Commit cec766f73c298d287c20d1bd830c159958fe177d | zig

author	Andrew Kelley <andrew@ziglang.org> 2021-03-31 18:30:23-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2021-03-31 18:30:23-07:00
log	cec766f73c298d287c20d1bd830c159958fe177d
tree	6e7c247f87a472aff9f7c42b70da8aba5e40916b
parent	fedc9ebd26175bf8309d665f3e1ee6769e8af86d

stage2: compile error for duplicate switch value on boolean

4 files changed, 61 insertions(+), 61 deletions(-)

BRANCH_TODO
src
- AstGen.zig
- Sema.zig
test
- stage2
  - cbe.zig

BRANCH_TODO-12

...	@@ -1,7 +1,6 @@	...	@@ -1,7 +1,6 @@
1	this is my WIP branch scratch pad, to be deleted before merging into master	1	this is my WIP branch scratch pad, to be deleted before merging into master
2		2
3	Merge TODO list:	3	Merge TODO list:
4	* uncomment the commented out stage2 tests
5	* remove the LazySrcLoc.todo tag	4	* remove the LazySrcLoc.todo tag
6	* update astgen.zig	5	* update astgen.zig
7	* finish updating Sema.zig	6	* finish updating Sema.zig
...	@@ -38,17 +37,6 @@ Performance optimizations to look into:	...	@@ -38,17 +37,6 @@ Performance optimizations to look into:
38	* make decl references in ZIR be u32 indexes to the Decl dependencies array hash map	37	* make decl references in ZIR be u32 indexes to the Decl dependencies array hash map
39	instead of duplicating *Decl entries in zir.Code.	38	instead of duplicating *Decl entries in zir.Code.
40		39
41	const item = try sema.resolveInst(item_ref);
42	if ((try sema.resolveConstValue(block, item.src, item)).toBool()) {
43	true_count += 1;
44	} else {
45	false_count += 1;
46	}
47	if (true_count + false_count > 2) {
48	return sema.mod.fail(&block.base, item.src, "duplicate switch value", .{});
49	}
50
51
52		40
53	for (inst.positionals.items) \|item\| {	41	for (inst.positionals.items) \|item\| {
54	const resolved = try sema.resolveInst(item);	42	const resolved = try sema.resolveInst(item);

src/AstGen.zig+3-1

 @@ -2551,13 +2551,15 @@ pub const SwitchProngSrc = union(enum) {
         item: u32,
     };
+    pub const RangeExpand = enum { none, first, last };
     /// This function is intended to be called only when it is certain that we need
     /// the LazySrcLoc in order to emit a compile error.
     pub fn resolve(
         prong_src: SwitchProngSrc,
         decl: *Decl,
         switch_node_offset: i32,
-        range_expand: enum { none, first, last },
+        range_expand: RangeExpand,
     ) LazySrcLoc {
         @setCold(true);
         const switch_node = decl.relativeToNodeIndex(switch_node_offset);

