Add GNU debug-info support to DwarfReader/Dwarf

- Add support to find separate debug info file using
  the .gnu_debuglink section
- Add support to also find the GNU alt debug info file
  created by the DWZ utility
- Add additional DW_FORMs to support alt data
- Add support to DwarfReader to find the special note section
  containing the build-id and then see if it can find the
  debug-info with that build-id

Change-Id: I0e43ba8af12396cdab4e085ad0c20fdec8c1d83e
Reviewed-on: https://git.eclipse.org/r/24034
Tested-by: Hudson CI
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-by: Jeff Johnston <jjohnstn@redhat.com>
Tested-by: Jeff Johnston <jjohnstn@redhat.com>

core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/ICompileOptionsFinder.java

@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.core;
+
+/**
+ * A class that can find compiler options for a given file name.
+ * 
+ * @noextend This interface is not intended to be extended by clients.
+ * @noimplement This interface is not intended to be implemented by clients.
+ * @since 5.7
+ */
+public interface ICompileOptionsFinder {
+
+	/**
+	 * Get compiler options for a given file name.
+	 * 
+	 * @param fileName - absolute source file name
+	 * @return a String containing the compiler options used or null.
+	 * 
+	 */
+	public String getCompileOptions(String fileName);
+}

core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/debug/dwarf/Dwarf.java

@@ -13,6 +13,7 @@
 
 package org.eclipse.cdt.utils.debug.dwarf;
 
+import java.io.File;
 import java.io.IOException;
 import java.lang.reflect.Array;
 import java.nio.ByteBuffer;
@@ -30,6 +31,8 @@ import org.eclipse.cdt.utils.debug.tools.DebugSym;
 import org.eclipse.cdt.utils.debug.tools.DebugSymsRequestor;
 import org.eclipse.cdt.utils.elf.Elf;
 import org.eclipse.cdt.utils.elf.Elf.Section;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.Path;
 
 public class Dwarf {
 
@@ -48,6 +51,11 @@ public class Dwarf {
 	final static String DWARF_DEBUG_VARNAMES = ".debug_varnames"; //$NON-NLS-1$
 	final static String DWARF_DEBUG_WEAKNAMES = ".debug_weaknames"; //$NON-NLS-1$
 	final static String DWARF_DEBUG_MACINFO = ".debug_macinfo"; //$NON-NLS-1$
+	final static String DWARF_DEBUG_MACRO = ".debug_macro"; //$NON-NLS-1$
+	final static String DWARF_DEBUG_TYPES = ".debug_types"; //$NON-NLS-1$
+	final static String DWARF_GNU_DEBUGLINK = ".gnu_debuglink"; //$NON-NLS-1$
+	final static String DWARF_GNU_DEBUGALTLINK = ".gnu_debugaltlink"; //$NON-NLS-1$
+
 	final static String[] DWARF_SCNNAMES =
 		{
 			DWARF_DEBUG_INFO,
@@ -65,6 +73,14 @@ public class Dwarf {
 			DWARF_DEBUG_WEAKNAMES,
 			DWARF_DEBUG_MACINFO };
 
+	final static String[] DWARF_ALT_SCNNAMES =
+		{
+			DWARF_DEBUG_INFO,
+			DWARF_DEBUG_TYPES,
+			DWARF_DEBUG_MACRO,
+			DWARF_DEBUG_STR,
+		};
+	
 	class CompilationUnitHeader {
 		long length;
 		short version;
@@ -166,6 +182,7 @@ public class Dwarf {
 	}
 
 	Map<String, ByteBuffer> dwarfSections = new HashMap<String, ByteBuffer>();
+	Map<String, ByteBuffer> dwarfAltSections = new HashMap<String, ByteBuffer>();
 	Map<Integer, Map<Long, AbbreviationEntry>> abbreviationMaps = new HashMap<Integer, Map<Long, AbbreviationEntry>>();
 
 	boolean isLE;
@@ -196,8 +213,78 @@ public class Dwarf {
 		isLE = header.e_ident[Elf.ELFhdr.EI_DATA] == Elf.ELFhdr.ELFDATA2LSB;
 
