Commit ff838d8631

mlugg <mlugg@mlugg.co.uk>
2023-11-17 14:16:39
translate-c: work around unnecessary uses of 'var'
1 parent 3c58573
Changed files (2)
src
translate_c
test
src/translate_c/common.zig
@@ -291,6 +291,14 @@ pub fn ScopeExtra(comptime Context: type, comptime Type: type) type {
         }
 
         pub fn skipVariableDiscard(inner: *Scope, name: []const u8) void {
+            if (true) {
+                // TODO: due to 'local variable is never mutated' errors, we can
+                // only skip discards if a variable is used as an lvalue, which
+                // we don't currently have detection for in translate-c.
+                // Once #17584 is completed, perhaps we can do away with this
+                // logic entirely, and instead rely on render to fixup code.
+                return;
+            }
             var scope = inner;
             while (true) {
                 switch (scope.id) {
test/translate_c.zig
@@ -37,6 +37,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_a: c_int) void {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    while (true) {
         \\        if (a != 0) break;
         \\    }
@@ -81,9 +82,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_x: c_ulong) c_ulong {
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    const union_unnamed_1 = extern union {
         \\        _x: c_ulong,
         \\    };
+        \\    _ = &union_unnamed_1;
         \\    return (union_unnamed_1{
         \\        ._x = x,
         \\    })._x;
@@ -142,6 +145,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub extern fn bar(...) c_int;
         \\pub export fn foo() void {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    if (a != 0) a = 2 else _ = bar();
         \\}
     });
@@ -194,6 +198,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\        B: c_int = @import("std").mem.zeroes(c_int),
         \\        C: c_int = @import("std").mem.zeroes(c_int),
         \\    };
+        \\    _ = &struct_Foo;
         \\    var a: struct_Foo = struct_Foo{
         \\        .A = @as(c_int, 0),
         \\        .B = 0,
@@ -206,6 +211,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\            B: c_int = @import("std").mem.zeroes(c_int),
         \\            C: c_int = @import("std").mem.zeroes(c_int),
         \\        };
+        \\        _ = &struct_Foo_1;
         \\        var a_2: struct_Foo_1 = struct_Foo_1{
         \\            .A = @as(c_int, 0),
         \\            .B = 0,
@@ -242,6 +248,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    };
         \\    _ = &union_unnamed_1;
         \\    const Foo = union_unnamed_1;
+        \\    _ = &Foo;
         \\    var a: Foo = Foo{
         \\        .A = @as(c_int, 0),
         \\    };
@@ -254,6 +261,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\        };
         \\        _ = &union_unnamed_2;
         \\        const Foo_1 = union_unnamed_2;
+        \\        _ = &Foo_1;
         \\        var a_2: Foo_1 = Foo_1{
         \\            .A = @as(c_int, 0),
         \\        };
@@ -268,6 +276,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\#define MEM_PHYSICAL_TO_K0(x) (void*)((uint32_t)(x) + SYS_BASE_CACHED)
     , &[_][]const u8{
         \\pub inline fn MEM_PHYSICAL_TO_K0(x: anytype) ?*anyopaque {
+        \\    _ = &x;
         \\    return @import("std").zig.c_translation.cast(?*anyopaque, @import("std").zig.c_translation.cast(u32, x) + SYS_BASE_CACHED);
         \\}
     });
@@ -310,6 +319,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub const VALUE = ((((@as(c_int, 1) + (@as(c_int, 2) * @as(c_int, 3))) + (@as(c_int, 4) * @as(c_int, 5))) + @as(c_int, 6)) << @as(c_int, 7)) | @intFromBool(@as(c_int, 8) == @as(c_int, 9));
         ,
         \\pub inline fn _AL_READ3BYTES(p: anytype) @TypeOf((@import("std").zig.c_translation.cast([*c]u8, p).* | ((@import("std").zig.c_translation.cast([*c]u8, p) + @as(c_int, 1)).* << @as(c_int, 8))) | ((@import("std").zig.c_translation.cast([*c]u8, p) + @as(c_int, 2)).* << @as(c_int, 16))) {
