From e8f82f643ae135fc8d1b056378fda0fcba0ce465 Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Sat, 1 Apr 2023 19:54:03 +0200
Subject: [PATCH] Cleanup compile time variables from generated code

---
 base_data_structures.cpp    | 11 ++++++++
 core_codegen_c_language.cpp |  1 +
 core_polymorph.cpp          | 50 +++++++++++++++++++++++++++++++++++--
 core_typechecking.cpp       |  4 +--
 4 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/base_data_structures.cpp b/base_data_structures.cpp
index c82d57e..597b7c0 100644
--- a/base_data_structures.cpp
+++ b/base_data_structures.cpp
@@ -117,6 +117,17 @@ struct Array {
         return result;
     }
 
+    void ordered_remove(T &item) {
+        assert(len > 0);
+        assert(&item >= begin() && &item < end());
+        int index = get_index(&item);
+        assert(index >= 0 && index < len);
+
+        int right_len = len - index - 1;
+        memmove(data + index, data + index + 1, right_len * sizeof(T));
+        len -= 1;
+    }
+
     force_inline B32 is_last(T *item) { return item == last(); }
     force_inline B32 is_first(T *item) { return item == begin(); }
     force_inline void clear() { len = 0; }
diff --git a/core_codegen_c_language.cpp b/core_codegen_c_language.cpp
index 2c1824f..a78362f 100644
--- a/core_codegen_c_language.cpp
+++ b/core_codegen_c_language.cpp
@@ -337,6 +337,7 @@ CORE_Static void
 gen_lambda(Intern_String name, Ast_Lambda *lambda, B32 generate_block = true) {
     gen_simple_decl(lambda->resolved_type->func.ret, name);
     gen("(");
+    if (lambda->args.len == 0) gen("void");
     For(lambda->args) {
         gen_var(it, DONT_EMIT_VALUE, true);
         if (&it != (lambda->args.end() - 1))
diff --git a/core_polymorph.cpp b/core_polymorph.cpp
index c6de734..942d0e7 100644
--- a/core_polymorph.cpp
+++ b/core_polymorph.cpp
@@ -328,5 +328,51 @@ Ast_Decl *get_or_instantiate_polymorph_type(Token *pos, Ast_Decl *poly, Array<As
     return result;
 }
 
-// Ast_Decl *get_or_instantiate_polymorph_lambda(Token *pos, Ast_Decl *poly, Array<Ast_Call_Item *> params, Ast_Scope *field_access_scope) {
-// }
\ No newline at end of file
+Ast_Decl *get_or_instantiate_polymorph_lambda(Token *pos, Ast_Decl *poly, Array<Ast_Call_Item *> params, Ast_Scope *field_access_scope) {
+    if (params.len != poly->polymorph_parameters.len) compiler_error(pos, "Invalid count of polymorphic arguments");
+
+    int i = 0;
+    uint64_t hash = 91;
+    For(params) {
+        Ast_Decl *poly_decl = poly->polymorph_parameters[i++];
+        resolve_decl(poly_decl);
+        if (poly_decl->type != pctx->type_type) compiler_error(poly_decl->pos, "Invalid type of polymorphic struct argument");
+
+        Operand op = resolve_expr(it->item, AST_CANT_BE_NULL, 0, field_access_scope);
+        if (!op.is_const) compiler_error(it->pos, "Argument is required to be compile time known");
+        if (op.type != pctx->type_type) compiler_error(it->pos, "Struct argument required to be a type");
+
+        hash = hash_mix(hash, hash_ptr(op.type_val));
+    }
+
+    Ast_Decl *result = 0;
+    For(poly->polymorphs) {
+        if (it->polymorph_hash == hash) {
+            result = it;
+            break;
+        }
+    }
+
+    if (!result) {
+        result = (Ast_Decl *)ast_copy(poly, poly->parent_scope, &poly->polymorph_parameters, &params);
+        For(result->lambda->args) {
+            if (it->flags & AST_IDENT_POLYMORPH) {
+                result->lambda->args.ordered_remove(it);
+            }
+        }
+
+        unset_flag(result->flags, AST_POLYMORPH);
+        unset_flag(result->flags, AST_PARENT_POLYMORPH);
+        result->polymorph_hash = hash;
+
+        assert(result->di != poly->di);
+        result->name = get_unique_name_for_decl(result);
+        result->unique_name = result->name;
+
+        poly->polymorphs.allocator = pctx->heap;
+        poly->polymorphs.add(result);
+    }
+
+    resolve_decl(result);
+    return result;
+}
diff --git a/core_typechecking.cpp b/core_typechecking.cpp
index 22d8005..9829a36 100644
--- a/core_typechecking.cpp
+++ b/core_typechecking.cpp
@@ -1703,8 +1703,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_and_const_str
                     }
 
                     Ast_Decl *poly = name.resolved_decl;
-                    assert(replacements.len == poly->polymorph_parameters.len);
-                    Ast_Decl *instance = get_or_instantiate_polymorph_type(node->pos, poly, replacements, field_access_scope);
+                    Ast_Decl *instance = get_or_instantiate_polymorph_lambda(node->pos, poly, replacements, field_access_scope);
                     node->resolved_decl = instance;
                     lambda = instance->lambda;
                 }
@@ -1714,6 +1713,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_and_const_str
                 For(matches) {
                     Ast_Call_Item *item = it.call_arg;
                     Ast_Decl *lambda_arg = it.lambda_arg;
+                    if (lambda_arg->flags & AST_IDENT_POLYMORPH) continue;
                     Operand expr = resolve_expr(item->item, AST_CANT_BE_NULL, lambda_arg->type, field_access_scope);
 
                     make_sure_value_is_compatible_with_type(item->pos, &expr, lambda_arg->type, TYPE_AND_EXPR_REQUIRED);