 		Elf.Section[] sections = exe.getSections();
+		IPath debugInfoPath = new Path(exe.getFilename());
+		// Look for a .gnu_debuglink section which will have the name of the debug info file
+		Elf.Section gnuDebugLink = exe.getSectionByName(DWARF_GNU_DEBUGLINK);
+		if (gnuDebugLink != null) {
+			ByteBuffer data = gnuDebugLink.mapSectionData();
+			if (data != null) { // we have non-empty debug info link
+				try {
+					// name is zero-byte terminated character string
+					String debugName = readString(data);
+					if (debugName.length() > 0) {
+						// try and open the debug info from 3 separate places in order
+						File debugFile = null;
+						IPath p = debugInfoPath.removeLastSegments(1);
+						// 1. try and open the file in the same directory as the executable
+						debugFile = p.append(debugName).toFile();
+						if (!debugFile.exists()) {
+							// 2. try and open the file in the .debug directory where the executable is 
+							debugFile = p.append(".debug").append(debugName).toFile(); //$NON-NLS-1$
+							if (!debugFile.exists())
+								// 3. try and open /usr/lib/debug/$(EXEPATH)/$(DEBUGINFO_NAME)
+								debugFile = new Path("/usr/lib/debug").append(p).append(debugName).toFile(); //$NON-NLS-1$
+						}
+						if (debugFile.exists()) {
+							// if the debug file exists from above, open it and get the section info from it
+							Elf debugInfo = new Elf(debugFile.getCanonicalPath());
+							sections = debugInfo.getSections();
+							debugInfoPath = new Path(debugFile.getCanonicalPath());
+						}
+					}
+				} catch (Exception e) {
+					e.printStackTrace();
+					CCorePlugin.log(e);
+				}
+			}
+				 
+		}
 		for (Section section : sections) {
 			String name = section.toString();
+			if (name.equals(DWARF_GNU_DEBUGALTLINK)) {
+				ByteBuffer data = section.mapSectionData();
+				try {
+					// name is zero-byte terminated character string
+					String altInfoName = readString(data);
+					if (altInfoName.length() > 0) {
+						IPath altPath = new Path(altInfoName);
+						if (!altPath.isAbsolute()) {
+							altPath = debugInfoPath.append(altPath);
+						}
+						File altFile = altPath.toFile();
+						if (altFile.exists()) {
+							Elf altInfo = new Elf(altFile.getCanonicalPath());
+							Elf.Section[] altSections = altInfo.getSections();
+							for (Section altSection : altSections) {
+								String altName = altSection.toString();
+								for (String element : DWARF_ALT_SCNNAMES) {
+									if (altName.equals(element)) {
+										try {
+											dwarfAltSections.put(element, altSection.mapSectionData());
+										} catch (Exception e) {
+											e.printStackTrace();
+											CCorePlugin.log(e);
+										}
+									}
+								}
+							}
+						}
+					}
+				} catch (Exception e) {
+					e.printStackTrace();
+					CCorePlugin.log(e);
+				}
+			} else {
 				for (String element : DWARF_SCNNAMES) {
 					if (name.equals(element)) {
 						try {
@@ -210,6 +297,7 @@ public class Dwarf {
 				}
 			}
 		}
+	}
 
 	/**
 	 * @since 5.1
@@ -463,7 +551,8 @@ public class Dwarf {
 					byte hasChildren = data.get();
 					AbbreviationEntry entry = new AbbreviationEntry(code, tag, hasChildren);
 
-					//System.out.println("\tAbrev Entry: " + code + " " + Long.toHexString(entry.tag) + " " + entry.hasChildren);
+					if (printEnabled)
+						System.out.println("\tAbrev Entry: " + code + " " + Long.toHexString(entry.tag) + " " + entry.hasChildren); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 
 					// attributes
 					long name = 0;
@@ -474,7 +563,8 @@ public class Dwarf {
 						if (name != 0) {
 							entry.attributes.add(new Attribute(name, form));
 						}
-						//System.out.println("\t\t " + Long.toHexString(name) + " " + Long.toHexString(value));
+						if (printEnabled)
+							System.out.println("\t\t " + Long.toHexString(name) + " " + Long.toHexString(form)); //$NON-NLS-1$ //$NON-NLS-2$
 					} while (name != 0 && form != 0);
 					abbrevs.put(new Long(code), entry);
 				}
@@ -505,6 +595,8 @@ public class Dwarf {
 		}
 	}
 
+	int oldForm = 0;
+
 	Object readAttribute(int form, ByteBuffer in, CompilationUnitHeader header) throws IOException {
 		Object obj = null;
 		switch (form) {
@@ -621,6 +713,34 @@ public class Dwarf {
 				}
 				break;
 
+			case DwarfConstants.DW_FORM_GNU_strp_alt :
+			    {
+			    	long offset;
+			    	if (header.offsetSize == 8)
+			    		offset = read_8_bytes(in);
+			    	else
+			    		offset = read_4_bytes(in) & 0xffffffffL;
+
+			    	ByteBuffer data = dwarfAltSections.get(DWARF_DEBUG_STR);
+			    	if (data == null) {
+			    		obj = new String();
+			    	} else if (offset < 0 || offset > data.capacity()) {
+			    		obj = new String();
+			    	} else {
+			    		StringBuffer sb = new StringBuffer();
+			    		data.position((int) offset);
+			    		while (data.hasRemaining()) {
+			    			byte c = data.get();
+			    			if (c == 0) {
+			    				break;
+			    			}
+			    			sb.append((char) c);
+			    		}
+			    		obj = sb.toString();
+			    	}
+			}
+			break;
+
 			case DwarfConstants.DW_FORM_ref1 :
 				obj = new Byte(in.get());
 				break;
@@ -646,6 +766,12 @@ public class Dwarf {
 					int f = (int) read_unsigned_leb128(in);
 					return readAttribute(f, in, header);
 				}
+			case DwarfConstants.DW_FORM_GNU_ref_alt :
+				if (header.offsetSize == 8)
+					obj = new Long(read_8_bytes(in));
+				else
+					obj = new Long(read_4_bytes(in)  & 0xffffffffL);
+				break;
 			case DwarfConstants.DW_FORM_sec_offset :
 					if (header.offsetSize == 8)
 						obj = new Long(read_8_bytes(in));
@@ -667,9 +793,14 @@ public class Dwarf {
 					break;
 
 			default :
+					if (printEnabled) {
+						System.out.println("Default for " + form); //$NON-NLS-1$
+						System.out.println("Last form is " + oldForm); //$NON-NLS-1$
+					}
 					break;
 		}
 