+        \\    _ = &p;
         \\    return (@import("std").zig.c_translation.cast([*c]u8, p).* | ((@import("std").zig.c_translation.cast([*c]u8, p) + @as(c_int, 1)).* << @as(c_int, 8))) | ((@import("std").zig.c_translation.cast([*c]u8, p) + @as(c_int, 2)).* << @as(c_int, 16));
         \\}
     });
@@ -390,6 +400,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub const Color = struct_Color;
         ,
         \\pub inline fn CLITERAL(@"type": anytype) @TypeOf(@"type") {
+        \\    _ = &@"type";
         \\    return @"type";
         \\}
         ,
@@ -407,6 +418,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\};
         ,
         \\pub inline fn A(_x: anytype) MyCStruct {
+        \\    _ = &_x;
         \\    return @import("std").mem.zeroInit(MyCStruct, .{
         \\        .x = _x,
         \\    });
@@ -438,6 +450,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\#define __ferror_unlocked_body(_fp) (((_fp)->_flags & _IO_ERR_SEEN) != 0)
     , &[_][]const u8{
         \\pub inline fn __ferror_unlocked_body(_fp: anytype) @TypeOf((_fp.*._flags & _IO_ERR_SEEN) != @as(c_int, 0)) {
+        \\    _ = &_fp;
         \\    return (_fp.*._flags & _IO_ERR_SEEN) != @as(c_int, 0);
         \\}
     });
@@ -447,6 +460,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\#define BAR 1 && 2 > 4
     , &[_][]const u8{
         \\pub inline fn FOO(x: anytype) @TypeOf(@intFromBool(x >= @as(c_int, 0)) + @intFromBool(x >= @as(c_int, 0))) {
+        \\    _ = &x;
         \\    return @intFromBool(x >= @as(c_int, 0)) + @intFromBool(x >= @as(c_int, 0));
         \\}
         ,
@@ -512,6 +526,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\};
         ,
         \\pub inline fn bar(x: anytype) @TypeOf(baz(@as(c_int, 1), @as(c_int, 2))) {
+        \\    _ = &x;
         \\    return blk_1: {
         \\        _ = &x;
         \\        _ = @as(c_int, 3);
@@ -642,6 +657,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\};
         \\pub export fn foo(arg_x: [*c]outer) void {
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    x.*.unnamed_0.unnamed_0.y = @as(c_int, @bitCast(@as(c_uint, x.*.unnamed_0.x)));
         \\}
     });
@@ -728,6 +744,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub const struct_opaque_2 = opaque {};
         \\pub export fn function(arg_opaque_1: ?*struct_opaque) void {
         \\    var opaque_1 = arg_opaque_1;
+        \\    _ = &opaque_1;
         \\    var cast: ?*struct_opaque_2 = @as(?*struct_opaque_2, @ptrCast(opaque_1));
         \\    _ = &cast;
         \\}
@@ -827,6 +844,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    _ = @as(c_int, 1);
         \\    _ = "hey";
         \\    _ = @as(c_int, 1) + @as(c_int, 1);
@@ -912,6 +930,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub extern fn foo() void;
         \\pub export fn bar() void {
         \\    var func_ptr: ?*anyopaque = @as(?*anyopaque, @ptrCast(&foo));
+        \\    _ = &func_ptr;
         \\    var typed_func_ptr: ?*const fn () callconv(.C) void = @as(?*const fn () callconv(.C) void, @ptrFromInt(@as(c_ulong, @intCast(@intFromPtr(func_ptr)))));
         \\    _ = &typed_func_ptr;
         \\}
@@ -953,8 +972,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn s() c_int {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    var b: c_int = undefined;
+        \\    _ = &b;
         \\    var c: c_int = undefined;
+        \\    _ = &c;
         \\    c = a + b;
         \\    c = a - b;
         \\    c = a * b;
@@ -964,8 +986,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\}
         \\pub export fn u() c_uint {
         \\    var a: c_uint = undefined;
+        \\    _ = &a;
         \\    var b: c_uint = undefined;
+        \\    _ = &b;
         \\    var c: c_uint = undefined;
+        \\    _ = &c;
         \\    c = a +% b;
         \\    c = a -% b;
         \\    c = a *% b;
