Add option to specify language of source files

Author: GalaxyShard

lib/std/Build/Module.zig

@@ -78,22 +78,36 @@ pub const SystemLib = struct {
     pub const SearchStrategy = enum { paths_first, mode_first, no_fallback };
 };
 
+pub const ForeignSourceLanguage = enum {
+    c,
+    cpp,
+    assembly,
+    assembly_with_cpp,
+    objc,
+    objcpp,
+
+    find_by_file_extension,
+};
+
 pub const CSourceFiles = struct {
     root: LazyPath,
     /// `files` is relative to `root`, which is
     /// the build root by default
     files: []const []const u8,
     flags: []const []const u8,
+    language: ForeignSourceLanguage,
 };
 
 pub const CSourceFile = struct {
     file: LazyPath,
     flags: []const []const u8 = &.{},
+    language: ForeignSourceLanguage = .find_by_file_extension,
 
     pub fn dupe(file: CSourceFile, b: *std.Build) CSourceFile {
         return .{
             .file = file.file.dupe(b),
             .flags = b.dupeStrings(file.flags),
+            .language = file.language,
         };
     }
 };
@@ -486,9 +500,10 @@ pub const AddCSourceFilesOptions = struct {
     root: ?LazyPath = null,
     files: []const []const u8,
     flags: []const []const u8 = &.{},
+    language: ForeignSourceLanguage = .find_by_file_extension,
 };
 
-/// Handy when you have many C/C++ source files and want them all to have the same flags.
+/// Handy when you have many non-Zig source files and want them all to have the same flags.
 pub fn addCSourceFiles(m: *Module, options: AddCSourceFilesOptions) void {
     const b = m.owner;
     const allocator = b.allocator;
@@ -507,6 +522,7 @@ pub fn addCSourceFiles(m: *Module, options: AddCSourceFilesOptions) void {
         .root = options.root orelse b.path(""),
         .files = b.dupeStrings(options.files),
         .flags = b.dupeStrings(options.flags),
+        .language = options.language,
     };
     m.link_objects.append(allocator, .{ .c_source_files = c_source_files }) catch @panic("OOM");
     addLazyPathDependenciesOnly(m, c_source_files.root);

lib/std/Build/Step/Compile.zig

@@ -800,7 +800,7 @@ pub fn linkFrameworkWeak(c: *Compile, name: []const u8) void {
     c.root_module.linkFramework(name, .{ .weak = true });
 }
 
-/// Handy when you have many C/C++ source files and want them all to have the same flags.
+/// Handy when you have many non-Zig source files and want them all to have the same flags.
 pub fn addCSourceFiles(compile: *Compile, options: Module.AddCSourceFilesOptions) void {
     compile.root_module.addCSourceFiles(options);
 }
@@ -1250,47 +1250,72 @@ fn getZigArgs(compile: *Compile, fuzz: bool) ![][]const u8 {
                     .c_source_file => |c_source_file| l: {
                         if (!my_responsibility) break :l;
 
-                        if (c_source_file.flags.len == 0) {
-                            if (prev_has_cflags) {
-                                try zig_args.append("-cflags");
-                                try zig_args.append("--");
-                                prev_has_cflags = false;
-                            }
-                        } else {
+                        if (prev_has_cflags or c_source_file.flags.len != 0) {
                             try zig_args.append("-cflags");
                             for (c_source_file.flags) |arg| {
                                 try zig_args.append(arg);
                             }
                             try zig_args.append("--");
-                            prev_has_cflags = true;
                         }
+                        prev_has_cflags = (c_source_file.flags.len != 0);
+
+                        if (c_source_file.language != .find_by_file_extension) {
+                            try zig_args.append("-x");
+                            try zig_args.append(switch (c_source_file.language) {
+                                .find_by_file_extension => unreachable,
+                                .c => "c",
+                                .cpp => "c++",
+                                .assembly => "assembler",
+                                .assembly_with_cpp => "assembler-with-cpp",
+                                .objc => "objective-c",
+                                .objcpp => "objective-c++",
+                            });
+                        }
+
                         try zig_args.append(c_source_file.file.getPath2(dep.module.owner, step));
+
+                        if (c_source_file.language != .find_by_file_extension) {
+                            try zig_args.append("-x");
+                            try zig_args.append("none");
+                        }
                         total_linker_objects += 1;
                     },
 
                     .c_source_files => |c_source_files| l: {
                         if (!my_responsibility) break :l;
 
-                        if (c_source_files.flags.len == 0) {
-                            if (prev_has_cflags) {
-                                try zig_args.append("-cflags");
-                                try zig_args.append("--");
-                                prev_has_cflags = false;
-                            }
-                        } else {
+                        if (prev_has_cflags or c_source_files.flags.len != 0) {
                             try zig_args.append("-cflags");
-                            for (c_source_files.flags) |flag| {
-                                try zig_args.append(flag);
+                            for (c_source_files.flags) |arg| {
+                                try zig_args.append(arg);
                             }
                             try zig_args.append("--");
-                            prev_has_cflags = true;
+                        }
+                        prev_has_cflags = (c_source_files.flags.len != 0);
+
+                        if (c_source_files.language != .find_by_file_extension) {
+                            try zig_args.append("-x");
+                            try zig_args.append(switch (c_source_files.language) {
+                                .find_by_file_extension => unreachable,
+                                .c => "c",
+                                .cpp => "c++",
+                                .assembly => "assembler",
+                                .assembly_with_cpp => "assembler-with-cpp",
+                                .objc => "objective-c",
+                                .objcpp => "objective-c++",
+                            });
                         }
 
                         const root_path = c_source_files.root.getPath2(dep.module.owner, step);
                         for (c_source_files.files) |file| {
                             try zig_args.append(b.pathJoin(&.{ root_path, file }));
                         }
 
+                        if (c_source_files.language != .find_by_file_extension) {
+                            try zig_args.append("-x");
+                            try zig_args.append("none");
+                        }
+
                         total_linker_objects += c_source_files.files.len;
                     },