allow linking bins that do not exist. (oven-sh#8605)

src/install/bin.zig

@@ -392,40 +392,41 @@ pub const Bin = extern struct {
                     };
                     defer file.close();
 
-                    const first_content_chunk = contents: {
-                        const fd = bun.sys.openatWindows(
-                            this.package_installed_node_modules,
-                            if (link_global)
-                                bun.strings.toWPathNormalized(
-                                    &filename3_buf,
-                                    target_path[this.relative_path_to_bin_for_windows_global_link_offset..],
-                                )
-                            else
-                                target_wpath,
-                            std.os.O.RDONLY,
-                        ).unwrap() catch |err| {
-                            this.err = err;
-                            return;
-                        };
-                        defer _ = bun.sys.close(fd);
-                        const reader = fd.asFile().reader();
-                        const read = reader.read(&read_in_buf) catch |err| {
-                            this.err = err;
-                            return;
+                    const shebang = shebang: {
+                        const first_content_chunk = contents: {
+                            const fd = bun.sys.openatWindows(
+                                this.package_installed_node_modules,
+                                if (link_global)
+                                    bun.strings.toWPathNormalized(
+                                        &filename3_buf,
+                                        target_path[this.relative_path_to_bin_for_windows_global_link_offset..],
+                                    )
+                                else
+                                    target_wpath,
+                                std.os.O.RDONLY,
+                            ).unwrap() catch break :contents null;
+                            defer _ = bun.sys.close(fd);
+                            const reader = fd.asFile().reader();
+                            const read = reader.read(&read_in_buf) catch break :contents null;
+                            if (read == 0) {
+                                break :contents null;
+                            }
+                            break :contents read_in_buf[0..read];
                         };
-                        if (read == 0) {
-                            this.err = error.FileNotFound;
-                            return;
+
+                        if (first_content_chunk) |chunk| {
+                            break :shebang WinBinLinkingShim.Shebang.parse(chunk, target_wpath) catch {
+                                this.err = error.InvalidBinContent;
+                                return;
+                            };
+                        } else {
+                            break :shebang WinBinLinkingShim.Shebang.parseFromBinPath(target_wpath);
                         }
-                        break :contents read_in_buf[0..read];
                     };
 
                     const shim = WinBinLinkingShim{
                         .bin_path = target_wpath,
-                        .shebang = WinBinLinkingShim.Shebang.parse(first_content_chunk, target_wpath) catch {
-                            this.err = error.InvalidBinContent;
-                            return;
-                        },
+                        .shebang = shebang,
                     };
 
                     const len = shim.encodedLength();

src/install/windows-shim/BinLinkingShim.zig

@@ -30,10 +30,13 @@ shebang: ?Shebang,
 /// These arbitrary numbers will probably not show up in the other fields.
 /// This will reveal off-by-one mistakes.
 pub const VersionFlag = enum(u13) {
-    pub const current = .v2;
+    pub const current = .v3;
 
     v1 = 5474,
+    // Fix bug where paths were not joined correctly
     v2 = 5475,
+    // Added an error message for when the process is not found
+    v3 = 5476,
     _,
 };
 

src/install/windows-shim/bun_shim_impl.zig

@@ -34,7 +34,7 @@
 //! Prior Art:
 //! - https://github.com/ScoopInstaller/Shim/blob/master/src/shim.cs
 //!
-//! The compiled binary is 10240 bytes and is `@embedFile`d into Bun itself.
+//! The compiled binary is 10752 bytes and is `@embedFile`d into Bun itself.
 //! When this file is updated, the new binary should be compiled and BinLinkingShim.VersionFlag.current should be updated.
 const std = @import("std");
 const builtin = @import("builtin");
@@ -148,6 +148,9 @@ const FailReason = enum {
     InvalidShimValidation,
     InvalidShimBounds,
     CouldNotDirectLaunch,
+    BinNotFound,
+    InterpreterNotFound,
+    ElevationRequired,
 
     pub fn render(reason: FailReason) []const u8 {
         return switch (reason) {
@@ -159,6 +162,12 @@ const FailReason = enum {
             .InvalidShimDataSize => "bin metadata is corrupt (size)",
             .InvalidShimValidation => "bin metadata is corrupt (validate)",
             .InvalidShimBounds => "bin metadata is corrupt (bounds)",
+            // The difference between these two is that one is with a shebang (#!/usr/bin/env node) and
+            // the other is without. This is a helpful distinction because it can detect if something
+            // like node or bun is not in %path%, vs the actual executable was not installed in node_modules.
+            .InterpreterNotFound => "interpreter executable could not be found",
+            .BinNotFound => "bin executable does not exist on disk",
+            .ElevationRequired => "process requires elevation",
             .CreateProcessFailed => "could not create process",
 
             .CouldNotDirectLaunch => if (!is_standalone)
@@ -678,17 +687,27 @@ fn launcher(bun_ctx: anytype) noreturn {
         &process,
     );
     if (did_process_spawn == 0) {
+        const spawn_err = k32.GetLastError();
         if (dbg) {
-            const spawn_err = k32.GetLastError();
             printError("CreateProcessW failed: {s}\n", .{@tagName(spawn_err)});
         }
-        // TODO: ERROR_ELEVATION_REQUIRED must take a fallback path, this path is potentially slower:
-        // This likely will not be an issue anyone runs into for a while, because it implies
-        // the shebang depends on something that requires UAC, which .... why?
-        //
-        // https://learn.microsoft.com/en-us/windows/security/application-security/application-control/user-account-control/how-it-works#user
-        // https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew
-        fail(.CreateProcessFailed);
+        switch (spawn_err) {
+            .FILE_NOT_FOUND => if (flags.has_shebang)
+                fail(.InterpreterNotFound)
+            else
+                fail(.BinNotFound),
+
+            // TODO: ERROR_ELEVATION_REQUIRED must take a fallback path, this path is potentially slower:
+            // This likely will not be an issue anyone runs into for a while, because it implies
+            // the shebang depends on something that requires UAC, which .... why?
+            //
+            // https://learn.microsoft.com/en-us/windows/security/application-security/application-control/user-account-control/how-it-works#user
+            // https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew
+            .ELEVATION_REQUIRED => fail(.ElevationRequired),
+
+            else => fail(.CreateProcessFailed),
+        }
+        comptime unreachable;
     }
 
     _ = k32.WaitForSingleObject(process.hProcess, w.INFINITE);