@@ -1361,6 +1386,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub export fn foo() void {
         \\    var a: c_int = undefined;
         \\    _ = &a;
+        \\    _ = &a;
         \\}
     });
 
@@ -1372,6 +1398,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() ?*anyopaque {
         \\    var x: [*c]c_ushort = undefined;
+        \\    _ = &x;
         \\    return @as(?*anyopaque, @ptrCast(x));
         \\}
     });
@@ -1496,6 +1523,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub export fn foo() void {
         \\    {
         \\        var i: c_int = 0;
+        \\        _ = &i;
         \\        while (i != 0) : (i += 1) {}
         \\    }
         \\}
@@ -1519,6 +1547,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var i: c_int = undefined;
+        \\    _ = &i;
         \\    {
         \\        i = 3;
         \\        while (i != 0) : (i -= 1) {}
@@ -1562,6 +1591,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn ptrcast() [*c]f32 {
         \\    var a: [*c]c_int = undefined;
+        \\    _ = &a;
         \\    return @as([*c]f32, @ptrCast(@alignCast(a)));
         \\}
     });
@@ -1574,6 +1604,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn ptrptrcast() [*c][*c]f32 {
         \\    var a: [*c][*c]c_int = undefined;
+        \\    _ = &a;
         \\    return @as([*c][*c]f32, @ptrCast(@alignCast(a)));
         \\}
     });
@@ -1597,6 +1628,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn test_ptr_cast() void {
         \\    var p: ?*anyopaque = undefined;
+        \\    _ = &p;
         \\    {
         \\        var to_char: [*c]u8 = @as([*c]u8, @ptrCast(@alignCast(p)));
         \\        _ = &to_char;
@@ -1633,8 +1665,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn while_none_bool() c_int {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    var b: f32 = undefined;
+        \\    _ = &b;
         \\    var c: ?*anyopaque = undefined;
+        \\    _ = &c;
         \\    while (a != 0) return 0;
         \\    while (b != 0) return 1;
         \\    while (c != null) return 2;
@@ -1655,8 +1690,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn for_none_bool() c_int {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    var b: f32 = undefined;
+        \\    _ = &b;
         \\    var c: ?*anyopaque = undefined;
+        \\    _ = &c;
         \\    while (a != 0) return 0;
         \\    while (b != 0) return 1;
         \\    while (c != null) return 2;
@@ -1693,6 +1731,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var x: [*c]c_int = undefined;
+        \\    _ = &x;
         \\    x.* = 1;
         \\}
     });
@@ -1706,7 +1745,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() c_int {
         \\    var x: c_int = 1234;
+        \\    _ = &x;
         \\    var ptr: [*c]c_int = &x;
+        \\    _ = &ptr;
         \\    return ptr.*;
         \\}
     });
@@ -1719,6 +1760,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() c_int {
         \\    var x: c_int = undefined;
+        \\    _ = &x;
         \\    return ~x;
         \\}
     });
@@ -1736,8 +1778,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() c_int {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    var b: f32 = undefined;
+        \\    _ = &b;
         \\    var c: ?*anyopaque = undefined;
+        \\    _ = &c;
         \\    return @intFromBool(!(a == @as(c_int, 0)));
         \\    return @intFromBool(!(a != 0));
         \\    return @intFromBool(!(b != 0));
@@ -2051,10 +2096,13 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub extern var c: c_int;
         ,
         \\pub inline fn BASIC(c_1: anytype) @TypeOf(c_1 * @as(c_int, 2)) {
+        \\    _ = &c_1;
         \\    return c_1 * @as(c_int, 2);
         \\}
         ,
         \\pub inline fn FOO(L: anytype, b: anytype) @TypeOf(L + b) {
+        \\    _ = &L;
+        \\    _ = &b;
         \\    return L + b;
         \\}
         ,
@@ -2109,7 +2157,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    var c_1 = arg_c_1;
