cc,wasi: store CRTFile enum in wasi_emulated_libs

* then, in `link/Wasm.zig` map `CRTFile` to full emulated libs name
* move logic for removing any mention of WASI snapshot
  `wasi_snapshot_preview1` from `Compilation.zig` into `link/Wasm.zig`

src/Compilation.zig

@@ -651,7 +651,7 @@ pub const InitOptions = struct {
     /// * getpid
     /// * mman
     /// * signal
-    wasi_emulated_libs: []const []const u8 = &[0][]const u8{},
+    wasi_emulated_libs: []const wasi_libc.CRTFile = &[0]wasi_libc.CRTFile{},
     link_libc: bool = false,
     link_libcpp: bool = false,
     link_libunwind: bool = false,
@@ -1434,11 +1434,11 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
             });
         }
         if (comp.wantBuildWasiLibcFromSource()) {
-            try comp.work_queue.ensureUnusedCapacity(6); // worst-case we need all components
             const wasi_emulated_libs = comp.bin_file.options.wasi_emulated_libs;
-            for (wasi_emulated_libs) |lib_name| {
+            try comp.work_queue.ensureUnusedCapacity(wasi_emulated_libs.len + 2); // worst-case we need all components
+            for (wasi_emulated_libs) |crt_file| {
                 comp.work_queue.writeItemAssumeCapacity(.{
-                    .wasi_libc_crt_file = wasi_libc.getEmulatedLibCRTFile(lib_name).?,
+                    .wasi_libc_crt_file = crt_file,
                 });
             }
             // TODO add logic deciding which crt1 we want here.
@@ -4157,12 +4157,6 @@ pub fn stage1AddLinkLib(comp: *Compilation, lib_name: []const u8) !void {
     if (comp.bin_file.options.skip_linker_dependencies) return;
 
     // This happens when an `extern "foo"` function is referenced by the stage1 backend.
-    if (comp.getTarget().os.tag == .wasi and mem.eql(u8, "wasi_snapshot_preview1", lib_name)) {
-        // Any referenced symbol from this lib, will be undefined until
-        // runtime as this lib is provided directly by the runtime.
-        return;
-    }
-
     // If we haven't seen this library yet and we're targeting Windows, we need to queue up
     // a work item to produce the DLL import library for this.
     const gop = try comp.bin_file.options.system_libs.getOrPut(comp.gpa, lib_name);

src/link.zig

@@ -13,6 +13,7 @@ const Type = @import("type.zig").Type;
 const Cache = @import("Cache.zig");
 const build_options = @import("build_options");
 const LibCInstallation = @import("libc_installation.zig").LibCInstallation;
+const wasi_libc = @import("wasi_libc.zig");
 
 pub const producer_string = if (std.builtin.is_test) "zig test" else "zig " ++ build_options.version;
 
@@ -110,7 +111,7 @@ pub const Options = struct {
     framework_dirs: []const []const u8,
     frameworks: []const []const u8,
     system_libs: std.StringArrayHashMapUnmanaged(void),
-    wasi_emulated_libs: []const []const u8,
+    wasi_emulated_libs: []const wasi_libc.CRTFile,
     lib_dirs: []const []const u8,
     rpath_list: []const []const u8,
 

src/link/Wasm.zig

@@ -15,6 +15,7 @@ const codegen = @import("../codegen/wasm.zig");
 const link = @import("../link.zig");
 const trace = @import("../tracy.zig").trace;
 const build_options = @import("build_options");
+const wasi_libc = @import("../wasi_libc.zig");
 const Cache = @import("../Cache.zig");
 const TypedValue = @import("../TypedValue.zig");
 
@@ -700,14 +701,22 @@ fn linkWithLLD(self: *Wasm, comp: *Compilation) !void {
                 (self.base.options.output_mode == .Lib and self.base.options.link_mode == .Dynamic);
             if (is_exe_or_dyn_lib) {
                 const system_libs = self.base.options.system_libs.keys();
+
                 for (system_libs) |link_lib| {
+                    if (mem.eql(u8, "wasi_snapshot_preview1", link_lib)) {
+                        // Any referenced symbol from this lib, will be undefined until
+                        // runtime as this lib is provided directly by the runtime.
+                        continue;
+                    }
                     try argv.append(try std.fmt.allocPrint(arena, "-l{s}", .{link_lib}));
                 }
 
                 const wasi_emulated_libs = self.base.options.wasi_emulated_libs;
-                for (wasi_emulated_libs) |lib_name| {
-                    const full_lib_name = try std.fmt.allocPrint(arena, "lib{s}.a", .{lib_name});
-                    try argv.append(try comp.get_libc_crt_file(arena, full_lib_name));
+                for (wasi_emulated_libs) |crt_file| {
+                    try argv.append(try comp.get_libc_crt_file(
+                        arena,
+                        wasi_libc.emulatedLibCRFileLibName(crt_file),
+                    ));
                 }
 
                 if (self.base.options.link_libc) {

src/main.zig

@@ -617,7 +617,7 @@ fn buildOutputType(
     var system_libs = std.ArrayList([]const u8).init(gpa);
     defer system_libs.deinit();
 
-    var wasi_emulated_libs = std.ArrayList([]const u8).init(gpa);
+    var wasi_emulated_libs = std.ArrayList(wasi_libc.CRTFile).init(gpa);
     defer wasi_emulated_libs.deinit();
 
     var clang_argv = std.ArrayList([]const u8).init(gpa);
@@ -1591,8 +1591,8 @@ fn buildOutputType(
                 fatal("cannot use absolute path as a system library: {s}", .{lib_name});
             }
             if (target_info.target.os.tag == .wasi) {
-                if (wasi_libc.getEmulatedLibCRTFile(lib_name)) |_| {
-                    try wasi_emulated_libs.append(lib_name);
+                if (wasi_libc.getEmulatedLibCRTFile(lib_name)) |crt_file| {
+                    try wasi_emulated_libs.append(crt_file);
                     _ = system_libs.orderedRemove(i);
                     continue;
                 }

src/wasi_libc.zig

@@ -35,6 +35,16 @@ pub fn getEmulatedLibCRTFile(lib_name: []const u8) ?CRTFile {
     return null;
 }
 
+pub fn emulatedLibCRFileLibName(crt_file: CRTFile) []const u8 {
+    return switch (crt_file) {
+        .libwasi_emulated_process_clocks_a => "libwasi-emulated-process-clocks.a",
+        .libwasi_emulated_getpid_a => "libwasi-emulated-getpid.a",
+        .libwasi_emulated_mman_a => "libwasi-emulated-mman.a",
+        .libwasi_emulated_signal_a => "libwasi-emulated-signal.a",
+        else => unreachable,
+    };
+}
+
 pub fn buildCRTFile(comp: *Compilation, crt_file: CRTFile) !void {
     if (!build_options.have_llvm) {
         return error.ZigCompilerNotBuiltWithLLVMExtensions;