[clang] [Driver] Treat MuslEABIHF as a hardfloat environment wrt multiarch directories (#77536)

If using multiarch directories with musl, the multiarch directory still
uses *-linux-gnu triples - which may or may not be intentional, while it
is somewhat consistent at least.

However, for musl armhf targets, make sure that this also picks
arm-linux-gnueabihf, rather than arm-linux-gnueabi.

Author: mstorsjo

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -2668,7 +2668,9 @@ void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
   case llvm::Triple::arm:
   case llvm::Triple::thumb:
     LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
-    if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
+    if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF ||
+        TargetTriple.getEnvironment() == llvm::Triple::MuslEABIHF ||
+        TargetTriple.getEnvironment() == llvm::Triple::EABIHF) {
       TripleAliases.append(begin(ARMHFTriples), end(ARMHFTriples));
     } else {
       TripleAliases.append(begin(ARMTriples), end(ARMTriples));
@@ -2677,7 +2679,9 @@ void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
   case llvm::Triple::armeb:
   case llvm::Triple::thumbeb:
     LibDirs.append(begin(ARMebLibDirs), end(ARMebLibDirs));
-    if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
+    if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF ||
+        TargetTriple.getEnvironment() == llvm::Triple::MuslEABIHF ||
+        TargetTriple.getEnvironment() == llvm::Triple::EABIHF) {
       TripleAliases.append(begin(ARMebHFTriples), end(ARMebHFTriples));
     } else {
       TripleAliases.append(begin(ARMebTriples), end(ARMebTriples));

clang/lib/Driver/ToolChains/Linux.cpp

@@ -61,12 +61,16 @@ std::string Linux::getMultiarchTriple(const Driver &D,
   case llvm::Triple::thumb:
     if (IsAndroid)
       return "arm-linux-androideabi";
-    if (TargetEnvironment == llvm::Triple::GNUEABIHF)
+    if (TargetEnvironment == llvm::Triple::GNUEABIHF ||
+        TargetEnvironment == llvm::Triple::MuslEABIHF ||
+        TargetEnvironment == llvm::Triple::EABIHF)
       return "arm-linux-gnueabihf";
     return "arm-linux-gnueabi";
   case llvm::Triple::armeb:
   case llvm::Triple::thumbeb:
-    if (TargetEnvironment == llvm::Triple::GNUEABIHF)
+    if (TargetEnvironment == llvm::Triple::GNUEABIHF ||
+        TargetEnvironment == llvm::Triple::MuslEABIHF ||
+        TargetEnvironment == llvm::Triple::EABIHF)
       return "armeb-linux-gnueabihf";
     return "armeb-linux-gnueabi";
   case llvm::Triple::x86:

clang/test/Driver/linux-ld.c

@@ -541,6 +541,15 @@
 // RUN:     --gcc-toolchain="" \
 // RUN:     --sysroot=%S/Inputs/ubuntu_12.04_LTS_multiarch_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-UBUNTU-12-04-ARM-HF %s
+//
+// Check that musleabihf is treated as a hardfloat config, with respect to
+// multiarch directories.
+//
+// RUN: %clang -### %s -no-pie 2>&1 \
+// RUN:     --target=arm-unknown-linux-musleabihf -rtlib=platform --unwindlib=platform \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/ubuntu_12.04_LTS_multiarch_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-UBUNTU-12-04-ARM-HF %s
 // CHECK-UBUNTU-12-04-ARM-HF: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
 // CHECK-UBUNTU-12-04-ARM-HF: "{{.*}}/usr/lib/arm-linux-gnueabihf{{/|\\\\}}crt1.o"
 // CHECK-UBUNTU-12-04-ARM-HF: "{{.*}}/usr/lib/arm-linux-gnueabihf{{/|\\\\}}crti.o"