Add == for booleans (#490)

Akuli · Dec 26, 2023 · d62daf8 · d62daf8
1 parent b37d0ff
commit d62daf8
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Showing 6 changed files with 103 additions and 25 deletions.
diff --git a/self_hosted/create_llvm_ir.jou b/self_hosted/create_llvm_ir.jou
@@ -242,9 +242,13 @@ class AstToIR:
         if rhs_type->kind == TypeKind::Enum:
             rhs_type = int_type
 
-        got_numbers = lhs_type->is_number_type() and rhs_type->is_number_type()
-        got_pointers = lhs_type->is_pointer_type() and rhs_type->is_pointer_type()
-        assert got_numbers or got_pointers
+        if lhs_type == &bool_type and rhs_type == &bool_type:
+            # bools are 1-bit integers in llvm
+            if op == AstExpressionKind::Eq:
+                return LLVMBuildICmp(self->builder, LLVMIntPredicate::EQ, lhs, rhs, "eq")
+            if op == AstExpressionKind::Ne:
+                return LLVMBuildICmp(self->builder, LLVMIntPredicate::NE, lhs, rhs, "ne")
+            assert False
 
         if lhs_type->kind == TypeKind::FloatingPoint and rhs_type->kind == TypeKind::FloatingPoint:
             if op == AstExpressionKind::Add:

diff --git a/self_hosted/typecheck.jou b/self_hosted/typecheck.jou
@@ -688,6 +688,7 @@ def check_binop(
         do_what = "compare"
         result_is_bool = True
 
+    got_bools = lhs_types->original_type == &bool_type and rhs_types->original_type == &bool_type
     got_integers = lhs_types->original_type->is_integer_type() and rhs_types->original_type->is_integer_type()
     got_numbers = lhs_types->original_type->is_number_type() and rhs_types->original_type->is_number_type()
     got_enums = lhs_types->original_type->kind == TypeKind::Enum and rhs_types->original_type->kind == TypeKind::Enum
@@ -703,7 +704,7 @@ def check_binop(
     )
 
     if (
-        (not got_numbers and not got_enums and not got_pointers)
+        (not got_bools and not got_numbers and not got_enums and not got_pointers)
         or (op != AstExpressionKind::Eq and op != AstExpressionKind::Ne and not got_numbers)
     ):
         message: byte[500]
@@ -714,7 +715,9 @@ def check_binop(
         )
         fail(location, message)
 
-    if got_integers:
+    if got_bools:
+        cast_type = &bool_type
+    elif got_integers:
         size = max(lhs_types->original_type->size_in_bits, rhs_types->original_type->size_in_bits)
         if (
             lhs_types->original_type->kind == TypeKind::SignedInteger

diff --git a/src/build_cfg.c b/src/build_cfg.c
@@ -167,6 +167,41 @@ static const LocalVariable *build_cast(
     assert(0);
 }
 
+static const LocalVariable *build_bool_eq(struct State *st, Location location, const LocalVariable *a, const LocalVariable *b)
+{
+    assert(a->type == boolType);
+    assert(b->type == boolType);
+
+    /*
+    Pseudo code:
+
+        if a:
+            result = b
+        else:
+            result = not b
+    */
+    const LocalVariable *result = add_local_var(st, boolType);
+
+    CfBlock *atrue = add_block(st);
+    CfBlock *afalse = add_block(st);
+    CfBlock *done = add_block(st);
+
+    // if a:
+    add_jump(st, a, atrue, afalse, atrue);
+
+    // result = b
+    add_unary_op(st, location, CF_VARCPY, b, result);
+
+    // else:
+    add_jump(st, NULL, done, done, afalse);
+
+    // result = not b
+    add_unary_op(st, location, CF_BOOL_NEGATE, b, result);
+
+    add_jump(st, NULL, done, done, done);
+    return result;
+}
+
 static const LocalVariable *build_binop(
     struct State *st,
     enum AstExpressionKind op,
@@ -175,32 +210,43 @@ static const LocalVariable *build_binop(
     const LocalVariable *rhs,
     const Type *result_type)
 {
+    bool got_bools = lhs->type == boolType && rhs->type == boolType;
     bool got_numbers = is_number_type(lhs->type) && is_number_type(rhs->type);
     bool got_pointers = is_pointer_type(lhs->type) && is_pointer_type(rhs->type);
-    assert(got_numbers || got_pointers);
+    assert(got_bools || got_numbers || got_pointers);
 
-    enum CfInstructionKind k;
     bool negate = false;
     bool swap = false;
 
-    switch(op) {
-        case AST_EXPR_ADD: k = CF_NUM_ADD; break;
-        case AST_EXPR_SUB: k = CF_NUM_SUB; break;
-        case AST_EXPR_MUL: k = CF_NUM_MUL; break;
-        case AST_EXPR_DIV: k = CF_NUM_DIV; break;
-        case AST_EXPR_MOD: k = CF_NUM_MOD; break;
-        case AST_EXPR_EQ: k = CF_NUM_EQ; break;
-        case AST_EXPR_NE: k = CF_NUM_EQ; negate=true; break;
-        case AST_EXPR_LT: k = CF_NUM_LT; break;
-        case AST_EXPR_GT: k = CF_NUM_LT; swap=true; break;
-        case AST_EXPR_LE: k = CF_NUM_LT; negate=true; swap=true; break;
-        case AST_EXPR_GE: k = CF_NUM_LT; negate=true; break;
-        default: assert(0);
+    const LocalVariable *destvar;
+    if (got_bools) {
+        assert(result_type == boolType);
+        destvar = build_bool_eq(st, location, lhs, rhs);
+        switch(op) {
+            case AST_EXPR_EQ: break;
+            case AST_EXPR_NE: negate=true; break;
+            default: assert(0); break;
+        }
+    } else {
+        destvar = add_local_var(st, result_type);
+        enum CfInstructionKind k;
+        switch(op) {
+            case AST_EXPR_ADD: k = CF_NUM_ADD; break;
+            case AST_EXPR_SUB: k = CF_NUM_SUB; break;
+            case AST_EXPR_MUL: k = CF_NUM_MUL; break;
+            case AST_EXPR_DIV: k = CF_NUM_DIV; break;
+            case AST_EXPR_MOD: k = CF_NUM_MOD; break;
+            case AST_EXPR_EQ: k = CF_NUM_EQ; break;
+            case AST_EXPR_NE: k = CF_NUM_EQ; negate=true; break;
+            case AST_EXPR_LT: k = CF_NUM_LT; break;
+            case AST_EXPR_GT: k = CF_NUM_LT; swap=true; break;
+            case AST_EXPR_LE: k = CF_NUM_LT; negate=true; swap=true; break;
+            case AST_EXPR_GE: k = CF_NUM_LT; negate=true; break;
+            default: assert(0);
+        }
+        add_binary_op(st, location, k, swap?rhs:lhs, swap?lhs:rhs, destvar);
     }
 
-    const LocalVariable *destvar = add_local_var(st, result_type);
-    add_binary_op(st, location, k, swap?rhs:lhs, swap?lhs:rhs, destvar);
-
     if (!negate)
         return destvar;
 

diff --git a/src/typecheck.c b/src/typecheck.c
@@ -696,6 +696,7 @@ static const Type *check_binop(
         assert(0);
     }
 
+    bool got_bools = lhstypes->type == boolType && rhstypes->type == boolType;
     bool got_integers = is_integer_type(lhstypes->type) && is_integer_type(rhstypes->type);
     bool got_numbers = is_number_type(lhstypes->type) && is_number_type(rhstypes->type);
     bool got_enums = lhstypes->type->kind == TYPE_ENUM && rhstypes->type->kind == TYPE_ENUM;
@@ -711,13 +712,15 @@ static const Type *check_binop(
     );
 
     if (
-        (!got_numbers && !got_enums && !got_pointers)
-        || (got_enums && op != AST_EXPR_EQ && op != AST_EXPR_NE)
+        (!got_bools && !got_numbers && !got_enums && !got_pointers)
+        || ((got_bools || got_enums) && op != AST_EXPR_EQ && op != AST_EXPR_NE)
         || (got_pointers && op != AST_EXPR_EQ && op != AST_EXPR_NE && op != AST_EXPR_GT && op != AST_EXPR_GE && op != AST_EXPR_LT && op != AST_EXPR_LE)
     )
         fail(location, "wrong types: cannot %s %s and %s", do_what, lhstypes->type->name, rhstypes->type->name);
 
     const Type *cast_type = NULL;
+    if (got_bools)
+        cast_type = boolType;
     if (got_integers) {
         cast_type = get_integer_type(
             max(lhstypes->type->data.width_in_bits, rhstypes->type->data.width_in_bits),

diff --git a/tests/should_succeed/bool_eq_bool.jou b/tests/should_succeed/bool_eq_bool.jou
@@ -0,0 +1,19 @@
+import "stdlib/io.jou"
+
+def do_stuff(a: bool, b: bool) -> None:
+    if a == b:
+        puts("Hi")
+
+def main() -> int:
+    do_stuff(False, False)  # Output: Hi
+
+    # Output: 1001
+    printf(
+        "%d%d%d%d\n",
+        True == True,       # Warning: this code will never run
+        True == False,      # Warning: this code will never run
+        False == True,      # Warning: this code will never run
+        False == False,     # Warning: this code will never run
+    )
+
+    return 0
diff --git a/tests/wrong_type/bool_plus_bool.jou b/tests/wrong_type/bool_plus_bool.jou
@@ -0,0 +1,3 @@
+def main() -> int:
+    x = True + False  # Error: wrong types: cannot add bool and bool
+    return 0