+		oldForm = form;
 		return obj;
 	}
 
@@ -775,6 +906,27 @@ public class Dwarf {
 		return new Long(value);
 	}
 
+	/**
+	 * Read a null-ended string from the given "data" stream.
+	 * data	:  IN, byte buffer
+	 */
+	String readString(ByteBuffer data)
+	{
+		String str;
+		
+		StringBuffer sb = new StringBuffer();
+		while (data.hasRemaining()) {
+			byte c = data.get();
+			if (c == 0) {
+				break;
+			}
+			sb.append((char) c);
+		}
+
+		str = sb.toString();
+		return str;
+	}
+	
 	void processSubProgram(IDebugEntryRequestor requestor, List<AttributeValue> list) {
 		long lowPC = 0;
 		long highPC = 0;

core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/debug/dwarf/DwarfConstants.java

@@ -65,6 +65,10 @@ public class DwarfConstants {
 	public final static int DW_TAG_variant_part = 0x33;
 	public final static int DW_TAG_variable = 0x34;
 	public final static int DW_TAG_volatile_type = 0x35;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_TAG_partial_unit = 0x3c;
 	public final static int DW_TAG_lo_user = 0x4080;
 	public final static int DW_TAG_MIPS_loop = 0x4081;
 	public final static int DW_TAG_format_label = 0x4101;
@@ -187,22 +191,42 @@ public class DwarfConstants {
 	public final static int DW_FORM_ref8 = 0x14;
 	public final static int DW_FORM_ref_udata = 0x15;
 	public final static int DW_FORM_indirect = 0x16;
+	
 	/**
-	 * @since 5.6
+	 * @since 5.7
 	 */
 	public final static int DW_FORM_sec_offset = 0x17;
 	/**
-	 * @since 5.6
+	 * @since 5.7
 	 */
 	public final static int DW_FORM_exprloc = 0x18;
 	/**
-	 * @since 5.6
+	 * @since 5.7
 	 */
 	public final static int DW_FORM_flag_present = 0x19;
 	/**
-	 * @since 5.6
+	 * @since 5.7
 	 */
 	public final static int DW_FORM_ref_sig8 = 0x20;
+	/* Extensions for Fission. See http://gcc.gnu.org/wiki/DebugFission. */
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_FORM_GNU_addr_index = 0x1f01;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_FORM_GNU_str_index = 0x1f02;
+	/* Extensions for DWZ multifile.
+	   See http://www.dwarfstd.org/ShowIssue.php?issue=120604.1&type=open . */	
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_FORM_GNU_ref_alt = 0x1f20;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_FORM_GNU_strp_alt = 0x1f21;
 
 	/* DWARF location operation encodings. */
 	public final static int DW_OP_addr = 0x03; /* Constant address. */
@@ -459,6 +483,60 @@ public class DwarfConstants {
 	public final static int DW_MACINFO_end_file = 4;
 	public final static int DW_MACINFO_vendor_ext = 255;
 
+	/* DWARF macro type encodings. */
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_end = 0;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_define = 1;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_undef = 2;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_start_file = 3;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_end_file = 4;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_define_indirect = 5;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_undef_indirect = 6;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_transparent_include = 7;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_define_indirect_alt = 0x08;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_undef_indirect_alt = 0x09;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_transparent_include_alt = 0x0a;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_lo_user = 0xe0;
+	/**
+	 * @since 5.7
+	 */
+	public final static int DW_MACRO_hi_user = 0xff;
+
 	/* DWARF call frame instruction encodings. */
 	public final static int DW_CFA_advance_loc = 0x40;
 	public final static int DW_CFA_offset = 0x80;

core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/debug/dwarf/DwarfReader.java

@@ -9,18 +9,26 @@
  *     Nokia - initial API and implementation
  *     Ling Wang (Nokia) bug 201000
  *     Serge Beauchamp (Freescale Semiconductor) - Bug 421070
+ *     Red Hat Inc. - add debuginfo and macro section support
  *******************************************************************************/
 
 package org.eclipse.cdt.utils.debug.dwarf;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import javax.xml.bind.DatatypeConverter;
 
 import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.ICompileOptionsFinder;
 import org.eclipse.cdt.core.ISymbolReader;
 import org.eclipse.cdt.utils.coff.Coff.SectionHeader;
 import org.eclipse.cdt.utils.coff.PE;
@@ -35,20 +43,26 @@ import org.eclipse.core.runtime.Path;
  * Light-weight parser of Dwarf2 data which is intended for getting only 
  * source files that contribute to the given executable.
  */
-public class DwarfReader extends Dwarf implements ISymbolReader {
+public class DwarfReader extends Dwarf implements ISymbolReader, ICompileOptionsFinder {
 
