[Driver] Allow for sparcv8plus subdir with Solaris/SPARC GCC

Since GCC 11, the bundled Solaris/SPARC GCC uses the `sparcv8plus`
subdirectory for 32-bit objects, just like upstream GCC.  Before that, it
used `32` instead from a local patch.

Since `clang` doesn't know about that `sparcv8plus` subdirectory, it
wouldn't properly use GCC 11+ installations.

The new `solaris-sparc-gcc-search.test` testcase wasn't run initially (like
the existing `crash-report-null.test`) because the `.test` suffix wasn't
handled.

Tested on `sparcv9-sun-solaris2.11`, `amd64-pc-solaris2.11`, and
`x86_64-pc-linux-gnu`.

Differential Revision: https://reviews.llvm.org/D157013

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -1874,6 +1874,12 @@ static bool findBiarchMultilibs(const Driver &D,
                         .flag("-m64", /*Disallow=*/true)
                         .flag("-mx32")
                         .makeMultilib();
+  Multilib Alt32sparc = MultilibBuilder()
+                            .gccSuffix("/sparcv8plus")
+                            .includeSuffix("/sparcv8plus")
+                            .flag("-m32")
+                            .flag("-m64", /*Disallow=*/true)
+                            .makeMultilib();
 
   // GCC toolchain for IAMCU doesn't have crtbegin.o, so look for libgcc.a.
   FilterNonExistent NonExistent(
@@ -1885,10 +1891,14 @@ static bool findBiarchMultilibs(const Driver &D,
   const bool IsX32 = TargetTriple.isX32();
   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32))
     Want = WANT64;
+  if (TargetTriple.isArch32Bit() && !NonExistent(Alt32sparc))
+    Want = WANT64;
   else if (TargetTriple.isArch64Bit() && IsX32 && !NonExistent(Altx32))
     Want = WANT64;
   else if (TargetTriple.isArch64Bit() && !IsX32 && !NonExistent(Alt64))
     Want = WANT32;
+  else if (TargetTriple.isArch64Bit() && !NonExistent(Alt32sparc))
+    Want = WANT64;
   else {
     if (TargetTriple.isArch32Bit())
       Want = NeedsBiarchSuffix ? WANT64 : WANT32;
@@ -1919,6 +1929,7 @@ static bool findBiarchMultilibs(const Driver &D,
   Result.Multilibs.push_back(Alt64);
   Result.Multilibs.push_back(Alt32);
   Result.Multilibs.push_back(Altx32);
+  Result.Multilibs.push_back(Alt32sparc);
 
   Result.Multilibs.FilterOut(NonExistent);
 
@@ -1932,7 +1943,8 @@ static bool findBiarchMultilibs(const Driver &D,
 
   if (Result.SelectedMultilibs.back() == Alt64 ||
       Result.SelectedMultilibs.back() == Alt32 ||
-      Result.SelectedMultilibs.back() == Altx32)
+      Result.SelectedMultilibs.back() == Altx32 ||
+      Result.SelectedMultilibs.back() == Alt32sparc)
     Result.BiarchSibling = Default;
 
   return true;

clang/test/Driver/lit.local.cfg

@@ -20,6 +20,7 @@ config.suffixes = [
     ".hipi",
     ".hlsl",
     ".yaml",
+    ".test",
 ]
 config.substitutions = list(config.substitutions)
 config.substitutions.insert(

