- Fix bug with @jump miscompile

- Remove "panic" text from unreachable() when safe mode is turned off.
2026-02-27 12:01:16 +00:00 · 2024-06-22 23:20:23 +02:00
parent e02f73417c
commit f2e5c5e9b9
7 changed files with 83 additions and 11 deletions
--- a/lib/std/core/builtin.c3
+++ b/lib/std/core/builtin.c3
@@ -143,7 +143,9 @@ fn void panicf(String fmt, String file, String function, uint line, args...)
 **/
 macro void unreachable(String string = "Unreachable statement reached.", ...) @builtin @noreturn
 {
+	$if env::COMPILER_SAFE_MODE:
 	panicf(string, $$FILE, $$FUNC, $$LINE, $vasplat());
+	$endif;
 	$$unreachable();
 }

--- a/releasenotes.md
+++ b/releasenotes.md
@@ -14,10 +14,12 @@
 - Fixed crash on certain recursive function definitions #1209.
 - Return the typekind "FUNC" for a function pointer.
 - No longer possible to dereference a function pointer.
+- Fix bug with @jump miscompile

 ### Stdlib changes
 - Added `remove_first_item` `remove_last_item` and `remove_item` as aliases for the `match` functions.
 - Added @str_hash, @str_upper, @str_lower, @str_find compile time macros.
+- Remove "panic" text from unreachable() when safe mode is turned off.

 ## 0.6.0 Change list

--- a/resources/grammar/grammar.y
+++ b/resources/grammar/grammar.y
@@ -886,8 +886,8 @@ opt_stmt_list
 switch_stmt
 	: SWITCH optional_label '{' switch_body '}'
 	| SWITCH optional_label '{' '}'
-	| SWITCH optional_label paren_cond '{' switch_body '}'
-	| SWITCH optional_label paren_cond '{' '}'
+	| SWITCH optional_label paren_cond  opt_attributes '{' switch_body '}'
+	| SWITCH optional_label paren_cond  opt_attributes '{' '}'
 	;

 expression_list
--- a/src/compiler/llvm_codegen_stmt.c
+++ b/src/compiler/llvm_codegen_stmt.c
@@ -752,7 +752,13 @@ static LLVMValueRef llvm_emit_switch_jump_stmt(GenContext *c,
 	BEValue min_val;
 	llvm_emit_expr(c, &min_val, exprptr(cases[min_index]->case_stmt.expr));
 	assert(llvm_value_is_const(&min_val));
-	switch_value->value = LLVMBuildSub(c->builder, switch_value->value, min_val.value, "");
+	llvm_value_rvalue(c, switch_value);
+	llvm_value_rvalue(c, &min_val);
+	LLVMValueRef min = min_val.value;
+	if (!LLVMIsConstant(min) || !LLVMIsNull(min))
+	{
+		switch_value->value = LLVMBuildSub(c->builder, switch_value->value, min_val.value, "");
+	}
 	LLVMValueRef is_valid = LLVMBuildICmp(c->builder, LLVMIntUGT, switch_value->value, llvm_const_int(c, switch_value->type, count - 1), "");
 	LLVMBasicBlockRef switch_block = llvm_basic_block_new(c, "jumpblock");
 	LLVMBuildCondBr(c->builder, is_valid, default_block, switch_block);
--- a/test/test_suite/assert/unreachable.c3t
+++ b/test/test_suite/assert/unreachable.c3t
@@ -17,7 +17,6 @@ fn void test()
 define void @unreachable.test() #0 {
 entry:
  %x = alloca i32, align 4
-  %indirectarg = alloca %"any[]", align 8
  %0 = call i32 @unreachable.foo()
  store i32 %0, ptr %x, align 4
  %1 = load i32, ptr %x, align 4
@@ -28,7 +27,5 @@ if.then:                                          ; preds = %entry
  ret void

