Commit 3bf72f2b3a

@@ -60,6 +60,7 @@ pub fn main() !void {
     const stderr_stream = io.getStdErr().writer();
     const stdout_stream = io.getStdOut().writer();
 
+    var install_prefix: ?[]const u8 = null;
     while (nextArg(args, &arg_idx)) |arg| {
         if (mem.startsWith(u8, arg, "-D")) {
             const option_contents = arg[2..];
@@ -82,7 +83,7 @@ pub fn main() !void {
             } else if (mem.eql(u8, arg, "-h") or mem.eql(u8, arg, "--help")) {
                 return usage(builder, false, stdout_stream);
             } else if (mem.eql(u8, arg, "--prefix")) {
-                builder.install_prefix = nextArg(args, &arg_idx) orelse {
+                install_prefix = nextArg(args, &arg_idx) orelse {
                     warn("Expected argument after --prefix\n\n", .{});
                     return usageAndErr(builder, false, stderr_stream);
                 };
@@ -134,7 +135,7 @@ pub fn main() !void {
         }
     }
 
-    builder.resolveInstallPrefix();
+    builder.resolveInstallPrefix(install_prefix);
     try runBuild(builder);
 
     if (builder.validateUserInputDidItFail())
@@ -162,8 +163,7 @@ fn runBuild(builder: *Builder) anyerror!void {
 fn usage(builder: *Builder, already_ran_build: bool, out_stream: anytype) !void {
     // run the build script to collect the options
     if (!already_ran_build) {
-        builder.setInstallPrefix(null);
-        builder.resolveInstallPrefix();
+        builder.resolveInstallPrefix(null);
         try runBuild(builder);
     }
 

@@ -51,7 +51,7 @@ pub const Builder = struct {
     default_step: *Step,
     env_map: *BufMap,
     top_level_steps: ArrayList(*TopLevelStep),
-    install_prefix: ?[]const u8,
+    install_prefix: []const u8,
     dest_dir: ?[]const u8,
     lib_dir: []const u8,
     exe_dir: []const u8,
@@ -156,7 +156,7 @@ pub const Builder = struct {
             .default_step = undefined,
             .env_map = env_map,
             .search_prefixes = ArrayList([]const u8).init(allocator),
-            .install_prefix = null,
+            .install_prefix = undefined,
             .lib_dir = undefined,
             .exe_dir = undefined,
             .h_dir = undefined,
@@ -190,22 +190,13 @@ pub const Builder = struct {
     }
 
     /// This function is intended to be called by std/special/build_runner.zig, not a build.zig file.
-    pub fn setInstallPrefix(self: *Builder, optional_prefix: ?[]const u8) void {
-        self.install_prefix = optional_prefix;
-    }
-
-    /// This function is intended to be called by std/special/build_runner.zig, not a build.zig file.
-    pub fn resolveInstallPrefix(self: *Builder) void {
+    pub fn resolveInstallPrefix(self: *Builder, install_prefix: ?[]const u8) void {
         if (self.dest_dir) |dest_dir| {
-            const install_prefix = self.install_prefix orelse "/usr";
-            self.install_path = fs.path.join(self.allocator, &[_][]const u8{ dest_dir, install_prefix }) catch unreachable;
+            self.install_prefix = install_prefix orelse "/usr";
+            self.install_path = fs.path.join(self.allocator, &[_][]const u8{ dest_dir, self.install_prefix }) catch unreachable;
         } else {
-            const install_prefix = self.install_prefix orelse blk: {
-                const p = self.cache_root;
-                self.install_prefix = p;
-                break :blk p;
-            };
-            self.install_path = install_prefix;
+            self.install_prefix = install_prefix orelse self.cache_root;
+            self.install_path = self.install_prefix;
         }
         self.lib_dir = fs.path.join(self.allocator, &[_][]const u8{ self.install_path, "lib" }) catch unreachable;
         self.exe_dir = fs.path.join(self.allocator, &[_][]const u8{ self.install_path, "bin" }) catch unreachable;