From 61249d6eaf4b29a7caa6da63ed1b6ccb584760a8 Mon Sep 17 00:00:00 2001
From: servostar <sven.vogel123@web.de>
Date: Wed, 29 May 2024 13:03:39 +0200
Subject: [PATCH] feature: implemented while statement

---
 src/llvm/func.c | 19 ++++++++++++-
 src/llvm/func.h |  4 +++
 src/llvm/stmt.c | 71 +++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 85 insertions(+), 9 deletions(-)

diff --git a/src/llvm/func.c b/src/llvm/func.c
index 5c6024d..dc6c8da 100644
--- a/src/llvm/func.c
+++ b/src/llvm/func.c
@@ -9,6 +9,21 @@
 #include <sys/log.h>
 #include <llvm/func.h>
 
+LLVMLocalScope* new_local_scope(LLVMLocalScope* parent) {
+    LLVMLocalScope* scope = malloc(sizeof(LLVMLocalScope));
+
+    scope->func_scope = parent->func_scope;
+    scope->vars = g_hash_table_new(g_str_hash, g_str_equal);
+    scope->parent_scope = parent;
+
+    return scope;
+}
+
+void delete_local_scope(LLVMLocalScope* scope) {
+    g_hash_table_destroy(scope->vars);
+    free(scope);
+}
+
 static LLVMValueRef get_parameter(const LLVMFuncScope* scope, const char* name) {
     if (g_hash_table_contains(scope->params, name)) {
         return g_hash_table_lookup(scope->params, name);
@@ -124,7 +139,9 @@ BackendError impl_func(LLVMBackendCompileUnit* unit, LLVMGlobalScope* global_sco
             g_hash_table_insert(func_scope->params, (gpointer) param->name, LLVMGetParam(llvm_func, i));
         }
 
-        // parse function body
+        // TODO: parse function body
+
+        LLVMDisposeBuilder(builder);
 
         // delete function scope GLib structs
         g_hash_table_destroy(func_scope->params);
diff --git a/src/llvm/func.h b/src/llvm/func.h
index ac27a83..e93eca4 100644
--- a/src/llvm/func.h
+++ b/src/llvm/func.h
@@ -22,6 +22,10 @@ typedef struct LLVMLocalScope_t {
     LLVMLocalScope* parent_scope;
 } LLVMLocalScope;
 
+LLVMLocalScope* new_local_scope(LLVMLocalScope* parent);
+
+void delete_local_scope(LLVMLocalScope*);
+
 LLVMValueRef get_variable(const LLVMLocalScope* scope, const char* name);
 
 #endif // LLVM_BACKEND_FUNC_H_
diff --git a/src/llvm/stmt.c b/src/llvm/stmt.c
index 471360c..a77ffed 100644
--- a/src/llvm/stmt.c
+++ b/src/llvm/stmt.c
@@ -6,11 +6,12 @@
 #include <llvm/func.h>
 #include <llvm/parser.h>
 #include <llvm/stmt.h>
+#include <llvm/expr.h>
 #include <sys/log.h>
 
-BackendError impl_assign_stmt(LLVMBackendCompileUnit* unit,
-                              const LLVMBuilderRef builder, const LLVMLocalScope* scope,
-                              const Assignment* assignment) {
+BackendError impl_assign_stmt(LLVMBackendCompileUnit *unit,
+                              const LLVMBuilderRef builder, const LLVMLocalScope *scope,
+                              const Assignment *assignment) {
     BackendError err = SUCCESS;
     DEBUG("implementing assignment for variabel: %s", assignment->variable->name);
 
@@ -21,15 +22,69 @@ BackendError impl_assign_stmt(LLVMBackendCompileUnit* unit,
         case VariableKindDeclaration:
         case VariableKindDefinition:
             const LLVMValueRef llvm_ptr =
-                get_variable(scope, assignment->variable->name);
-        LLVMBuildStore(builder, llvm_value, llvm_ptr);
-        break;
+                    get_variable(scope, assignment->variable->name);
+            LLVMBuildStore(builder, llvm_value, llvm_ptr);
+            break;
         case VariableKindBoxMember:
             // TODO: resolve LLVMValueRef from BoxAccess
-                break;
+            break;
     }
 
     return err;
 }
 
-BackendError impl_stmt(LLVMBackendCompileUnit* unit, Statement* stmt) {}
+BackendError impl_basic_block(LLVMBackendCompileUnit *unit,
+                              LLVMBuilderRef builder, LLVMLocalScope *scope,
+                              const Block *block, LLVMBasicBlockRef *llvm_block) {
+    BackendError err = SUCCESS;
+
+    LLVMLocalScope *block_scope = new_local_scope(scope);
+    // append a new LLVM basic block
+    *llvm_block = LLVMAppendBasicBlockInContext(unit->context, scope->func_scope->llvm_func,
+                                                "basic block");
+    LLVMPositionBuilderAtEnd(builder, *llvm_block);
+
+    for (size_t i = 0; i < block->statemnts->len; i++) {
+        Statement *stmt = ((Statement *) block->statemnts->data) + i;
+
+        // TODO: implement statement
+    }
+
+    delete_local_scope(block_scope);
+
+    return err;
+}
+
+BackendError impl_while(LLVMBackendCompileUnit *unit,
+                        LLVMBuilderRef builder, LLVMLocalScope *scope,
+                        const While *while_stmt) {
+    BackendError err;
+
+    // Create condition block
+    LLVMBasicBlockRef while_cond_block = LLVMAppendBasicBlockInContext(unit->context, scope->func_scope->llvm_func,
+                                                                       "loop.while.cond");
+    LLVMPositionBuilderAtEnd(builder, while_cond_block);
+    // Resolve condition in block to a variable
+    LLVMValueRef cond_result = NULL;
+    impl_expr(unit, scope, builder, &while_stmt->conditon, &cond_result);
+
+    // build body of loop
+    LLVMBasicBlockRef while_body_block = NULL;
+    err = impl_basic_block(unit, builder, scope, &while_stmt->block, &while_body_block);
+    LLVMPositionBuilderAtEnd(builder, while_body_block);
+    // jump back to condition after body end
+    LLVMBuildBr(builder, while_cond_block);
+
+    // builder will continue after the loop
+    LLVMBasicBlockRef while_after_block = LLVMAppendBasicBlockInContext(unit->context, scope->func_scope->llvm_func,
+                                                                        "loop.while.after");
+    // build conditional branch at end of condition block
+    LLVMPositionBuilderAtEnd(builder, while_cond_block);
+    LLVMBuildCondBr(builder, cond_result, while_body_block, while_after_block);
+
+    LLVMPositionBuilderAtEnd(builder, while_after_block);
+
+    return err;
+}
+
+BackendError impl_stmt(LLVMBackendCompileUnit *unit, Statement *stmt) {}