 	// These are sections that need be parsed to get the source file list.
-	final static String[] DWARF_SectionsToParse =
+	final static String[] DWARF_SectionsToParse = { 
-		{
 		DWARF_DEBUG_INFO, 
 		DWARF_DEBUG_LINE,
 		DWARF_DEBUG_ABBREV, 
-			DWARF_DEBUG_STR		// this is optional. Some compilers don't generate it.
+		DWARF_DEBUG_STR, // this is optional. Some compilers don't generate it.
-		};
+		DWARF_DEBUG_MACRO, };
+	
+	final static String[] DWARF_ALT_SectionsToParse = { 
+		DWARF_DEBUG_STR, 
+		DWARF_DEBUG_MACRO };
 
 	private final Collection<String>	m_fileCollection = new HashSet<String>();
+	private final Map<Long, String>  m_stmtFileMap = new HashMap<Long, String>();
+	private final Map<String, ArrayList<String>> m_compileOptionsMap = new HashMap<String, ArrayList<String>>();
 	private String[] 	m_fileNames = null;
 	private boolean		m_parsed = false;
+	private boolean		m_macros_parsed = false;
 	private final ArrayList<Integer>	m_parsedLineTableOffsets = new ArrayList<Integer>();
 	private long			m_parsedLineTableSize = 0;
 		
@@ -74,12 +88,148 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 		Elf.ELFhdr header = exe.getELFhdr();
 		isLE = header.e_ident[Elf.ELFhdr.EI_DATA] == Elf.ELFhdr.ELFDATA2LSB;
 
+		IPath debugInfoPath = new Path(exe.getFilename());
 		Elf.Section[] sections = exe.getSections();
 		
+		boolean have_build_id = false;
+		
+		// Look for a special GNU build-id note which means the debug data resides in a separate
+		// file with a name based on the build-id.
+		for (Section section : sections) {
+			if (section.sh_type == Elf.Section.SHT_NOTE) {
+				ByteBuffer data = section.mapSectionData();
+				try {
+					// Read .note section, looking to see if it is named "GNU" and is of GNU_BUILD_ID type
+					@SuppressWarnings("unused")
+					int name_sz = read_4_bytes(data);
+					int data_sz = read_4_bytes(data);
+					int note_type = read_4_bytes(data);
+
+					String noteName = readString(data);
+					String buildId = null;
+					if (noteName.equals("GNU") && note_type == Elf.Section.NT_GNU_BUILD_ID) { //$NON-NLS-1$
+						// We have the special GNU build-id note section.  Skip over the name to
+						// a 4-byte boundary.
+						byte[] byteArray = new byte[data_sz];
+						while ((data.position() & 0x3) != 0)
+							data.get();
+						int i = 0;
+						// Read in the hex bytes from the note section's data.
+						while (data.hasRemaining() && data_sz-- > 0) {
+							byteArray[i++] = data.get();
+						}
+						// The build-id location is taken by converting the binary bytes to hex string.
+						// The first byte is used as a directory specifier (e.g. 51/a4578fe2).
+						String bName = DatatypeConverter.printHexBinary(byteArray).toLowerCase();
+						buildId = bName.substring(0, 2) + "/" + bName.substring(2) + ".debug"; //$NON-NLS-1$ //$NON-NLS-2$
+						// The build-id file should be in the special directory /usr/lib/debug/.build-id
+						IPath buildIdPath = new Path("/usr/lib/debug/.build-id").append(buildId); //$NON-NLS-1$
+						File buildIdFile = buildIdPath.toFile();
+						if (buildIdFile.exists()) {
+							// if the debug file exists from above, open it and get the section info from it
+							Elf debugInfo = new Elf(buildIdFile.getCanonicalPath());
+							sections = debugInfo.getSections();
+							have_build_id = true;
+							debugInfoPath = new Path(buildIdFile.getCanonicalPath()).removeLastSegments(1);
+							break;
+						}
+					}
+				} catch (Exception e) {
+					e.printStackTrace();
+					CCorePlugin.log(e);
+				}
+			}
+		}
+		
+		if (!have_build_id) {
+			// No build-id.  Look for a .gnu_debuglink section which will have the name of the debug info file
+			Elf.Section gnuDebugLink = exe.getSectionByName(DWARF_GNU_DEBUGLINK);
+			if (gnuDebugLink != null) {
+				ByteBuffer data = gnuDebugLink.mapSectionData();
+				if (data != null) { // we have non-empty debug info link
+					try {
+						// name is zero-byte terminated character string
+						String debugName = ""; //$NON-NLS-1$
+						if (data.hasRemaining()) {
+							int c;
+							StringBuffer sb = new StringBuffer();
+							while ((c = data.get()) != -1) {
+								if (c == 0) {
+									break;
+								}
+								sb.append((char) c);
+							}
+							debugName = sb.toString();
+						}
+						if (debugName.length() > 0) {
+							// try and open the debug info from 3 separate places in order
+							File debugFile = null;
+							IPath exePath = new Path(exe.getFilename());
+							IPath p = exePath.removeLastSegments(1);
+							// 1. try and open the file in the same directory as the executable
+							debugFile = p.append(debugName).toFile();
+							if (!debugFile.exists()) {
+								// 2. try and open the file in the .debug directory where the executable is 
+								debugFile = p.append(".debug").append(debugName).toFile(); //$NON-NLS-1$
+								if (!debugFile.exists())
+									// 3. try and open /usr/lib/debug/$(EXE_DIR)/$(DEBUGINFO_NAME)
+									debugFile = new Path("/usr/lib/debug").append(p).append(debugName).toFile(); //$NON-NLS-1$
+							}
+							if (debugFile.exists()) {
+								// if the debug file exists from above, open it and get the section info from it
+								Elf debugInfo = new Elf(debugFile.getCanonicalPath());
+								sections = debugInfo.getSections();
+								debugInfoPath = new Path(debugFile.getCanonicalPath()).removeLastSegments(1);
+							}
+						}
+					} catch (Exception e) {
+						e.printStackTrace();
+						CCorePlugin.log(e);
+					}
+				}
+
+			}
+		}
+		
 		// Read in sections (and only the sections) we care about.
 		//
 		for (Section section : sections) {
 			String name = section.toString();
+			if (name.equals(DWARF_GNU_DEBUGALTLINK)) {
+				ByteBuffer data = section.mapSectionData();
+				try {
+					// name is zero-byte terminated character string
+					String altInfoName = readString(data);
+					if (altInfoName.length() > 0) {
+						IPath altPath = new Path(altInfoName);
+						if (!altPath.isAbsolute()) {
+							altPath = debugInfoPath.append(altPath);
+						}
+						File altFile = altPath.toFile();
+						if (altFile.exists()) {
+							Elf altInfo = new Elf(altFile.getCanonicalPath());
+							Elf.Section[] altSections = altInfo.getSections();
+							for (Section altSection : altSections) {
+								String altName = altSection.toString();
+								for (String element : DWARF_ALT_SectionsToParse) {
+									if (altName.equals(element)) {
+										try {
+											dwarfAltSections.put(element, altSection.mapSectionData());
+										} catch (Exception e) {
+											e.printStackTrace();
+											CCorePlugin.log(e);
+										}
+									}
+								}
+							}
+						}
+					}
+				} catch (Exception e) {
+					e.printStackTrace();
+					CCorePlugin.log(e);
+				}
+			} 
+			else {
 				for (String element : DWARF_SectionsToParse) {
 					if (name.equals(element)) {
 						// catch out of memory exceptions which might happen trying to
@@ -94,6 +244,7 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 					}
 				}
 			}
+		}
 		