         \\    _ = &c_1;
         \\    var a_2: c_int = undefined;
+        \\    _ = &a_2;
         \\    var b_3: u8 = 123;
+        \\    _ = &b_3;
         \\    b_3 = @as(u8, @bitCast(@as(i8, @truncate(a_2))));
         \\    {
         \\        var d: c_int = 5;
@@ -2150,7 +2200,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    var b: c_int = undefined;
+        \\    _ = &b;
         \\    a = blk: {
         \\        const tmp = @as(c_int, 2);
         \\        b = tmp;
@@ -2180,11 +2232,13 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() c_int {
         \\    var a: c_int = 5;
+        \\    _ = &a;
         \\    while (true) {
         \\        a = 2;
         \\    }
         \\    while (true) {
         \\        var a_1: c_int = 4;
+        \\        _ = &a_1;
         \\        a_1 = 9;
         \\        return blk: {
         \\            _ = @as(c_int, 6);
@@ -2193,6 +2247,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    }
         \\    while (true) {
         \\        var a_1: c_int = 2;
+        \\        _ = &a_1;
         \\        a_1 = 12;
         \\    }
         \\    while (true) {
@@ -2214,10 +2269,12 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub export fn foo() void {
         \\    {
         \\        var i: c_int = 2;
+        \\        _ = &i;
         \\        var b: c_int = 4;
         \\        _ = &b;
         \\        while ((i + @as(c_int, 2)) != 0) : (i = 2) {
         \\            var a: c_int = 2;
+        \\            _ = &a;
         \\            _ = blk: {
         \\                _ = blk_1: {
         \\                    a = 6;
@@ -2309,7 +2366,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn switch_fn(arg_i: c_int) void {
         \\    var i = arg_i;
+        \\    _ = &i;
         \\    var res: c_int = 0;
+        \\    _ = &res;
         \\    while (true) {
         \\        switch (i) {
         \\            @as(c_int, 0) => {
@@ -2398,7 +2457,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int) void {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var tmp: c_int = undefined;
+        \\    _ = &tmp;
         \\    tmp = a;
         \\    a = tmp;
         \\}
@@ -2412,8 +2473,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int) void {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b: c_int = undefined;
+        \\    _ = &b;
         \\    var c: c_int = undefined;
+        \\    _ = &c;
         \\    c = blk: {
         \\        const tmp = a;
         \\        b = tmp;
@@ -2442,6 +2506,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn int_from_float(arg_a: f32) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    return @as(c_int, @intFromFloat(a));
         \\}
     });
@@ -2505,11 +2570,13 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_int = 2;
+        \\    _ = &a;
         \\    while (true) {
         \\        a = a - @as(c_int, 1);
         \\        if (!(a != 0)) break;
         \\    }
         \\    var b: c_int = 2;
+        \\    _ = &b;
         \\    while (true) {
         \\        b = b - @as(c_int, 1);
         \\        if (!(b != 0)) break;
@@ -2550,21 +2617,37 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
             \\pub const SomeTypedef = c_int;
             \\pub export fn and_or_non_bool(arg_a: c_int, arg_b: f32, arg_c: ?*anyopaque) c_int {
             \\    var a = arg_a;
+            \\    _ = &a;
             \\    var b = arg_b;
+            \\    _ = &b;
             \\    var c = arg_c;
+            \\    _ = &c;
             \\    var d: enum_Foo = @as(c_uint, @bitCast(FooA));
+            \\    _ = &d;
             \\    var e: c_int = @intFromBool((a != 0) and (b != 0));
+            \\    _ = &e;
             \\    var f: c_int = @intFromBool((b != 0) and (c != null));
+            \\    _ = &f;
             \\    var g: c_int = @intFromBool((a != 0) and (c != null));
+            \\    _ = &g;
