Commit fb28349349

Vexu <git@vexu.eu>
2020-08-26 11:34:41
stage2: astgen catch
1 parent bf014d5
Changed files (4)
src-self-hosted/astgen.zig
@@ -275,9 +275,9 @@ pub fn expr(mod: *Module, scope: *Scope, rl: ResultLoc, node: *ast.Node) InnerEr
         .ErrorType => return rlWrap(mod, scope, rl, try errorType(mod, scope, node.castTag(.ErrorType).?)),
         .For => return forExpr(mod, scope, rl, node.castTag(.For).?),
         .ArrayAccess => return arrayAccess(mod, scope, rl, node.castTag(.ArrayAccess).?),
+        .Catch => return catchExpr(mod, scope, rl, node.castTag(.Catch).?),
 
         .Defer => return mod.failNode(scope, node, "TODO implement astgen.expr for .Defer", .{}),
-        .Catch => return mod.failNode(scope, node, "TODO implement astgen.expr for .Catch", .{}),
         .Range => return mod.failNode(scope, node, "TODO implement astgen.expr for .Range", .{}),
         .OrElse => return mod.failNode(scope, node, "TODO implement astgen.expr for .OrElse", .{}),
         .Await => return mod.failNode(scope, node, "TODO implement astgen.expr for .Await", .{}),
@@ -750,6 +750,93 @@ fn errorType(mod: *Module, scope: *Scope, node: *ast.Node.OneToken) InnerError!*
     });
 }
 
+fn catchExpr(mod: *Module, scope: *Scope, rl: ResultLoc, node: *ast.Node.Catch) InnerError!*zir.Inst {
+    const tree = scope.tree();
+    const src = tree.token_locs[node.op_token].start;
+
+    const err_union_ptr = try expr(mod, scope, .ref, node.lhs);
+    // TODO we could avoid an unnecessary copy if .iserr took a pointer
+    const err_union = try addZIRUnOp(mod, scope, src, .deref, err_union_ptr);
+    const cond = try addZIRUnOp(mod, scope, src, .iserr, err_union);
+
+    var block_scope: Scope.GenZIR = .{
+        .parent = scope,
+        .decl = scope.decl().?,
+        .arena = scope.arena(),
+        .instructions = .{},
+    };
+    defer block_scope.instructions.deinit(mod.gpa);
+
+    const condbr = try addZIRInstSpecial(mod, &block_scope.base, src, zir.Inst.CondBr, .{
+        .condition = cond,
+        .then_body = undefined, // populated below
+        .else_body = undefined, // populated below
+    }, .{});
+
+    const block = try addZIRInstBlock(mod, scope, src, .{
+        .instructions = try block_scope.arena.dupe(*zir.Inst, block_scope.instructions.items),
+    });
+
+    // Most result location types can be forwarded directly; however
+    // if we need to write to a pointer which has an inferred type,
+    // proper type inference requires peer type resolution on the if's
+    // branches.
+    const branch_rl: ResultLoc = switch (rl) {
+        .discard, .none, .ty, .ptr, .ref => rl,
+        .inferred_ptr, .bitcasted_ptr, .block_ptr => .{ .block_ptr = block },
+    };
+
+    var err_scope: Scope.GenZIR = .{
+        .parent = scope,
+        .decl = block_scope.decl,
+        .arena = block_scope.arena,
+        .instructions = .{},
+    };
+    defer err_scope.instructions.deinit(mod.gpa);
+
+    var err_val_scope: Scope.LocalVal = undefined;
+    const err_sub_scope = blk: {
+        const payload = node.payload orelse
+            break :blk &err_scope.base;
+
+        const err_name = tree.tokenSlice(payload.castTag(.Payload).?.error_symbol.firstToken());
+        if (mem.eql(u8, err_name, "_"))
+            break :blk &err_scope.base;
+    
+        const unwrapped_err_ptr = try addZIRUnOp(mod, &err_scope.base, src, .unwrap_err_code, err_union_ptr);
+        err_val_scope = .{
+            .parent = &err_scope.base,
+            .gen_zir = &err_scope,
+            .name = err_name,
+            .inst = try addZIRUnOp(mod, &err_scope.base, src, .deref, unwrapped_err_ptr),
+        };
+        break :blk &err_val_scope.base;
+    };
+
+    _ = try addZIRInst(mod, &err_scope.base, src, zir.Inst.Break, .{
+        .block = block,
+        .operand = try expr(mod, err_sub_scope, branch_rl, node.rhs),
+    }, .{});
+
+    var not_err_scope: Scope.GenZIR = .{
+        .parent = scope,
+        .decl = block_scope.decl,
+        .arena = block_scope.arena,
+        .instructions = .{},
+    };
+    defer not_err_scope.instructions.deinit(mod.gpa);
+
+    const unwrapped_payload = try addZIRUnOp(mod, &not_err_scope.base, src, .unwrap_err_unsafe, err_union_ptr);
+    _ = try addZIRInst(mod, &not_err_scope.base, src, zir.Inst.Break, .{
+        .block = block,
+        .operand = unwrapped_payload,
+    }, .{});
+
+    condbr.positionals.then_body = .{ .instructions = try err_scope.arena.dupe(*zir.Inst, err_scope.instructions.items) };
+    condbr.positionals.else_body = .{ .instructions = try not_err_scope.arena.dupe(*zir.Inst, not_err_scope.instructions.items) };
+    return rlWrap(mod, scope, rl, &block.base);
+}
+
 /// Return whether the identifier names of two tokens are equal. Resolves @"" tokens without allocating.
 /// OK in theory it could do it without allocating. This implementation allocates when the @"" form is used.
 fn tokenIdentEql(mod: *Module, scope: *Scope, token1: ast.TokenIndex, token2: ast.TokenIndex) !bool {
@@ -1317,7 +1404,7 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
         .inferred_ptr, .bitcasted_ptr, .block_ptr => .{ .block_ptr = for_block },
     };
 