 if.exit:                                          ; preds = %entry
-  store %"any[]" zeroinitializer, ptr %indirectarg, align 8
-  call void @std.core.builtin.panicf(ptr @.str, i64 30, ptr @.str.1, i64 14, ptr @.str.2, i64 4, i32 10, ptr byval(%"any[]") align 8 %indirectarg)
  unreachable
 }
--- a/test/test_suite/switch/jump_with_inc.c3t
+++ b/test/test_suite/switch/jump_with_inc.c3t
@@ -0,0 +1,65 @@
+// #target: macos-aarch64
+module test;
+extern fn int b(int y);
+
+fn int foo(int x) @export
+{
+	switch (x) @jump
+	{
+		case 1:
+			nextcase (b(x));
+		case 0:
+			x++;
+			nextcase x;
+		default:
+			unreachable();
+	}
+}
+/* #expect: test.ll
+
+define i32 @test_foo(i32 %0) #0 {
+entry:
+  %x = alloca i32, align 4
+  %switch = alloca i32, align 4
+  store i32 %0, ptr %x, align 4
+  %1 = load i32, ptr %x, align 4
+  store i32 %1, ptr %switch, align 4
+  br label %switch.entry
+
+switch.entry:                                     ; preds = %entry
+  %2 = load i32, ptr %switch, align 4
+  %3 = icmp ugt i32 %2, 1
+  br i1 %3, label %switch.default, label %jumpblock
+
+jumpblock:                                        ; preds = %switch.entry
+  %ptroffset = getelementptr inbounds [8 x i8], ptr @jumptable, i32 %2
+  %target = load ptr, ptr %ptroffset, align 8
+  indirectbr ptr %target, [label %switch.case, label %switch.case4]
+
+switch.case:                                      ; preds = %jumpblock5, %jumpblock1, %jumpblock
+  %4 = load i32, ptr %x, align 4
+  %5 = call i32 @b(i32 %4)
+  %6 = icmp ugt i32 %5, 1
+  br i1 %6, label %switch.default, label %jumpblock1
+
+jumpblock1:                                       ; preds = %switch.case
+  %ptroffset2 = getelementptr inbounds [8 x i8], ptr @jumptable, i32 %5
+  %target3 = load ptr, ptr %ptroffset2, align 8
+  indirectbr ptr %target3, [label %switch.case, label %switch.case4, label %switch.default]
+
+switch.case4:                                     ; preds = %jumpblock5, %jumpblock, %jumpblock1
+  %7 = load i32, ptr %x, align 4
+  %add = add i32 %7, 1
+  store i32 %add, ptr %x, align 4
+  %8 = load i32, ptr %x, align 4
+  %9 = icmp ugt i32 %8, 1
+  br i1 %9, label %switch.default, label %jumpblock5
+
+jumpblock5:                                       ; preds = %switch.case4
+  %ptroffset6 = getelementptr inbounds [8 x i8], ptr @jumptable, i32 %8
+  %target7 = load ptr, ptr %ptroffset6, align 8
+  indirectbr ptr %target7, [label %switch.case, label %switch.case4, label %switch.default]
+
+switch.default:                                   ; preds = %jumpblock5, %switch.case4, %jumpblock1, %switch.case, %switch.entry
+  unreachable
+}
--- a/test/test_suite/switch/simple_jump.c3t
+++ b/test/test_suite/switch/simple_jump.c3t
@@ -71,6 +71,8 @@ fn void test6(int a)
@jumptable.2 = private constant [3 x ptr] [ptr blockaddress(@simple_jump.test3, %switch.case), ptr blockaddress(@simple_jump.test3, %switch.exit), ptr blockaddress(@simple_jump.test3, %switch.case1)], align 4
@jumptable.3 = private constant [1 x ptr] [ptr blockaddress(@simple_jump.test4, %switch.case)], align 4
@jumptable.4 = private constant [4 x ptr] [ptr blockaddress(@simple_jump.test5, %switch.case), ptr blockaddress(@simple_jump.test5, %switch.default), ptr blockaddress(@simple_jump.test5, %switch.default), ptr blockaddress(@simple_jump.test5, %switch.case1)], align 4
+@jumptable.5 = private constant [5 x ptr] [ptr blockaddress(@simple_jump.test6, %switch.case), ptr blockaddress(@simple_jump.test6, %switch.default), ptr blockaddress(@simple_jump.test6, %switch.default), ptr blockaddress(@simple_jump.test6, %switch.case1), ptr blockaddress(@simple_jump.test6, %switch.case2)], align 4
+

 after_check12:                                    ; preds = %noerr_block8
  br label %noerr_block14
@@ -87,7 +89,6 @@ voiderr:                                          ; preds = %noerr_block14, %gua
  ret void
 }

-; Function Attrs: nounwind uwtable
 define void @simple_jump.test1(i32 %0) #0 {
 entry:
  %switch = alloca i32, align 4
@@ -96,12 +97,11 @@ entry:

 switch.entry:                                     ; preds = %entry
  %1 = load i32, ptr %switch, align 4
-  %2 = sub i32 %1, 0
-  %3 = icmp ugt i32 %2, 2
-  br i1 %3, label %switch.exit, label %jumpblock
+  %2 = icmp ugt i32 %1, 2
+  br i1 %2, label %switch.exit, label %jumpblock

 jumpblock:                                        ; preds = %switch.entry
-  %ptroffset = getelementptr inbounds [8 x i8], ptr @jumptable, i32 %2
+  %ptroffset = getelementptr inbounds [8 x i8], ptr @jumptable, i32 %1
  %target = load ptr, ptr %ptroffset, align 8
  indirectbr ptr %target, [label %switch.case, label %switch.case1]