             \\    var h: c_int = @intFromBool((a != 0) or (b != 0));
+            \\    _ = &h;
             \\    var i: c_int = @intFromBool((b != 0) or (c != null));
+            \\    _ = &i;
             \\    var j: c_int = @intFromBool((a != 0) or (c != null));
+            \\    _ = &j;
             \\    var k: c_int = @intFromBool((a != 0) or (@as(c_int, @bitCast(d)) != 0));
+            \\    _ = &k;
             \\    var l: c_int = @intFromBool((@as(c_int, @bitCast(d)) != 0) and (b != 0));
+            \\    _ = &l;
             \\    var m: c_int = @intFromBool((c != null) or (d != 0));
+            \\    _ = &m;
             \\    var td: SomeTypedef = 44;
+            \\    _ = &td;
             \\    var o: c_int = @intFromBool((td != 0) or (b != 0));
+            \\    _ = &o;
             \\    var p: c_int = @intFromBool((c != null) and (td != 0));
+            \\    _ = &p;
             \\    return (((((((((e + f) + g) + h) + i) + j) + k) + l) + m) + o) + p;
             \\}
         ,
@@ -2604,7 +2687,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int, arg_b: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b = arg_b;
+        \\    _ = &b;
         \\    return (a & b) ^ (a | b);
         \\}
     });
@@ -2623,14 +2708,23 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn test_comparisons(arg_a: c_int, arg_b: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b = arg_b;
+        \\    _ = &b;
         \\    var c: c_int = @intFromBool(a < b);
+        \\    _ = &c;
         \\    var d: c_int = @intFromBool(a > b);
+        \\    _ = &d;
         \\    var e: c_int = @intFromBool(a <= b);
+        \\    _ = &e;
         \\    var f: c_int = @intFromBool(a >= b);
+        \\    _ = &f;
         \\    var g: c_int = @intFromBool(c < d);
+        \\    _ = &g;
         \\    var h: c_int = @intFromBool(e < f);
+        \\    _ = &h;
         \\    var i: c_int = @intFromBool(g < h);
+        \\    _ = &i;
         \\    return i;
         \\}
     });
@@ -2646,7 +2740,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int, arg_b: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b = arg_b;
+        \\    _ = &b;
         \\    if (a == b) return a;
         \\    if (a != b) return b;
         \\    return a;
@@ -2663,6 +2759,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub const yes = [*c]u8;
         \\pub export fn foo() void {
         \\    var a: yes = undefined;
+        \\    _ = &a;
         \\    if (a != null) {
         \\        _ = @as(c_int, 2);
         \\    }
@@ -2682,6 +2779,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    return blk: {
         \\        var a: c_int = 1;
         \\        _ = &a;
+        \\        _ = &a;
         \\        break :blk a;
         \\    };
         \\}
@@ -2707,6 +2805,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub export var b: f32 = 2.0;
         \\pub export fn foo() void {
         \\    var c: [*c]struct_Foo = undefined;
+        \\    _ = &c;
         \\    _ = a.b;
         \\    _ = c.*.b;
         \\}
@@ -2726,6 +2825,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub export var array: [100]c_int = [1]c_int{0} ** 100;
         \\pub export fn foo(arg_index: c_int) c_int {
         \\    var index = arg_index;
+        \\    _ = &index;
         \\    return array[@as(c_uint, @intCast(index))];
         \\}
         ,
@@ -2740,7 +2840,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: [10]c_int = undefined;
+        \\    _ = &a;
         \\    var i: c_int = 0;
+        \\    _ = &i;
         \\    a[@as(c_uint, @intCast(i))] = 0;
         \\}
     });
@@ -2753,7 +2855,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: [10]c_longlong = undefined;
+        \\    _ = &a;
         \\    var i: c_longlong = 0;
+        \\    _ = &i;
         \\    a[@as(usize, @intCast(i))] = 0;
         \\}
     });
@@ -2766,7 +2870,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: [10]c_uint = undefined;
