Inst.NoOp) !CValue {
}
fn genBlock(o: *Object, inst: *Inst.Block) !CValue {
- return o.dg.fail(o.dg.decl.src(), "TODO: C backend: implement blocks", .{});
+ const block_id: usize = o.next_block_index;
+ o.next_block_index += 1;
+ const writer = o.writer();
+
+ // store the block id in relocs.capacity as it is not used for anything else in the C backend.
+ inst.codegen.relocs.capacity = block_id;
+ const result = if (inst.base.ty.tag() != .void and !inst.base.isUnused()) blk: {
+ // allocate a location for the result
+ const local = try o.allocLocal(inst.base.ty, .Mut);
+ try writer.writeAll(";\n");
+ break :blk local;
+ } else
+ CValue{ .none = {} };
+
+ inst.codegen.mcv = @bitCast(@import("../codegen.zig").AnyMCValue, result);
+ try genBody(o, inst.body);
+ try o.indent_writer.insertNewline();
+ // label must be followed by an expression, add an empty one.
+ try writer.print("zig_block_{d}:;\n", .{block_id});
+ return result;
+}
+
+fn genBr(o: *Object, inst: *Inst.Br) !CValue {
+ const result = @bitCast(CValue, inst.block.codegen.mcv);
+ const writer = o.writer();
+
+ // If result is .none then the value of the block is unused.
+ if (inst.operand.ty.tag() != .void and result != .none) {
+ const operand = try o.resolveInst(inst.operand);
+ try o.writeCValue(writer, result);
+ try writer.writeAll(" = ");
+ try o.writeCValue(writer, operand);
+ try writer.writeAll(";\n");
+ }
+
+ return genBrVoid(o, inst.block);
+}
+
+fn genBrVoid(o: *Object, block: *Inst.Block) !CValue {
+ try o.writer().print("goto zig_block_{d};\n", .{block.codegen.relocs.capacity});
+ return CValue.none;
}
fn genBitcast(o: *Object, inst: *Inst.UnOp) !CValue {
const operand = try o.resolveInst(inst.operand);
- const writer = o.code.writer();
- try o.indent();
+ const writer = o.writer();
if (inst.base.ty.zigTypeTag() == .Pointer and inst.operand.ty.zigTypeTag() == .Pointer) {
const local = try o.allocLocal(inst.base.ty, .Const);
try writer.writeAll(" = (");
@@ -602,7 +674,6 @@ fn genBitcast(o: *Object, inst: *Inst.UnOp) !CValue {
const local = try o.allocLocal(inst.base.ty, .Mut);
try writer.writeAll(";\n");
- try o.indent();
try writer.writeAll("memcpy(&");
try o.writeCValue(writer, local);
@@ -616,14 +687,61 @@ fn genBitcast(o: *Object, inst: *Inst.UnOp) !CValue {
}
fn genBreakpoint(o: *Object, inst: *Inst.NoOp) !CValue {
- try o.indent();
- try o.code.writer().writeAll("zig_breakpoint();\n");
+ try o.writer().writeAll("zig_breakpoint();\n");
return CValue.none;
}
fn genUnreach(o: *Object, inst: *Inst.NoOp) !CValue {
- try o.indent();
- try o.code.writer().writeAll("zig_unreachable();\n");
+ try o.writer().writeAll("zig_unreachable();\n");
+ return CValue.none;
+}
+
+fn genLoop(o: *Object, inst: *Inst.Loop) !CValue {
+ try o.writer().writeAll("while (true) ");
+ try genBody(o, inst.body);
+ try o.indent_writer.insertNewline();
+ return CValue.none;
+}
+
+fn genCondBr(o: *Object, inst: *Inst.CondBr) !CValue {
+ const cond = try o.resolveInst(inst.condition);
+ const writer = o.writer();
+
+ try writer.writeAll("if (");
+ try o.writeCValue(writer, cond);
+ try writer.writeAll(") ");
+ try genBody(o, inst.then_body);
+ try writer.writeAll(" else ");
+ try genBody(o, inst.else_body);
+ try o.indent_writer.insertNewline();
+
+ return CValue.none;
+}
+
+fn genSwitchBr(o: *Object, inst: *Inst.SwitchBr) !CValue {
+ const target = try o.resolveInst(inst.target);
+ const writer = o.writer();
+
+ try writer.writeAll("switch (");
+ try o.writeCValue(writer, target);
+ try writer.writeAll(") {\n");
