Add extra check for llvm::Any::TypeId visibility

This check should ensure we don't reproduce the problem fixed by
02df443

More accurately, it checks every llvm::Any::TypeId symbol in libLLVM-x.so and
make sure they have weak linkage and are not local to the library, which would
lead to duplicate definition if another weak version of the symbol is defined in
another linked library.

Differential Revision: https://reviews.llvm.org/D109252

Author: serge-sans-paille

llvm/test/lit.cfg.py

@@ -240,6 +240,14 @@ def get_asan_rtlib():
 if not config.build_shared_libs and not config.link_llvm_dylib:
     config.available_features.add('static-libs')
 
+if config.link_llvm_dylib:
+    config.available_features.add('llvm-dylib')
+    config.substitutions.append(
+        ('%llvmdylib',
+         '{}/libLLVM-{}{}'.format(config.llvm_shlib_dir,
+                                  config.llvm_dylib_version,
+                                  config.llvm_shlib_ext)))
+
 if config.have_tf_aot:
     config.available_features.add("have_tf_aot")
 

llvm/test/lit.site.cfg.py.in

@@ -45,6 +45,7 @@ config.build_examples = @LLVM_BUILD_EXAMPLES@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
+config.llvm_dylib_version = "@LLVM_VERSION_MAJOR@@LLVM_VERSION_SUFFIX@"
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@

llvm/test/tools/llvm-shlib/typeids.test

@@ -0,0 +1,14 @@
+# REQUIRES: x86_64-linux, llvm-dylib
+
+# Make sure there's no llvm::Any::TypeId symbol local to the shared library.  As
+# the adress of llvm::Any::TypeId::Id is used as a global unique identifier for
+# each type, having another visibility defeats the original purpose.
+#
+# This happens when llvm::Any::TypeId is parametrized by a type with hidden
+# visibility.
+
+# RUN: llvm-nm -C %llvmdylib | FileCheck %s
+# RUN: llvm-nm -C %llvmdylib | FileCheck %s --check-prefix=SAFETY-CHECK
+
+# CHECK-NOT: {{[^V]}} llvm::Any::TypeId
+# SAFETY-CHECK: V llvm::Any::TypeId