+        \\    _ = &a;
         \\    var i: c_uint = 0;
+        \\    _ = &i;
         \\    a[i] = 0;
         \\}
     });
@@ -2776,6 +2882,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\int bar(int x) { return x; }
     , &[_][]const u8{
         \\pub inline fn CALL(arg: anytype) @TypeOf(bar(arg)) {
+        \\    _ = &arg;
         \\    return bar(arg);
         \\}
     });
@@ -2801,7 +2908,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int, arg_b: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b = arg_b;
+        \\    _ = &b;
         \\    if ((a < b) or (a == b)) return b;
         \\    if ((a >= b) and (a == b)) return a;
         \\    return a;
@@ -2823,7 +2932,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn max(arg_a: c_int, arg_b: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var b = arg_b;
+        \\    _ = &b;
         \\    if (a < b) return b;
         \\    if (a < b) return b else return a;
         \\    if (a < b) {} else {}
@@ -2874,9 +2985,13 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
             \\;
             \\pub export fn if_none_bool(arg_a: c_int, arg_b: f32, arg_c: ?*anyopaque, arg_d: enum_SomeEnum) c_int {
             \\    var a = arg_a;
+            \\    _ = &a;
             \\    var b = arg_b;
+            \\    _ = &b;
             \\    var c = arg_c;
+            \\    _ = &c;
             \\    var d = arg_d;
+            \\    _ = &d;
             \\    if (a != 0) return 0;
             \\    if (b != 0) return 1;
             \\    if (c != null) return 2;
@@ -2904,6 +3019,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn abs(arg_a: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    return if (a < @as(c_int, 0)) -a else a;
         \\}
     });
@@ -2924,16 +3040,19 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo1(arg_a: c_uint) c_uint {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    a +%= 1;
         \\    return a;
         \\}
         \\pub export fn foo2(arg_a: c_int) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    a += 1;
         \\    return a;
         \\}
         \\pub export fn foo3(arg_a: [*c]c_int) [*c]c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    a += 1;
         \\    return a;
         \\}
@@ -2959,7 +3078,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\}
         \\pub export fn bar() void {
         \\    var f: ?*const fn () callconv(.C) void = &foo;
+        \\    _ = &f;
         \\    var b: ?*const fn () callconv(.C) c_int = &baz;
+        \\    _ = &b;
         \\    f.?();
         \\    f.?();
         \\    foo();
@@ -2985,7 +3106,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var i: c_int = 0;
+        \\    _ = &i;
         \\    var u: c_uint = 0;
+        \\    _ = &u;
         \\    i += 1;
         \\    i -= 1;
         \\    u +%= 1;
@@ -3024,7 +3147,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn log2(arg_a: c_uint) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var i: c_int = 0;
+        \\    _ = &i;
         \\    while (a > @as(c_uint, @bitCast(@as(c_int, 0)))) {
         \\        a >>= @intCast(@as(c_int, 1));
         \\    }
@@ -3044,7 +3169,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn log2(arg_a: u32) c_int {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    var i: c_int = 0;
+        \\    _ = &i;
         \\    while (a > @as(u32, @bitCast(@as(c_int, 0)))) {
         \\        a >>= @intCast(@as(c_int, 1));
         \\    }
@@ -3072,7 +3199,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_int = 0;
+        \\    _ = &a;
         \\    var b: c_uint = 0;
+        \\    _ = &b;
         \\    a += blk: {
         \\        const ref = &a;
         \\        ref.* += @as(c_int, 1);
@@ -3151,6 +3280,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_uint = 0;
+        \\    _ = &a;
         \\    a +%= blk: {
         \\        const ref = &a;
         \\        ref.* +%= @as(c_uint, @bitCast(@as(c_int, 1)));