+ o.indent_writer.pushIndent();
+
+ for (inst.cases) |case| {
+ try writer.writeAll("case ");
+ try o.dg.renderValue(writer, inst.target.ty, case.item);
+ try writer.writeAll(": ");
+ // the case body must be noreturn so we don't need to insert a break
+ try genBody(o, case.body);
+ try o.indent_writer.insertNewline();
+ }
+
+ try writer.writeAll("default: ");
+ try genBody(o, inst.else_body);
+ try o.indent_writer.insertNewline();
+
+ o.indent_writer.popIndent();
+ try writer.writeAll("}\n");
return CValue.none;
}
@@ -631,13 +749,12 @@ fn genAsm(o: *Object, as: *Inst.Assembly) !CValue {
if (as.base.isUnused() and !as.is_volatile)
return CValue.none;
- const writer = o.code.writer();
+ const writer = o.writer();
for (as.inputs) |i, index| {
if (i[0] == '{' and i[i.len - 1] == '}') {
const reg = i[1 .. i.len - 1];
const arg = as.args[index];
const arg_c_value = try o.resolveInst(arg);
- try o.indent();
try writer.writeAll("register ");
try o.dg.renderType(writer, arg.ty);
@@ -648,7 +765,6 @@ fn genAsm(o: *Object, as: *Inst.Assembly) !CValue {
return o.dg.fail(o.dg.decl.src(), "TODO non-explicit inline asm regs", .{});
}
}
- try o.indent();
const volatile_string: []const u8 = if (as.is_volatile) "volatile " else "";
try writer.print("__asm {s}(\"{s}\"", .{ volatile_string, as.asm_source });
if (as.output) |_| {
diff --git a/src/ir.zig b/src/ir.zig
@@ -521,7 +521,7 @@ pub const Inst = struct {
pub const base_tag = Tag.switchbr;
base: Inst,
- target_ptr: *Inst,
+ target: *Inst,
cases: []Case,
/// Set of instructions whose lifetimes end at the start of one of the cases.
/// In same order as cases, deaths[0..case_0_count, case_0_count .. case_1_count, ... ].
@@ -544,7 +544,7 @@ pub const Inst = struct {
var i = index;
if (i < 1)
- return self.target_ptr;
+ return self.target;
i -= 1;
return null;
diff --git a/src/link/C.zig b/src/link/C.zig
@@ -95,7 +95,9 @@ pub fn updateDecl(self: *C, module: *Module, decl: *Module.Decl) !void {
.gpa = module.gpa,
.code = code.toManaged(module.gpa),
.value_map = codegen.CValueMap.init(module.gpa),
+ .indent_writer = undefined, // set later so we can get a pointer to object.code
};
+ object.indent_writer = std.io.autoIndentingStream(4, object.code.writer());
defer object.value_map.deinit();
defer object.code.deinit();
defer object.dg.fwd_decl.deinit();
diff --git a/src/zir.zig b/src/zir.zig
@@ -338,6 +338,12 @@ pub const Inst = struct {
enum_type,
/// Does nothing; returns a void value.
void_value,
+ /// A switch expression.
+ switchbr,
+ /// A range in a switch case, `lhs...rhs`.
+ /// Only checks that `lhs >= rhs` if they are ints, everything else is
+ /// validated by the .switch instruction.
+ switch_range,
pub fn Type(tag: Tag) type {
return switch (tag) {
@@ -435,6 +441,7 @@ pub const Inst = struct {
.error_union_type,
.merge_error_sets,
.slice_start,
+ .switch_range,
=> BinOp,
.block,
@@ -478,6 +485,7 @@ pub const Inst = struct {
.enum_type => EnumType,
.union_type => UnionType,
.struct_type => StructType,
+ .switchbr => SwitchBr,
};
}
@@ -605,6 +613,8 @@ pub const Inst = struct {
.union_type,
.struct_type,
.void_value,
+ .switch_range,
+ .switchbr,
=> false,
.@"break",
@@ -1171,6 +1181,36 @@ pub const Inst = struct {
none,
};
};
+
+ pub const SwitchBr = struct {
+ pub const base_tag = Tag.switchbr;
+ base: Inst,
+
+ positionals: struct {
+ target: *Inst,
+ /// List of all individual items and ranges
+ items: []*Inst,
+ cases: []Case,
+ else_body: Body,
+ },
+ kw_args: struct {
+ /// Pointer to first range if such exists.