 		// Don't print during parsing.
 		printEnabled = false;
@@ -411,13 +562,19 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 		parse(null);
 	}
 
-	private void addSourceFile(String dir, String name)
+	private String addSourceFileWithStmt(String dir, String name, int stmt) {
+		String fullName = addSourceFile(dir, name);
+		m_stmtFileMap.put(Long.valueOf(stmt), fullName);
+		return fullName;
+	}
+
+	private String addSourceFile(String dir, String name)
 	{
 		if (name == null || name.length() == 0)
-			return;
+			return null;
 		
 		if (name.charAt(0) == '<')	//  don't count the entry "<internal>" from GCCE compiler
-			return;
+			return null;
 		
 		String fullName = name;
 		
@@ -434,27 +591,8 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 		
 		if (!m_fileCollection.contains(fullName))
 			m_fileCollection.add(fullName);
-	}
 		
-	/**
+		return fullName;
-	 * Read a null-ended string from the given "data" stream.
-	 * data	:  IN, byte buffer
-	 */
-	String readString(ByteBuffer data)
-	{
-		String str;
-		
-		StringBuffer sb = new StringBuffer();
-		while (data.hasRemaining()) {
-			byte c = data.get();
-			if (c == 0) {
-				break;
-			}
-			sb.append((char) c);
-		}
-
-		str = sb.toString();
-		return str;
 	}
 	
 	// Override parent: only handle TAG_Compile_Unit.
@@ -502,7 +640,7 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 			}
 		}
 
-		addSourceFile(cuCompDir, cuName);
+		addSourceFileWithStmt(cuCompDir, cuName, stmtList);
 		if (stmtList > -1)	// this CU has "stmt_list" attribute
 			parseSourceInCULineInfo(cuCompDir, stmtList);
 	}
@@ -515,4 +653,406 @@ public class DwarfReader extends Dwarf implements ISymbolReader {
 		return getSourceFiles();
 	}
 