@@ -3210,7 +3340,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var i: c_int = 0;
+        \\    _ = &i;
         \\    var u: c_uint = 0;
+        \\    _ = &u;
         \\    i += 1;
         \\    i -= 1;
         \\    u +%= 1;
@@ -3305,6 +3437,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\pub fn bar() callconv(.C) void {}
         \\pub export fn foo(arg_baz: ?*const fn () callconv(.C) [*c]c_int) void {
         \\    var baz = arg_baz;
+        \\    _ = &baz;
         \\    bar();
         \\    _ = baz.?();
         \\}
@@ -3375,10 +3508,14 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\#define MAX(a, b) ((b) > (a) ? (b) : (a))
     , &[_][]const u8{
         \\pub inline fn MIN(a: anytype, b: anytype) @TypeOf(if (b < a) b else a) {
+        \\    _ = &a;
+        \\    _ = &b;
         \\    return if (b < a) b else a;
         \\}
         ,
         \\pub inline fn MAX(a: anytype, b: anytype) @TypeOf(if (b > a) b else a) {
+        \\    _ = &a;
+        \\    _ = &b;
         \\    return if (b > a) b else a;
         \\}
     });
@@ -3390,7 +3527,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_p: [*c]c_int, arg_x: c_int) c_int {
         \\    var p = arg_p;
+        \\    _ = &p;
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    return blk: {
         \\        const tmp = x;
         \\        (blk_1: {
@@ -3417,6 +3556,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\}
         \\pub export fn bar(arg_x: c_long) c_ushort {
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    return @as(c_ushort, @bitCast(@as(c_short, @truncate(x))));
         \\}
     });
@@ -3429,6 +3569,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_bar_1: c_int) void {
         \\    var bar_1 = arg_bar_1;
+        \\    _ = &bar_1;
         \\    bar_1 = 2;
         \\}
         \\pub export var bar: c_int = 4;
@@ -3442,6 +3583,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_bar_1: c_int) void {
         \\    var bar_1 = arg_bar_1;
+        \\    _ = &bar_1;
         \\    bar_1 = 2;
         \\}
         ,
@@ -3475,10 +3617,12 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\}
         \\pub export fn bar(arg_a: [*c]const c_int) void {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    foo(@as([*c]c_int, @ptrCast(@volatileCast(@constCast(a)))));
         \\}
         \\pub export fn baz(arg_a: [*c]volatile c_int) void {
         \\    var a = arg_a;
+        \\    _ = &a;
         \\    foo(@as([*c]c_int, @ptrCast(@volatileCast(@constCast(a)))));
         \\}
     });
@@ -3493,9 +3637,13 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo(arg_x: bool) bool {
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    var a: bool = @as(c_int, @intFromBool(x)) != @as(c_int, 1);
+        \\    _ = &a;
         \\    var b: bool = @as(c_int, @intFromBool(a)) != @as(c_int, 0);
+        \\    _ = &b;
         \\    var c: bool = @intFromPtr(&foo) != 0;
+        \\    _ = &c;
         \\    return foo(@as(c_int, @intFromBool(c)) != @as(c_int, @intFromBool(b)));
         \\}
     });
@@ -3506,7 +3654,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\}
     , &[_][]const u8{
         \\pub export fn max(x: c_int, arg_y: c_int) c_int {
+        \\    _ = &x;
         \\    var y = arg_y;
+        \\    _ = &y;
         \\    return if (x > y) x else y;
         \\}
     });
@@ -3567,6 +3717,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\
     , &[_][]const u8{
         \\pub inline fn DefaultScreen(dpy: anytype) @TypeOf(@import("std").zig.c_translation.cast(_XPrivDisplay, dpy).*.default_screen) {
+        \\    _ = &dpy;
         \\    return @import("std").zig.c_translation.cast(_XPrivDisplay, dpy).*.default_screen;
         \\}
     });
@@ -3809,6 +3960,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    const foo = struct {
         \\        var static: struct_FOO = @import("std").mem.zeroes(struct_FOO);
         \\    };
+        \\    _ = &foo;
