[Driver] Change CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL to affect driver default instead of cc1 default

[MaskRay]

Summary

The current cc1 CLANG_ENABLE_OPAQUE_POINTERS=on default difference is not ideal
in that people contribute %clang_cc1 tests may assume the default ON behavior,
which will cause failures on systems set to OFF.

cc1 option default dependent on CMake options should be used prudently
(generally avoided). We prefer to limit target differences to Driver.

Change the CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL mechanism introduced in D123122
to use a driver default instead. This is similar to the mechanism used for the
-flegacy-pass-manager transition to new PM transition.

[MaskRay]

Add tests

clang/include/clang/Driver/Options.td

defm enable_noundef_analysis : BoolOption<"",
   CodeGenOpts<"EnableNoundefAttrs">,
   DefaultTrue,
   PosFlag<SetTrue, [], "Enable">,
   NegFlag<SetFalse, [], "Disable">,
   BothFlags<[], " analyzing function argument and return types for mandatory definedness">>;
 defm opaque_pointers : BoolOption<"",
   "opaque-pointers",
   CodeGenOpts<"OpaquePointers">,
-  Default<"CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL">,
+  DefaultTrue,
   PosFlag<SetTrue, [], "Enable">,
   NegFlag<SetFalse, [], "Disable">,
   BothFlags<[], " opaque pointers">>;
 def discard_value_names : Flag<["-"], "discard-value-names">,
   HelpText<"Discard value names in LLVM IR">,
   MarshallingInfoFlag<CodeGenOpts<"DiscardValueNames">>;
 def plugin_arg : JoinedAndSeparate<["-"], "plugin-arg-">,
     MetaVarName<"<name> <arg>">,

clang/lib/Driver/ToolChains/Clang.cpp

 #include "MSP430.h"
 #include "PS4CPU.h"
 #include "clang/Basic/CLWarnings.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/ObjCRuntime.h"
 #include "clang/Basic/Version.h"
+#include "clang/Config/config.h"
 #include "clang/Driver/Action.h"
 #include "clang/Driver/Distro.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/InputInfo.h"
 #include "clang/Driver/Options.h"
 #include "clang/Driver/SanitizerArgs.h"
 #include "clang/Driver/Types.h"
 #include "clang/Driver/XRayArgs.h"
if (Args.hasFlag(options::OPT_fpch_instantiate_templates,
     CmdArgs.push_back("-fpch-instantiate-templates");
   if (Args.hasFlag(options::OPT_fpch_codegen, options::OPT_fno_pch_codegen,
                    false))
     CmdArgs.push_back("-fmodules-codegen");
   if (Args.hasFlag(options::OPT_fpch_debuginfo, options::OPT_fno_pch_debuginfo,
                    false))
     CmdArgs.push_back("-fmodules-debuginfo");
 
+  if (!CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL)
+    CmdArgs.push_back("-no-opaque-pointers");
+
   ObjCRuntime Runtime = AddObjCRuntimeArgs(Args, Inputs, CmdArgs, rewriteKind);
   RenderObjCOptions(TC, D, RawTriple, Args, Runtime, rewriteKind != RK_None,
                     Input, CmdArgs);
 
   if (types::isObjC(Input.getType()) &&
       Args.hasFlag(options::OPT_fobjc_encode_cxx_class_template_spec,
                    options::OPT_fno_objc_encode_cxx_class_template_spec,
                    !Runtime.isNeXTFamily()))

clang/test/CMakeLists.txt

 # Test runner infrastructure for Clang. This configures the Clang test trees
 # for use by Lit, and delegates to LLVM's lit test handlers.
 