src/Sema.zig+43-47

 @@ -2474,7 +2474,7 @@ fn analyzeSwitch(
             var extra_index: usize = special.end;
             {
-                var scalar_i: usize = 0;
+                var scalar_i: u32 = 0;
                 while (scalar_i < scalar_cases_len) : (scalar_i += 1) {
                     const item_ref = @intToEnum(zir.Inst.Ref, sema.code.extra[extra_index]);
                     extra_index += 1;
 @@ -2489,11 +2489,12 @@ fn analyzeSwitch(
                         &false_count,
                         item_ref,
                         src_node_offset,
+                        .{ .scalar = scalar_i },
                     );
                 }
             }
             {
-                var multi_i: usize = 0;
+                var multi_i: u32 = 0;
                 while (multi_i < multi_cases_len) : (multi_i += 1) {
                     const items_len = sema.code.extra[extra_index];
                     extra_index += 1;
 @@ -2504,13 +2505,14 @@ fn analyzeSwitch(
                     const items = sema.code.refSlice(extra_index, items_len);
                     extra_index += items_len + body_len;
-                    for (items) |item_ref| {
+                    for (items) |item_ref, item_i| {
                         try sema.validateSwitchItemBool(
                             block,
                             &true_count,
                             &false_count,
                             item_ref,
                             src_node_offset,
+                            .{ .multi = .{ .prong = multi_i, .item = @intCast(u32, item_i) } },
                         );
                     }
 @@ -2877,6 +2879,29 @@ fn analyzeSwitch(
     return sema.analyzeBlockBody(block, &child_block, merges);
 }
+fn resolveSwitchItemVal(
+    sema: *Sema,
+    block: *Scope.Block,
+    item_ref: zir.Inst.Ref,
+    switch_node_offset: i32,
+    switch_prong_src: AstGen.SwitchProngSrc,
+    range_expand: AstGen.SwitchProngSrc.RangeExpand,
+) InnerError!Value {
+    const item = try sema.resolveInst(item_ref);
+    // We have to avoid the other helper functions here because we cannot construct a LazySrcLoc
+    // because we only have the switch AST node. Only if we know for sure we need to report
+    // a compile error do we resolve the full source locations.
+    if (item.value()) |val| {
+        if (val.isUndef()) {
+            const src = switch_prong_src.resolve(block.src_decl, switch_node_offset, range_expand);
+            return sema.failWithUseOfUndef(block, src);
+        }
+        return val;
+    }
+    const src = switch_prong_src.resolve(block.src_decl, switch_node_offset, range_expand);
+    return sema.failWithNeededComptime(block, src);
+}
 fn validateSwitchRange(
     sema: *Sema,
     block: *Scope.Block,
 @@ -2886,33 +2911,8 @@ fn validateSwitchRange(
     src_node_offset: i32,
     switch_prong_src: AstGen.SwitchProngSrc,
 ) InnerError!void {
-    const first = try sema.resolveInst(first_ref);
+    const first_val = try sema.resolveSwitchItemVal(block, first_ref, src_node_offset, switch_prong_src, .first);
-    const last = try sema.resolveInst(last_ref);
+    const last_val = try sema.resolveSwitchItemVal(block, last_ref, src_node_offset, switch_prong_src, .last);
-    // We have to avoid the helper functions here because we cannot construct a LazySrcLoc
-    // because we only have the switch AST node. Only if we know for sure we need to report
-    // a compile error do we resolve the full source locations.
-    const first_val = val: {
-        if (first.value()) |val| {
-            if (val.isUndef()) {
-                const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .first);
-                return sema.failWithUseOfUndef(block, src);
-            }
-            break :val val;
-        }
-        const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .first);
-        return sema.failWithNeededComptime(block, src);
-    };
-    const last_val = val: {
-        if (last.value()) |val| {
-            if (val.isUndef()) {
-                const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .last);
-                return sema.failWithUseOfUndef(block, src);
-            }
-            break :val val;
-        }
-        const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .last);
-        return sema.failWithNeededComptime(block, src);
-    };
     const maybe_prev_src = try range_set.add(first_val, last_val, switch_prong_src);
     return sema.validateSwitchDupe(block, maybe_prev_src, switch_prong_src, src_node_offset);
 }
 @@ -2925,22 +2925,8 @@ fn validateSwitchItem(
     src_node_offset: i32,
     switch_prong_src: AstGen.SwitchProngSrc,
 ) InnerError!void {
-    const item = try sema.resolveInst(item_ref);
+    const item_val = try sema.resolveSwitchItemVal(block, item_ref, src_node_offset, switch_prong_src, .none);
-    // We have to avoid the helper functions here because we cannot construct a LazySrcLoc
+    const maybe_prev_src = try range_set.add(item_val, item_val, switch_prong_src);
-    // because we only have the switch AST node. Only if we know for sure we need to report
-    // a compile error do we resolve the full source locations.
-    const value = val: {
-        if (item.value()) |val| {
-            if (val.isUndef()) {
-                const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .none);
-                return sema.failWithUseOfUndef(block, src);
-            }
-            break :val val;
-        }
-        const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .none);
-        return sema.failWithNeededComptime(block, src);
-    };
-    const maybe_prev_src = try range_set.add(value, value, switch_prong_src);
     return sema.validateSwitchDupe(block, maybe_prev_src, switch_prong_src, src_node_offset);
 }
 @@ -2981,8 +2967,18 @@ fn validateSwitchItemBool(
     false_count: *u8,
     item_ref: zir.Inst.Ref,
     src_node_offset: i32,
+    switch_prong_src: AstGen.SwitchProngSrc,
 ) InnerError!void {
-    @panic("TODO");
+    const item_val = try sema.resolveSwitchItemVal(block, item_ref, src_node_offset, switch_prong_src, .none);
+    if (item_val.toBool()) {
+        true_count.* += 1;
+    } else {
+        false_count.* += 1;
+    }
+    if (true_count.* + false_count.* > 2) {
+        const src = switch_prong_src.resolve(block.src_decl, src_node_offset, .none);
+        return sema.mod.fail(&block.base, src, "duplicate switch value", .{});
+    }
 }
 fn validateSwitchItemSparse(

test/stage2/cbe.zig+15-1

...	@@ -327,7 +327,7 @@ pub fn addCases(ctx: *TestContext) !void {	...	@@ -327,7 +327,7 @@ pub fn addCases(ctx: *TestContext) !void {
327	\\}	327	\\}
328	, "");	328	, "");
329		329
330	// Switch expression has duplicate case value.	330	// Integer switch expression has duplicate case value.
331	case.addError(	331	case.addError(
332	\\export fn main() c_int {	332	\\export fn main() c_int {
333	\\ var cond: c_int = 0;	333	\\ var cond: c_int = 0;
...	@@ -345,6 +345,20 @@ pub fn addCases(ctx: *TestContext) !void {	...	@@ -345,6 +345,20 @@ pub fn addCases(ctx: *TestContext) !void {
345	":8:13: error: duplicate switch value",	345	":8:13: error: duplicate switch value",
346	":6:15: note: previous value here",	346	":6:15: note: previous value here",
347	});	347	});
		348
		349	// Boolean switch expression has duplicate case value.
		350	case.addError(
		351	\\export fn main() c_int {
		352	\\ var a: bool = false;
		353	\\ const b: c_int = switch (a) {
		354	\\ false => 1,
		355	\\ true => 2,
		356	\\ false => 3,
		357	\\ };
		358	\\}
		359	, &.{
		360	":6:9: error: duplicate switch value",
		361	});
348	}	362	}
349	//{	363	//{
350	// var case = ctx.exeFromCompiledC("optionals", .{});	364	// var case = ctx.exeFromCompiledC("optionals", .{});