         \\    return foo.static.x;
         \\}
     });
@@ -3830,12 +3982,14 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn bar(arg_x: c_int, arg_y: c_int) c_int {
         \\    var x = arg_x;
+        \\    _ = &x;
         \\    var y = arg_y;
         \\    _ = &y;
         \\    return x;
         \\}
         ,
         \\pub inline fn FOO(A: anytype, B: anytype) @TypeOf(A) {
+        \\    _ = &A;
         \\    _ = &B;
         \\    return A;
         \\}
@@ -3911,6 +4065,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var a: c_int = undefined;
+        \\    _ = &a;
         \\    if ((blk: {
         \\        const tmp = @intFromBool(@as(c_int, 1) > @as(c_int, 0));
         \\        a = tmp;
@@ -3929,7 +4084,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         , &[_][]const u8{
             \\pub export fn foo() void {
             \\    var a: S = undefined;
+            \\    _ = &a;
             \\    var b: S = undefined;
+            \\    _ = &b;
             \\    var c: c_longlong = @divExact(@as(c_longlong, @bitCast(@intFromPtr(a) -% @intFromPtr(b))), @sizeOf(u8));
             \\    _ = &c;
             \\}
@@ -3944,7 +4101,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         , &[_][]const u8{
             \\pub export fn foo() void {
             \\    var a: S = undefined;
+            \\    _ = &a;
             \\    var b: S = undefined;
+            \\    _ = &b;
             \\    var c: c_long = @divExact(@as(c_long, @bitCast(@intFromPtr(a) -% @intFromPtr(b))), @sizeOf(u8));
             \\    _ = &c;
             \\}
@@ -3973,7 +4132,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var tmp: c_int = 1;
+        \\    _ = &tmp;
         \\    if ((blk: {
         \\        const tmp_1 = tmp;
         \\        n = tmp_1;
@@ -3990,7 +4151,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var tmp: c_int = undefined;
+        \\    _ = &tmp;
         \\    var n: c_int = 1;
+        \\    _ = &n;
         \\    if ((blk: {
         \\        const tmp_1 = n;
         \\        tmp = tmp_1;
@@ -4007,7 +4170,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var ref: c_int = 1;
+        \\    _ = &ref;
         \\    if ((blk: {
         \\        const tmp = blk_1: {
         \\            const ref_2 = &ref;
@@ -4028,7 +4193,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var ref: c_int = 1;
+        \\    _ = &ref;
         \\    if ((blk: {
         \\        const tmp = blk_1: {
         \\            const ref_2 = &ref;
@@ -4050,7 +4217,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var ref: c_int = 1;
+        \\    _ = &ref;
         \\    if ((blk: {
         \\        const ref_1 = &n;
         \\        ref_1.* += ref;
@@ -4067,7 +4236,9 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var ref: c_int = undefined;
+        \\    _ = &ref;
         \\    var n: c_int = 1;
+        \\    _ = &n;
         \\    if ((blk: {
         \\        const ref_1 = &ref;
         \\        ref_1.* += n;
@@ -4085,8 +4256,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var f: c_int = 1;
+        \\    _ = &f;
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var cond_temp: c_int = 1;
+        \\    _ = &cond_temp;
         \\    if ((blk: {
         \\        const tmp = blk_1: {
         \\            const cond_temp_2 = cond_temp;
@@ -4107,8 +4281,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn foo() void {
         \\    var cond_temp: c_int = 1;
+        \\    _ = &cond_temp;
         \\    var n: c_int = undefined;
+        \\    _ = &n;
         \\    var f: c_int = 1;
+        \\    _ = &f;
         \\    if ((blk: {
         \\        const tmp = blk_1: {
         \\            const cond_temp_2 = f;
@@ -4149,6 +4326,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub export fn somefunc() void {
         \\    var y: c_int = undefined;
+        \\    _ = &y;
         \\    _ = blk: {
         \\        y = 1;
         \\    };