+ range: ?*Inst = null,
+ special_prong: SpecialProng = .none,
+ },
+
+ // Not anonymous due to stage1 limitations
+ pub const SpecialProng = enum {
+ none,
+ @"else",
+ underscore,
+ };
+
+ pub const Case = struct {
+ item: *Inst,
+ body: Body,
+ };
+ };
};
pub const ErrorMsg = struct {
@@ -1431,6 +1471,26 @@ const Writer = struct {
}
try stream.writeByte(']');
},
+ []Inst.SwitchBr.Case => {
+ if (param.len == 0) {
+ return stream.writeAll("{}");
+ }
+ try stream.writeAll("{\n");
+ for (param) |*case, i| {
+ if (i != 0) {
+ try stream.writeAll(",\n");
+ }
+ try stream.writeByteNTimes(' ', self.indent);
+ self.indent += 2;
+ try self.writeParamToStream(stream, &case.item);
+ try stream.writeAll(" => ");
+ try self.writeParamToStream(stream, &case.body);
+ self.indent -= 2;
+ }
+ try stream.writeByte('\n');
+ try stream.writeByteNTimes(' ', self.indent - 2);
+ try stream.writeByte('}');
+ },
else => |T| @compileError("unimplemented: rendering parameter of type " ++ @typeName(T)),
}
}
diff --git a/src/zir_sema.zig b/src/zir_sema.zig
@@ -154,6 +154,8 @@ pub fn analyzeInst(mod: *Module, scope: *Scope, old_inst: *zir.Inst) InnerError!
.bool_and => return zirBoolOp(mod, scope, old_inst.castTag(.bool_and).?),
.bool_or => return zirBoolOp(mod, scope, old_inst.castTag(.bool_or).?),
.void_value => return mod.constVoid(scope, old_inst.src),
+ .switchbr => return zirSwitchBr(mod, scope, old_inst.castTag(.switchbr).?),
+ .switch_range => return zirSwitchRange(mod, scope, old_inst.castTag(.switch_range).?),
.container_field_named,
.container_field_typed,
@@ -1535,6 +1537,232 @@ fn zirSliceStart(mod: *Module, scope: *Scope, inst: *zir.Inst.BinOp) InnerError!
return mod.analyzeSlice(scope, inst.base.src, array_ptr, start, null, null);
}
+fn zirSwitchRange(mod: *Module, scope: *Scope, inst: *zir.Inst.BinOp) InnerError!*Inst {
+ const tracy = trace(@src());
+ defer tracy.end();
+ const start = try resolveInst(mod, scope, inst.positionals.lhs);
+ const end = try resolveInst(mod, scope, inst.positionals.rhs);
+
+ switch (start.ty.zigTypeTag()) {
+ .Int, .ComptimeInt => {},
+ else => return mod.constVoid(scope, inst.base.src),
+ }
+ switch (end.ty.zigTypeTag()) {
+ .Int, .ComptimeInt => {},
+ else => return mod.constVoid(scope, inst.base.src),
+ }
+ // .switch_range must be inside a comptime scope
+ const start_val = start.value().?;
+ const end_val = end.value().?;
+ if (start_val.compare(.gte, end_val)) {
+ return mod.fail(scope, inst.base.src, "range start value must be smaller than the end value", .{});
+ }
+ return mod.constVoid(scope, inst.base.src);
+}
+
+fn zirSwitchBr(mod: *Module, scope: *Scope, inst: *zir.Inst.SwitchBr) InnerError!*Inst {
+ const tracy = trace(@src());
+ defer tracy.end();
+ const target = try resolveInst(mod, scope, inst.positionals.target);
+ try validateSwitch(mod, scope, target, inst);
+
+ if (try mod.resolveDefinedValue(scope, target)) |target_val| {
+ for (inst.positionals.cases) |case| {
+ const resolved = try resolveInst(mod, scope, case.item);
+ const casted = try mod.coerce(scope, target.ty, resolved);
+ const item = try mod.resolveConstValue(scope, casted);
+
+ if (target_val.eql(item)) {
+ try analyzeBody(mod, scope.cast(Scope.Block).?, case.body);
+ return mod.constNoReturn(scope, inst.base.src);
+ }
+ }
+ try analyzeBody(mod, scope.cast(Scope.Block).?, inst.positionals.else_body);
+ return mod.constNoReturn(scope, inst.base.src);
+ }
+
+ if (inst.positionals.cases.len == 0) {
+ // no cases just analyze else_branch
+ try analyzeBody(mod, scope.cast(Scope.Block).?, inst.positionals.else_body);
+ return mod.constNoReturn(scope, inst.base.src);
+ }
+
+ const parent_block = try mod.requireRuntimeBlock(scope, inst.base.src);
+ const cases = try parent_block.arena.alloc(Inst.SwitchBr.Case, inst.positionals.cases.len);
+
+ var case_block: Scope.Block = .{
+ .parent = parent_block,
+ .inst_table = parent_block.inst_table,
+ .func = parent_block.func,
+ .owner_decl = parent_block.owner_decl,
+ .src_decl = parent_block.src_decl,
+ .instructions = .{},
+ .arena = parent_block.arena,
+ .inlining = parent_block.inlining,
+ .is_comptime = parent_block.is_comptime,
+ .branch_quota = parent_block.branch_quota,
+ };
+ defer case_block.instructions.deinit(mod.gpa);
+
+ for (inst.positionals.cases) |case, i| {
+ // Reset without freeing.
