[clang][driver] When -fveclib=ArmPL flag is in use, always link against libamath

Using `-fveclib=ArmPL` without `-lamath` likely effects in the
link-time errors.

Author: pawosm-arm

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -490,6 +490,16 @@ void tools::AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs,
     else
       A.renderAsInput(Args, CmdArgs);
   }
+  if (const Arg *A = Args.getLastArg(options::OPT_fveclib)) {
+    if (A->getNumValues() == 1) {
+      StringRef V = A->getValue();
+      if ((V == "ArmPL") && TC.getTriple().isOSLinux()) {
+        CmdArgs.push_back(Args.MakeArgString("-lamath"));
+        CmdArgs.push_back(Args.MakeArgString("-lm"));
+        addArchSpecificRPath(TC, Args, CmdArgs);
+      }
+    }
+  }
 }
 
 void tools::addLinkerCompressDebugSectionsOption(

clang/test/Driver/fveclib.c

@@ -102,3 +102,14 @@
 /* Verify no warning when math-errno is re-enabled for a different veclib (that does not imply -fno-math-errno). */
 // RUN: %clang -### --target=aarch64-linux-gnu -fveclib=ArmPL -fmath-errno -fveclib=LIBMVEC %s 2>&1 | FileCheck --check-prefix=CHECK-REPEAT-VECLIB %s
 // CHECK-REPEAT-VECLIB-NOT: math errno enabled
+
+/* Verify that vectorized routines library is being linked in. */
+// RUN: %clang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL %s
+// CHECK-LINKING-ARMPL: "-lamath"
+// CHECK-LINKING-ARMPL-SAME: "-lm"
+
+/* Verify that the RPATH is being set when needed. */
+// RUN: %clang -### --target=aarch64-linux-gnu -resource-dir=%S/../../../clang/test/Driver/Inputs/resource_dir_with_arch_subdir -frtlib-add-rpath -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-RPATH-ARMPL %s
+// CHECK-RPATH-ARMPL: "-lamath"
+// CHECK-RPATH-ARMPL-SAME: "-lm"
+// CHECK-RPATH-ARMPL-SAME: "-rpath"

flang/test/Driver/fveclib.f90

@@ -30,3 +30,14 @@
 
 ! TODO: if we add support for -nostdlib or -nodefaultlibs we need to test that
 ! these prevent "-framework Accelerate" being added on Darwin
+
+! RUN: %flang -### --target=aarch64-linux-gnu -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-LINKING-ARMPL %s
+! CHECK-LINKING-ARMPL: "-lamath"
+! CHECK-LINKING-ARMPL-SAME: "-lm"
+
+! RUN: %flang -### --target=aarch64-linux-gnu -resource-dir=%S/../../../clang/test/Driver/Inputs/resource_dir_with_arch_subdir -frtlib-add-rpath -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-RPATH-ARMPL %s
+! CHECK-RPATH-ARMPL: "-lamath"
+! CHECK-RPATH-ARMPL-SAME: "-lm"
+! We need to see "-rpath" at least twice, one for veclib, one for the Fortran runtime
+! CHECK-RPATH-ARMPL-SAME: "-rpath"
+! CHECK-RPATH-ARMPL-SAME: "-rpath"