From ae69dfe6e739b1b2d4ae76923d04bc69c23b07fa Mon Sep 17 00:00:00 2001
From: Krzysztof Wolicki
 <46651553+der-teufel-programming@users.noreply.github.com>
Date: Mon, 16 Jan 2023 17:28:07 +0100
Subject: [PATCH] autodoc: Better handling of variable decls (#14301)

---
 lib/docs/main.js | 54 +++++++++++++++++++++++++++++++++++++++++-------
 src/Autodoc.zig  | 41 ++++++++++++++++++++++++++++++------
 2 files changed, 82 insertions(+), 13 deletions(-)

diff --git a/lib/docs/main.js b/lib/docs/main.js
index f35a20f57f..253b7c02b4 100644
--- a/lib/docs/main.js
+++ b/lib/docs/main.js
@@ -2250,12 +2250,49 @@ var zigAnalysis;
   }
 
   function renderVar(decl) {
-    let declTypeRef = typeOfDecl(decl);
-    domFnProtoCode.innerHTML =
-      '<span class="tok-kw">var</span> ' +
-      escapeHtml(decl.name) +
-      ": " +
-      typeValueName(declTypeRef, true, true);
+    let resolvedVar = resolveValue(decl.value);
+
+    if (resolvedVar.expr.fieldRef) {
+      const declRef = decl.value.expr.refPath[0].declRef;
+      const type = getDecl(declRef);
+      domFnProtoCode.innerHTML =
+        '<span class="tok-kw">var</span> ' +
+        escapeHtml(decl.name) +
+        ": " +
+        type.name +
+        " = " +
+        exprName(decl.value.expr, { wantHtml: true, wantLink: true }) +
+        ";";
+    } else if (
+      resolvedVar.expr.string !== undefined ||
+      resolvedVar.expr.call !== undefined ||
+      resolvedVar.expr.comptimeExpr
+    ) {
+      domFnProtoCode.innerHTML =
+        '<span class="tok-kw">var</span> ' +
+        escapeHtml(decl.name) +
+        ": " +
+        exprName(resolvedVar.expr, { wantHtml: true, wantLink: true }) +
+        " = " +
+        exprName(decl.value.expr, { wantHtml: true, wantLink: true }) +
+        ";";
+    } else if (resolvedVar.expr.compileError) {
+      domFnProtoCode.innerHTML =
+        '<span class="tok-kw">var</span> ' +
+        escapeHtml(decl.name) +
+        " = " +
+        exprName(decl.value.expr, { wantHtml: true, wantLink: true }) +
+        ";";
+    } else {
+      domFnProtoCode.innerHTML =
+        '<span class="tok-kw">var</span> ' +
+        escapeHtml(decl.name) +
+        ": " +
+        exprName(resolvedVar.typeRef, { wantHtml: true, wantLink: true }) +
+        " = " +
+        exprName(decl.value.expr, { wantHtml: true, wantLink: true }) +
+        ";";
+    }
 
     let docs = getAstNode(decl.src).docs;
     if (docs != null) {
@@ -2546,7 +2583,10 @@ var zigAnalysis;
         tdNameA.setAttribute("href", navLinkDecl(decl.name));
         tdNameA.textContent = decl.name;
 
-        tdType.innerHTML = typeValueName(typeOfDecl(decl), true, true);
+        tdType.innerHTML = exprName(walkResultTypeRef(decl.value), {
+          wantHtml: true,
+          wantLink: true,
+        });
 
         let docs = getAstNode(decl.src).docs;
         if (docs != null) {
diff --git a/src/Autodoc.zig b/src/Autodoc.zig
index fa0b64a929..b368626847 100644
--- a/src/Autodoc.zig
+++ b/src/Autodoc.zig
@@ -2506,16 +2506,25 @@ fn walkInstruction(
                     };
                 },
                 .variable => {
+                    const extra = file.zir.extraData(Zir.Inst.ExtendedVar, extended.operand);
+
                     const small = @bitCast(Zir.Inst.ExtendedVar.Small, extended.small);
-                    var extra_index: usize = extended.operand;
+                    var extra_index: usize = extra.end;
                     if (small.has_lib_name) extra_index += 1;
                     if (small.has_align) extra_index += 1;
 
-                    const value: DocData.WalkResult = if (small.has_init) .{
-                        .expr = .{ .void = .{} },
-                    } else .{
-                        .expr = .{ .void = .{} },
+                    const var_type = try self.walkRef(file, parent_scope, parent_src, extra.data.var_type, need_type);
+                    
+                    var value: DocData.WalkResult = .{
+                        .typeRef = var_type.expr,
+                        .expr = .{ .undefined = .{} },
                     };
+                    
+                    if (small.has_init) {
+                        const var_init_ref = @intToEnum(Ref, file.zir.extra[extra_index]);
+                        const var_init = try self.walkRef(file, parent_scope, parent_src, var_init_ref, need_type);
+                        value.expr = var_init.expr;
+                    }
 
                     return value;
                 },
@@ -3213,13 +3222,15 @@ fn walkDecls(
         //     .declRef => |d| .{ .declRef = d },
         // };
 
+        const kind: []const u8 = if (try self.declIsVar(file, value_pl_node.src_node, parent_src)) "var" else "const";
+
         self.decls.items[decls_slot_index] = .{
             ._analyzed = true,
             .name = name,
             .src = ast_node_index,
             //.typeRef = decl_type_ref,
             .value = walk_result,
-            .kind = "const", // find where this information can be found
+            .kind = kind,
         };
 
         // Unblock any pending decl path that was waiting for this decl.
@@ -4383,3 +4394,21 @@ fn srcLocInfo(
         .src_node = sn,
     };
 }
+
+fn declIsVar(
+    self: Autodoc,
+    file: *File,
+    src_node: i32,
+    parent_src: SrcLocInfo,
+) !bool {
+    const sn = @intCast(u32, @intCast(i32, parent_src.src_node) + src_node);
+    const tree = try file.getTree(self.module.gpa);
+    const node_idx = @bitCast(Ast.Node.Index, sn);
+    const tokens = tree.nodes.items(.main_token);
+    const tags = tree.tokens.items(.tag);
+
+    const tok_idx = tokens[node_idx];
+
+    // tags[tok_idx] is the token called 'mut token' in AstGen
+    return (tags[tok_idx] == .keyword_var);
+}