revive translateC support

tests/language_features/cimport.zig

@@ -8,6 +8,24 @@ const translate_c = zls.translate_c;
 
 const allocator: std.mem.Allocator = std.testing.allocator;
 
+test "zig compile server - translate c" {
+    var result1 = try testTranslate(
+        \\void foo(int);
+        \\void bar(float*);
+    );
+    defer result1.deinit(allocator);
+    try std.testing.expect(result1 == .success);
+
+    // TODO the zig compiler doesn't seem to report error bundles for translate-c
+    // Hopefully I can fix that once llvm-16 finished compiling :)
+
+    var result2 = testTranslate(
+        \\#include <this_file_doesnt_exist>
+    );
+    defer if (result2) |*r| r.deinit(allocator) else |_| {};
+    try std.testing.expectError(error.Timeout, result2);
+}
+
 test "convertCInclude - empty" {
     try testConvertCInclude("@cImport()", "");
     try testConvertCInclude("@cImport({})", "");
@@ -29,7 +47,7 @@ test "convertCInclude - cInclude" {
     );
 }
 
-test "translate_c - cDefine" {
+test "convertCInclude - cDefine" {
     try testConvertCInclude(
         \\@cImport(@cDefine("FOO", "BAR"))
     ,
@@ -42,7 +60,7 @@ test "translate_c - cDefine" {
     );
 }
 
-test "translate_c - cUndef" {
+test "convertCInclude - cUndef" {
     try testConvertCInclude(
         \\@cImport(@cUndef("FOO"))
     ,
@@ -85,3 +103,33 @@ fn testConvertCInclude(cimport_source: []const u8, expected: []const u8) !void {
 
     try std.testing.expectEqualStrings(expected, trimmed_output);
 }
+
+fn testTranslate(c_source: []const u8) !translate_c.Result {
+    if (!std.process.can_spawn) return error.SkipZigTest;
+
+    var config: zls.Config = .{};
+    defer std.json.parseFree(zls.Config, allocator, config);
+
+    var runtime_zig_version: ?zls.ZigVersionWrapper = null;
+    defer if (runtime_zig_version) |*v| v.free();
+
+    try zls.configuration.configChanged(&config, &runtime_zig_version, allocator, null);
+
+    if (config.global_cache_path == null or
+        config.zig_exe_path == null or
+        config.zig_lib_path == null) return error.SkipZigTest;
+
+    const result = (try translate_c.translate(allocator, config, &.{}, c_source)).?;
+
+    switch (result) {
+        .success => |uri| {
+            const path = try zls.URI.parse(allocator, uri);
+            defer allocator.free(path);
+            try std.testing.expect(std.fs.path.isAbsolute(path));
+        },
+        .failure => |message| {
+            try std.testing.expect(message.len != 0);
+        },
+    }
+    return result;
+}