Make the gem build on TruffleRuby (#27660)

* replace darwin checks in extconf.rb to exclude TruffleRuby

* inherit RANLIB and STRIP from RbConfig, set LDXX

* enable overriding ranlib command in top-level makefile

* ensure the -no_warning_for_no_symbols flag is only used with Apple's ranlib

* don't embed openssl & zlib on truffleruby

* add RbConfig's cppflag to CPPFLAGS when using TruffleRuby

* this ensure the paths to find the system's OpenSSL are set up correctly with TruffleRuby (includes being able to find an OpenSSL installed via Homebrew etc)

* don't statically link standard libraries on Linux with Truffleruby

* This does not work when compiling to bitcode.

* Prefer SIGTERM to SIGQUIT for graceful shutdown in examples

* Overriding SIGQUIT is suboptimal, for example on JVM where it is very
  useful to dump the thread stacktraces.

* Keep the rb_tr_abi_version symbol for TruffleRuby in grpc_c.so

* Otherwise TruffleRuby cannot verify the ABI version is correct.
* See oracle/truffleruby#2386

* Use RbConfig::CONFIG['STRIP'] instead of just `strip`

* Use a local variable for apple_toolchain for consistency

* Add a comment about -static-libgcc -static-libstdc++ and TruffleRuby

* Split comment into two for openssl/zlib

Co-authored-by: Nicolas Laurent <nicolas.laurent@oracle.com>

examples/ruby/greeter_server.rb

@@ -39,10 +39,10 @@ def main
   s = GRPC::RpcServer.new
   s.add_http2_port('0.0.0.0:50051', :this_port_is_insecure)
   s.handle(GreeterServer)
-  # Runs the server with SIGHUP, SIGINT and SIGQUIT signal handlers to 
+  # Runs the server with SIGHUP, SIGINT and SIGTERM signal handlers to
   #   gracefully shutdown.
   # User could also choose to run server via call to run_till_terminated
-  s.run_till_terminated_or_interrupted([1, 'int', 'SIGQUIT'])
+  s.run_till_terminated_or_interrupted([1, 'int', 'SIGTERM'])
 end
 
 main

examples/ruby/route_guide/route_guide_server.rb

@@ -172,10 +172,10 @@ def main
   s.add_http2_port(port, :this_port_is_insecure)
   GRPC.logger.info("... running insecurely on #{port}")
   s.handle(ServerImpl.new(feature_db))
-  # Runs the server with SIGHUP, SIGINT and SIGQUIT signal handlers to 
+  # Runs the server with SIGHUP, SIGINT and SIGTERM signal handlers to
   #   gracefully shutdown.
   # User could also choose to run server via call to run_till_terminated
-  s.run_till_terminated_or_interrupted([1, 'int', 'SIGQUIT'])
+  s.run_till_terminated_or_interrupted([1, 'int', 'SIGTERM'])
 end
 
 main

src/ruby/ext/grpc/ext-export-truffleruby.clang

@@ -0,0 +1,2 @@
+_Init_grpc_c
+_rb_tr_abi_version

src/ruby/ext/grpc/ext-export-truffleruby.gcc

@@ -0,0 +1,7 @@
+grpc_1.0 { 
+  global: 
+    Init_grpc_c;
+    rb_tr_abi_version;
+  local: 
+    *;
+};

src/ruby/ext/grpc/extconf.rb

@@ -20,49 +20,74 @@
 darwin = RUBY_PLATFORM =~ /darwin/
 linux = RUBY_PLATFORM =~ /linux/
 cross_compiling = ENV['RCD_HOST_RUBY_VERSION'] # set by rake-compiler-dock in build containers
+# TruffleRuby uses the Sulong LLVM runtime, which is different from Apple's.
+apple_toolchain = darwin && RUBY_ENGINE != 'truffleruby'
 
 grpc_root = File.expand_path(File.join(File.dirname(__FILE__), '../../../..'))
 
 grpc_config = ENV['GRPC_CONFIG'] || 'opt'
 
 ENV['MACOSX_DEPLOYMENT_TARGET'] = '10.10'
 
-if ENV['AR'].nil? || ENV['AR'].size == 0
-    ENV['AR'] = RbConfig::CONFIG['AR']
+def env_unset?(name)
+  ENV[name].nil? || ENV[name].size == 0
 end
-if ENV['CC'].nil? || ENV['CC'].size == 0
-    ENV['CC'] = RbConfig::CONFIG['CC']
+
+def rbconfig_set?(name)
+  RbConfig::CONFIG[name] && RbConfig::CONFIG[name].size > 0
 end
-if ENV['CXX'].nil? || ENV['CXX'].size == 0
-    ENV['CXX'] = RbConfig::CONFIG['CXX']
+
+def inherit_rbconfig(name)
+  ENV[name] = RbConfig::CONFIG[name] if env_unset?(name) && rbconfig_set?(name)
 end
-if ENV['LD'].nil? || ENV['LD'].size == 0
-    ENV['LD'] = ENV['CC']
+
+def env_append(name, string)
+  ENV[name] ||= ''
+  ENV[name] += ' ' + string
 end
 
