Add `#+feature integer-division-by-zero:<string>`

src/build_settings.cpp

@@ -352,12 +352,24 @@ u64 get_vet_flag_from_name(String const &name) {
 enum OptInFeatureFlags : u64 {
 	OptInFeatureFlag_NONE            = 0,
 	OptInFeatureFlag_DynamicLiterals = 1u<<0,
+
+	OptInFeatureFlag_IntegerDivisionByZero_Trap = 1u<<1,
+	OptInFeatureFlag_IntegerDivisionByZero_Zero = 1u<<2,
+
+	OptInFeatureFlag_IntegerDivisionByZero_ALL = OptInFeatureFlag_IntegerDivisionByZero_Trap|OptInFeatureFlag_IntegerDivisionByZero_Zero,
+
 };
 
 u64 get_feature_flag_from_name(String const &name) {
 	if (name == "dynamic-literals") {
 		return OptInFeatureFlag_DynamicLiterals;
 	}
+	if (name == "integer-division-by-zero:trap") {
+		return OptInFeatureFlag_IntegerDivisionByZero_Trap;
+	}
+	if (name == "integer-division-by-zero:zero") {
+		return OptInFeatureFlag_IntegerDivisionByZero_Zero;
+	}
 	return OptInFeatureFlag_NONE;
 }
 

src/check_expr.cpp

@@ -129,7 +129,7 @@ gb_internal bool check_is_castable_to(CheckerContext *c, Operand *operand, Type
 
 gb_internal bool is_exact_value_zero(ExactValue const &v);
 
-gb_internal IntegerDivisionByZeroKind check_for_integer_division_by_zero(Ast *node);
+gb_internal IntegerDivisionByZeroKind check_for_integer_division_by_zero(CheckerContext *c, Ast *node);
 
 enum LoadDirectiveResult {
 	LoadDirective_Success  = 0,
@@ -4311,7 +4311,7 @@ gb_internal void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Typ
 
 			if (fail) {
 				if (is_type_integer(x->type) || (x->mode == Addressing_Constant && x->value.kind == ExactValue_Integer)) {
-					if (check_for_integer_division_by_zero(node) == IntegerDivisionByZero_Zero) {
+					if (check_for_integer_division_by_zero(c, node) == IntegerDivisionByZero_Zero) {
 						// Okay
 						break;
 					}
@@ -4371,7 +4371,7 @@ gb_internal void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Typ
 		match_exact_values(&a, &b);
 
 
-		if (check_for_integer_division_by_zero(node) == IntegerDivisionByZero_Zero &&
+		if (check_for_integer_division_by_zero(c, node) == IntegerDivisionByZero_Zero &&
 		    b.kind == ExactValue_Integer && big_int_is_zero(&b.value_integer) &&
 		    (op.kind == Token_QuoEq || op.kind == Token_Mod || op.kind == Token_ModMod)) {
 		    	if (op.kind == Token_QuoEq) {
@@ -9638,8 +9638,15 @@ gb_internal bool check_for_dynamic_literals(CheckerContext *c, Ast *node, AstCom
 	return cl->elems.count > 0;
 }
 
-gb_internal IntegerDivisionByZeroKind check_for_integer_division_by_zero(Ast *node) {
+gb_internal IntegerDivisionByZeroKind check_for_integer_division_by_zero(CheckerContext *c, Ast *node) {
 	// TODO(bill): per file `#+feature` flags
+	u64 flags = check_feature_flags(c, node);
+	if ((flags & OptInFeatureFlag_IntegerDivisionByZero_Trap) != 0) {
+		return IntegerDivisionByZero_Trap;
+	}
+	if ((flags & OptInFeatureFlag_IntegerDivisionByZero_Zero) != 0) {
+		return IntegerDivisionByZero_Zero;
+	}
 	return build_context.integer_division_by_zero_behaviour;
 }
 

src/llvm_backend_expr.cpp

@@ -283,8 +283,26 @@ gb_internal lbValue lb_emit_unary_arith(lbProcedure *p, TokenKind op, lbValue x,
 	return res;
 }
 
-gb_internal IntegerDivisionByZeroKind lb_check_for_integer_division_by_zero(lbProcedure *p) {
-	// TODO(bill): per file `#+feature` flags
+gb_internal IntegerDivisionByZeroKind lb_check_for_integer_division_by_zero_behaviour(lbProcedure *p) {
+	AstFile *file = nullptr;
+
+	if (p->body && p->body->file()) {
+		file = p->body->file();
+	} else if (p->type_expr && p->type_expr->file()) {
+		file = p->type_expr->file();
+	} else if (p->entity && p->entity->file) {
+		file = p->entity->file;
+	}
+
+	if (file != nullptr && file->feature_flags_set) {
+		u64 flags = file->feature_flags;
+		if (flags & OptInFeatureFlag_IntegerDivisionByZero_Trap) {
+			return IntegerDivisionByZero_Trap;
+		}
+		if (flags & OptInFeatureFlag_IntegerDivisionByZero_Zero) {
+			return IntegerDivisionByZero_Zero;
+		}
+	}
 	return build_context.integer_division_by_zero_behaviour;
 }
 
@@ -1143,7 +1161,7 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L
 
 	incoming_values[1] = zero;
 
-	switch (lb_check_for_integer_division_by_zero(p))  {
+	switch (lb_check_for_integer_division_by_zero_behaviour(p))  {
 	case IntegerDivisionByZero_Trap:
 		lb_call_intrinsic(p, "llvm.trap", nullptr, 0, nullptr, 0);
 		LLVMBuildUnreachable(p->builder);
@@ -1158,7 +1176,7 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L
 
