require extenally defined functions to be declared as external

dosisod · Oct 19, 2020 · f5e268b · f5e268b
1 parent d76d245
commit f5e268b
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diff --git a/docs/c-integration.md b/docs/c-integration.md
@@ -21,6 +21,8 @@ and in Skull:
 ```python
 # hello.sk
 
+external hello
+
 hello[]
 
 return 0
@@ -31,6 +33,7 @@ Now, to compile these files together:
 ```
 $ skull hello.sk -- hello.c
 $ ./hello
+hello from hello.c!
 ```
 
 Everything after `--` is passed as arguments to `cc`, in this case, `hello.c`.
@@ -41,6 +44,7 @@ Skull can also compile `.o` and `.so` files, but you will need to compile them y
 $ cc -c hello.c
 $ skull hello.sk -- hello.o
 $ ./hello
+hello from hello.c!
 ```
 
 For the time being, Skull can only run C functions prototypes like: `void f(void)`

diff --git a/docs/skull/llvm/ast.md b/docs/skull/llvm/ast.md
@@ -60,6 +60,12 @@ LLVMValueRef llvm_make_div(Variable *var, const Token *lhs, const Token *rhs)
 
 > Build LLVM for assining division of `lhs` and `rhs` to `var`.
 
+```c
+void declare_external_function(AstNode *node)
+```
+
+> Store function name of externaly declared function in `node`.
+
 ```c
 void llvm_make_function(AstNode *node)
 ```

diff --git a/skull/llvm/ast.c b/skull/llvm/ast.c
@@ -38,6 +38,10 @@ static LLVMModuleRef module;
 
 extern LLVMBuilderRef builder;
 
+#define EXTERNAL_FUNCTIONS_MAX 256
+unsigned external_functions = 0;
+char *external_function[EXTERNAL_FUNCTIONS_MAX] = {0};
+
 void llvm_assign_identifier(Variable *const var, const AstNode *const node);
 
 /*
@@ -61,6 +65,12 @@ void str_to_llvm_ir(char *const str_, LLVMValueRef func_, LLVMModuleRef module_)
 	node_to_llvm_ir(node);
 	free_ast_tree(node);
 	free(str);
+
+	char **current_function = external_function;
+	while (*current_function) {
+		free(*current_function);
+		current_function++;
+	}
 }
 
 /*
@@ -82,6 +92,10 @@ void node_to_llvm_ir(AstNode *node) {
 			llvm_make_if(node);
 		}
 
+		else if (node->node_type == AST_NODE_EXTERNAL) {
+			declare_external_function(node);
+		}
+
 		else if (
 			node->node_type == AST_NODE_IDENTIFIER &&
 			node->token->next &&
@@ -375,6 +389,18 @@ LLVMValueRef llvm_make_div(Variable *var, const Token *lhs, const Token *rhs) {
 	return div;
 }
 
+/*
+Store function name of externaly declared function in `node`.
+*/
+void declare_external_function(AstNode *node) {
+	char32_t *const tmp = token_str(node->token->next);
+	char *const func_name = c32stombs(tmp);
+	free(tmp);
+
+	external_function[external_functions] = func_name;
+	external_functions++;
+}
+
 /*
 Builds a function declaration from `node`.
 */
@@ -390,6 +416,19 @@ void llvm_make_function(AstNode *node) {
 
 	char32_t *const tmp = token_str(node->token);
 	char *const func_name = c32stombs(tmp);
+
+	char **current_function = external_function;
+	while (*current_function) {
+		if (strcmp(*current_function, func_name) == 0) {
+			break;
+		}
+		current_function++;
+	}
+
+	if (!*current_function) {
+		PANIC(FMT_ERROR(U"external function \"%\" missing external declaration", { .real = tmp }));
+	}
+
 	free(tmp);
 
 	LLVMValueRef function = LLVMAddFunction(

diff --git a/skull/llvm/ast.h b/skull/llvm/ast.h
@@ -8,6 +8,7 @@
 void str_to_llvm_ir(char *const, LLVMValueRef, LLVMModuleRef);
 void node_to_llvm_ir(AstNode *);
 
+void declare_external_function(AstNode *);
 void llvm_make_return(AstNode *);
 void llvm_make_var_def(AstNode **);
 void llvm_make_if(AstNode *);

diff --git a/test/docs/c-integration/hello.sk b/test/docs/c-integration/hello.sk
@@ -1,3 +1,5 @@
+external hello
+
 hello[]
 
 return 0
diff --git a/test/sh/_multiple_externals.sk.ll b/test/sh/_multiple_externals.sk.ll
@@ -0,0 +1,6 @@
+; ModuleID = './test/sh/multiple_externals.sk'
+source_filename = "./test/sh/multiple_externals.sk"
+
+define i64 @main() {
+entry:
+}
diff --git a/test/sh/error/missing_external.sk b/test/sh/error/missing_external.sk
@@ -0,0 +1 @@
+x[]
diff --git a/test/sh/main.sh b/test/sh/main.sh
@@ -71,6 +71,7 @@ test "mult_int_consts.sk"
 test "mult_float_consts.sk"
 test "div_int_consts.sk"
 test "div_float_consts.sk"
+test "multiple_externals.sk"
 
 test_err "missing_file_extension_fails" "missing required \".sk\" extension, exiting"
 test_err ".sk" "\".sk\" is not a valid name, exiting"
@@ -102,6 +103,7 @@ test_err "error/sub_mismatched_consts.sk" "Compilation error: cannot subtract \"
 test_err "error/mult_mismatched_consts.sk" "Compilation error: cannot multiply \"1\" and \"\"fail\"\""
 test_err "error/div_mismatched_consts.sk" "Compilation error: cannot divide \"1\" and \"\"fail\"\""
 test_err "error/assign_mismatch_var_type.sk" "Compilation error: type mismatch: expected type \"bool\""
+test_err "error/missing_external.sk" "Compilation error: external function \"x\" missing external declaration"
 
 touch test/sh/error/read_protected.sk
 chmod 200 test/sh/error/read_protected.sk

diff --git a/test/sh/multiple_externals.sk b/test/sh/multiple_externals.sk
@@ -0,0 +1,2 @@
+external a
+external b
diff --git a/test/sh/nodes_after_call_not_ignored.sk b/test/sh/nodes_after_call_not_ignored.sk
@@ -1,3 +1,5 @@
+external x
+
 x[]
 
 return 1
diff --git a/test/sh/simple_function_call.sk b/test/sh/simple_function_call.sk
@@ -1 +1,3 @@
+external x
+
 x[]