Bug 510987 - Properly support PIE executables as build output

When checking whether gathering the build output from a
CBuildConfiguration, if a binary is a shared library and is an
ELF file, dig deeper and see if it has an INTERP section in the
program header. That tells us it's actually a PIE executable and
add it to the list.

As a rider to this bill, improve the error message when a Qt install
can't be found for a given toolchain/target.

Change-Id: I8fd0bf2d204e9425b02916d7b17f4309a5ad9dd5
(cherry picked from commit 14b07f490c)

core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/build/CBuildConfiguration.java

@@ -32,6 +32,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 
 import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.IBinaryParser;
 import org.eclipse.cdt.core.IConsoleParser;
 import org.eclipse.cdt.core.IMarkerGenerator;
 import org.eclipse.cdt.core.ProblemMarkerInfo;
@@ -53,6 +54,9 @@ import org.eclipse.cdt.internal.core.build.Messages;
 import org.eclipse.cdt.internal.core.model.BinaryRunner;
 import org.eclipse.cdt.internal.core.model.CModelManager;
 import org.eclipse.cdt.internal.core.parser.ParserSettings2;
+import org.eclipse.cdt.utils.elf.Elf;
+import org.eclipse.cdt.utils.elf.Elf.PHdr;
+import org.eclipse.cdt.utils.elf.parser.ElfBinaryShared;
 import org.eclipse.core.filesystem.URIUtil;
 import org.eclipse.core.resources.IBuildConfiguration;
 import org.eclipse.core.resources.IContainer;
@@ -246,8 +250,27 @@ public abstract class CBuildConfiguration extends PlatformObject
 		IPath outputPath = getBuildContainer().getFullPath();
 		List<IBinary> outputs = new ArrayList<>();
 		for (IBinary binary : binaries.getBinaries()) {
-			if (binary.isExecutable() && outputPath.isPrefixOf(binary.getPath())) {
+			if (outputPath.isPrefixOf(binary.getPath())) {
+				if (binary.isExecutable()) {
 					outputs.add(binary);
+				} else if (binary.isSharedLib()) {
+					// Special case of PIE executable that looks like shared
+					// library
+					IBinaryParser.IBinaryObject bin = binary.getAdapter(IBinaryParser.IBinaryObject.class);
+					if (bin instanceof ElfBinaryShared) {
+						try {
+							Elf elf = new Elf(bin.getPath().toOSString());
+							for (PHdr phdr : elf.getPHdrs()) {
+								if (phdr.p_type == PHdr.PT_INTERP) {
+									outputs.add(binary);
+									break;
+								}
+							}
+						} catch (IOException e) {
+							CCorePlugin.log(e);
+						}
+					}
+				}
 			}
 		}
 

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/build/Messages.java

@@ -0,0 +1,15 @@
+package org.eclipse.cdt.internal.qt.core.build;
+
+import org.eclipse.osgi.util.NLS;
+
+public class Messages extends NLS {
+	private static final String BUNDLE_NAME = "org.eclipse.cdt.internal.qt.core.build.messages"; //$NON-NLS-1$
+	public static String QtBuildConfigurationProvider_NoQtInstall;
+	static {
+		// initialize resource bundle
+		NLS.initializeMessages(BUNDLE_NAME, Messages.class);
+	}
+
+	private Messages() {
+	}
+}

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/build/QtBuildConfigurationProvider.java

@@ -10,6 +10,7 @@ package org.eclipse.cdt.internal.qt.core.build;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.build.ICBuildConfiguration;
 import org.eclipse.cdt.core.build.ICBuildConfigurationManager;
 import org.eclipse.cdt.core.build.ICBuildConfigurationProvider;
@@ -23,7 +24,9 @@ import org.eclipse.core.resources.IBuildConfiguration;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
 
 public class QtBuildConfigurationProvider implements ICBuildConfigurationProvider {
 
@@ -101,9 +104,10 @@ public class QtBuildConfigurationProvider implements ICBuildConfigurationProvide
 					launchMode);
 			configManager.addBuildConfiguration(config, qtConfig);
 			return qtConfig;
+		} else {
+			throw new CoreException(
+					new Status(IStatus.ERROR, CCorePlugin.PLUGIN_ID, Messages.QtBuildConfigurationProvider_NoQtInstall));
 		}
-
-		return null;
 	}
 
 	private IQtInstall getQtInstall(IToolChain toolChain) {

qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/build/messages.properties

@@ -0,0 +1 @@
+QtBuildConfigurationProvider_NoQtInstall=No Qt install available for this target