 llvm_canonicalize_cmake_booleans(
   CLANG_BUILD_EXAMPLES
   CLANG_DEFAULT_PIE_ON_LINUX
+  CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL
   CLANG_ENABLE_ARCMT
   CLANG_ENABLE_STATIC_ANALYZER
   CLANG_PLUGIN_SUPPORT
   CLANG_SPAWN_CC1
   ENABLE_BACKTRACES
   LLVM_ENABLE_ZLIB
   LLVM_ENABLE_PER_TARGET_RUNTIME_DIR
   LLVM_ENABLE_THREADS

clang/test/Driver/opaque-pointers-off.c

+// UNSUPPORTED: enable-opaque-pointers
+/// Test -DCLANG_ENABLE_OPAQUE_POINTERS=OFF.
+
+// RUN: %clang -### --target=aarch64-linux-gnu %s 2>&1 | FileCheck %s
+/// User -Xclang -opaque-pointers overrides the default.
+// RUN: %clang -### --target=aarch64-linux-gnu -Xclang -opaque-pointers %s 2>&1 | FileCheck %s --check-prefix=CHECK2
+
+// CHECK:       "-no-opaque-pointers"
+
+// CHECK2:      "-no-opaque-pointers"
+// CHECK2-SAME: "-opaque-pointers"

clang/test/Driver/rewrite-legacy-objc.m

 // RUN: %clang -no-canonical-prefixes -target x86_64-apple-macosx10.7.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST0 %s
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1" "-fobjc-runtime=macosx-fragile" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16"
+// TEST0: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1"{{.*}} "-fobjc-runtime=macosx-fragile" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16"
 // TEST0: rewrite-legacy-objc.m"
 // RUN: %clang -no-canonical-prefixes -target i386-apple-macosx10.9.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST1 %s
 // RUN: %clang -no-canonical-prefixes -target i386-apple-macosx10.6.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST2 %s
-// TEST1: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16"
-// TEST2: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16"
+// TEST1: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1"{{.*}} "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16"
+// TEST2: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1"{{.*}} "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16"

clang/test/Driver/rewrite-objc.m

 // RUN: %clang -no-canonical-prefixes -target x86_64-apple-macosx10.7.0 -rewrite-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST0 %s
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1" "-fobjc-runtime=macosx" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16"
+// TEST0: "-stack-protector" "1" "-fblocks" "-fencode-extended-block-signature" "-fregister-global-dtors-with-atexit" "-fgnuc-version=4.2.1"{{.*}} "-fobjc-runtime=macosx" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16"

clang/test/lit.cfg.py

 
 # Plugins (loadable modules)
 if config.has_plugins and config.llvm_plugin_ext:
     config.available_features.add('plugins')
 
 if config.clang_default_pie_on_linux:
     config.available_features.add('default-pie-on-linux')
 
+if config.clang_enable_opaque_pointers:
+    config.available_features.add('enable-opaque-pointers')
+
 # Set available features we allow tests to conditionalize on.
 #
 if config.clang_default_cxx_stdlib != '':
     config.available_features.add('default-cxx-stdlib-set')
 
 # As of 2011.08, crash-recovery tests still do not pass on FreeBSD.
 if platform.system() not in ['FreeBSD']:
     config.available_features.add('crash-recovery')

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

 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.host_cc = "@CMAKE_C_COMPILER@"
 config.host_cxx = "@CMAKE_CXX_COMPILER@"
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.clang_arcmt = @CLANG_ENABLE_ARCMT@
 config.clang_default_pie_on_linux = @CLANG_DEFAULT_PIE_ON_LINUX@
+config.clang_enable_opaque_pointers = @CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL@
 config.clang_default_cxx_stdlib = "@CLANG_DEFAULT_CXX_STDLIB@"
 config.clang_staticanalyzer = @CLANG_ENABLE_STATIC_ANALYZER@
 config.clang_staticanalyzer_z3 = @LLVM_WITH_Z3@
 config.clang_examples = @CLANG_BUILD_EXAMPLES@
 config.enable_shared = @ENABLE_SHARED@
 config.enable_backtrace = @ENABLE_BACKTRACES@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.host_arch = "@HOST_ARCH@"