[mips] Explicitly specify the linker emulation for MIPS on FreeBSD.

[bsdjhb]

Summary

FreeBSD's mips64 builds O32 binaries for /usr/lib32 by default and
thus needs to be able to link O32 binaries which requires an explicit
linker emulation. Go ahead and list all the linker emulation variants
for MIPS so that any supported MIPS ABI binary can be linked by any
linker support MIPS.

[atanasyan]

lib/Driver/ToolChains/FreeBSD.cpp

197 ↗

(On Diff #152545)

Does it make a sense to handle N32 ABI case here?

[bsdjhb]

lib/Driver/ToolChains/FreeBSD.cpp

197 ↗

(On Diff #152545)

For whatever reason, FreeBSD only supports N32 on big-endian. However, binutils does ship elf32ltsmipsn32_fbsd linker scripts after all, so I could handle little-endian N32 here.

[atanasyan]

lib/Driver/ToolChains/FreeBSD.cpp

197 ↗

(On Diff #152545)

LGTM with handling the elf32ltsmipsn32_fbsd case.

[bsdjhb]

• Add N32EL.

cfe/trunk/lib/Driver/ToolChains/FreeBSD.cpp

if (ToolChain.getTriple().getOSMajorVersion() >= 9) {
       if (Arch == llvm::Triple::arm || Arch == llvm::Triple::sparc ||
           Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64) {
         CmdArgs.push_back("--hash-style=both");
       }
     }
     CmdArgs.push_back("--enable-new-dtags");
   }
 
-  // When building 32-bit code on FreeBSD/amd64, we have to explicitly
-  // instruct ld in the base system to link 32-bit code.
-  if (Arch == llvm::Triple::x86) {
+  // Explicitly set the linker emulation for platforms that might not
+  // be the default emulation for the linker.
+  switch (Arch) {
+  case llvm::Triple::x86:
     CmdArgs.push_back("-m");
     CmdArgs.push_back("elf_i386_fbsd");
-  }
-
-  if (Arch == llvm::Triple::ppc) {
+    break;
+  case llvm::Triple::ppc:
     CmdArgs.push_back("-m");
     CmdArgs.push_back("elf32ppc_fbsd");
+    break;
+  case llvm::Triple::mips:
+    CmdArgs.push_back("-m");
+    CmdArgs.push_back("elf32btsmip_fbsd");
+    break;
+  case llvm::Triple::mipsel:
+    CmdArgs.push_back("-m");
+    CmdArgs.push_back("elf32ltsmip_fbsd");
+    break;
+  case llvm::Triple::mips64:
+    CmdArgs.push_back("-m");
+    if (tools::mips::hasMipsAbiArg(Args, "n32"))
+      CmdArgs.push_back("elf32btsmipn32_fbsd");
+    else
+      CmdArgs.push_back("elf64btsmip_fbsd");
+    break;
+  case llvm::Triple::mips64el:
+    CmdArgs.push_back("-m");
+    if (tools::mips::hasMipsAbiArg(Args, "n32"))
+      CmdArgs.push_back("elf32ltsmipn32_fbsd");
+    else
+      CmdArgs.push_back("elf64ltsmip_fbsd");
+    break;
   }
 
   if (Arg *A = Args.getLastArg(options::OPT_G)) {
     if (ToolChain.getTriple().isMIPS()) {
       StringRef v = A->getValue();
       CmdArgs.push_back(Args.MakeArgString("-G" + v));
       A->claim();
     }

cfe/trunk/test/Driver/freebsd.c

 // CHECK-LIB32PATHS: libraries: ={{.*:?}}/usr/lib32
 //
 // Check that O32 MIPS uses /usr/lib32 on a 64-bit tree.
 //
 // RUN: %clang -target mips-freebsd12 %s \
 // RUN:   --sysroot=%S/Inputs/multiarch_freebsd64_tree -print-search-dirs 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-LIB32PATHS %s
 //
+// Check that MIPS passes the correct linker emulation.
+//
+// RUN: %clang -target mips-freebsd %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS-LD %s
+// CHECK-MIPS-LD: ld{{.*}}" {{.*}} "-m" "elf32btsmip_fbsd"
+// RUN: %clang -target mipsel-freebsd %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPSEL-LD %s
+// CHECK-MIPSEL-LD: ld{{.*}}" {{.*}} "-m" "elf32ltsmip_fbsd"
+// RUN: %clang -target mips64-freebsd %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS64-LD %s
+// CHECK-MIPS64-LD: ld{{.*}}" {{.*}} "-m" "elf64btsmip_fbsd"
+// RUN: %clang -target mips64el-freebsd %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS64EL-LD %s
+// CHECK-MIPS64EL-LD: ld{{.*}}" {{.*}} "-m" "elf64ltsmip_fbsd"
+// RUN: %clang -target mips64-freebsd -mabi=n32 %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPSN32-LD %s
+// CHECK-MIPSN32-LD: ld{{.*}}" {{.*}} "-m" "elf32btsmipn32_fbsd"
+// RUN: %clang -target mips64el-freebsd -mabi=n32 %s -### %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPSN32EL-LD %s
+// CHECK-MIPSN32EL-LD: ld{{.*}}" {{.*}} "-m" "elf32ltsmipn32_fbsd"
+//
 // Check that the new linker flags are passed to FreeBSD
 // RUN: %clang -no-canonical-prefixes -target x86_64-pc-freebsd8 -m32 %s \
 // RUN:   --sysroot=%S/Inputs/multiarch_freebsd64_tree -### 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-LDFLAGS8 %s
 // RUN: %clang -no-canonical-prefixes -target x86_64-pc-freebsd9 -m32 %s \
 // RUN:   --sysroot=%S/Inputs/multiarch_freebsd64_tree -### 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-LDFLAGS9 %s
 // RUN: %clang -no-canonical-prefixes -target x86_64-pc-freebsd10.0 -m32 %s \