[flang] Add *BSD support to Optimizer/CodeGen/Target.cpp

[brad]

Summary

Add OpenBSD, FreeBSD, NetBSD and DragonFly to the aarch64 / x86 and x86_64 targets as appropriate.

Fixes 53 tests.

[brad]

ping.

[rovka]

Hi, I have a couple of questions:

• Are you actually testing on all these platforms? I don't think I've seen any BSD binaries for LLVM 15.
• Do you plan to add any buildbots with flang on *BSD?
• How different is the ABI from plain Linux? Will you need any changes in the handling of Complex / Character types (see the target-rewrite-* tests like this one) ?

[brad]

In D133554#3794660, @rovka wrote:

Hi, I have a couple of questions:

• Are you actually testing on all these platforms? I don't think I've seen any BSD binaries for LLVM 15.
• Do you plan to add any buildbots with flang on *BSD?
• How different is the ABI from plain Linux? Will you need any changes in the handling of Complex / Character types (see the target-rewrite-* tests like this one) ?

• I am only testing on OpenBSD. I see there was a bootstrapping issue with 15 on FreeBSD due to an issue with libc++ and their libc++ ABI library.
• I think there is work on going to create a CI bot for FreeBSD to build libc++ due to the bootstrapping issue. Maybe that CI bot could have a build as well.

[MaskRay]

This patch is fine but I do not know why there are these OS dispatches. If Linux is allowed, it seems to me that all ELF based OSes should be allowed as well.

[MaskRay]

In D133554#3794660, @rovka wrote:

Hi, I have a couple of questions:

• Are you actually testing on all these platforms? I don't think I've seen any BSD binaries for LLVM 15.
• Do you plan to add any buildbots with flang on *BSD?
• How different is the ABI from plain Linux? Will you need any changes in the handling of Complex / Character types (see the target-rewrite-* tests like this one) ?

The ELF operating systems have identical codegen behaviors since they follow the same ABI documents: System V Application Binary Interface + Processor Supplementary ABIs.
If some compatibility check is needed, it should be among Mach-O/Windows/ELF. But I don't think such a restriction is useful in codegen. Such check should be moved to Driver.
Sent D135100

[brad]

Closing, superseded by D135100.

flang/lib/Optimizer/CodeGen/Target.cpp

default:
     break;
   case llvm::Triple::ArchType::x86:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
     case llvm::Triple::OSType::Darwin:
     case llvm::Triple::OSType::MacOSX:
+    case llvm::Triple::OSType::DragonFly:
+    case llvm::Triple::OSType::FreeBSD:
+    case llvm::Triple::OSType::NetBSD:
+    case llvm::Triple::OSType::OpenBSD:
     case llvm::Triple::OSType::Solaris:
     case llvm::Triple::OSType::Win32:
       return std::make_unique<TargetI386>(ctx, std::move(trp),
                                           std::move(kindMap));
     }
     break;
   case llvm::Triple::ArchType::x86_64:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
     case llvm::Triple::OSType::Darwin:
     case llvm::Triple::OSType::MacOSX:
+    case llvm::Triple::OSType::DragonFly:
+    case llvm::Triple::OSType::FreeBSD:
+    case llvm::Triple::OSType::NetBSD:
+    case llvm::Triple::OSType::OpenBSD:
     case llvm::Triple::OSType::Solaris:
     case llvm::Triple::OSType::Win32:
       return std::make_unique<TargetX86_64>(ctx, std::move(trp),
                                             std::move(kindMap));
     }
     break;
   case llvm::Triple::ArchType::aarch64:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
     case llvm::Triple::OSType::Darwin:
     case llvm::Triple::OSType::MacOSX:
+    case llvm::Triple::OSType::FreeBSD:
+    case llvm::Triple::OSType::NetBSD:
+    case llvm::Triple::OSType::OpenBSD:
     case llvm::Triple::OSType::Win32:
       return std::make_unique<TargetAArch64>(ctx, std::move(trp),
                                              std::move(kindMap));
     }
     break;
   case llvm::Triple::ArchType::ppc64le:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
+    case llvm::Triple::OSType::FreeBSD:
       return std::make_unique<TargetPPC64le>(ctx, std::move(trp),
                                              std::move(kindMap));
     }
     break;
   case llvm::Triple::ArchType::sparc:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
+    case llvm::Triple::OSType::NetBSD:
     case llvm::Triple::OSType::Solaris:
       return std::make_unique<TargetSparc>(ctx, std::move(trp),
                                            std::move(kindMap));
     }
     break;
   case llvm::Triple::ArchType::sparcv9:
     switch (trp.getOS()) {
     default:
       break;
     case llvm::Triple::OSType::Linux:
+    case llvm::Triple::OSType::NetBSD:
+    case llvm::Triple::OSType::OpenBSD:
     case llvm::Triple::OSType::Solaris:
       return std::make_unique<TargetSparcV9>(ctx, std::move(trp),
                                              std::move(kindMap));
     }
     break;
   }
   TODO(mlir::UnknownLoc::get(ctx), "target not implemented");
 }