-if darwin && !cross_compiling
+inherit_rbconfig 'AR'
+inherit_rbconfig 'CC'
+inherit_rbconfig 'CXX'
+inherit_rbconfig 'RANLIB'
+inherit_rbconfig 'STRIP'
+inherit_rbconfig 'CPPFLAGS'
+inherit_rbconfig 'LDFLAGS'
+
+ENV['LD'] = ENV['CC'] if env_unset?('LD')
+ENV['LDXX'] = ENV['CXX'] if env_unset?('LDXX')
+
+if RUBY_ENGINE == 'truffleruby'
+  # ensure we can find the system's OpenSSL
+  env_append 'CPPFLAGS', RbConfig::CONFIG['cppflags']
+end
+
+if apple_toolchain && !cross_compiling
   ENV['AR'] = 'libtool'
   ENV['ARFLAGS'] = '-o'
 end
 
-ENV['EMBED_OPENSSL'] = 'true'
-ENV['EMBED_ZLIB'] = 'true'
+# Don't embed on TruffleRuby (constant-time crypto is unsafe with Sulong, slow build times)
+ENV['EMBED_OPENSSL'] = (RUBY_ENGINE != 'truffleruby').to_s
+# Don't embed on TruffleRuby (the system zlib is already linked for the zlib C extension, slow build times)
+ENV['EMBED_ZLIB'] = (RUBY_ENGINE != 'truffleruby').to_s
+
 ENV['EMBED_CARES'] = 'true'
 
 ENV['ARCH_FLAGS'] = RbConfig::CONFIG['ARCH_FLAG']
-if darwin && !cross_compiling
+if apple_toolchain && !cross_compiling
   if RUBY_PLATFORM =~ /arm64/
     ENV['ARCH_FLAGS'] = '-arch arm64'
   else
     ENV['ARCH_FLAGS'] = '-arch i386 -arch x86_64'
   end
 end
 
-ENV['CPPFLAGS'] = '-DGPR_BACKWARDS_COMPATIBILITY_MODE'
-ENV['CPPFLAGS'] += ' -DGRPC_XDS_USER_AGENT_NAME_SUFFIX="\"RUBY\"" '
+env_append 'CPPFLAGS', '-DGPR_BACKWARDS_COMPATIBILITY_MODE'
+env_append 'CPPFLAGS', '-DGRPC_XDS_USER_AGENT_NAME_SUFFIX="\"RUBY\""'
 
 require_relative '../../lib/grpc/version'
-ENV['CPPFLAGS'] += ' -DGRPC_XDS_USER_AGENT_VERSION_SUFFIX="\"' + GRPC::VERSION + '\"" '
+env_append 'CPPFLAGS', '-DGRPC_XDS_USER_AGENT_VERSION_SUFFIX="\"' + GRPC::VERSION + '\""'
 
 output_dir = File.expand_path(RbConfig::CONFIG['topdir'])
 grpc_lib_dir = File.join(output_dir, 'libs', grpc_config)
@@ -87,8 +112,9 @@
 $CFLAGS << ' -I' + File.join(grpc_root, 'include')
 
 ext_export_file = File.join(grpc_root, 'src', 'ruby', 'ext', 'grpc', 'ext-export')
+ext_export_file += '-truffleruby' if RUBY_ENGINE == 'truffleruby'
 $LDFLAGS << ' -Wl,--version-script="' + ext_export_file + '.gcc"' if linux
-$LDFLAGS << ' -Wl,-exported_symbols_list,"' + ext_export_file + '.clang"' if darwin
+$LDFLAGS << ' -Wl,-exported_symbols_list,"' + ext_export_file + '.clang"' if apple_toolchain
 
 $LDFLAGS << ' ' + File.join(grpc_lib_dir, 'libgrpc.a') unless windows
 if grpc_config == 'gcov'
@@ -101,7 +127,10 @@
 end
 
 $LDFLAGS << ' -Wl,-wrap,memcpy' if linux
-$LDFLAGS << ' -static-libgcc -static-libstdc++' if linux
+# Do not statically link standard libraries on TruffleRuby as this does not work when compiling to bitcode
+if linux && RUBY_ENGINE != 'truffleruby'
+  $LDFLAGS << ' -static-libgcc -static-libstdc++'
+end
 $LDFLAGS << ' -static' if windows
 
 $CFLAGS << ' -std=c11 '
@@ -114,7 +143,7 @@
 create_makefile(output)
 
 strip_tool = RbConfig::CONFIG['STRIP']
-strip_tool += ' -x' if darwin
+strip_tool += ' -x' if apple_toolchain
 
 if grpc_config == 'opt'
   File.open('Makefile.new', 'w') do |o|

templates/Makefile.template

@@ -185,6 +185,13 @@
   INSTALL ?= install
   RM ?= rm -f
   PKG_CONFIG ?= pkg-config
+  RANLIB ?= ranlib
+  ifeq ($(SYSTEM),Darwin)
+  APPLE_RANLIB = $(shell [[ "`$(RANLIB) -V 2>/dev/null`" == "Apple Inc."* ]]; echo $$?)
+  ifeq ($(APPLE_RANLIB),0)
+  RANLIBFLAGS = -no_warning_for_no_symbols
+  endif
+  endif
 
   ifndef VALID_CONFIG_$(CONFIG)
   $(error Invalid CONFIG value '$(CONFIG)')
@@ -941,7 +948,7 @@
   % endif
 
   ifeq ($(SYSTEM),Darwin)
-  	$(Q) ranlib -no_warning_for_no_symbols $(LIBDIR)/$(CONFIG)/lib${lib.name}.a
+  	$(Q) $(RANLIB) $(RANLIBFLAGS) $(LIBDIR)/$(CONFIG)/lib${lib.name}.a
   endif
 
   <%