diff options
| author | Carlos Maniero <carlosmaniero@gmail.com> | 2023-04-20 13:42:10 -0300 |
|---|---|---|
| committer | Johnny Richard <johnny@johnnyrichard.com> | 2023-04-20 18:57:43 +0200 |
| commit | 219dfdfdc98529ce173f894b79d88919a65c2808 (patch) | |
| tree | 8792c686d05b107875d43f570ed6666f91dda19e /src/gas_assembly_generator.c | |
| parent | 58da5195ef7d517f851ebfabfe79cfa27c0b2dde (diff) | |
parser: Create the literal node type
Since we want to extend our code to support multiple kind of expression
it does not make sense that the return statement always return a number.
For now on, return statement has an ast_node_t as argument, meaning that
it could be anything. The literal_node_t was also implemented in order
to keep the application behavior.
Following the C's calling convention the literal values are stored at
%eax and the return takes this argument to do anything it is needed.
Signed-off-by: Carlos Maniero <carlosmaniero@gmail.com>
Reviewed-by: Johnny Richard <johnny@johnnyrichard.com>
Diffstat (limited to 'src/gas_assembly_generator.c')
| -rw-r--r-- | src/gas_assembly_generator.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/src/gas_assembly_generator.c b/src/gas_assembly_generator.c index afbfebd..755b0be 100644 --- a/src/gas_assembly_generator.c +++ b/src/gas_assembly_generator.c @@ -22,6 +22,7 @@ static void gas_assembly_generator_visit_function(ast_visitor_t *visitor, ast_function_declaration_t *func); static void gas_assembly_generator_visit_return_stmt(ast_visitor_t *visitor, ast_return_stmt_t *return_stmt); +static void gas_assembly_generator_visit_literal(ast_visitor_t *visitor, ast_literal_t *return_stmt); void gas_assembly_generator_init(gas_assembly_generator_t *gen, FILE *out) @@ -29,6 +30,7 @@ gas_assembly_generator_init(gas_assembly_generator_t *gen, FILE *out) assert(gen && out); gen->super = (ast_visitor_t) { .visit_function = &gas_assembly_generator_visit_function, + .visit_literal = &gas_assembly_generator_visit_literal, .visit_return_stmt = &gas_assembly_generator_visit_return_stmt }; gen->out = out; @@ -59,8 +61,23 @@ gas_assembly_generator_visit_return_stmt(ast_visitor_t *visitor, ast_return_stmt assert(visitor && return_stmt); gas_assembly_generator_t *gen = (gas_assembly_generator_t *) visitor; + ast_visitor_visit(visitor, return_stmt->argument); + + fprintf(gen->out, " mov %%eax, %%ebx\n"); + fprintf(gen->out, " mov $1, %%al\n"); fprintf(gen->out, " mov $1, %%al\n"); - fprintf(gen->out, " mov $%d, %%ebx\n", return_stmt->number); fprintf(gen->out, " int $0x80\n"); } +static void +gas_assembly_generator_visit_literal(ast_visitor_t *visitor, ast_literal_t *literal) +{ + gas_assembly_generator_t *gen = (gas_assembly_generator_t *) visitor; + switch (literal->kind) { + case AST_LITERAL_INTEGER: + fprintf(gen->out, " mov $%d, %%eax\n", literal->value.integer); + return; + default: + assert(false && "No code generation strategy."); + } +} |