AstGen: allow locals with same name as primitives with `@""` syntax

This makes local names follow the same rule as declaration names.

1 files changed, 35 insertions, 22 deletions

diff --git a/src/AstGen.zig b/src/AstGen.zig
index 2b8e6a76a8..a425540a38 100644
--- a/src/AstGen.zig
+++ b/src/AstGen.zig
@@ -2385,7 +2385,7 @@ fn varDecl(
     }
     const ident_name = try astgen.identAsString(name_token);
 
-    try astgen.detectLocalShadowing(scope, ident_name, name_token);
+    try astgen.detectLocalShadowing(scope, ident_name, name_token, ident_name_raw);
 
     if (var_decl.ast.init_node == 0) {
         return astgen.failNode(node, "variables must be initialized", .{});
@@ -2952,12 +2952,13 @@ fn fnDecl(
             } else false;
 
             const param_name: u32 = if (param.name_token) |name_token| blk: {
-                if (mem.eql(u8, "_", tree.tokenSlice(name_token)))
+                const name_bytes = tree.tokenSlice(name_token);
+                if (mem.eql(u8, "_", name_bytes))
                     break :blk 0;
 
                 const param_name = try astgen.identAsString(name_token);
                 if (!is_extern) {
-                    try astgen.detectLocalShadowing(params_scope, param_name, name_token);
+                    try astgen.detectLocalShadowing(params_scope, param_name, name_token, name_bytes);
                 }
                 break :blk param_name;
             } else if (!is_extern) {
@@ -5035,7 +5036,7 @@ fn ifExpr(
                 const token_name_str = tree.tokenSlice(token_name_index);
                 if (mem.eql(u8, "_", token_name_str))
                     break :s &then_scope.base;
-                try astgen.detectLocalShadowing(&then_scope.base, ident_name, token_name_index);
+                try astgen.detectLocalShadowing(&then_scope.base, ident_name, token_name_index, token_name_str);
                 payload_val_scope = .{
                     .parent = &then_scope.base,
                     .gen_zir = &then_scope,
@@ -5054,11 +5055,12 @@ fn ifExpr(
                 .optional_payload_unsafe_ptr
             else
                 .optional_payload_unsafe;
-            if (mem.eql(u8, "_", tree.tokenSlice(ident_token)))
+            const ident_bytes = tree.tokenSlice(ident_token);
+            if (mem.eql(u8, "_", ident_bytes))
                 break :s &then_scope.base;
             const payload_inst = try then_scope.addUnNode(tag, cond.inst, node);
             const ident_name = try astgen.identAsString(ident_token);
-            try astgen.detectLocalShadowing(&then_scope.base, ident_name, ident_token);
+            try astgen.detectLocalShadowing(&then_scope.base, ident_name, ident_token, ident_bytes);
             payload_val_scope = .{
                 .parent = &then_scope.base,
                 .gen_zir = &then_scope,
@@ -5100,7 +5102,7 @@ fn ifExpr(
                 const error_token_str = tree.tokenSlice(error_token);
                 if (mem.eql(u8, "_", error_token_str))
                     break :s &else_scope.base;
-                try astgen.detectLocalShadowing(&else_scope.base, ident_name, error_token);
+                try astgen.detectLocalShadowing(&else_scope.base, ident_name, error_token, error_token_str);
                 payload_val_scope = .{
                     .parent = &else_scope.base,
                     .gen_zir = &else_scope,
@@ -5291,11 +5293,12 @@ fn whileExpr(
                     .err_union_payload_unsafe;
                 const payload_inst = try then_scope.addUnNode(tag, cond.inst, node);
                 const ident_token = if (payload_is_ref) payload_token + 1 else payload_token;
-                if (mem.eql(u8, "_", tree.tokenSlice(ident_token)))
+                const ident_bytes = tree.tokenSlice(ident_token);
+                if (mem.eql(u8, "_", ident_bytes))
                     break :s &then_scope.base;
                 const payload_name_loc = payload_token + @boolToInt(payload_is_ref);
                 const ident_name = try astgen.identAsString(payload_name_loc);
-                try astgen.detectLocalShadowing(&then_scope.base, ident_name, payload_name_loc);
+                try astgen.detectLocalShadowing(&then_scope.base, ident_name, payload_name_loc, ident_bytes);
                 payload_val_scope = .{
                     .parent = &then_scope.base,
                     .gen_zir = &then_scope,
@@ -5316,9 +5319,10 @@ fn whileExpr(
                 .optional_payload_unsafe;
             const payload_inst = try then_scope.addUnNode(tag, cond.inst, node);
             const ident_name = try astgen.identAsString(ident_token);
-            if (mem.eql(u8, "_", tree.tokenSlice(ident_token)))
+            const ident_bytes = tree.tokenSlice(ident_token);
+            if (mem.eql(u8, "_", ident_bytes))
                 break :s &then_scope.base;
-            try astgen.detectLocalShadowing(&then_scope.base, ident_name, ident_token);
+            try astgen.detectLocalShadowing(&then_scope.base, ident_name, ident_token, ident_bytes);
             payload_val_scope = .{
                 .parent = &then_scope.base,
                 .gen_zir = &then_scope,
@@ -5374,9 +5378,10 @@ fn whileExpr(
                     .err_union_code;
                 const payload_inst = try else_scope.addUnNode(tag, cond.inst, node);
                 const ident_name = try astgen.identAsString(error_token);
-                if (mem.eql(u8, tree.tokenSlice(error_token), "_"))
+                const ident_bytes = tree.tokenSlice(error_token);
+                if (mem.eql(u8, ident_bytes, "_"))
                     break :s &else_scope.base;
-                try astgen.detectLocalShadowing(&else_scope.base, ident_name, error_token);
+                try astgen.detectLocalShadowing(&else_scope.base, ident_name, error_token, ident_bytes);
                 payload_val_scope = .{
                     .parent = &else_scope.base,
                     .gen_zir = &else_scope,
@@ -5523,7 +5528,7 @@ fn forExpr(
             const name_str_index = try astgen.identAsString(ident);
             const tag: Zir.Inst.Tag = if (is_ptr) .elem_ptr else .elem_val;
             const payload_inst = try then_scope.addBin(tag, array_ptr, index);
-            try astgen.detectLocalShadowing(&then_scope.base, name_str_index, ident);
+            try astgen.detectLocalShadowing(&then_scope.base, name_str_index, ident, value_name);
             payload_val_scope = .{
                 .parent = &then_scope.base,
                 .gen_zir = &then_scope,
@@ -5543,11 +5548,12 @@ fn forExpr(
             ident + 2
         else
             break :blk payload_sub_scope;
-        if (mem.eql(u8, tree.tokenSlice(index_token), "_")) {
+        const token_bytes = tree.tokenSlice(index_token);
+        if (mem.eql(u8, token_bytes, "_")) {
             return astgen.failTok(index_token, "discard of index capture; omit it instead", .{});
         }
         const index_name = try astgen.identAsString(index_token);
-        try astgen.detectLocalShadowing(payload_sub_scope, index_name, index_token);
+        try astgen.detectLocalShadowing(payload_sub_scope, index_name, index_token, token_bytes);
         index_scope = .{
             .parent = payload_sub_scope,
             .gen_zir = &then_scope,
@@ -10059,7 +10065,7 @@ fn declareNewName(
                 const ns = scope.cast(Scope.Namespace).?;
                 const gop = try ns.decls.getOrPut(gpa, name_index);
                 if (gop.found_existing) {
-                    const name = try gpa.dupe(u8, mem.spanZ(astgen.nullTerminatedString(name_index)));
+                    const name = try gpa.dupe(u8, mem.span(astgen.nullTerminatedString(name_index)));
                     defer gpa.free(name);
                     return astgen.failNodeNotes(node, "redeclaration of '{s}'", .{
                         name,
@@ -10094,13 +10100,17 @@ fn detectLocalShadowing(
     scope: *Scope,
     ident_name: u32,
     name_token: ast.TokenIndex,
+    token_bytes: []const u8,
 ) !void {
     const gpa = astgen.gpa;
-    const name_slice = mem.spanZ(astgen.nullTerminatedString(ident_name));
-    if (isPrimitive(name_slice)) {
-        const name = try gpa.dupe(u8, name_slice);
-        defer gpa.free(name);
-        return astgen.failTok(name_token, "local shadows primitive '{s}'", .{name});
+    if (token_bytes[0] != '@' and isPrimitive(token_bytes)) {
+        return astgen.failTokNotes(name_token, "name shadows primitive '{s}'", .{
+            token_bytes,
+        }, &[_]u32{
+            try astgen.errNoteTok(name_token, "consider using @\"{s}\" to disambiguate", .{
+                token_bytes,
+            }),
+        });
     }
 
