stage2 Sema: Resolve source locations of @TypeOf parameters

1 files changed, 57 insertions, 10 deletions

diff --git a/src/Sema.zig b/src/Sema.zig
index 6d5480c53d..4471d76d44 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -1516,7 +1516,7 @@ fn zirResolveInferredAlloc(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Inde
 
     if (ptr_val.castTag(.inferred_alloc)) |inferred_alloc| {
         const peer_inst_list = inferred_alloc.data.stored_inst_list.items;
-        const final_elem_ty = try sema.resolvePeerTypes(block, ty_src, peer_inst_list);
+        const final_elem_ty = try sema.resolvePeerTypes(block, ty_src, peer_inst_list, null);
         if (var_is_mut) {
             try sema.validateVarType(block, ty_src, final_elem_ty);
         }
@@ -2123,7 +2123,7 @@ fn analyzeBlockBody(
     // Need to set the type and emit the Block instruction. This allows machine code generation
     // to emit a jump instruction to after the block when it encounters the break.
     try parent_block.instructions.append(gpa, merges.block_inst);
-    const resolved_ty = try sema.resolvePeerTypes(parent_block, src, merges.results.items);
+    const resolved_ty = try sema.resolvePeerTypes(parent_block, src, merges.results.items, null);
     try sema.air_extra.ensureUnusedCapacity(gpa, @typeInfo(Air.Block).Struct.fields.len +
         child_block.instructions.items.len);
     sema.air_instructions.items(.data)[merges.block_inst] = .{ .ty_pl = .{
@@ -4768,7 +4768,7 @@ fn zirBitwise(
     const rhs_ty = sema.typeOf(rhs);
 
     const instructions = &[_]Air.Inst.Ref{ lhs, rhs };
-    const resolved_type = try sema.resolvePeerTypes(block, src, instructions);
+    const resolved_type = try sema.resolvePeerTypes(block, src, instructions, null);
     const casted_lhs = try sema.coerce(block, resolved_type, lhs, lhs_src);
     const casted_rhs = try sema.coerce(block, resolved_type, rhs, rhs_src);
 
@@ -4914,7 +4914,7 @@ fn analyzeArithmetic(
     }
 
     const instructions = &[_]Air.Inst.Ref{ lhs, rhs };
-    const resolved_type = try sema.resolvePeerTypes(block, src, instructions);
+    const resolved_type = try sema.resolvePeerTypes(block, src, instructions, null);
     const casted_lhs = try sema.coerce(block, resolved_type, lhs, lhs_src);
     const casted_rhs = try sema.coerce(block, resolved_type, rhs, rhs_src);
 
@@ -5223,7 +5223,7 @@ fn analyzeCmp(
         return sema.cmpNumeric(block, src, lhs, rhs, op, lhs_src, rhs_src);
     }
     const instructions = &[_]Air.Inst.Ref{ lhs, rhs };
-    const resolved_type = try sema.resolvePeerTypes(block, src, instructions);
+    const resolved_type = try sema.resolvePeerTypes(block, src, instructions, null);
     if (!resolved_type.isSelfComparable(is_equality_cmp)) {
         return sema.mod.fail(&block.base, src, "{s} operator not allowed for type '{}'", .{
             @tagName(op), resolved_type,
@@ -5433,7 +5433,7 @@ fn zirTypeofPeer(
         inst_list[i] = sema.resolveInst(arg_ref);
     }
 
-    const result_type = try sema.resolvePeerTypes(block, src, inst_list);
+    const result_type = try sema.resolvePeerTypes(block, src, inst_list, extra.data.src_node);
     return sema.addType(result_type);
 }
 
