From a71385d5088d7fd85069eeb9d57c48cb334cf5bc Mon Sep 17 00:00:00 2001
From: servostar <sven.vogel123@web.de>
Date: Thu, 10 Oct 2024 21:13:57 +0200
Subject: [PATCH] feat: added support for entry point flag in ld.lld

---
 src/link/lldc/lldc.c |  8 +++++++-
 src/llvm/link/lld.c  |  1 +
 src/mem/cache.c      | 16 ++++++++++++++++
 src/mem/cache.h      |  9 +++++++++
 src/set/set.c        | 16 +++++++++++++++-
 src/set/types.h      |  2 ++
 6 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/src/link/lldc/lldc.c b/src/link/lldc/lldc.c
index aad0e56..274ecc4 100644
--- a/src/link/lldc/lldc.c
+++ b/src/link/lldc/lldc.c
@@ -11,7 +11,8 @@
 extern int lld_main(int Argc, const char **Argv, const char **outstr);
 
 const char* FLAGS[] = {
-    "--fatal-warnings"
+    "--fatal-warnings",
+    "--nostdlib"
 };
 
 const char* get_optimization_level_string(TargetConfig* config)
@@ -35,6 +36,11 @@ bool lldc_link(TargetConfig* target_config, TargetLinkConfig* link_config) {
         g_array_append_val(arguments, colored_diagnostics);
     }
 
+    if (link_config->entry != NULL) {
+        char* colored_diagnostics = mem_asprintf(MemoryNamespaceLld, "--entry=%s", link_config->entry);
+        g_array_append_val(arguments, colored_diagnostics);
+    }
+
     const char* optimization_level = get_optimization_level_string(target_config);
     g_array_append_val(arguments, optimization_level);
 
diff --git a/src/llvm/link/lld.c b/src/llvm/link/lld.c
index 385304c..90b4c62 100644
--- a/src/llvm/link/lld.c
+++ b/src/llvm/link/lld.c
@@ -55,6 +55,7 @@ TargetLinkConfig* lld_create_link_config(__attribute__((unused))
       mem_new_g_array(MemoryNamespaceLld, sizeof(char*));
     config->colorize = stdout_supports_ansi_esc();
     config->driver   = target_config->driver;
+    config->entry    = module->entry;
 
     // append build object file
     char* basename = g_strjoin(".", target_config->name, "o", NULL);
diff --git a/src/mem/cache.c b/src/mem/cache.c
index dcbcf0f..fab3c87 100644
--- a/src/mem/cache.c
+++ b/src/mem/cache.c
@@ -369,3 +369,19 @@ GHashTable* mem_new_g_hash_table(MemoryNamespaceName name, GHashFunc hash_func,
 
     return namespace_new_g_hash_table(cache, hash_func, key_equal_func);
 }
+
+char* mem_asprintf(MemoryNamespaceName name, const char* format, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    char* buffer = NULL;
+    int chars = vasprintf(&buffer, format, args);
+
+    va_end(args);
+
+    char* cached = mem_clone(name, buffer, chars);
+
+    free(buffer);
+
+    return cached;
+}
diff --git a/src/mem/cache.h b/src/mem/cache.h
index c2c6f58..b91025c 100644
--- a/src/mem/cache.h
+++ b/src/mem/cache.h
@@ -87,6 +87,15 @@ char* mem_strdup(MemoryNamespaceName name, char* string);
  */
 void* mem_clone(MemoryNamespaceName name, void* data, size_t size);
 
+/**
+ * @brief Write formatted output into a dynamically allocated buffer managed by this cache,
+ * @param name
+ * @param format
+ * @param ...
+ * @return
+ */
+char* mem_asprintf(MemoryNamespaceName name, const char* format, ...);
+
 void print_memory_statistics();
 
 GArray* mem_new_g_array(MemoryNamespaceName name, guint element_size);
diff --git a/src/set/set.c b/src/set/set.c
index 0eb0f95..6039e0e 100644
--- a/src/set/set.c
+++ b/src/set/set.c
@@ -2868,6 +2868,7 @@ Module* create_set(AST_NODE_PTR currentNode) {
     rootModule->variables = variables;
     rootModule->imports   = imports;
     rootModule->includes  = includes;
+    rootModule->entry     = NULL;
 
     DEBUG("created Module struct");
 
@@ -2922,11 +2923,24 @@ Module* create_set(AST_NODE_PTR currentNode) {
                     Function* function =
                       mem_alloc(MemoryNamespaceSet, sizeof(Function));
 
-                    if (createFunction(function, AST_get_node(currentNode, i))
+                    AST_NODE_PTR function_node = AST_get_node(currentNode, i);
+                    if (createFunction(function, function_node)
                         == SEMANTIC_ERROR) {
                         return NULL;
                     }
 
+                    if (function_node->annotation.kind == AnnotationKindArray) {
+                        if (AST_annotation_array_contains_flag(&function_node->annotation, "entry")) {
+
+                            if (rootModule->entry != NULL) {
+                                print_diagnostic(&function_node->location, Error, "Multiple functions marked as entry points");
+                                return NULL;
+                            }
+
+                            rootModule->entry = function->name;
+                        }
+                    }
+
                     g_hash_table_insert(rootModule->functions, function->name, function);
 
                     DEBUG("created function successfully");
diff --git a/src/set/types.h b/src/set/types.h
index a5a37e5..c836f37 100644
--- a/src/set/types.h
+++ b/src/set/types.h
@@ -602,6 +602,8 @@ typedef struct Module_t {
     // parent modules in descending order
     // root > submodule > current-module
     GArray* path;
+    // entry point symbol
+    char* entry;
 } Module;
 
 // .------------------------------------------------.