Using an external toolchain to run address sanitizer runs.

Clang+libc++ detects some more situations.

Signed-off-by: Henner Zeller <[email protected]>

.bazelrc

@@ -20,11 +20,11 @@ common:macos --features=-supports_dynamic_linker --cxxopt=-std=c++17 --host_cxxo
 common:windows --compiler=clang-cl --cxxopt=/std:c++17 --host_cxxopt=/std:c++17 --client_env=BAZEL_CXXOPTS=/std:c++17
 
 # Address sanitizer settings.
+build:asan --crosstool_top=@sanitizer_toolchain//:toolchain
 build:asan --strip=never
 build:asan --copt -fsanitize=address
 build:asan --copt -DADDRESS_SANITIZER
 build:asan --copt -O1
 build:asan --copt -g
 build:asan --copt -fno-omit-frame-pointer
 build:asan --linkopt -fsanitize=address
-

.github/workflows/verible-ci.yml

@@ -91,7 +91,6 @@ jobs:
         mode:
         - test
         - smoke-test
-        - asan
         - asan-clang
         - compile
         - compile-clang

WORKSPACE

@@ -199,3 +199,38 @@ http_archive(
     strip_prefix = "bazel-compilation-database-ace73b04e76111afa09934f8771a2798847e724e",
     urls = ["https://github.com/grailbio/bazel-compilation-database/archive/ace73b04e76111afa09934f8771a2798847e724e.tar.gz"],
 )
+
+# Toolchain that we use for sanitizer runs in the CI
+http_archive(
+    name = "com_grail_bazel_toolchain",
+    sha256 = "77c368349e1a90e6e133c7a16743c622856a0e6b4c9935d7d40ece53cf9d3576",
+    strip_prefix = "bazel-toolchain-7e7c7cf1f965f348861085183d79b6a241764390",
+    urls = ["https://github.com/grailbio/bazel-toolchain/archive/7e7c7cf1f965f348861085183d79b6a241764390.tar.gz"],
+)
+
+load("@com_grail_bazel_toolchain//toolchain:deps.bzl", "bazel_toolchain_dependencies")
+
+bazel_toolchain_dependencies()
+
+load("@com_grail_bazel_toolchain//toolchain:rules.bzl", "llvm_toolchain")
+
+llvm_toolchain(
+    name = "sanitizer_toolchain",
+    llvm_version = "10.0.1",
+    sha256 = {
+        "linux": "02a73cfa031dfe073ba8d6c608baf795aa2ddc78eed1b3e08f3739b803545046",
+    },
+    strip_prefix = {
+        "linux": "clang+llvm-10.0.1-x86_64-pc-linux-gnu",
+    },
+    urls = {
+        "linux": [
+            # Use a custom built Clang+LLVM binrary distribution that is more portable than
+            # the official builds because it's built against an older glibc and does not have
+            # dynamic library dependencies to tinfo, gcc_s or stdlibc++.
+            #
+            # For more details, see the files under toolchains/clang.
+            "https://github.com/retone/deps/releases/download/na5/clang+llvm-10.0.1-x86_64-pc-linux-gnu.tar.xz",
+        ],
+    },
+)