From 2962203bd20473cf3f00b347fcaa329373a35589 Mon Sep 17 00:00:00 2001
From: Simeon Andreev <simeon.danailov.andreev@gmail.com>
Date: Wed, 9 Dec 2020 14:42:50 +0100
Subject: [PATCH] Bug 569581 - Rethrow IOException in
 ElfParser.hasInterpProgramHeader()

This change adjusts behavior in ElfParser.hasInterpProgramHeader()
(added for bug 512822) to throw an IOException that occurred, as opposed
to logging the exception and continuing. This excludes exceptions thrown
by Elf.getSections() indicating that ELFhdr.ELFCLASSNONE is read; a new,
more specific IOException type is defined to allow handling this as a
special case.

A "generic" IOException indicates an I/O problem with the binary. E.g.
the binary can be deleted by the user or by Eclipse, while being visited
in CModelManager. If hasInterpProgramHeader() returns instead of
throwing, more problems can occur "later on".

Change-Id: I8852d9cbaa17dc97f668bb1666e9b046bbde1fca
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>
---
 .../utils/org/eclipse/cdt/utils/elf/Elf.java  | 19 +++++++++++++++++--
 .../cdt/utils/elf/parser/ElfParser.java       |  3 ++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/Elf.java b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/Elf.java
index c6334470ccc..42f67a68947 100644
--- a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/Elf.java
+++ b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/Elf.java
@@ -1029,6 +1029,9 @@ public class Elf implements AutoCloseable {
 		return slist.toArray(new Section[0]);
 	}
 
+	/**
+	 * @throws ElfClassNoneException if {@link ELFhdr#ELFCLASSNONE} header is read
+	 */
 	public Section[] getSections() throws IOException {
 		if (sections == null) {
 			if (ehdr.e_shoff == 0) {
@@ -1063,7 +1066,7 @@ public class Elf implements AutoCloseable {
 					break;
 				case ELFhdr.ELFCLASSNONE:
 				default:
-					throw new IOException("Unknown ELF class " + ehdr.e_ident[ELFhdr.EI_CLASS]); //$NON-NLS-1$
+					throw new ElfClassNoneException("Unknown ELF class " + ehdr.e_ident[ELFhdr.EI_CLASS]); //$NON-NLS-1$
 				}
 
 				sections[i].sh_link = efile.readIntE();
@@ -1081,7 +1084,7 @@ public class Elf implements AutoCloseable {
 					break;
 				case ELFhdr.ELFCLASSNONE:
 				default:
-					throw new IOException("Unknown ELF class " + ehdr.e_ident[ELFhdr.EI_CLASS]); //$NON-NLS-1$
+					throw new ElfClassNoneException("Unknown ELF class " + ehdr.e_ident[ELFhdr.EI_CLASS]); //$NON-NLS-1$
 				}
 			}
 		}
@@ -1316,4 +1319,16 @@ public class Elf implements AutoCloseable {
 		}
 		return result;
 	}
+
+	/**
+	 * Exception indicating that {@link ELFhdr#ELFCLASSNONE} header is read.
+	 *
+	 * @since 7.1
+	 */
+	public static class ElfClassNoneException extends IOException {
+
+		ElfClassNoneException(String message) {
+			super(message);
+		}
+	}
 }
diff --git a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/parser/ElfParser.java b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/parser/ElfParser.java
index c1c245a1f3b..0e4da98b046 100644
--- a/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/parser/ElfParser.java
+++ b/core/org.eclipse.cdt.core/utils/org/eclipse/cdt/utils/elf/parser/ElfParser.java
@@ -29,6 +29,7 @@ import org.eclipse.cdt.utils.AR;
 import org.eclipse.cdt.utils.elf.Elf;
 import org.eclipse.cdt.utils.elf.Elf.Attribute;
 import org.eclipse.cdt.utils.elf.Elf.ELFhdr;
+import org.eclipse.cdt.utils.elf.Elf.ElfClassNoneException;
 import org.eclipse.cdt.utils.elf.Elf.PHdr;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
@@ -177,7 +178,7 @@ public class ElfParser extends AbstractCExtension implements IBinaryParser {
 		try {
 			/* No PHdr.PT_INTERP found in the hints meaning we need to read the file itself */
 			return Arrays.stream(getPHdrs(path)).anyMatch(phdr -> phdr.p_type == PHdr.PT_INTERP);
-		} catch (IOException e) {
+		} catch (ElfClassNoneException e) {
 			CCorePlugin.log(e);
 		}
 		return false;