+ case_block.instructions.items.len = 0;
+
+ const resolved = try resolveInst(mod, scope, case.item);
+ const casted = try mod.coerce(scope, target.ty, resolved);
+ const item = try mod.resolveConstValue(scope, casted);
+
+ try analyzeBody(mod, &case_block, case.body);
+
+ cases[i] = .{
+ .item = item,
+ .body = .{ .instructions = try parent_block.arena.dupe(*Inst, case_block.instructions.items) },
+ };
+ }
+
+ case_block.instructions.items.len = 0;
+ try analyzeBody(mod, &case_block, inst.positionals.else_body);
+
+ const else_body: ir.Body = .{
+ .instructions = try parent_block.arena.dupe(*Inst, case_block.instructions.items),
+ };
+
+ return mod.addSwitchBr(parent_block, inst.base.src, target, cases, else_body);
+}
+
+fn validateSwitch(mod: *Module, scope: *Scope, target: *Inst, inst: *zir.Inst.SwitchBr) InnerError!void {
+ // validate usage of '_' prongs
+ if (inst.kw_args.special_prong == .underscore and target.ty.zigTypeTag() != .Enum) {
+ return mod.fail(scope, inst.base.src, "'_' prong only allowed when switching on non-exhaustive enums", .{});
+ // TODO notes "'_' prong here" inst.positionals.cases[last].src
+ }
+
+ // check that target type supports ranges
+ if (inst.kw_args.range) |range_inst| {
+ switch (target.ty.zigTypeTag()) {
+ .Int, .ComptimeInt => {},
+ else => {
+ return mod.fail(scope, target.src, "ranges not allowed when switching on type {}", .{target.ty});
+ // TODO notes "range used here" range_inst.src
+ },
+ }
+ }
+
+ // validate for duplicate items/missing else prong
+ switch (target.ty.zigTypeTag()) {
+ .Enum => return mod.fail(scope, inst.base.src, "TODO validateSwitch .Enum", .{}),
+ .ErrorSet => return mod.fail(scope, inst.base.src, "TODO validateSwitch .ErrorSet", .{}),
+ .Union => return mod.fail(scope, inst.base.src, "TODO validateSwitch .Union", .{}),
+ .Int, .ComptimeInt => {
+ var range_set = @import("RangeSet.zig").init(mod.gpa);
+ defer range_set.deinit();
+
+ for (inst.positionals.items) |item| {
+ const maybe_src = if (item.castTag(.switch_range)) |range| blk: {
+ const start_resolved = try resolveInst(mod, scope, range.positionals.lhs);
+ const start_casted = try mod.coerce(scope, target.ty, start_resolved);
+ const end_resolved = try resolveInst(mod, scope, range.positionals.rhs);
+ const end_casted = try mod.coerce(scope, target.ty, end_resolved);
+
+ break :blk try range_set.add(
+ try mod.resolveConstValue(scope, start_casted),
+ try mod.resolveConstValue(scope, end_casted),
+ item.src,
+ );
+ } else blk: {
+ const resolved = try resolveInst(mod, scope, item);
+ const casted = try mod.coerce(scope, target.ty, resolved);
+ const value = try mod.resolveConstValue(scope, casted);
+ break :blk try range_set.add(value, value, item.src);
+ };
+
+ if (maybe_src) |previous_src| {
+ return mod.fail(scope, item.src, "duplicate switch value", .{});
+ // TODO notes "previous value is here" previous_src
+ }
+ }
+
+ if (target.ty.zigTypeTag() == .Int) {
+ var arena = std.heap.ArenaAllocator.init(mod.gpa);
+ defer arena.deinit();
+
+ const start = try target.ty.minInt(&arena, mod.getTarget());
+ const end = try target.ty.maxInt(&arena, mod.getTarget());
+ if (try range_set.spans(start, end)) {
+ if (inst.kw_args.special_prong == .@"else") {
