Commit c3dadfa95b

Evan Haas <evan@lagerdata.com>
2021-01-18 04:22:48
translate-c: Add Wide, UTF-16, and UTF-32 character literals
Add support for L'<wchar_t>', u'<char16_t>', and U'<char32_t>'. Currently this just translates wide char literals to \u{NNNNNN} escape codes (e.g. U'💯' -> '\u{1f4af}') Another approach would be to emit UTF-8 encoded character literals directly, but in my opinion this approaches Unicode-complete because it would require knowledge of which Unicode codepoints have graphical representations for the emitted source to be readable. We could also just emit integer literals, but the current method makes it clear that we have translated a wide character literal and not just an integer constant.
master
1 parent 384ccaa
Changed files (2)
src
translate_c.zig
test
run_translated_c.zig
src/translate_c.zig
@@ -2942,9 +2942,9 @@ fn transCharLiteral(
     suppress_as: SuppressCast,
 ) TransError!*ast.Node {
     const kind = stmt.getKind();
+    const val = stmt.getValue();
     const int_lit_node = switch (kind) {
         .Ascii, .UTF8 => blk: {
-            const val = stmt.getValue();
             if (kind == .Ascii) {
                 // C has a somewhat obscure feature called multi-character character
                 // constant
@@ -2960,13 +2960,15 @@ fn transCharLiteral(
             };
             break :blk &node.base;
         },
-        .UTF16, .UTF32, .Wide => return revertAndWarn(
-            rp,
-            error.UnsupportedTranslation,
-            @ptrCast(*const clang.Stmt, stmt).getBeginLoc(),
-            "TODO: support character literal kind {}",
-            .{kind},
-        ),
+        .Wide, .UTF16, .UTF32 => blk: {
+            const token = try appendTokenFmt(rp.c, .CharLiteral, "'\\u{{{x}}}'", .{val});
+            const node = try rp.c.arena.create(ast.Node.OneToken);
+            node.* = .{
+                .base = .{ .tag = .CharLiteral },
+                .token = token,
+            };
+            break :blk &node.base;
+        },
     };
     if (suppress_as == .no_as) {
         return maybeSuppressResult(rp, scope, result_used, int_lit_node);
test/run_translated_c.zig
@@ -719,4 +719,22 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
         \\    return 0;
         \\}
     , "");
+
+    cases.add("Wide, UTF-16, and UTF-32 character literals",
+        \\#include <wchar.h>
+        \\#include <stdlib.h>
+        \\int main() {
+        \\    wchar_t wc = L'™';
+        \\    int utf16_char = u'™';
+        \\    int utf32_char = U'💯';
+        \\    if (wc != 8482) abort();
+        \\    if (utf16_char != 8482) abort();
+        \\    if (utf32_char != 128175) abort();
+        \\    unsigned char c = wc;
+        \\    if (c != 0x22) abort();
+        \\    c = utf32_char;
+        \\    if (c != 0xaf) abort();
+        \\    return 0;
+        \\}
+    , "");
 }