@@ -8324,11 +8324,42 @@ fn wrapErrorUnion(
     }
 }
 
+fn resolveTypeOfArgSrcLoc(
+    gpa: *Allocator,
+    decl: *Decl,
+    typeof_builtin_call_node_offset: i32,
+    candidates: usize,
+    candidate_i: usize,
+) LazySrcLoc {
+    @setCold(true);
+    if (candidates <= 2) {
+        switch (candidate_i) {
+            0 => return LazySrcLoc{ .node_offset_builtin_call_arg0 = typeof_builtin_call_node_offset },
+            1 => return LazySrcLoc{ .node_offset_builtin_call_arg1 = typeof_builtin_call_node_offset },
+            else => unreachable,
+        }
+    }
+
+    const tree = decl.namespace.file_scope.getTree(gpa) catch |err| {
+        // In this case we emit a warning + a less precise source location.
+        log.warn("unable to load {s}: {s}", .{
+            decl.namespace.file_scope.sub_file_path, @errorName(err),
+        });
+        return LazySrcLoc{ .node_offset = 0 };
+    };
+    const node = decl.relativeToNodeIndex(typeof_builtin_call_node_offset);
+    const node_datas = tree.nodes.items(.data);
+    const params = tree.extra_data[node_datas[node].lhs..node_datas[node].rhs];
+
+    return LazySrcLoc{ .node_abs = params[candidate_i] };
+}
+
 fn resolvePeerTypes(
     sema: *Sema,
     block: *Scope.Block,
     src: LazySrcLoc,
     instructions: []Air.Inst.Ref,
+    typeof_builtin_call_node_offset: ?i32,
 ) !Type {
     if (instructions.len == 0)
         return Type.initTag(.noreturn);
@@ -8339,7 +8370,8 @@ fn resolvePeerTypes(
     const target = sema.mod.getTarget();
 
     var chosen = instructions[0];
-    for (instructions[1..]) |candidate| {
+    var chosen_i: usize = 0;
+    for (instructions[1..]) |candidate, candidate_i| {
         const candidate_ty = sema.typeOf(candidate);
         const chosen_ty = sema.typeOf(chosen);
         if (candidate_ty.eql(chosen_ty))
@@ -8348,12 +8380,14 @@ fn resolvePeerTypes(
             continue;
         if (chosen_ty.zigTypeTag() == .NoReturn) {
             chosen = candidate;
+            chosen_i = candidate_i + 1;
             continue;
         }
         if (candidate_ty.zigTypeTag() == .Undefined)
             continue;
         if (chosen_ty.zigTypeTag() == .Undefined) {
             chosen = candidate;
+            chosen_i = candidate_i + 1;
             continue;
         }
         if (chosen_ty.isInt() and
@@ -8362,18 +8396,21 @@ fn resolvePeerTypes(
         {
             if (chosen_ty.intInfo(target).bits < candidate_ty.intInfo(target).bits) {
                 chosen = candidate;
+                chosen_i = candidate_i + 1;
             }
             continue;
         }
         if (chosen_ty.isFloat() and candidate_ty.isFloat()) {
             if (chosen_ty.floatBits(target) < candidate_ty.floatBits(target)) {
                 chosen = candidate;
+                chosen_i = candidate_i + 1;
             }
             continue;
         }
 
         if (chosen_ty.zigTypeTag() == .ComptimeInt and candidate_ty.isInt()) {
             chosen = candidate;
+            chosen_i = candidate_i + 1;
             continue;
         }
 
@@ -8383,6 +8420,7 @@ fn resolvePeerTypes(
 
         if (chosen_ty.zigTypeTag() == .ComptimeFloat and candidate_ty.isFloat()) {
             chosen = candidate;
+            chosen_i = candidate_i + 1;
             continue;
         }
 
@@ -8395,15 +8433,24 @@ fn resolvePeerTypes(
         }
         if (chosen_ty.zigTypeTag() == .EnumLiteral and candidate_ty.zigTypeTag() == .Enum) {
             chosen = candidate;
+            chosen_i = candidate_i + 1;
             continue;
         }
 
+        // At this point, we hit a compile error. If the call to
+        // resolvePeerTypes originated from the @TypeOf builtin, we
+        // need to recover the source locations
         const msg = msg: {
             const msg = try sema.mod.errMsg(&block.base, src, "incompatible types: '{}' and '{}'", .{ chosen_ty, candidate_ty });
             errdefer msg.destroy(sema.gpa);
-            // TODO add error notes
-            // try sema.mod.errNote(&block.base, chosen.src, msg, "type '{}' here", .{chosen_ty});
-            // try sema.mod.errNote(&block.base, candidate.src, msg, "type '{}' here", .{candidate_ty});
+            // TODO add error notes for other scenarios
+            if (typeof_builtin_call_node_offset) |node_offset| {
+                const chosen_src = resolveTypeOfArgSrcLoc(sema.gpa, block.src_decl, node_offset, instructions.len, chosen_i);
+                const candidate_src = resolveTypeOfArgSrcLoc(sema.gpa, block.src_decl, node_offset, instructions.len, candidate_i + 1);
+
+                try sema.mod.errNote(&block.base, chosen_src, msg, "type '{}' here", .{chosen_ty});
+                try sema.mod.errNote(&block.base, candidate_src, msg, "type '{}' here", .{candidate_ty});
+            }
             break :msg msg;
         };
         return sema.mod.failWithOwnedErrorMsg(&block.base, msg);