diff options
| -rw-r--r-- | include/stdarg.h | 1 | ||||
| -rw-r--r-- | src/codegen.c | 42 | ||||
| -rw-r--r-- | src/parse.c | 10 | ||||
| -rw-r--r-- | tests/variadic_functions.sh | 20 |
4 files changed, 70 insertions, 3 deletions
diff --git a/include/stdarg.h b/include/stdarg.h index 609e6af..f879db1 100644 --- a/include/stdarg.h +++ b/include/stdarg.h @@ -16,6 +16,7 @@ typedef struct __ducc_va_list va_list[1]; #define va_start(args, start) __ducc_va_start(args, start) #define va_end(args) +#define va_arg(args, T) (*(T*)__ducc_va_arg(args, sizeof(T))) // For glibc: typedef va_list __gnuc_va_list; diff --git a/src/codegen.c b/src/codegen.c index 7adff5a..1c7abf7 100644 --- a/src/codegen.c +++ b/src/codegen.c @@ -447,6 +447,48 @@ static void codegen_func_call(CodeGen* g, AstNode* ast) { return; } + if (strcmp(func_name, "__ducc_va_arg") == 0) { + fprintf(g->out, " # __ducc_va_arg BEGIN\n"); + + // Evaluate va_list argument (first argument) + AstNode* va_list_arg = &ast->node_args->node_items[0]; + codegen_expr(g, va_list_arg, GenMode_rval); + fprintf(g->out, " pop rdi\n"); // rdi = pointer to va_list + + // Evaluate size argument (second argument) + AstNode* size_arg = &ast->node_args->node_items[1]; + codegen_expr(g, size_arg, GenMode_rval); + fprintf(g->out, " pop rsi\n"); // rsi = size + + int label = codegen_new_label(g); + + // Check if gp_offset < 48 (6 registers * 8 bytes) + fprintf(g->out, " mov eax, DWORD PTR [rdi]\n"); // eax = gp_offset + fprintf(g->out, " cmp eax, 48\n"); + fprintf(g->out, " jae .Lva_arg_overflow%d\n", label); + + // Fetch from register save area + fprintf(g->out, " mov rcx, QWORD PTR [rdi+16]\n"); // rcx = reg_save_area + fprintf(g->out, " movsx rdx, eax\n"); // rdx = gp_offset (sign-extended) + fprintf(g->out, " add rcx, rdx\n"); // rcx = reg_save_area + gp_offset + fprintf(g->out, " add eax, 8\n"); // gp_offset += 8 + fprintf(g->out, " mov DWORD PTR [rdi], eax\n"); // store updated gp_offset + fprintf(g->out, " mov rax, rcx\n"); // return pointer to argument + fprintf(g->out, " jmp .Lva_arg_end%d\n", label); + + // Fetch from overflow area (stack) + fprintf(g->out, ".Lva_arg_overflow%d:\n", label); + fprintf(g->out, " mov rcx, QWORD PTR [rdi+8]\n"); // rcx = overflow_arg_area + fprintf(g->out, " mov rax, rcx\n"); // return pointer to argument + fprintf(g->out, " add rcx, 8\n"); // overflow_arg_area += 8 + fprintf(g->out, " mov QWORD PTR [rdi+8], rcx\n"); // store updated overflow_arg_area + + fprintf(g->out, ".Lva_arg_end%d:\n", label); + fprintf(g->out, " push rax\n"); + fprintf(g->out, " # __ducc_va_arg END\n"); + return; + } + AstNode* args = ast->node_args; int gp_regs = 6; diff --git a/src/parse.c b/src/parse.c index b201aaf..c602073 100644 --- a/src/parse.c +++ b/src/parse.c @@ -165,8 +165,11 @@ static Parser* parser_new(TokenArray* tokens) { Func* va_start_func = funcs_push_new(&p->funcs); va_start_func->name = "__ducc_va_start"; - va_start_func->ty = calloc(1, sizeof(Type)); - va_start_func->ty->kind = TypeKind_void; + va_start_func->ty = type_new_func(type_new(TypeKind_void), NULL); + + Func* va_arg_func = funcs_push_new(&p->funcs); + va_arg_func->name = "__ducc_va_arg"; + va_arg_func->ty = type_new_func(type_new_ptr(type_new(TypeKind_void)), NULL); return p; } @@ -524,6 +527,7 @@ static bool is_type_token(Parser* p, Token* tok) { } static Type* parse_type_name(Parser* p); +static AstNode* parse_cast_expr(Parser* p); static AstNode* parse_prefix_expr(Parser* p) { TokenKind op = peek_token(p)->kind; @@ -540,7 +544,7 @@ static AstNode* parse_prefix_expr(Parser* p) { AstNode* operand = parse_prefix_expr(p); return ast_new_ref_expr(operand); } else if (consume_token_if(p, TokenKind_star)) { - AstNode* operand = parse_prefix_expr(p); + AstNode* operand = parse_cast_expr(p); return ast_new_deref_expr(operand); } else if (consume_token_if(p, TokenKind_plusplus)) { AstNode* operand = parse_prefix_expr(p); diff --git a/tests/variadic_functions.sh b/tests/variadic_functions.sh index 4f899ee..155fc1a 100644 --- a/tests/variadic_functions.sh +++ b/tests/variadic_functions.sh @@ -29,3 +29,23 @@ int main() { return 0; } EOF + +test_exit_code 0 <<'EOF' +#include <stdarg.h> +#include <helpers.h> + +int sum(int n, ...) { + va_list args; + va_start(args, n); + int s = 0; + for (int i = 0; i < n; ++i) { + s += va_arg(args, int); + } + va_end(args); + return s; +} + +int main() { + ASSERT_EQ(400, sum(5, 100, 90, 80, 70, 60)); +} +EOF |