clang/test/Driver/solaris-sparc-gcc-search.test

@@ -0,0 +1,56 @@
+/// Check that clang can handle both old-style (32) and new-style (sparcv8plus)
+/// 32-bit sparc multilib subdirs.
+
+/// Check sparc-sun-solaris2.11, 32-bit, GCC 4.8 tree
+// RUN: %clang -v 2>&1 --target=sparc-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparc_tree/usr/gcc/4.8 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC32-GCC48 %s
+// CHECK-SPARC32-GCC48: Selected GCC installation: {{.*}}4.8/lib/gcc/sparc-sun-solaris2.11/4.8.2
+// CHECK-SPARC32-GCC48-NEXT: Candidate multilib: .;@m32
+// CHECK-SPARC32-GCC48-NEXT: Candidate multilib: sparcv9;@m64
+// CHECK-SPARC32-GCC48-NEXT: Selected multilib: .;@m32
+
+/// Check sparc-sun-solaris2.11, 32-bit, GCC 10 tree
+// RUN: %clang -v 2>&1 --target=sparc-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparc32_tree/usr/gcc/10 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC32-GCC10 %s
+// CHECK-SPARC32-GCC10: Selected GCC installation: {{.*}}10/lib/gcc/sparcv9-sun-solaris2.11/10.4.0
+// CHECK-SPARC32-GCC10-NEXT: Candidate multilib: .;@m64
+// CHECK-SPARC32-GCC10-NEXT: Candidate multilib: 32;@m32
+// CHECK-SPARC32-GCC10-NEXT: Selected multilib: 32;@m32
+
+/// Check sparc-sun-solaris2.11, 32-bit, GCC 11 tree
+// RUN: %clang -v 2>&1 --target=sparc-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparcv8+_tree/usr/gcc/11 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC32-GCC11 %s
+// CHECK-SPARC32-GCC11: Selected GCC installation: {{.*}}11/lib/gcc/sparcv9-sun-solaris2.11/11.3.0
+// CHECK-SPARC32-GCC11-NEXT: Candidate multilib: .;@m64
+// CHECK-SPARC32-GCC11-NEXT: Candidate multilib: sparcv8plus;@m32
+// CHECK-SPARC32-GCC11-NEXT: Selected multilib: sparcv8plus;@m32
+
+/// Check sparcv9-sun-solaris2.11, 64-bit, GCC 4.8 tree
+// RUN: %clang -v 2>&1 --target=sparcv9-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparc_tree/usr/gcc/4.8 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC64-GCC48 %s
+// CHECK-SPARC64-GCC48: Selected GCC installation: {{.*}}gcc/4.8/lib/gcc/sparc-sun-solaris2.11/4.8.2
+// CHECK-SPARC64-GCC48-NEXT: Candidate multilib: .;@m32
+// CHECK-SPARC64-GCC48-NEXT: Candidate multilib: sparcv9;@m64
+// CHECK-SPARC64-GCC48-NEXT: Selected multilib: sparcv9;@m64
+
+/// Check sparcv9-sun-solaris2.11, 64-bit, GCC 10 tree
+// RUN: %clang -v 2>&1 --target=sparcv9-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparc32_tree/usr/gcc/10 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC64-GCC10 %s
+// CHECK-SPARC64-GCC10: Selected GCC installation: {{.*}}10/lib/gcc/sparcv9-sun-solaris2.11/10.4.0
+// CHECK-SPARC64-GCC10-NEXT: Candidate multilib: .;@m64
+// CHECK-SPARC64-GCC10-NEXT: Candidate multilib: 32;@m32
+// CHECK-SPARC64-GCC10-NEXT: Selected multilib: .;@m64
+
+/// Check sparcv9-sun-solaris2.11, 64-bit, GCC 11 tree
+// RUN: %clang -v 2>&1 --target=sparcv9-sun-solaris2.11 \
+// RUN:     --gcc-toolchain=%S/Inputs/solaris_sparcv8+_tree/usr/gcc/11 \
+// RUN:   | FileCheck --check-prefix=CHECK-SPARC64-GCC11 %s
+// CHECK-SPARC64-GCC11: Selected GCC installation: {{.*}}11/lib/gcc/sparcv9-sun-solaris2.11/11.3.0
+// CHECK-SPARC64-GCC11-NEXT: Candidate multilib: .;@m64
+// CHECK-SPARC64-GCC11-NEXT: Candidate multilib: sparcv8plus;@m32
+// CHECK-SPARC64-GCC11-NEXT: Selected multilib: .;@m64