readelf: Handle compressed sections and extend -z to cover -x and -p.

When printing a (non-string, non-data) section use uncompressed data when
possible. For dumping hex and string sections (-x and -p) -z will dump the
uncompressed data (otherwise the compressed data is dumped).

-z, --decompress           Show compression information for compressed
                           sections (when used with -S); decompress section
                           before dumping data (when used with -p or -x)

Includes test cases for ET_REL files using compressed relocation (target)
debug sections to test libdwfl transparent uncompression of sections.

Signed-off-by: Mark Wielaard <[email protected]>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 97242213..1b5be54c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2015-10-20  Mark Wielaard  <[email protected]>
+
+	* readelf.c (options): Expand -z help text.
+	(dump_data_section): Check whether we need and can decompress section
+	data and call elf_rawzdata if so,
+	(print_string_section): Likewise.
+	(elf_contains_chdrs): New function.
+	(process_elf_file): Rename print_unrelocated to print_unchanged,
+	use elf_contains_chdrs.
+	(print_scngrp): Check whether section is compressed before use.
+	(print_symtab): Likewise.
+	(handle_hash): Likewise.
+
 2015-10-16  Mark Wielaard  <[email protected]>
 
 	* readelf.c (argp_option): Describe --decompress,-z.