From 362fc7e3efbef6ba0e2e0ac20807cb35d0ac52f5 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Fri, 27 Sep 2019 15:12:30 -0300
Subject: [PATCH] analysis: add name type resolution

this only adds resolution for the types. for the actual metadata, such
as e.g parameters, that isn't available, so codegen isn't helped by
this.
---
 examples/hello.ry |  3 +--
 src/analysis.zig  |  6 +++++-
 src/comp_ctx.zig  | 39 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/examples/hello.ry b/examples/hello.ry
index 0d93592..9be2bf2 100644
--- a/examples/hello.ry
+++ b/examples/hello.ry
@@ -43,8 +43,7 @@ fn multwo(num: i32, double_flag: bool) i32 {
 }
 
 fn multwo_with_one(b: i32) i32 {
-    // TODO replace by b
-    return multwo(2, false) + 2;
+    return multwo(b, false) + b;
 }
 
 fn add(a: i32, b: i32) i32 {
diff --git a/src/analysis.zig b/src/analysis.zig
index e9cbf26..f3471d8 100644
--- a/src/analysis.zig
+++ b/src/analysis.zig
@@ -275,7 +275,11 @@ pub const TypeSolver = struct {
                 return func_sym.return_type;
             },
 
-            // TODO analysis for .Variable
+            .Variable => |vari| {
+                // TODO maybe we can modify vari and add the current scope
+                // it was found for codegen purposes
+                return try ctx.resolveVarType(vari.lexeme);
+            },
 
             .Get => |get| {
                 var target = get.target.*;
diff --git a/src/comp_ctx.zig b/src/comp_ctx.zig
index 749a518..431eb92 100644
--- a/src/comp_ctx.zig
+++ b/src/comp_ctx.zig
@@ -1,7 +1,10 @@
 const std = @import("std");
 const ast = @import("ast.zig");
 
-pub const CompilationError = error{TypeError};
+pub const CompilationError = error{
+    TypeError,
+    UnknownName,
+};
 
 pub const SymbolTable = std.hash_map.StringHashMap(SymbolData);
 pub const TypeList = std.ArrayList(SymbolUnderlyingType);
@@ -289,4 +292,38 @@ pub const CompilationContext = struct {
 
         return sym_kv.?.value;
     }
+
+    fn resolveVarTypeInScope(
+        self: *@This(),
+        scope_opt: ?*Scope,
+        name: []const u8,
+    ) ?SymbolUnderlyingType {
+        if (scope_opt == null) return null;
+        var scope = scope_opt.?;
+
+        var kv_opt = scope.env.get(name);
+        if (kv_opt) |kv| {
+            // TODO maybe return the scope it was found in
+            return kv.value;
+        } else {
+            return self.resolveVarTypeInScope(scope.parent, name);
+        }
+    }
+
+    fn resolveVarType(self: *@This(), name: []const u8) !SymbolUnderlyingType {
+        var var_type: ?SymbolUnderlyingType = null;
+
+        if (self.current_scope) |scope| {
+            var_type = self.resolveVarTypeInScope(scope, name);
+            if (var_type) |typ| return typ;
+        }
+
+        if (self.cur_function) |cur_function| {
+            var kv_opt = cur_function.parameters.get(name);
+            if (kv_opt) |kv| return kv.value;
+        }
+
+        std.debug.warn("Unknown name {}\n", name);
+        return CompilationError.UnknownName;
+    }
 };