From 22661f3d67251688a1fabf9e5fe65210ce284b9f Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Tue, 8 Oct 2024 21:57:08 -0700
Subject: [PATCH] link tests: add a way to check prefix and use it

---
 lib/std/Build/Step/Compile.zig | 12 ++++++++++++
 test/link/elf.zig              |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/std/Build/Step/Compile.zig b/lib/std/Build/Step/Compile.zig
index 0f0b5d3201..a977dc3056 100644
--- a/lib/std/Build/Step/Compile.zig
+++ b/lib/std/Build/Step/Compile.zig
@@ -235,6 +235,7 @@ sanitize_coverage_trace_pc_guard: ?bool = null,
 pub const ExpectedCompileErrors = union(enum) {
     contains: []const u8,
     exact: []const []const u8,
+    starts_with: []const u8,
 };
 
 pub const Entry = union(enum) {
@@ -1958,6 +1959,17 @@ fn checkCompileErrors(compile: *Compile) !void {
 
     // TODO merge this with the testing.expectEqualStrings logic, and also CheckFile
     switch (expect_errors) {
+        .starts_with => |expect_starts_with| {
+            if (std.mem.startsWith(u8, actual_stderr, expect_starts_with)) return;
+            return compile.step.fail(
+                \\
+                \\========= should start with: ============
+                \\{s}
+                \\========= but not found: ================
+                \\{s}
+                \\=========================================
+            , .{ expect_starts_with, actual_stderr });
+        },
         .contains => |expect_line| {
             while (actual_line_it.next()) |actual_line| {
                 if (!matchCompileError(actual_line, expect_line)) continue;
diff --git a/test/link/elf.zig b/test/link/elf.zig
index d261185851..2d66051cdf 100644
--- a/test/link/elf.zig
+++ b/test/link/elf.zig
@@ -3916,7 +3916,7 @@ fn testUnknownFileTypeError(b: *Build, opts: Options) *Step {
     //     "note: while parsing /?/liba.dylib",
     // } });
     expectLinkErrors(exe, test_step, .{
-        .contains = "error: invalid token in LD script: '\\x00\\x00\\x00\\x0c\\x00\\x00\\x00/usr/lib/dyld\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0d' (0:1069)",
+        .starts_with = "error: invalid token in LD script: '\\x00\\x00\\x00\\x0c\\x00\\x00\\x00/usr/lib/dyld\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0d' (",
     });
 
     return test_step;