[Driver][SYCL] Do not emit mismatch warning with -fsycl-force-target (#17013)

The use of -fsycl-force-target=arg allows for a user to override the
default target triple that is used to unbundle device objects from the
fat objects. A diagnostic warning is emitted to inform the user that the
expected target values within the given objects is not found. This
diagnostic is not valid when -fsycl-force-target is used with the
matching target value.

Avoid emitting this warning when the -fsycl-force-target=arg matches
what is found in the incoming objects.

Author: mdtoguchi

clang/lib/Driver/Driver.cpp

@@ -6488,6 +6488,20 @@ class OffloadingActionBuilder final {
                 break;
               }
             }
+            // Use of -fsycl-force-target=triple forces the compiler to use the
+            // specified target triple when extracting device code from any of
+            // the given objects on the command line. If the target specified
+            // in -fsycl-force-target is found in a fat object, do not emit the
+            // target mismatch warning.
+            if (const Arg *ForceTarget = C.getInputArgs().getLastArg(
+                    options::OPT_fsycl_force_target_EQ)) {
+              StringRef Val(ForceTarget->getValue());
+              llvm::Triple TT(C.getDriver().getSYCLDeviceTriple(Val));
+              if (TT.normalize() == Section) {
+                SectionFound = true;
+                break;
+              }
+            }
           }
           if (SectionFound)
             continue;

clang/test/Driver/sycl-target-mismatch.cpp

@@ -22,4 +22,7 @@
 // RUN: %clangxx -fsycl -fsycl-targets=spir64_gen %S/Inputs/SYCL/liblin64.a \
 // RUN:   -Wno-sycl-target -### %s 2>&1 \
 // RUN:  | FileCheck %s -check-prefix=SPIR64_DIAG
-// SPIR64_DIAG-NOT: linked binaries do not contain expected
+// RUN: %clangxx -fsycl -fsycl-targets=spir64_gen %S/Inputs/SYCL/liblin64.a \
+// RUN:   -fsycl-force-target=spir64 -### %s 2>&1 \
+// RUN:  | FileCheck %s -check-prefix=SPIR64_DIAG
+// SPIR64_DIAG-NOT: linked binaries do not contain expected {{.*}} target; found targets: