[SystemZ][z/OS] Set aligned allocation unavailable by default for z/OS

[fanbo-meng]

Summary

Aligned allocation is not supported on z/OS. This patch sets -faligned-alloc-unavailable as default in z/OS toolchain.

[fanbo-meng]

emit the correct diagnostics for z/OS.

[fanbo-meng]

Previous diff is incorrect and didn't include the entire change set, making a new one.

[hubert.reinterpretcast]

clang/lib/Driver/ToolChains/ZOS.cpp

25–27

Please be consistent in using/not using additional namespace qualification. The declaration above this one takes advantage of the using directive for llvm::opt.

clang/lib/Sema/SemaExprCXX.cpp

1841 ↗

(On Diff #291593)

Just to ensure we are on the same page:
Passing -Xclang -faligned-alloc-unavailable on the non-Apple platforms does very bad things (hits "unreachable" and otherwise falls off the end of a function without initializing a return value). Part of this patch makes passing -Xclang -faligned-alloc-unavailable okay on z/OS.

[fanbo-meng]

clang/lib/Sema/SemaExprCXX.cpp

1841 ↗

(On Diff #291593)

Yes, as we are trying to solve the same problem like Darwin (lack of support in system libraries), we use the same mechanism that are introduced for that.

[fanbo-meng]

be consistent with namespace qualification

[fanbo-meng]

change vendor name from ibm to none for tests.

[ahatanak]

clang/include/clang/Basic/DiagnosticSemaKinds.td

7216 ↗

(On Diff #291590)

Is it possible to merge these two diagnostics?

"aligned %select{allocation|deallocation}0 function of type '%1' is %select{only|not}4 "
"available on %2 %select{%3 or newer|}4"

[fanbo-meng]

clang/include/clang/Basic/DiagnosticSemaKinds.td

7216 ↗

(On Diff #291590)

Thanks for reviewing Akira! This merged format does look better, I'll make the change.

[fanbo-meng]

merge diagnostics

[fanbo-meng]

get platform name from triple instead of hardcoding, and convert its spelling

[abhina.sreeskantharajan]

clang/lib/Basic/Targets/OSTargets.h

773–774 ↗

(On Diff #292237)

There is an extra semi-colon.

[fanbo-meng]

fix typo

[abhina.sreeskantharajan]

LGTM

[hubert.reinterpretcast]

clang/include/clang/Basic/DiagnosticSemaKinds.td

7216 ↗

(On Diff #291949)

Can something be done about the trailing space?

clang/test/SemaCXX/unavailable_aligned_allocation.cpp

158 ↗

(On Diff #291949)

Try to use the regex form to check against trailing whitespace.

[fanbo-meng]

clang/include/clang/Basic/DiagnosticSemaKinds.td

7216 ↗

(On Diff #291949)

Thanks for catching that Hubert, I'll fix it.

[fanbo-meng]

remove trailing whitespace from diagnostic

[hubert.reinterpretcast]

LGTM; thanks.

clang/lib/Driver/ToolChains/ZOS.h

ZOS(const Driver &D, const llvm::Triple &Triple,
       const llvm::opt::ArgList &Args);
   ~ZOS() override;
 
   bool isPICDefault() const override { return false; }
   bool isPIEDefault() const override { return false; }
   bool isPICDefaultForced() const override { return false; }
 
   bool IsIntegratedAssemblerDefault() const override { return true; }
+
+  void addClangTargetOptions(
+      const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
+      Action::OffloadKind DeviceOffloadingKind) const override;
 };
 
 } // end namespace toolchains
 } // end namespace driver
 } // end namespace clang
 
 #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ZOS_H

clang/lib/Driver/ToolChains/ZOS.cpp

 using namespace clang::driver::toolchains;
 using namespace llvm::opt;
 using namespace clang;
 
 ZOS::ZOS(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     : ToolChain(D, Triple, Args) {}
 