-    var index_scope: Scope.LocalPtr = undefined;
+    var index_scope: Scope.LocalVal = undefined;
     const then_sub_scope = blk: {
         const payload = for_node.payload.castTag(.PointerIndexPayload).?;
         const is_ptr = payload.ptr_token != null;
@@ -1335,12 +1422,11 @@ fn forExpr(mod: *Module, scope: *Scope, rl: ResultLoc, for_node: *ast.Node.For)
         if (mem.eql(u8, index_name, "_")) {
             break :blk &then_scope.base;
         }
-        // TODO ensure this is const
         index_scope = .{
             .parent = &then_scope.base,
             .gen_zir = &then_scope,
             .name = index_name,
-            .ptr = index_ptr,
+            .inst = index,
         };
         break :blk &index_scope.base;
     };
src-self-hosted/Module.zig
@@ -2570,7 +2570,17 @@ pub fn analyzeIsNull(
     operand: *Inst,
     invert_logic: bool,
 ) InnerError!*Inst {
-    return self.fail(scope, src, "TODO implement analysis of isnull and isnotnull", .{});
+    if (operand.value()) |opt_val| {
+        const is_null = opt_val.isNull();
+        return self.constBool(scope, src, invert_logic);
+    }
+    const b = try self.requireRuntimeBlock(scope, src);
+    const inst_tag: Inst.Tag = if (invert_logic) .isnonnull else .isnull;
+    return self.addUnOp(b, src, Type.initTag(.bool), inst_tag, operand);
+}
+
+pub fn analyzeIsErr(self: *Module, scope: *Scope, src: usize, operand: *Inst) InnerError!*Inst {
+    return self.fail(scope, src, "TODO implement analysis of iserr", .{});
 }
 
 /// Asserts that lhs and rhs types are both numeric.
src-self-hosted/zir.zig
@@ -253,6 +253,8 @@ pub const Inst = struct {
         unwrap_err_safe,
         /// Same as previous, but without safety checks. Used for orelse, if and while
         unwrap_err_unsafe,
+        /// Gets the error code value of an error union
+        unwrap_err_code,
         /// Takes a *E!T and raises a compiler error if T != void
         ensure_err_payload_void,
         /// Enum literal
@@ -298,6 +300,7 @@ pub const Inst = struct {
                 .unwrap_optional_unsafe,
                 .unwrap_err_safe,
                 .unwrap_err_unsafe,
+                .unwrap_err_code,
                 .ensure_err_payload_void,
                 .anyframe_type,
                 .bitnot,
@@ -454,6 +457,7 @@ pub const Inst = struct {
                 .unwrap_optional_unsafe,
                 .unwrap_err_safe,
                 .unwrap_err_unsafe,
+                .unwrap_err_code,
                 .ptr_type,
                 .ensure_err_payload_void,
                 .enum_literal,
src-self-hosted/zir_sema.zig
@@ -120,6 +120,7 @@ pub fn analyzeInst(mod: *Module, scope: *Scope, old_inst: *zir.Inst) InnerError!
         .unwrap_optional_unsafe => return analyzeInstUnwrapOptional(mod, scope, old_inst.castTag(.unwrap_optional_unsafe).?, false),
         .unwrap_err_safe => return analyzeInstUnwrapErr(mod, scope, old_inst.castTag(.unwrap_err_safe).?, true),
         .unwrap_err_unsafe => return analyzeInstUnwrapErr(mod, scope, old_inst.castTag(.unwrap_err_unsafe).?, false),
+        .unwrap_err_code => return analyzeInstUnwrapErrCode(mod, scope, old_inst.castTag(.unwrap_err_code).?),
         .ensure_err_payload_void => return analyzeInstEnsureErrPayloadVoid(mod, scope, old_inst.castTag(.ensure_err_payload_void).?),
         .array_type => return analyzeInstArrayType(mod, scope, old_inst.castTag(.array_type).?),
         .array_type_sentinel => return analyzeInstArrayTypeSentinel(mod, scope, old_inst.castTag(.array_type_sentinel).?),
@@ -800,11 +801,12 @@ fn analyzeInstUnwrapOptional(mod: *Module, scope: *Scope, unwrap: *zir.Inst.UnOp
     const operand = try resolveInst(mod, scope, unwrap.positionals.operand);
     assert(operand.ty.zigTypeTag() == .Pointer);
 
