assertions.c

(78 lines)
   1 // This file defines how to compile assertions
   2 
   3 #include "../ast.h"
   4 #include "../config.h"
   5 #include "../environment.h"
   6 #include "../stdlib/datatypes.h"
   7 #include "../stdlib/text.h"
   8 #include "../stdlib/util.h"
   9 #include "../typecheck.h"
  10 #include "compilation.h"
  11 
  12 public
  13 Text_t compile_assertion(env_t *env, ast_t *ast) {
  14     ast_t *expr = Match(ast, Assert)->expr;
  15     ast_t *message = Match(ast, Assert)->message;
  16     const char *failure = NULL;
  17     switch (expr->tag) {
  18     case And: {
  19         DeclareMatch(and_, expr, And);
  20         return Texts(compile_statement(env, WrapAST(ast, Assert, .expr = and_->lhs, .message = message)),
  21                      compile_statement(env, WrapAST(ast, Assert, .expr = and_->rhs, .message = message)));
  22     }
  23     case Equals: failure = "!="; goto assert_comparison;
  24     case NotEquals: failure = "=="; goto assert_comparison;
  25     case LessThan: failure = ">="; goto assert_comparison;
  26     case LessThanOrEquals: failure = ">"; goto assert_comparison;
  27     case GreaterThan: failure = "<="; goto assert_comparison;
  28     case GreaterThanOrEquals:
  29         failure = "<";
  30         goto assert_comparison;
  31     assert_comparison: {
  32         binary_operands_t cmp = BINARY_OPERANDS(expr);
  33         type_t *lhs_t = get_type(env, cmp.lhs);
  34         type_t *rhs_t = get_type(with_enum_scope(env, lhs_t), cmp.rhs);
  35         type_t *operand_t;
  36         if (type_eq(lhs_t, rhs_t)) {
  37             operand_t = lhs_t;
  38         } else if (cmp.lhs->tag == Int && is_numeric_type(rhs_t)) {
  39             operand_t = rhs_t;
  40         } else if (cmp.rhs->tag == Int && is_numeric_type(lhs_t)) {
  41             operand_t = lhs_t;
  42         } else if (can_compile_to_type(with_enum_scope(env, lhs_t), cmp.rhs, lhs_t)) {
  43             operand_t = lhs_t;
  44         } else if (can_compile_to_type(env, cmp.lhs, rhs_t)) {
  45             operand_t = rhs_t;
  46         } else {
  47             code_err(ast, "I can't do comparisons between ", type_to_text(lhs_t), " and ", type_to_text(rhs_t));
  48         }
  49 
  50         ast_t *lhs_var = FakeAST(InlineCCode, .chunks = new (ast_list_t, .ast = FakeAST(TextLiteral, Text("_lhs"))),
  51                                  .type = operand_t);
  52         ast_t *rhs_var = FakeAST(InlineCCode, .chunks = new (ast_list_t, .ast = FakeAST(TextLiteral, Text("_rhs"))),
  53                                  .type = operand_t);
  54         ast_t *var_comparison = new (ast_t, .file = expr->file, .start = expr->start, .end = expr->end,
  55                                      .tag = expr->tag, .__data.Equals = {.lhs = lhs_var, .rhs = rhs_var});
  56         int64_t line = get_line_number(ast->file, ast->start);
  57         return Texts(
  58             "{ // assertion\n", compile_declaration(operand_t, Text("_lhs")), " = ",
  59             compile_to_type(env, cmp.lhs, operand_t), ";\n", "\n#line ", line, "\n",
  60             compile_declaration(operand_t, Text("_rhs")), " = ", compile_to_type(env, cmp.rhs, operand_t), ";\n",
  61             "\n#line ", line, "\n", "if (!(", compile_condition(env, var_comparison), "))\n", "#line ", line, "\n",
  62             Texts("fail_source(", quoted_str(ast->file->filename), ", ", (int64_t)(expr->start - expr->file->text),
  63                   ", ", (int64_t)(expr->end - expr->file->text), ", Text$concat(",
  64                   message ? compile_to_type(env, message, Type(TextType)) : Text("Text(\"This assertion failed!\")"),
  65                   ", Text(\" (\"), ", expr_as_text(Text("_lhs"), operand_t, Text("no")), ", Text(\" ", failure,
  66                   " \"), ", expr_as_text(Text("_rhs"), operand_t, Text("no")), ", Text(\")\")));\n"),
  67             "}\n");
  68     }
  69     default: {
  70         int64_t line = get_line_number(ast->file, ast->start);
  71         return Texts("if (!(", compile_condition(env, expr), "))\n", "#line ", line, "\n", "fail_source(",
  72                      quoted_str(ast->file->filename), ", ", (int64_t)(expr->start - expr->file->text), ", ",
  73                      (int64_t)(expr->end - expr->file->text), ", ",
  74                      message ? compile_to_type(env, message, Type(TextType)) : Text("Text(\"This assertion failed!\")"),
  75                      ");\n");
  76     }
  77     }
  78 }