 ZOS::~ZOS() {}
+
+void ZOS::addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                                llvm::opt::ArgStringList &CC1Args,
+                                Action::OffloadKind DeviceOffloadKind) const {
+  // Pass "-faligned-alloc-unavailable" only when the user hasn't manually
+  // enabled or disabled aligned allocations.
+  if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,
+                                options::OPT_fno_aligned_allocation))
+    CC1Args.push_back("-faligned-alloc-unavailable");
+}

clang/test/Driver/unavailable_aligned_allocation.cpp

 // RUN: %clang -target x86_64-apple-darwin -mtvos-simulator-version-min=10 \
 // RUN: -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=UNAVAILABLE
 //
 // RUN: %clang -target x86_64-apple-darwin -mwatchos-simulator-version-min=3 \
 // RUN: -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=UNAVAILABLE
 //
+// RUN: %clang -target s390x-ibm-zos -c -### %s 2>&1 \
+// RUN:   | FileCheck %s -check-prefix=UNAVAILABLE
+
 // UNAVAILABLE: "-faligned-alloc-unavailable"
 
 // RUN: %clang -target x86_64-apple-macosx10.14 -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=AVAILABLE
 //
 // RUN: %clang -target arm64-apple-ios11 -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=AVAILABLE
 //

 // Check that passing -faligned-allocation or -fno-aligned-allocation stops the
 // driver from passing -faligned-alloc-unavailable to cc1.
 //
 // RUN: %clang -target x86_64-apple-macosx10.13 -faligned-allocation -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=AVAILABLE
 //
 // RUN: %clang -target x86_64-apple-macosx10.13 -fno-aligned-allocation -c -### %s 2>&1 \
 // RUN:   | FileCheck %s -check-prefix=AVAILABLE
+//
+// RUN: %clang -target s390x-ibm-zos -faligned-allocation -c -### %s 2>&1 \
+// RUN:   | FileCheck %s -check-prefix=AVAILABLE
+//
+// RUN: %clang -target s390x-ibm-zos -fno-aligned-allocation -c -### %s 2>&1 \
+// RUN:   | FileCheck %s -check-prefix=AVAILABLE
 
 // AVAILABLE-NOT: "-faligned-alloc-unavailable"

clang/test/Lexer/aligned-allocation.cpp

 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.12.0 -fexceptions -std=c++17 -verify %s \
 // RUN:   -DEXPECT_DEFINED
 //
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.12.0 -fexceptions -std=c++17 -verify %s \
 // RUN:   -faligned-alloc-unavailable
 //
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.12.0 -fexceptions -std=c++17 -verify %s \
 // RUN:   -faligned-allocation -faligned-alloc-unavailable
+//
+// RUN: %clang_cc1 -triple s390x-ibm-zos -fexceptions -std=c++17 -verify %s \
+// RUN:   -DEXPECT_DEFINED
+//
+// RUN: %clang_cc1 -triple s390x-ibm-zos -fexceptions -std=c++17 -verify %s \
+// RUN:   -faligned-alloc-unavailable
+//
+// RUN: %clang_cc1 -triple s390x-ibm-zos -fexceptions -std=c++17 -verify %s \
+// RUN:   -faligned-allocation -faligned-alloc-unavailable
 
 // Test that __cpp_aligned_new is not defined when CC1 is passed
-// -faligned-alloc-unavailable by the Darwin driver, even when aligned
-// allocation is actually enabled.
+// -faligned-alloc-unavailable by the Darwin and the z/OS driver, even when
+// aligned allocation is actually enabled.
 
 // expected-no-diagnostics
 #ifdef EXPECT_DEFINED
 # ifndef __cpp_aligned_new
 #   error "__cpp_aligned_new" should be defined
 # endif
 #else
 # ifdef __cpp_aligned_new
 #   error "__cpp_aligned_new" should not be defined
 # endif
 #endif