From eee43a65aec2e2b104ff64cb23488a86437578e4 Mon Sep 17 00:00:00 2001
From: xackus <14938807+xackus@users.noreply.github.com>
Date: Fri, 5 Mar 2021 20:51:19 +0100
Subject: [PATCH] add tests

---
 lib/std/meta.zig     | 32 +++++++++++++++++++++++++++-----
 test/translate_c.zig | 20 ++++++++++++++++++++
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/lib/std/meta.zig b/lib/std/meta.zig
index 46d31a87c3..fd3e03bdbd 100644
--- a/lib/std/meta.zig
+++ b/lib/std/meta.zig
@@ -1096,7 +1096,7 @@ test "sizeof" {
 
 pub const CIntLiteralRadix = enum { decimal, octal, hexadecimal };
 
-fn PromoteIntLiteralReturnType(comptime SuffixType: type, comptime target: comptime_int, comptime radix: CIntLiteralRadix) type {
+fn PromoteIntLiteralReturnType(comptime SuffixType: type, comptime number: comptime_int, comptime radix: CIntLiteralRadix) type {
     const signed_decimal = [_]type{ c_int, c_long, c_longlong };
     const signed_oct_hex = [_]type{ c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong };
     const unsigned = [_]type{ c_uint, c_ulong, c_ulonglong };
@@ -1111,17 +1111,39 @@ fn PromoteIntLiteralReturnType(comptime SuffixType: type, comptime target: compt
     var pos = mem.indexOfScalar(type, list, SuffixType).?;
 
     while (pos < list.len) : (pos += 1) {
-        if (target >= math.minInt(list[pos]) and target <= math.maxInt(list[pos])) {
+        if (number >= math.minInt(list[pos]) and number <= math.maxInt(list[pos])) {
             return list[pos];
         }
     }
-    @compileError("Integer literal does not fit in compatible types");
+    @compileError("Integer literal is too large");
 }
 
 /// Promote the type of an integer literal until it fits as C would.
 /// This is for translate-c and is not intended for general use.
-pub fn promoteIntLiteral(comptime SuffixType: type, comptime target: comptime_int, comptime radix: CIntLiteralRadix) PromoteIntLiteralReturnType(SuffixType, target, radix) {
-    return target;
+pub fn promoteIntLiteral(
+    comptime SuffixType: type,
+    comptime number: comptime_int,
+    comptime radix: CIntLiteralRadix,
+) PromoteIntLiteralReturnType(SuffixType, number, radix) {
+    return number;
+}
+
+test "promoteIntLiteral" {
+    const signed_hex = promoteIntLiteral(c_int, math.maxInt(c_int) + 1, .hexadecimal);
+    testing.expectEqual(c_uint, @TypeOf(signed_hex));
+
+    if (math.maxInt(c_longlong) == math.maxInt(c_int)) return;
+
+    const signed_decimal = promoteIntLiteral(c_int, math.maxInt(c_int) + 1, .decimal);
+    const unsigned = promoteIntLiteral(c_uint, math.maxInt(c_uint) + 1, .hexadecimal);
+
+    if (math.maxInt(c_long) > math.maxInt(c_int)) {
+        testing.expectEqual(c_long, @TypeOf(signed_decimal));
+        testing.expectEqual(c_ulong, @TypeOf(unsigned));
+    } else {
+        testing.expectEqual(c_longlong, @TypeOf(signed_decimal));
+        testing.expectEqual(c_ulonglong, @TypeOf(unsigned));
+    }
 }
 
 /// For a given function type, returns a tuple type which fields will
diff --git a/test/translate_c.zig b/test/translate_c.zig
index 6134190efb..5785d07311 100644
--- a/test/translate_c.zig
+++ b/test/translate_c.zig
@@ -3392,4 +3392,24 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    unnamed_0: struct_unnamed_2,
         \\};
     });
+
+    cases.add("integer literal promotion",
+        \\#define GUARANTEED_TO_FIT_1 1024
+        \\#define GUARANTEED_TO_FIT_2 10241024L
+        \\#define GUARANTEED_TO_FIT_3 20482048LU
+        \\#define MAY_NEED_PROMOTION_1 10241024
+        \\#define MAY_NEED_PROMOTION_2 307230723072L
+        \\#define MAY_NEED_PROMOTION_3 819281928192LU
+        \\#define MAY_NEED_PROMOTION_HEX 0x80000000
+        \\#define MAY_NEED_PROMOTION_OCT 020000000000
+    , &[_][]const u8{
+        \\pub const GUARANTEED_TO_FIT_1 = @as(c_int, 1024);
+        \\pub const GUARANTEED_TO_FIT_2 = @as(c_long, 10241024);
+        \\pub const GUARANTEED_TO_FIT_3 = @as(c_ulong, 20482048);
+        \\pub const MAY_NEED_PROMOTION_1 = @import("std").meta.promoteIntLiteral(c_int, 10241024, .decimal);
+        \\pub const MAY_NEED_PROMOTION_2 = @import("std").meta.promoteIntLiteral(c_long, 307230723072, .decimal);
+        \\pub const MAY_NEED_PROMOTION_3 = @import("std").meta.promoteIntLiteral(c_ulong, 819281928192, .decimal);
+        \\pub const MAY_NEED_PROMOTION_HEX = @import("std").meta.promoteIntLiteral(c_int, 0x80000000, .hexadecimal);
+        \\pub const MAY_NEED_PROMOTION_OCT = @import("std").meta.promoteIntLiteral(c_int, 0o020000000000, .octal);
+    });
 }