-    if (operand.ty.elemType().zigTypeTag() != .Optional) {
-        return mod.fail(scope, unwrap.base.src, "expected optional type, found {}", .{operand.ty.elemType()});
+    const elem_type = operand.ty.elemType();
+    if (elem_type.zigTypeTag() != .Optional) {
+        return mod.fail(scope, unwrap.base.src, "expected optional type, found {}", .{elem_type});
     }
 
-    const child_type = try operand.ty.elemType().optionalChildAlloc(scope.arena());
+    const child_type = try elem_type.optionalChildAlloc(scope.arena());
     const child_pointer = try mod.simplePtrType(scope, unwrap.base.src, child_type, operand.ty.isConstPtr(), .One);
 
     if (operand.value()) |val| {
@@ -829,6 +831,10 @@ fn analyzeInstUnwrapErr(mod: *Module, scope: *Scope, unwrap: *zir.Inst.UnOp, saf
     return mod.fail(scope, unwrap.base.src, "TODO implement analyzeInstUnwrapErr", .{});
 }
 
+fn analyzeInstUnwrapErrCode(mod: *Module, scope: *Scope, unwrap: *zir.Inst.UnOp) InnerError!*Inst {
+    return mod.fail(scope, unwrap.base.src, "TODO implement analyzeInstUnwrapErrCode", .{});
+}
+
 fn analyzeInstEnsureErrPayloadVoid(mod: *Module, scope: *Scope, unwrap: *zir.Inst.UnOp) InnerError!*Inst {
     return mod.fail(scope, unwrap.base.src, "TODO implement analyzeInstEnsureErrPayloadVoid", .{});
 }
@@ -964,7 +970,8 @@ fn analyzeInstFieldPtr(mod: *Module, scope: *Scope, fieldptr: *zir.Inst.FieldPtr
                     const entry = if (val.cast(Value.Payload.ErrorSet)) |payload|
                         (payload.fields.getEntry(field_name) orelse
                             return mod.fail(scope, fieldptr.base.src, "no error named '{}' in '{}'", .{ field_name, child_type })).*
-                    else try mod.getErrorValue(field_name);
+                    else
+                        try mod.getErrorValue(field_name);
 
                     const error_payload = try scope.arena().create(Value.Payload.Error);
                     error_payload.* = .{
@@ -1298,17 +1305,7 @@ fn analyzeInstCmp(
     {
         // comparing null with optionals
         const opt_operand = if (lhs_ty_tag == .Optional) lhs else rhs;
-        if (opt_operand.value()) |opt_val| {
-            const is_null = opt_val.isNull();
-            return mod.constBool(scope, inst.base.src, if (op == .eq) is_null else !is_null);
-        }
-        const b = try mod.requireRuntimeBlock(scope, inst.base.src);
-        const inst_tag: Inst.Tag = switch (op) {
-            .eq => .isnull,
-            .neq => .isnonnull,
-            else => unreachable,
-        };
-        return mod.addUnOp(b, inst.base.src, Type.initTag(.bool), inst_tag, opt_operand);
+        return mod.analyzeIsNull(scope, inst.base.src, opt_operand, op == .neq);
     } else if (is_equality_cmp and
         ((lhs_ty_tag == .Null and rhs.ty.isCPtr()) or (rhs_ty_tag == .Null and lhs.ty.isCPtr())))
     {
@@ -1356,8 +1353,9 @@ fn analyzeInstIsNonNull(mod: *Module, scope: *Scope, inst: *zir.Inst.UnOp, inver
     return mod.analyzeIsNull(scope, inst.base.src, operand, invert_logic);
 }
 
-fn analyzeInstIsErr(mod: *Module, scope: *Scope, inst: *zir.Inst.UnOp, invert_logic: bool) InnerError!*Inst {
-    return mod.fail(scope, inst.base.src, "TODO implement analyzeInstIsErr", .{});
+fn analyzeInstIsErr(mod: *Module, scope: *Scope, inst: *zir.Inst.UnOp) InnerError!*Inst {
+    const operand = try resolveInst(mod, scope, inst.positionals.operand);
+    return mod.analyzeIsErr(scope, inst.base.src, operand);
 }
 
 fn analyzeInstCondBr(mod: *Module, scope: *Scope, inst: *zir.Inst.CondBr) InnerError!*Inst {