Add some minimal testing with LLVM stable (v19)

Fixes: emscripten-core#11362

Author: sbc100

.circleci/config.yml

@@ -802,6 +802,32 @@ jobs:
             core2.test_exceptions_wasm
             core2.test_pthread_unhandledrejection"
       - upload-test-results
+  test-llvm-stable:
+    executor: focal
+    environment:
+      LANG: "C.UTF-8"
+      EMTEST_SKIP_V8: "1"
+    steps:
+      - run:
+          name: install llvm
+          command: |
+            echo "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-19 main" >> /etc/apt/sources.list
+            wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -
+            apt-get update
+            apt-get install -q -y clang-19 lld-19
+      - checkout
+      - run:
+          name: submodule update
+          command: git submodule update --init
+      - pip-install
+      - install-emsdk
+      - install-rust
+      - run:
+          name: configure LLVM
+          command: echo "LLVM_ROOT='/usr/lib/llvm-19/bin'" >> ~/emsdk/.emscripten
+      - run: apt-get install -q -y ninja-build scons ccache
+      - run-tests:
+          test_targets: "core0.test_hello_world"
   test-other:
     executor: focal
     environment:
@@ -979,59 +1005,5 @@ jobs:
 workflows:
   build-test:
     jobs:
-      - ruff
-      - mypy
-      - eslint
-      - build-docs
-      - build-linux
-      - test-sanity:
-          requires:
-            - build-linux
-      - test-posixtest:
-          requires:
-            - build-linux
-      - test-core0:
-          requires:
-            - build-linux
-      - test-core2:
-          requires:
-            - build-linux
-      - test-core3:
-          requires:
-            - build-linux
-      - test-wasm64:
-          requires:
-            - build-linux
-      - test-wasm64-4gb:
-          requires:
-            - build-linux
-      - test-wasm2js1:
-          requires:
-            - build-linux
-      - test-other:
-          requires:
-            - build-linux
-      - test-browser-chrome:
-          requires:
-            - build-linux
-      - test-browser-chrome-2gb:
-          requires:
-            - build-linux
-      - test-browser-chrome-wasm64:
-          requires:
-            - build-linux
-      - test-browser-chrome-wasm64-4gb:
-          requires:
-            - build-linux
-      - test-browser-firefox:
-          requires:
-            - build-linux
-      - test-browser-firefox-wasm64
-      - test-sockets-chrome:
-          requires:
-            - build-linux
-      - test-jsc
-      - test-spidermonkey
-      - test-node-compat
-      - test-windows
-      - test-mac-arm64
+      - test-llvm-stable
+

emcc.py

@@ -385,6 +385,14 @@ def get_clang_flags(user_args):
     if '-mbulk-memory' not in user_args:
       flags.append('-mbulk-memory')
 
+  if shared.is_llvm_stable():
+    # LLVM 19 doesn't enable these features by default, but we want
+    # them on-by-default, like they are on LLVM tot.
+    if '-mbulk-memory' not in user_args:
+      flags.append('-mbulk-memory')
+    if '-mnontrapping-fptoint' not in user_args:
+      flags.append('-mnontrapping-fptoint')
+
   if settings.RELOCATABLE and '-fPIC' not in user_args:
     flags.append('-fPIC')
 

tools/shared.py

@@ -60,6 +60,7 @@
 # This version currently matches the node version that we ship with emsdk
 # which means that we can say for sure that this version is well supported.
 MINIMUM_NODE_VERSION = (16, 20, 0)
+EXPECTED_LLVM_STABLE_VERSION = 19
 EXPECTED_LLVM_VERSION = 20
 
 # These get set by setup_temp_dirs
@@ -298,17 +299,22 @@ def get_clang_version():
   return m and m.group(1)
 
 
+def is_llvm_stable():
+  return get_clang_version().startswith('%d.' % EXPECTED_LLVM_STABLE_VERSION)
+
+
 def check_llvm_version():
   actual = get_clang_version()
-  if actual.startswith('%d.' % EXPECTED_LLVM_VERSION):
+  expected = [EXPECTED_LLVM_VERSION, EXPECTED_LLVM_STABLE_VERSION]
+  if any(actual.startswith('%d.' % e) for e in expected):
     return True
   # When running in CI environment we also silently allow the next major
   # version of LLVM here so that new versions of LLVM can be rolled in
   # without disruption.
   if 'BUILDBOT_BUILDNUMBER' in os.environ:
     if actual.startswith('%d.' % (EXPECTED_LLVM_VERSION + 1)):
       return True
-  diagnostics.warning('version-check', 'LLVM version for clang executable "%s" appears incorrect (seeing "%s", expected "%s")', CLANG_CC, actual, EXPECTED_LLVM_VERSION)
+  diagnostics.warning('version-check', f'LLVM version for clang executable "{CLANG_CC}" appears incorrect (seeing "{actual}", expected "{EXPECTED_LLVM_VERSION}" or "{EXPECTED_LLVM_STABLE_VERSION}")')
   return False