[Driver][SYCL] Do not add integration header to integration footer compile (#3907)

When compiling the integration footer with -fsycl-host-compiler, we need
to be sure that the integration header is only added to the preprocessing
step as opposed to being added all the time.  When added all the time, the
header would be processed twice, causing compilation errors due to code
duplication.

Author: mdtoguchi

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4331,6 +4331,15 @@ void Clang::ConstructHostCompilerJob(Compilation &C, const JobAction &JA,
       }
     } else
       HostCompileArgs.push_back("-E");
+
+    // Add the integration header.
+    StringRef Header =
+        TC.getDriver().getIntegrationHeader(InputFile.getBaseInput());
+    if (types::getPreprocessedType(InputFile.getType()) != types::TY_INVALID &&
+        !Header.empty()) {
+      HostCompileArgs.push_back(IsMSVCHostCompiler ? "-FI" : "-include");
+      HostCompileArgs.push_back(TCArgs.MakeArgString(Header));
+    }
   } else if (isa<AssembleJobAction>(JA)) {
     HostCompileArgs.push_back("-c");
     if (IsMSVCHostCompiler)
@@ -4375,15 +4384,6 @@ void Clang::ConstructHostCompilerJob(Compilation &C, const JobAction &JA,
     HostCompileArgs.push_back(Output.getFilename());
   }
 
-  // Add the integration header.
-  StringRef Header =
-      TC.getDriver().getIntegrationHeader(InputFile.getBaseInput());
-  if (types::getPreprocessedType(InputFile.getType()) != types::TY_INVALID &&
-      !Header.empty()) {
-    HostCompileArgs.push_back(IsMSVCHostCompiler ? "-FI" : "-include");
-    HostCompileArgs.push_back(TCArgs.MakeArgString(Header));
-  }
-
   SmallString<128> ExecPath;
   if (HostCompilerDefArg) {
     ExecPath = HostCompilerDefArg->getValue();

clang/test/Driver/sycl-host-compiler.cpp

@@ -5,15 +5,15 @@
 // RUN: %clangxx -fsycl-use-footer -fsycl -fsycl-host-compiler=/some/dir/g++ %s -### 2>&1 \
 // RUN:  | FileCheck -check-prefix=HOST_COMPILER %s
 // HOST_COMPILER: clang{{.*}} "-fsycl-is-device"{{.*}} "-fsycl-int-header=[[INTHEADER:.+\.h]]" "-fsycl-int-footer={{.*}}"
-// HOST_COMPILER: g++{{.*}} "-E" "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}} "-o" "[[TMPII:.+\.ii]]"{{.*}} "-include" "[[INTHEADER]]"
-// HOST_COMPILER: g++{{.*}} "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}} "-o" "[[HOSTOBJ:.+\.o]]"{{.*}}
+// HOST_COMPILER: g++{{.*}} "-E" "-include" "[[INTHEADER]]" "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}} "-o" "[[TMPII:.+\.ii]]"
+// HOST_COMPILER: g++{{.*}} "-c" "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}} "-o" "[[HOSTOBJ:.+\.o]]"{{.*}}
 // HOST_COMPILER: ld{{.*}} "[[HOSTOBJ]]"
 
 // RUN: %clang_cl -fsycl-use-footer -fsycl -fsycl-host-compiler=/some/dir/cl %s -### 2>&1 \
 // RUN:  | FileCheck -check-prefix=HOST_COMPILER_CL %s
 // HOST_COMPILER_CL: clang{{.*}} "-fsycl-is-device"{{.*}} "-fsycl-int-header=[[INTHEADER:.+\.h]]" "-fsycl-int-footer={{.*}}"
-// HOST_COMPILER_CL: cl{{.*}} "-P" "-Fi[[TMPII:.+\.ii]]"{{.*}} "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}} "-FI" "[[INTHEADER]]"
-// HOST_COMPILER_CL: cl{{.*}} "-Fo[[HOSTOBJ:.+\.obj]]"{{.*}} "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}}
+// HOST_COMPILER_CL: cl{{.*}} "-P" "-Fi[[TMPII:.+\.ii]]" "-FI" "[[INTHEADER]]"{{.*}} "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"
+// HOST_COMPILER_CL: cl{{.*}} "-c" "-Fo[[HOSTOBJ:.+\.obj]]"{{.*}} "-I" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl"{{.*}}
 // HOST_COMPILER_CL: link{{.*}} "[[HOSTOBJ]]"
 
 /// check for additional host options