 	LLVMValueRef res = incoming_values[0];
 
-	switch (lb_check_for_integer_division_by_zero(p))  {
+	switch (lb_check_for_integer_division_by_zero_behaviour(p))  {
 	case IntegerDivisionByZero_Trap:
 		res = incoming_values[0];
 		break;
@@ -1226,7 +1244,7 @@ gb_internal LLVMValueRef lb_integer_modulo(lbProcedure *p, LLVMValueRef lhs, LLV
 	*/
 	incoming_values[1] = lhs;
 
-	switch (lb_check_for_integer_division_by_zero(p))  {
+	switch (lb_check_for_integer_division_by_zero_behaviour(p))  {
 	case IntegerDivisionByZero_Trap:
 		lb_call_intrinsic(p, "llvm.trap", nullptr, 0, nullptr, 0);
 		LLVMBuildUnreachable(p->builder);
@@ -1241,7 +1259,7 @@ gb_internal LLVMValueRef lb_integer_modulo(lbProcedure *p, LLVMValueRef lhs, LLV
 
 	LLVMValueRef res = incoming_values[0];
 
-	switch (lb_check_for_integer_division_by_zero(p))  {
+	switch (lb_check_for_integer_division_by_zero_behaviour(p))  {
 	case IntegerDivisionByZero_Trap:
 		res = incoming_values[0];
 		break;

src/parser.cpp

@@ -6289,7 +6289,7 @@ gb_internal bool parse_build_tag(Token token_for_pos, String s) {
 	return any_correct;
 }
 
-gb_internal String vet_tag_get_token(String s, String *out) {
+gb_internal String vet_tag_get_token(String s, String *out, bool allow_colon) {
 	s = string_trim_whitespace(s);
 	isize n = 0;
 	while (n < s.len) {
@@ -6297,7 +6297,7 @@ gb_internal String vet_tag_get_token(String s, String *out) {
 		isize width = utf8_decode(&s[n], s.len-n, &rune);
 		if (n == 0 && rune == '!') {
 
-		} else if (!rune_is_letter(rune) && !rune_is_digit(rune) && rune != '-') {
+		} else if (!rune_is_letter(rune) && !rune_is_digit(rune) && rune != '-' && !(allow_colon && rune == ':')) {
 			isize k = gb_max(gb_max(n, width), 1);
 			*out = substring(s, k, s.len);
 			return substring(s, 0, k);
@@ -6323,7 +6323,7 @@ gb_internal u64 parse_vet_tag(Token token_for_pos, String s) {
 	u64 vet_not_flags = 0;
 
 	while (s.len > 0) {
-		String p = string_trim_whitespace(vet_tag_get_token(s, &s));
+		String p = string_trim_whitespace(vet_tag_get_token(s, &s, /*allow_colon*/false));
 		if (p.len == 0) {
 			break;
 		}
@@ -6391,7 +6391,7 @@ gb_internal u64 parse_feature_tag(Token token_for_pos, String s) {
 	u64 feature_not_flags = 0;
 
 	while (s.len > 0) {
-		String p = string_trim_whitespace(vet_tag_get_token(s, &s));
+		String p = string_trim_whitespace(vet_tag_get_token(s, &s, /*allow_colon*/true));
 		if (p.len == 0) {
 			break;
 		}
@@ -6413,26 +6413,44 @@ gb_internal u64 parse_feature_tag(Token token_for_pos, String s) {
 			} else {
 				feature_flags     |= flag;
 			}
+			if (is_notted) {
+				switch (flag) {
+				case OptInFeatureFlag_IntegerDivisionByZero_Trap:
+				case OptInFeatureFlag_IntegerDivisionByZero_Zero:
+					syntax_error(token_for_pos, "Feature flag does not support notting with '!' - '%.*s'", LIT(p));
+					break;
+				}
+			}
 		} else {
 			ERROR_BLOCK();
 			syntax_error(token_for_pos, "Invalid feature flag name: %.*s", LIT(p));
 			error_line("\tExpected one of the following\n");
 			error_line("\tdynamic-literals\n");
+			error_line("\tinteger-division-by-zero:trap\n");
+			error_line("\tinteger-division-by-zero:zero\n");
 			return OptInFeatureFlag_NONE;
 		}
 	}
 
+	u64 res = OptInFeatureFlag_NONE;
+
 	if (feature_flags == 0 && feature_not_flags == 0) {
-		return OptInFeatureFlag_NONE;
-	}
-	if (feature_flags == 0 && feature_not_flags != 0) {
-		return OptInFeatureFlag_NONE &~ feature_not_flags;
+		res = OptInFeatureFlag_NONE;
+	} else if (feature_flags == 0 && feature_not_flags != 0) {
+		res = OptInFeatureFlag_NONE &~ feature_not_flags;
+	} else if (feature_flags != 0 && feature_not_flags == 0) {
+		res = feature_flags;
+	} else {
+		GB_ASSERT(feature_flags != 0 && feature_not_flags != 0);
+		res = feature_flags &~ feature_not_flags;
 	}
-	if (feature_flags != 0 && feature_not_flags == 0) {
-		return feature_flags;
+
+	if ((res & OptInFeatureFlag_IntegerDivisionByZero_ALL) ==
+	           OptInFeatureFlag_IntegerDivisionByZero_ALL) {
+		syntax_error(token_for_pos, "Only one integer-division-by-zero feature flag can be enabled");
 	}
-	GB_ASSERT(feature_flags != 0 && feature_not_flags != 0);
-	return feature_flags &~ feature_not_flags;
+
+	return res;
 }
 
 gb_internal String dir_from_path(String path) {