Build changes to allow cleaner downstream integrations (#1810)

Integrating `openxla/stablehlo` into our (Cruise's) downstream monorepo
requires maintaining a patch file (like
[this](https://gist.github.com/sjain-stanford/cbb2ffdc8d702abbb0dc62096895fdd8))
which fixes references to `//` with `@stablehlo//` among other things.
This PR explicitly defines a `stablehlo` workspace and uses that to
populate the lit config replacements, thereby completely eliminating the
need for a downstream patch that needs to constantly be updated during
upgrades. We also add test_suites which allow better downstream CI
integrations which can be run as follows:

```
bazel test //:all_tests
```

BUILD.bazel

@@ -1311,3 +1311,12 @@ gentbl_cc_library(
         ":vhlo_ops_td_files",
     ],
 )
+
+test_suite(
+    name = "stablehlo_ci_tests",
+    tests = [
+        "//stablehlo/tests:stablehlo_tests",
+        "//stablehlo/testdata:stablehlo_testdata_tests",
+        "//stablehlo/conversions/tosa/tests:stablehlo_tosa_tests"
+    ],
+)

WORKSPACE.bazel

@@ -13,6 +13,8 @@
 # limitations under the License.
 """Workspace for StableHLO."""
 
+workspace(name = "stablehlo")
+
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 SKYLIB_VERSION = "1.3.0"

stablehlo/conversions/tosa/tests/BUILD.bazel

@@ -27,8 +27,8 @@ expand_template(
     substitutions = {
         "@LIT_SITE_CFG_IN_HEADER@": "# Autogenerated, do not edit.",
         "@LLVM_TOOLS_DIR@": package_path("@llvm-project//llvm:BUILD"),
-        "@STABLEHLO_TOOLS_DIR@": ".",
-        "@STABLEHLO_SOURCE_DIR@": ".",
+        "\"@STABLEHLO_TOOLS_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
+        "\"@STABLEHLO_SOURCE_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
     },
     template = "lit.site.cfg.py.in",
 )
@@ -45,6 +45,12 @@ expand_template(
             "@llvm-project//llvm:FileCheck",
         ],
         size = "small",
+        tags = ["stablehlo_tosa_tests"],
     )
     for src in glob(["**/*.mlir"])
 ]
+
+test_suite(
+    name = "stablehlo_tosa_tests",
+    tags = ["stablehlo_tosa_tests"],
+)

stablehlo/conversions/tosa/tests/lit.site.cfg.py.in

@@ -17,4 +17,4 @@ import lit.llvm
 lit.llvm.initialize(lit_config, config)
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.stablehlo_tools_dir = "@STABLEHLO_TOOLS_DIR@"
-lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@/stablehlo/conversions/tosa/tests/lit.cfg.py")
+lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@" + "/stablehlo/conversions/tosa/tests/lit.cfg.py")

stablehlo/testdata/BUILD.bazel

@@ -27,8 +27,8 @@ expand_template(
     substitutions = {
         "@LIT_SITE_CFG_IN_HEADER@": "# Autogenerated, do not edit.",
         "@LLVM_TOOLS_DIR@": package_path("@llvm-project//llvm:BUILD"),
-        "@STABLEHLO_TOOLS_DIR@": ".",
-        "@STABLEHLO_SOURCE_DIR@": ".",
+        "\"@STABLEHLO_TOOLS_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
+        "\"@STABLEHLO_SOURCE_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
     },
     template = "lit.site.cfg.py.in",
 )
@@ -46,6 +46,13 @@ expand_template(
             "@llvm-project//llvm:FileCheck",
         ],
         size = "small",
+        tags = ["stablehlo_testdata_tests"],
+
     )
     for src in glob(["**/*.mlir"])
 ]
+
+test_suite(
+    name = "stablehlo_testdata_tests",
+    tags = ["stablehlo_testdata_tests"],
+)

stablehlo/testdata/lit.site.cfg.py.in

@@ -18,4 +18,4 @@ import lit.llvm
 lit.llvm.initialize(lit_config, config)
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.stablehlo_tools_dir = "@STABLEHLO_TOOLS_DIR@"
-lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@/stablehlo/testdata/lit.cfg.py")
+lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@" + "/stablehlo/testdata/lit.cfg.py")

stablehlo/tests/BUILD.bazel

@@ -130,8 +130,8 @@ expand_template(
     substitutions = {
         "@LIT_SITE_CFG_IN_HEADER@": "# Autogenerated, do not edit.",
         "@LLVM_TOOLS_DIR@": package_path("@llvm-project//llvm:BUILD"),
-        "@STABLEHLO_TOOLS_DIR@": ".",
-        "@STABLEHLO_SOURCE_DIR@": ".",
+        "\"@STABLEHLO_TOOLS_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
+        "\"@STABLEHLO_SOURCE_DIR@\"": "os.path.join(os.environ['TEST_SRCDIR'], 'stablehlo')",
     },
     template = "lit.site.cfg.py.in",
 )
@@ -150,6 +150,12 @@ expand_template(
             "@llvm-project//llvm:not",
         ] + glob(["%s.bc" % src]),
         size = "small",
+        tags = ["stablehlo_tests"],
     )
     for src in glob(["**/*.mlir"])
 ]
+
+test_suite(
+    name = "stablehlo_tests",
+    tags = ["stablehlo_tests"],
+)

stablehlo/tests/lit.site.cfg.py.in

@@ -18,4 +18,4 @@ import lit.llvm
 lit.llvm.initialize(lit_config, config)
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.stablehlo_tools_dir = "@STABLEHLO_TOOLS_DIR@"
-lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@/stablehlo/tests/lit.cfg.py")
+lit_config.load_config(config, "@STABLEHLO_SOURCE_DIR@" + "/stablehlo/tests/lit.cfg.py")