+	private class OpcodeInfo {
+		private int numArgs;
+		private final boolean offset_size_8;
+		ArrayList<Integer> argTypes;
+		
+		public OpcodeInfo (boolean offset_size_8) {
+			this.offset_size_8 = offset_size_8;
+		}
+		
+		public void setNumArgs (int numArgs) {
+			this.numArgs = numArgs;
+		}
+		
+		public void addArgType(int argType) {
+			argTypes.add(Integer.valueOf(argType));
+		}
+		
+		public void readPastEntry(ByteBuffer data) {
+			for (int i = 0; i < numArgs; ++i) {
+				int argType = argTypes.get(i).intValue();
+				switch (argType) {
+				case DwarfConstants.DW_FORM_flag:
+				case DwarfConstants.DW_FORM_data1:
+					data.get();
+					break;
+				case DwarfConstants.DW_FORM_data2:
+					data.getShort();
+					break;
+				case DwarfConstants.DW_FORM_data4:
+					data.getInt();
+					break;
+				case DwarfConstants.DW_FORM_data8:
+					data.getLong();
+					break;
+				case DwarfConstants.DW_FORM_sdata:
+				case DwarfConstants.DW_FORM_udata:
+					try {
+						read_signed_leb128(data);
+					} catch (IOException e) {
+						e.printStackTrace();
+					}
+					break;
+				case DwarfConstants.DW_FORM_block: {
+					try {
+						long off = read_signed_leb128(data);
+						data.position((int)(data.position() + off));
+					} catch (IOException e) {
+						e.printStackTrace();
+					}
+				}
+				break;
+				case DwarfConstants.DW_FORM_block1: {
+					int off = data.get();
+					data.position(data.position() + off + 1);
+				}
+				break;
+				case DwarfConstants.DW_FORM_block2: {
+					int off = data.getShort();
+					data.position(data.position() + off + 2);
+				}
+				break;
+				case DwarfConstants.DW_FORM_block4: {
+					int off = data.getInt();
+					data.position(data.position() + off + 4);
+				}
+				break;
+				case DwarfConstants.DW_FORM_string:
+					while (data.get() != 0) {
+						// loop until we find 0 byte
+					}
+					break;
+				case DwarfConstants.DW_FORM_strp:
+				case DwarfConstants.DW_FORM_GNU_strp_alt:
+				case DwarfConstants.DW_FORM_GNU_ref_alt:
+				case DwarfConstants.DW_FORM_sec_offset:
+					if (offset_size_8)
+						data.getLong();
+					else
+						data.getInt();
+					break;
+				}
+			}
+		}
+	}
+	
+	// Convert a macro to its command line form.
+	private String getCommandLineMacro(String macro) {
+		String commandLineMacro = "-D" + macro; //$NON-NLS-1$
+		commandLineMacro = commandLineMacro.replaceFirst(" ", "="); //$NON-NLS-1$ //$NON-NLS-2$
+		return commandLineMacro;
+	}
+
+	// Go through regular and alt macro sections and find any macros that were set on the
+	// compilation command line (e.g. gcc -Dflagx=1 my.c).  Built-in macros and macros that
+	// are set within files (source and include) are ignored since they can and will be
+	// discovered by indexing.
+	private void getCommandMacrosFromMacroSection() {
+		ByteBuffer data = dwarfSections.get(DWARF_DEBUG_MACRO);
+		ByteBuffer str = dwarfSections.get(DWARF_DEBUG_STR);
+		ByteBuffer altdata = dwarfAltSections.get(DWARF_DEBUG_MACRO);
+		ByteBuffer altstr = dwarfAltSections.get(DWARF_DEBUG_STR);
+		Set<String> fixupList = new HashSet<String>();
+		Set<String> fixupAltList = new HashSet<String>();
+		boolean DEBUG = false;
+		if (data == null)
+			return;
+
+		HashMap <Long, ArrayList<String>> t_macros = new HashMap<Long, ArrayList<String>>();
+		HashMap <Long, ArrayList<String>> t_alt_macros = new HashMap<Long, ArrayList<String>>();
+		
+		// Parse the macro section, looking for command-line macros meant for compiling files (i.e.
+		// not internal macro definitions in headers or C/C++ files.  Keep track of any forward
+		// references to fix-up later when we have a complete list of command-line macros.
+		parseMacroSection(data, str, altstr, fixupList, fixupAltList, "=FIXUP=", DEBUG, t_macros); //$NON-NLS-1$
+       
+		// Check if there is an alternate macro section.  If there is, parse the alternate section, but any references
+		// found there should be considered referring to the alternate string and macro sections.
+		// All forward reference fix-ups should be put on the alternate fix-up list.
+		if (altdata != null) {
+			if (DEBUG)
+				System.out.println("Processing Alternate Macro Section"); //$NON-NLS-1$
+			parseMacroSection(altdata, altstr, altstr, fixupAltList, fixupAltList, "=FIXUPALT=", DEBUG, t_alt_macros); //$NON-NLS-1$
+		}
+			
+		// Fix up all forward references from transparent includes
+		fixupMacros(fixupList, "=FIXUP=", DEBUG, t_macros); //$NON-NLS-1$
+		
+		// Fix up all forward references from transparent alt includes
+		if (DEBUG)
+			System.out.println("Fix up forward references in alternate macro section"); //$NON-NLS-1$
+		fixupMacros(fixupAltList, "=FIXUPALT=", DEBUG, t_alt_macros); //$NON-NLS-1$
+	}
+
+	// Fix up forward references made by transparent includes now that a complete macro list has been retrieved.
+	private void fixupMacros(Set<String> fixupList, String fixupMarker, boolean DEBUG,
+			HashMap<Long, ArrayList<String>> t_macros) {
+		for (String name: fixupList) {
+			ArrayList<String> macros = m_compileOptionsMap.get(name);
+			for (int i = 0; i < macros.size(); ++i) {
