From 16fcd6c8e2feb328b752318613fe963694914d66 Mon Sep 17 00:00:00 2001
From: servostar <sven.vogel123@web.de>
Date: Thu, 16 May 2024 00:44:02 +0200
Subject: [PATCH] added backend lib

---
 src/codegen/backend.c | 72 +++++++++++++++++++++++++++++++++++++++++++
 src/codegen/backend.h | 68 ++++++++++++++++++++++++++++++++++++++++
 src/main.c            |  9 ++++++
 3 files changed, 149 insertions(+)
 create mode 100644 src/codegen/backend.c
 create mode 100644 src/codegen/backend.h

diff --git a/src/codegen/backend.c b/src/codegen/backend.c
new file mode 100644
index 0000000..c305961
--- /dev/null
+++ b/src/codegen/backend.c
@@ -0,0 +1,72 @@
+
+#include <codegen/backend.h>
+#include <sys/log.h>
+
+static struct CodegenBackend_t {
+    codegen_init init_func;
+    codegen_deinit deinit_func;
+    codegen codegen_func;
+    const char* name;
+} CodegenBackend;
+
+BackendError init_backend(void) {
+    DEBUG("initializing backend: %s", CodegenBackend.name);
+
+    if (CodegenBackend.init_func == NULL) {
+        ERROR("backend: %s is not properly initialized", CodegenBackend.name);
+        return NoBackend;
+    }
+
+    size_t code = CodegenBackend.init_func();
+
+    if (code) {
+        ERROR("failed to initialize backend: %s with code: %ld", CodegenBackend.name, code);
+        return Other;
+    }
+
+    return Success;
+}
+
+BackendError deinit_backend(void) {
+    DEBUG("undoing initializing of backend: %s", CodegenBackend.name);
+
+    if (CodegenBackend.deinit_func == NULL) {
+        ERROR("backend: %s is not properly initialized", CodegenBackend.name);
+        return NoBackend;
+    }
+
+    size_t code = CodegenBackend.deinit_func();
+
+    if (code) {
+        ERROR("failed to undo initialization of backend: %s with code: %ld", CodegenBackend.name, code);
+        return Other;
+    }
+
+    return Success;
+}
+
+BackendError set_backend(const codegen_init init_func, const codegen_deinit deinit_func, const codegen codegen_func, const char* name) {
+    CodegenBackend.init_func = init_func;
+    CodegenBackend.deinit_func = deinit_func;
+    CodegenBackend.codegen_func = codegen_func;
+    CodegenBackend.name = name;
+
+    return Success;
+}
+
+BackendError generate_code(const AST_NODE_PTR root, void** output) {
+    DEBUG("generating code with backend: %s", CodegenBackend.name);
+
+    if (CodegenBackend.codegen_func == NULL) {
+        ERROR("backend: %s is not properly initialized", CodegenBackend.name);
+        return NoBackend;
+    }
+
+    size_t code = CodegenBackend.codegen_func(root, output);
+    if (code) {
+        ERROR("code generation of backend: %s failed with code: %ld", CodegenBackend.name, code);
+        return Other;
+    }
+
+    return Success;
+}
diff --git a/src/codegen/backend.h b/src/codegen/backend.h
new file mode 100644
index 0000000..6e733c3
--- /dev/null
+++ b/src/codegen/backend.h
@@ -0,0 +1,68 @@
+
+#ifndef CODEGN_BACKEND_H_
+#define CODEGN_BACKEND_H_
+
+#include <ast/ast.h>
+
+typedef enum BackendError_t {
+    Success,
+    NoBackend,
+    BackendAlreadySet,
+    Other
+} BackendError;
+
+/**
+ * @brief Function called by the compiler backend to generate an intermediate format
+ *        from AST. Returns a custom container for its intermediate language.
+ */
+typedef size_t (*codegen)(const AST_NODE_PTR, void**);
+
+/**
+ * @brief Initialize the code generation backend.
+ */
+typedef size_t (*codegen_init)(void);
+
+/**
+ * @brief Undo initialization of code generation backend.
+ */
+typedef size_t (*codegen_deinit)(void);
+
+/**
+ * @brief Set the backend functions to use
+ * 
+ * @param init_func the function to call for initializing the backend 
+ * @param deinit_func the function to call for undoing the initialization of the backend 
+ * @param codegen_func the function to call when generating code
+ * @param name name of the backend
+ */
+[[nodiscard]]
+[[gnu::nonnull(1), gnu::nonnull(2), gnu::nonnull(3), gnu::nonnull(3)]]
+BackendError set_backend(const codegen_init init_func, const codegen_deinit deinit_func, const codegen codegen_func, const char* name);
+
+/**
+ * @brief Call the initialization function of the backend
+ * 
+ * @return BackendError 
+ */
+[[nodiscard]]
+BackendError init_backend(void);
+
+/**
+ * @brief Call the undo initialization function of the backend
+ * 
+ * @return BackendError 
+ */
+[[nodiscard]]
+BackendError deinit_backend(void);
+
+/**
+ * @brief Generate intermediate code with the registered backend
+ * 
+ * @param root the root node of the AST
+ * @param code output pointer to the intermediate code
+ * @return BackendError 
+ */
+[[nodiscard]]
+BackendError generate_code(const AST_NODE_PTR root, void** code);
+
+#endif // CODEGN_BACKEND_H_
diff --git a/src/main.c b/src/main.c
index 27bca44..45d991c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -4,6 +4,7 @@
 #include <yacc/parser.tab.h>
 #include <sys/col.h>
 #include <lex/util.h>
+#include <codegen/backend.h>
 
 #define LOG_LEVEL LOG_LEVEL_DEBUG
 
@@ -75,6 +76,14 @@ int main(int argc, char *argv[]) {
   root = AST_new_node(AST_Module, NULL);
   yyparse();
 
+  set_backend(NULL, NULL, NULL, "LLVM");
+
+  init_backend();
+
+  generate_code(root, NULL);
+
+  deinit_backend();
+
   FILE *output = fopen("test.txt", "w");
   AST_fprint_graphviz(output, root);
   fclose(output);