     var s = scope;
@@ -10108,6 +10118,7 @@ fn detectLocalShadowing(
         .local_val => {
             const local_val = s.cast(Scope.LocalVal).?;
             if (local_val.name == ident_name) {
+                const name_slice = mem.span(astgen.nullTerminatedString(ident_name));
                 const name = try gpa.dupe(u8, name_slice);
                 defer gpa.free(name);
                 return astgen.failTokNotes(name_token, "redeclaration of {s} '{s}'", .{
@@ -10125,6 +10136,7 @@ fn detectLocalShadowing(
         .local_ptr => {
             const local_ptr = s.cast(Scope.LocalPtr).?;
             if (local_ptr.name == ident_name) {
+                const name_slice = mem.span(astgen.nullTerminatedString(ident_name));
                 const name = try gpa.dupe(u8, name_slice);
                 defer gpa.free(name);
                 return astgen.failTokNotes(name_token, "redeclaration of {s} '{s}'", .{
@@ -10145,6 +10157,7 @@ fn detectLocalShadowing(
                 s = ns.parent;
                 continue;
             };
+            const name_slice = mem.span(astgen.nullTerminatedString(ident_name));
             const name = try gpa.dupe(u8, name_slice);
             defer gpa.free(name);
             return astgen.failTokNotes(name_token, "local shadows declaration of '{s}'", .{