From ed113282a01bc3eb8da34d3d1283590cf07383a5 Mon Sep 17 00:00:00 2001
From: Jacob Young <jacobly0@users.noreply.github.com>
Date: Wed, 8 May 2024 23:01:03 -0400
Subject: [PATCH] msvc

---
 .github/workflows/ci.yaml |   2 +-
 ci/build.zig              | 108 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 9997ca7f3cf1..5f254330901e 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -178,7 +178,7 @@ jobs:
           fetch-depth: 0
       - name: Build and Test
         working-directory: ci
-        run: '& $Env:USERPROFILE\deps\zig-x86_64-windows-gnu-${{env.ci-zig-version}}\bin\zig.exe build -Dbuild-type=Debug -Dskip-non-native cmake-bootstrap tidy update-stage1'
+        run: '& $Env:USERPROFILE\deps\zig-x86_64-windows-gnu-${{env.ci-zig-version}}\bin\zig.exe build -Dbuild-type=Debug -Dskip-non-native cmake-bootstrap tidy update-stage1 msvc'
   x86_64-windows-release:
     if: github.repository_owner == 'ziglang'
     runs-on: [self-hosted, Windows, x86_64]
diff --git a/ci/build.zig b/ci/build.zig
index a8fad42d9021..b6588ade8c1e 100644
--- a/ci/build.zig
+++ b/ci/build.zig
@@ -553,5 +553,113 @@ pub fn build(b: *std.Build) void {
             run_tests_with_updated_stage4.addFileArg(b.path("../test/behavior.zig"));
             update_stage1_step.dependOn(&run_tests_with_updated_stage4.step);
         }
+
+        if (std.zig.WindowsSdk.find(b.allocator)) |sdk| sdk: {
+            const msvc_step = b.step("msvc", "Run the behavior tests compiled with MSVC");
+
+            const msvc_arch = switch (host.result.cpu.arch) {
+                .x86 => "x86",
+                .x86_64 => "x64",
+                .arm, .armeb, .thumb, .thumbeb => "arm",
+                .aarch64 => "arm64",
+                else => break :sdk,
+            };
+            const cl_exe = std.fs.path.resolve(b.allocator, &.{
+                sdk.msvc_lib_dir orelse break :sdk,
+                "..",
+                "..",
+                "bin",
+                b.fmt("Host{s}", .{msvc_arch}),
+                msvc_arch,
+                b.fmt("cl{s}", .{host_exe_file_ext}),
+            }) catch @panic("OOM");
+            const msvc_triple = triple: {
+                var msvc_target = host.result;
+                msvc_target.abi = .msvc;
+                break :triple msvc_target.linuxTriple(b.allocator) catch @panic("OOM");
+            };
+
+            const build_msvc_behavior_tests = std.Build.Step.Run.create(b, "build msvc behavior tests");
+            build_msvc_behavior_tests.step.max_rss = 213_237_760;
+            if (false)
+                build_msvc_behavior_tests.addFileArg(stage3_exe)
+            else
+                build_msvc_behavior_tests.addArg(b.cache_root.join(b.allocator, &.{
+                    "o",
+                    "4aeed00bc8dFaa6ee10d8a09a88bd97b",
+                    "build",
+                    "stage3",
+                    "bin",
+                    b.fmt("zig{s}", .{host_exe_file_ext}),
+                }) catch @panic("OOM"));
+            build_msvc_behavior_tests.addArgs(&.{
+                "test",
+                "-ofmt=c",
+                "--test-no-exec",
+                "-target",
+                msvc_triple,
+                "-lc",
+            });
+            build_msvc_behavior_tests.addFileArg(b.path("../test/behavior.zig"));
+            const behavior_msvc_source =
+                build_msvc_behavior_tests.addPrefixedOutputFileArg("-femit-bin=", "behavior-msvc.c");
+
+            const build_msvc_compiler_rt = std.Build.Step.Run.create(b, "build msvc compiler-rt");
+            build_msvc_compiler_rt.step.max_rss = 164_306_944;
+            if (false)
+                build_msvc_compiler_rt.addFileArg(stage3_exe)
+            else
+                build_msvc_compiler_rt.addArg(b.cache_root.join(b.allocator, &.{
+                    "o",
+                    "4aeed00bc8dFaa6ee10d8a09a88bd97b",
+                    "build",
+                    "stage3",
+                    "bin",
+                    b.fmt("zig{s}", .{host_exe_file_ext}),
+                }) catch @panic("OOM"));
+            build_msvc_compiler_rt.addArgs(&.{
+                "build-obj",
+                "-ofmt=c",
+                "-OReleaseSmall",
+                "--name",
+                "compiler_rt",
+                "-target",
+                msvc_triple,
+                "-lc",
+            });
+            build_msvc_compiler_rt.addFileArg(b.path("../lib/compiler_rt.zig"));
+            const compiler_rt_msvc_source =
+                build_msvc_compiler_rt.addPrefixedOutputFileArg("-femit-bin=", "compiler_rt-msvc.c");
+
+            const build_msvc_tests = std.Build.Step.Run.create(b, "build msvc tests");
+            build_msvc_tests.step.max_rss = 1;
+            build_msvc_tests.addArgs(&.{ cl_exe, "/W3", "/Z7" });
+            build_msvc_tests.addPrefixedDirectoryArg("/I", b.path("../lib"));
+            build_msvc_tests.addFileArg(behavior_msvc_source);
+            build_msvc_tests.addFileArg(compiler_rt_msvc_source);
+            const msvc_tests_exe = build_msvc_tests.addPrefixedOutputFileArg(
+                "/Fe:",
+                b.fmt("behavior-msvc{s}", .{host_exe_file_ext}),
+            );
+            // Link args must appear after all other args.
+            build_msvc_tests.addArgs(&.{
+                "/link",
+                "/nologo",
+                "/debug",
+                "/subsystem:console",
+                "kernel32.lib",
+                "ntdll.lib",
+                "libcmt.lib",
+            });
+
+            const run_msvc_tests = std.Build.Step.Run.create(b, "run msvc tests");
+            run_msvc_tests.step.max_rss = 2;
+            run_msvc_tests.addFileArg(msvc_tests_exe);
+            msvc_step.dependOn(&run_msvc_tests.step);
+        } else |err| switch (err) {
+            error.NotFound => {},
+
+            else => |e| @panic(@errorName(e)),
+        }
     }
 }