+				String macroLine = macros.get(i);
+				if (macroLine.startsWith(fixupMarker)) {
+					Long offset = Long.valueOf(macroLine.substring(7));
+					if (DEBUG)
+						System.out.println("Found fixup needed for offset: " + offset + " for file: " + name); //$NON-NLS-1$ //$NON-NLS-2$
+					ArrayList<String> insertMacros = t_macros.get(offset);
+					if (DEBUG)
+						System.out.println("insert macros are: " + insertMacros.toString()); //$NON-NLS-1$
+					macros.remove(i);
+					macros.addAll(i, insertMacros);
+					i += insertMacros.size();
+				}
+			}
+			m_compileOptionsMap.put(name,  macros); // replace updated list
+		}
+	}
+
+	// Parse a macro section, looking for command-line macros that are used as flags to compile source files.
+	// Keep track of any forward references to macros not yet defined in the file.  We will later
+	// fix-up these references when we have seen all command-line macros for the file.
+	private void parseMacroSection(ByteBuffer data, ByteBuffer str, ByteBuffer altstr,
+			Set<String> fixupList, Set<String> fixupAltList, String fixupMarker, boolean DEBUG,
+			HashMap<Long, ArrayList<String>> t_macros) {
+		byte op;
+		while (data.hasRemaining()) {
+			try {
+				int original_position = data.position();
+				int type = read_2_bytes(data);
+				byte flags = data.get();
+				boolean offset_size_8;
+				long lt_offset = -1;
+				String fileName = null;
+				
+				HashMap<Integer, OpcodeInfo> opcodeInfos = null;
+
+				if (DEBUG)
+					System.out.println("type is " + type); //$NON-NLS-1$
+
+				// bottom bit 0 tells us whether we have 8 byte offsets or 4 byte offsets
+				offset_size_8 = (flags & 0x1) == 1;
+				if (DEBUG)
+					System.out.println("offset size is " + (offset_size_8 ? 8 : 4)); //$NON-NLS-1$
+				// bit 1 indicates we have an offset from the start of .debug_line section
+				if ((flags & 0x2) != 0) {
+					lt_offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+					fileName = m_stmtFileMap.get(Long.valueOf(lt_offset));
+					if (DEBUG)
+						System.out.println("debug line offset is " + lt_offset); //$NON-NLS-1$
+				}
+
+				// if bit 2 flag is on, then we have a macro entry table which may
+				// have non-standard entry types defined which we need to know when
+				// we come across macro entries later
+				if ((flags & 0x4) != 0) {
+					opcodeInfos = new HashMap<Integer, OpcodeInfo>();
+					int num_opcodes = data.get();
+					for (int i = 0; i < num_opcodes; ++i) {
+						OpcodeInfo info = new OpcodeInfo(offset_size_8);
+
+						int opcode = data.get();
+						long numArgs = read_unsigned_leb128(data);
+						info.setNumArgs((int)numArgs);
+						for (int j = 0; j < numArgs; ++j) {
+							int argType = data.get();
+							info.addArgType(argType);
+						}
+						opcodeInfos.put(Integer.valueOf(opcode), info);
+					}
+				}
+
+				ArrayList<String> macros = new ArrayList<String>();
+
+				boolean done = false;
+
+				while (!done) {
+					op = data.get();
+					switch (op) {
+
+					case DwarfConstants.DW_MACRO_start_file: {
+						long filenum;
+						long lineno;
+						lineno = read_signed_leb128(data);
+						filenum = read_signed_leb128(data);
+						// All command line macros are defined as being included before start of file
+						if (filenum == 1 && lt_offset >= 0) {
+							// we have a source file so add all macros defined before it with lineno 0
+							m_compileOptionsMap.put(fileName, macros);
+							if (DEBUG)
+								System.out.println("following macros found for file " + macros.toString()); //$NON-NLS-1$
+							macros = new ArrayList<String>();
+						}
+						if (fileName != null)
+							if (DEBUG)
+								System.out.println(" DW_MACRO_start_file - lineno: " + lineno + " filenum: " //$NON-NLS-1$ //$NON-NLS-2$
+										+ filenum + " " + fileName); //$NON-NLS-1$
+						else if (DEBUG)
+							System.out.println(" DW_MACRO_start_file - lineno: " + lineno + " filenum: " //$NON-NLS-1$ //$NON-NLS-2$
+									+ filenum);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_end_file: {
+						if (DEBUG)
+							System.out.println(" DW_MACRO_end_file"); //$NON-NLS-1$
+					}
+					break;
+					case DwarfConstants.DW_MACRO_define: {
+						long lineno;
+						String string;
+						lineno = read_signed_leb128(data);
+						string = readString(data);
+						if (lineno == 0)
+							macros.add(getCommandLineMacro(string));
+						if (DEBUG)
+							System.out.println(" DW_MACRO_define - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ string);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_undef: {
+						long lineno;
+						String macro;
+						lineno = read_signed_leb128(data);
+						macro = readString(data);
+						if (DEBUG)
+							System.out.println(" DW_MACRO_undef - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ macro);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_define_indirect: {
+						long lineno;
+						long offset;
+						lineno = read_signed_leb128(data);
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						str.position((int)offset);
+						String macro = readString(str);
