diff --git a/build/org.eclipse.cdt.build.gcc.core/src/org/eclipse/cdt/build/gcc/core/GCCToolChain.java b/build/org.eclipse.cdt.build.gcc.core/src/org/eclipse/cdt/build/gcc/core/GCCToolChain.java
index 75c7b3d1c10..974aa96a8be 100644
--- a/build/org.eclipse.cdt.build.gcc.core/src/org/eclipse/cdt/build/gcc/core/GCCToolChain.java
+++ b/build/org.eclipse.cdt.build.gcc.core/src/org/eclipse/cdt/build/gcc/core/GCCToolChain.java
@@ -10,7 +10,6 @@ package org.eclipse.cdt.build.gcc.core;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -32,6 +31,7 @@ import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.launchbar.core.target.ILaunchTarget;
 import org.eclipse.launchbar.core.target.ILaunchTargetManager;
@@ -151,23 +151,26 @@ public class GCCToolChain implements IToolChain {
 				if (files.length > 0) {
 					// replace it with a temp file
 					Path parentPath = filePath.getParent();
-					int n = 0;
-					while (true) {
-						// TODO need to know the language
-						tmpFile = parentPath.resolve(".sc" + n + ".cpp"); //$NON-NLS-1$ //$NON-NLS-2$
-						commandLine.set(i, tmpFile.toString());
-						try {
-							Files.createFile(tmpFile);
-							break;
-						} catch (FileAlreadyExistsException e) {
-							// try again
-							++n;
-						}
+					String extension = files[0].getFileExtension();
+					if (extension == null) {
+						// Not sure if this is a reasonable choice when there's
+						// no extension
+						extension = ".cpp"; //$NON-NLS-1$
+					} else {
+						extension = '.' + extension;
 					}
-					break;
+					tmpFile = Files.createTempFile(parentPath, ".sc", extension); //$NON-NLS-1$
+					commandLine.set(i, tmpFile.toString());
 				}
 			}
 		}
+		if (tmpFile == null) {
+			// Have to assume there wasn't a source file. Add one in the
+			// resource's container
+			IPath parentPath = resource instanceof IFile ? resource.getParent().getLocation() : resource.getLocation();
+			tmpFile = Files.createTempFile(parentPath.toFile().toPath(), ".sc", ".cpp"); //$NON-NLS-1$ //$NON-NLS-2$
+			commandLine.add(tmpFile.toString());
+		}
 
 		Files.createDirectories(buildDirectory);
 
diff --git a/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/core/QtBuildConfiguration.java b/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/core/QtBuildConfiguration.java
index 669000a309a..ec3028bb3d4 100644
--- a/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/core/QtBuildConfiguration.java
+++ b/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/qt/core/QtBuildConfiguration.java
@@ -28,6 +28,7 @@ import org.eclipse.cdt.core.parser.IExtendedScannerInfo;
 import org.eclipse.cdt.core.parser.IScannerInfo;
 import org.eclipse.cdt.internal.qt.core.Activator;
 import org.eclipse.core.resources.IBuildConfiguration;
+import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
@@ -208,7 +209,16 @@ public class QtBuildConfiguration extends CBuildConfiguration {
 			args.addAll(Arrays.asList(getProperty("QMAKE_CXXFLAGS").split(" "))); //$NON-NLS-1$ //$NON-NLS-2$
 			args.add("-o"); //$NON-NLS-1$
 			args.add("-"); //$NON-NLS-1$
-			args.add(resource.getLocation().toString());
+
+			String srcFile;
+			if (resource instanceof IFile) {
+				srcFile = resource.getLocation().toOSString();
+				// Only add file if it's an IFile
+				args.add(srcFile);
+			} else {
+				// Doesn't matter, the toolchain will create a tmp file for this
+				srcFile = "scannerInfo.cpp"; //$NON-NLS-1$
+			}
 
 			String[] includePaths = getProperty("INCLUDEPATH").split(" "); //$NON-NLS-1$ //$NON-NLS-2$
 			for (int i = 0; i < includePaths.length; ++i) {
@@ -219,7 +229,7 @@ public class QtBuildConfiguration extends CBuildConfiguration {
 			}
 
 			ILanguage language = LanguageManager.getInstance()
-					.getLanguage(CCorePlugin.getContentType(getProject(), resource.getName()), getProject()); // $NON-NLS-1$
+					.getLanguage(CCorePlugin.getContentType(getProject(), srcFile), getProject()); // $NON-NLS-1$
 			Path dir = Paths.get(getProject().getLocationURI());
 			IExtendedScannerInfo extendedInfo = getToolChain().getScannerInfo(command, args,
 					Arrays.asList(includePaths), resource, dir);