avoid calling into stage1 backend when AstGen fails

The motivation for this commit is that there exists source files which
produce ast-check errors, but crash stage1 or otherwise trigger stage1
bugs. Previously to this commit, Zig would run AstGen, collect the
compile errors, run stage1, report stage1 compile errors and exit if
any, and then report AstGen compile errors.

The main change in this commit is to report AstGen errors prior to
invoking stage1, and in fact if any AstGen errors occur, do not invoke
stage1 at all.

This caused most of the compile error tests to fail due to things such
as unused local variables and mismatched stage1/stage2 error messages.
It was taking a long time to update the test cases one-by-one, so I
took this opportunity to unify the stage1 and stage2 testing harness,
specifically with regards to compile errors. In this way we can start
keeping track of which tests pass for 1, 2, or both.
`zig build test-compile-errors` no longer works; it is now integrated
into `zig build test-stage2`.

This is one step closer to executing compile error tests in parallel; in
fact the ThreadPool object is already in scope.

There are some cases where the stage1 compile errors were actually
better; those are left failing in this commit, to be addressed in a
follow-up commit.

Other changes in this commit:

 * build.zig: improve support for -Dstage1 used with the test step.
 * AstGen: minor cosmetic changes to error messages.
 * stage2: add -fstage1 and -fno-stage1 flags. This now allows one to
   download a binary of the zig compiler and use the llvm backend of
   self-hosted. This was also needed for hooking up the test harness.
   However, I realized that stage1 calls exit() and also has memory
   leaks, so had to complicate the test harness by not using this flag
   after all and instead invoking as a child process.
   - These CLI flags will disappear once we start shipping the
     self-hosted compiler as the main compiler. Until then, they can be
     used to try out the work-in-progress stage2.
 * stage2: select the LLVM backend by default for release modes, as long
   as the target architecture is supported by LLVM.
 * test harness: support setting the optimize mode

1 files changed, 20 insertions, 12 deletions

diff --git a/build.zig b/build.zig
index dcc60e6622..40e1b36e71 100644
--- a/build.zig
+++ b/build.zig
@@ -40,7 +40,7 @@ pub fn build(b: *Builder) !void {
 
     var test_stage2 = b.addTest("src/test.zig");
     test_stage2.setBuildMode(mode);
-    test_stage2.addPackagePath("stage2_tests", "test/stage2/test.zig");
+    test_stage2.addPackagePath("test_cases", "test/cases.zig");
 
     const fmt_build_zig = b.addFmt(&[_][]const u8{"build.zig"});
 
@@ -113,11 +113,15 @@ pub fn build(b: *Builder) !void {
         if (is_stage1) {
             exe.addIncludeDir("src");
             exe.addIncludeDir("deps/SoftFloat-3e/source/include");
+
+            test_stage2.addIncludeDir("src");
+            test_stage2.addIncludeDir("deps/SoftFloat-3e/source/include");
             // This is intentionally a dummy path. stage1.zig tries to @import("compiler_rt") in case
             // of being built by cmake. But when built by zig it's gonna get a compiler_rt so that
             // is pointless.
             exe.addPackagePath("compiler_rt", "src/empty.zig");
             exe.defineCMacro("ZIG_LINK_MODE", "Static");
+            test_stage2.defineCMacro("ZIG_LINK_MODE", "Static");
 
             const softfloat = b.addStaticLibrary("softfloat", null);
             softfloat.setBuildMode(.ReleaseFast);
@@ -126,10 +130,15 @@ pub fn build(b: *Builder) !void {
             softfloat.addIncludeDir("deps/SoftFloat-3e/source/8086");
             softfloat.addIncludeDir("deps/SoftFloat-3e/source/include");
             softfloat.addCSourceFiles(&softfloat_sources, &[_][]const u8{ "-std=c99", "-O3" });
+
             exe.linkLibrary(softfloat);
+            test_stage2.linkLibrary(softfloat);
 
             exe.addCSourceFiles(&stage1_sources, &exe_cflags);
             exe.addCSourceFiles(&optimized_c_sources, &[_][]const u8{ "-std=c99", "-O3" });
+
+            test_stage2.addCSourceFiles(&stage1_sources, &exe_cflags);
+            test_stage2.addCSourceFiles(&optimized_c_sources, &[_][]const u8{ "-std=c99", "-O3" });
         }
         if (cmake_cfg) |cfg| {
             // Inside this code path, we have to coordinate with system packaged LLVM, Clang, and LLD.
@@ -139,8 +148,8 @@ pub fn build(b: *Builder) !void {
                 b.addSearchPrefix(cfg.cmake_prefix_path);
             }
 