+ return mod.fail(scope, inst.base.src, "unreachable else prong, all cases already handled", .{});
+ }
+ return;
+ }
+ }
+
+ if (inst.kw_args.special_prong != .@"else") {
+ return mod.fail(scope, inst.base.src, "switch must handle all possibilities", .{});
+ }
+ },
+ .Bool => {
+ var true_count: u8 = 0;
+ var false_count: u8 = 0;
+ for (inst.positionals.items) |item| {
+ const resolved = try resolveInst(mod, scope, item);
+ const casted = try mod.coerce(scope, Type.initTag(.bool), resolved);
+ if ((try mod.resolveConstValue(scope, casted)).toBool()) {
+ true_count += 1;
+ } else {
+ false_count += 1;
+ }
+
+ if (true_count + false_count > 2) {
+ return mod.fail(scope, item.src, "duplicate switch value", .{});
+ }
+ }
+ if ((true_count + false_count < 2) and inst.kw_args.special_prong != .@"else") {
+ return mod.fail(scope, inst.base.src, "switch must handle all possibilities", .{});
+ }
+ if ((true_count + false_count == 2) and inst.kw_args.special_prong == .@"else") {
+ return mod.fail(scope, inst.base.src, "unreachable else prong, all cases already handled", .{});
+ }
+ },
+ .EnumLiteral, .Void, .Fn, .Pointer, .Type => {
+ if (inst.kw_args.special_prong != .@"else") {
+ return mod.fail(scope, inst.base.src, "else prong required when switching on type '{}'", .{target.ty});
+ }
+
+ var seen_values = std.HashMap(Value, usize, Value.hash, Value.eql, std.hash_map.DefaultMaxLoadPercentage).init(mod.gpa);
+ defer seen_values.deinit();
+
+ for (inst.positionals.items) |item| {
+ const resolved = try resolveInst(mod, scope, item);
+ const casted = try mod.coerce(scope, target.ty, resolved);
+ const val = try mod.resolveConstValue(scope, casted);
+
+ if (try seen_values.fetchPut(val, item.src)) |prev| {
+ return mod.fail(scope, item.src, "duplicate switch value", .{});
+ // TODO notes "previous value here" prev.value
+ }
+ }
+ },
+
+ .ErrorUnion,
+ .NoReturn,
+ .Array,
+ .Struct,
+ .Undefined,
+ .Null,
+ .Optional,
+ .BoundFn,
+ .Opaque,
+ .Vector,
+ .Frame,
+ .AnyFrame,
+ .ComptimeFloat,
+ .Float,
+ => {
+ return mod.fail(scope, target.src, "invalid switch target type '{}'", .{target.ty});
+ },
+ }
+}
+
fn zirImport(mod: *Module, scope: *Scope, inst: *zir.Inst.UnOp) InnerError!*Inst {
const tracy = trace(@src());
defer tracy.end();
diff --git a/test/stage2/cbe.zig b/test/stage2/cbe.zig
@@ -185,6 +185,52 @@ pub fn addCases(ctx: *TestContext) !void {
\\}
, "");
}
+ {
+ var case = ctx.exeFromCompiledC("control flow", .{});
+
+ // Simple while loop
+ case.addCompareOutput(
+ \\export fn main() c_int {
+ \\ var a: c_int = 0;
+ \\ while (a < 5) : (a+=1) {}
+ \\ return a - 5;
+ \\}
+ , "");
+ case.addCompareOutput(
+ \\export fn main() c_int {
+ \\ var a = true;
+ \\ while (!a) {}
+ \\ return 0;
+ \\}
+ , "");
+
+ // If expression
+ case.addCompareOutput(
+ \\export fn main() c_int {
+ \\ var cond: c_int = 0;
+ \\ var a: c_int = @as(c_int, if (cond == 0)
+ \\ 2
+ \\ else
+ \\ 3) + 9;
+ \\ return a - 11;
+ \\}
+ , "");
+
+ // Switch expression
+ case.addCompareOutput(
+ \\export fn main() c_int {
+ \\ var cond: c_int = 0;
+ \\ var a: c_int = switch (cond) {
+ \\ 1 => 1,
+ \\ 2 => 2,
+ \\ 99...300, 12 => 3,
+ \\ 0 => 4,
+ \\ else => 5,
+ \\ };
+ \\ return a - 4;
+ \\}
+ , "");
+ }
ctx.c("empty start function", linux_x64,
\\export fn _start() noreturn {
\\ unreachable;