+						if (lineno == 0)
+							macros.add(getCommandLineMacro(macro));
+						if (DEBUG)
+							System.out.println(" DW_MACRO_define_indirect - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ macro);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_define_indirect_alt: {
+						long lineno;
+						long offset;
+						lineno = read_signed_leb128(data);
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						altstr.position((int)offset);
+						String macro = readString(altstr);
+						if (lineno == 0)
+							macros.add(getCommandLineMacro(macro));
+						if (DEBUG)
+							System.out.println(" DW_MACRO_define_indirect_alt - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ macro);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_undef_indirect: {
+						long lineno;
+						long offset;
+						String macro;
+						lineno = read_signed_leb128(data);
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						str.position((int)offset);
+						macro = readString(str);
+						if (DEBUG)
+							System.out.println(" DW_MACRO_undef_indirect - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ macro);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_undef_indirect_alt: {
+						long lineno;
+						long offset;
+						String macro;
+						lineno = read_signed_leb128(data);
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						altstr.position((int)offset);
+						macro = readString(altstr);
+						if (DEBUG)
+							System.out.println(" DW_MACRO_undef_indirect_alt - lineno : " + lineno + " macro : " //$NON-NLS-1$ //$NON-NLS-2$
+									+ macro);
+					}
+					break;
+					case DwarfConstants.DW_MACRO_transparent_include: {
+						long offset;
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						ArrayList<String> foundMacros = t_macros.get(Long.valueOf(offset));
+						if (foundMacros != null)
+							macros.addAll(foundMacros);
+						else if (lt_offset >= 0) {
+							macros.add(fixupMarker + offset); // leave a marker we can fix up later
+							if (DEBUG)
+								System.out.println("Adding fixup for offset: " + offset + " for file: " + fileName); //$NON-NLS-1$ //$NON-NLS-2$
+							fixupList.add(fileName);
+						}
+							
+						if (DEBUG)
+							System.out.println(" DW_MACRO_transparent_include - offset : " + offset); //$NON-NLS-1$
+					}
+					break;
+					case DwarfConstants.DW_MACRO_transparent_include_alt: {
+						long offset;
+						offset = (offset_size_8 ? read_8_bytes(data) : read_4_bytes(data));
+						if (lt_offset >= 0) {
+							macros.add("=FIXUPALT=" + offset); // leave a marker we can fix up later //$NON-NLS-1$
+							if (DEBUG)
+								System.out.println("Adding alt fixup for offset: " + offset + " for file: " + fileName); //$NON-NLS-1$ //$NON-NLS-2$
+							fixupAltList.add(fileName);
+						}
+							
+						if (DEBUG)
+							System.out.println(" DW_MACRO_transparent_include - offset : " + offset); //$NON-NLS-1$
+					}
+					break;
+					case DwarfConstants.DW_MACRO_end: {
+						if (lt_offset < 0) {
+							if (DEBUG)
+								System.out.println("creating transparent include macros for offset: " + original_position); //$NON-NLS-1$
+							t_macros.put(Long.valueOf(original_position), macros);
+						}
+						done = true;
+					}
+					break;
+					default: {
+						if (opcodeInfos != null) {
+							OpcodeInfo info = opcodeInfos.get(op);
+							info.readPastEntry(data);
+						}
+					}
+					break;
+					}
+				}
+			}  catch (IOException e) {
+				// do nothing
+			}
+		}
+	}
+
+	/**
+	 * Get the set of command line flags used for a particular file name.
+	 * 
+	 * @param fileName - name of file
+	 * @return string containing all macros used on command line to compile the file
+	 * 
+	 * @since 5.7
+	 */
+	@Override
+	public String getCompileOptions(String fileName) {
+		if (!m_macros_parsed) {
+			getSourceFiles();
+			getCommandMacrosFromMacroSection();
+			m_macros_parsed = true;
+		}
+		ArrayList<String>macros = m_compileOptionsMap.get(fileName);
+		if (macros == null)
+			return ""; //$NON-NLS-1$
+		
+		StringBuffer sb = new StringBuffer();
+		for (String option: macros) {
+			sb.append(option);
+			sb.append(" "); //$NON-NLS-1$
+		}
+		return sb.toString();
+	}
+
 }

core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/Elf.java

@@ -11,12 +11,11 @@
  *******************************************************************************/
 package org.eclipse.cdt.utils.elf;
 
-import java.io.EOFException;
-
-import static org.eclipse.cdt.internal.core.ByteUtils.makeShort;
 import static org.eclipse.cdt.internal.core.ByteUtils.makeInt;
 import static org.eclipse.cdt.internal.core.ByteUtils.makeLong;
+import static org.eclipse.cdt.internal.core.ByteUtils.makeShort;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel.MapMode;
@@ -302,6 +301,12 @@ public class Elf {
 		public final static int SHF_ALLOC = 2;
 		public final static int SHF_EXECINTR = 4;
 		
+		/* note_types */
+		/**
+		 * @since 5.7
+		 */
+		public final static int NT_GNU_BUILD_ID = 3;
+
 		public long sh_name;
 		public long sh_type;
 		public long sh_flags;