-            try addCmakeCfgOptionsToExe(b, cfg, tracy, exe);
-            try addCmakeCfgOptionsToExe(b, cfg, tracy, test_stage2);
+            try addCmakeCfgOptionsToExe(b, cfg, exe);
+            try addCmakeCfgOptionsToExe(b, cfg, test_stage2);
         } else {
             // Here we are -Denable-llvm but no cmake integration.
             try addStaticLlvmOptionsToExe(exe);
@@ -233,7 +242,9 @@ pub fn build(b: *Builder) !void {
     const is_darling_enabled = b.option(bool, "enable-darling", "[Experimental] Use Darling to run cross compiled macOS tests") orelse false;
     const glibc_multi_dir = b.option([]const u8, "enable-foreign-glibc", "Provide directory with glibc installations to run cross compiled tests that link glibc");
 
+    test_stage2.addBuildOption(bool, "enable_logging", enable_logging);
     test_stage2.addBuildOption(bool, "skip_non_native", skip_non_native);
+    test_stage2.addBuildOption(bool, "skip_compile_errors", skip_compile_errors);
     test_stage2.addBuildOption(bool, "is_stage1", is_stage1);
     test_stage2.addBuildOption(bool, "omit_stage2", omit_stage2);
     test_stage2.addBuildOption(bool, "have_llvm", enable_llvm);
@@ -243,7 +254,8 @@ pub fn build(b: *Builder) !void {
     test_stage2.addBuildOption(u32, "mem_leak_frames", mem_leak_frames * 2);
     test_stage2.addBuildOption(bool, "enable_darling", is_darling_enabled);
     test_stage2.addBuildOption(?[]const u8, "glibc_multi_install_dir", glibc_multi_dir);
-    test_stage2.addBuildOption([]const u8, "version", version);
+    test_stage2.addBuildOption([:0]const u8, "version", try b.allocator.dupeZ(u8, version));
+    test_stage2.addBuildOption(std.SemanticVersion, "semver", semver);
 
     const test_stage2_step = b.step("test-stage2", "Run the stage2 compiler tests");
     test_stage2_step.dependOn(&test_stage2.step);
@@ -339,9 +351,6 @@ pub fn build(b: *Builder) !void {
     }
     // tests for this feature are disabled until we have the self-hosted compiler available
     // toolchain_step.dependOn(tests.addGenHTests(b, test_filter));
-    if (!skip_compile_errors) {
-        toolchain_step.dependOn(tests.addCompileErrorTests(b, test_filter, modes));
-    }
 
     const std_step = tests.addPkgTests(
         b,
@@ -383,7 +392,6 @@ const exe_cflags = [_][]const u8{
 fn addCmakeCfgOptionsToExe(
     b: *Builder,
     cfg: CMakeConfig,
-    tracy: ?[]const u8,
     exe: *std.build.LibExeObjStep,
 ) !void {
     exe.addObjectFile(fs.path.join(b.allocator, &[_][]const u8{
@@ -397,7 +405,7 @@ fn addCmakeCfgOptionsToExe(
     addCMakeLibraryList(exe, cfg.lld_libraries);
     addCMakeLibraryList(exe, cfg.llvm_libraries);
 
-    const need_cpp_includes = tracy != null;
+    const need_cpp_includes = true;
 
     // System -lc++ must be used because in this code path we are attempting to link
     // against system-provided LLVM, Clang, LLD.
@@ -486,9 +494,9 @@ fn addCxxKnownPath(
     if (need_cpp_includes) {
         // I used these temporarily for testing something but we obviously need a
         // more general purpose solution here.
-        //exe.addIncludeDir("/nix/store/b3zsk4ihlpiimv3vff86bb5bxghgdzb9-gcc-9.2.0/lib/gcc/x86_64-unknown-linux-gnu/9.2.0/../../../../include/c++/9.2.0");
-        //exe.addIncludeDir("/nix/store/b3zsk4ihlpiimv3vff86bb5bxghgdzb9-gcc-9.2.0/lib/gcc/x86_64-unknown-linux-gnu/9.2.0/../../../../include/c++/9.2.0/x86_64-unknown-linux-gnu");
-        //exe.addIncludeDir("/nix/store/b3zsk4ihlpiimv3vff86bb5bxghgdzb9-gcc-9.2.0/lib/gcc/x86_64-unknown-linux-gnu/9.2.0/../../../../include/c++/9.2.0/backward");
+        //exe.addIncludeDir("/nix/store/fvf3qjqa5qpcjjkq37pb6ypnk1mzhf5h-gcc-9.3.0/lib/gcc/x86_64-unknown-linux-gnu/9.3.0/../../../../include/c++/9.3.0");
+        //exe.addIncludeDir("/nix/store/fvf3qjqa5qpcjjkq37pb6ypnk1mzhf5h-gcc-9.3.0/lib/gcc/x86_64-unknown-linux-gnu/9.3.0/../../../../include/c++/9.3.0/x86_64-unknown-linux-gnu");
+        //exe.addIncludeDir("/nix/store/fvf3qjqa5qpcjjkq37pb6ypnk1mzhf5h-gcc-9.3.0/lib/gcc/x86_64-unknown-linux-gnu/9.3.0/../../../../include/c++/9.3.0/backward");
     }
 }