[binutils-gdb] Sign-extend start and stop address inputs to objdump

[Faraz Shahbazker <farazs at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2379f9c475505ecedc97607b39af7184bd67aa88

commit 2379f9c475505ecedc97607b39af7184bd67aa88
Author: Faraz Shahbazker <fshahbazker@wavecomp.com>
Date:   Fri May 3 18:21:49 2019 -0700

    Sign-extend start and stop address inputs to objdump
    
    For targets that treat addresses as signed (MIPS/SH64), user-specified
    start/stop address limits cannot be compared directly to section VMAs.
    We must sign-extend user-specified 32-bit address limits which have
    bit 31 set for such targets.
    
    binutils/
    	* objdump.c (sign_extend_address): New function.
    	(dump_bfd): Sign-extend user-specified start/stop addresses
    	for targets that need it.
    	* testsuite/binutils-all/objdump.exp: Add tests for objdump
    	with start and stop addresses in higher address ranges.

Diff:
---
 binutils/ChangeLog                          |  8 +++++
 binutils/objdump.c                          | 26 ++++++++++++++
 binutils/testsuite/binutils-all/objdump.exp | 54 +++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index b3140a9..ecbe759 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,11 @@
+2019-05-08  Faraz Shahbazker  <fshahbazker@wavecomp.com>
+
+	* objdump.c (sign_extend_address): New function.
+	(dump_bfd): Sign-extend user-specified start/stop addresses
+	for targets that need it.
+	* testsuite/binutils-all/objdump.exp: Add tests for objdump
+	with start and stop addresses in higher address ranges.
+
 2019-05-01  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* testsuite/binutils-all/objdump.exp: Correct executable
diff --git a/binutils/objdump.c b/binutils/objdump.c
index 644638c..05d503e 100644
--- a/binutils/objdump.c
+++ b/binutils/objdump.c
@@ -3749,11 +3749,25 @@ adjust_addresses (bfd *abfd ATTRIBUTE_UNUSED,
     }
 }
 
+/* Return the sign-extended form of an ARCH_SIZE sized VMA.  */
+
+static bfd_vma
+sign_extend_address (bfd *abfd ATTRIBUTE_UNUSED,
+		     bfd_vma vma,
+		     unsigned arch_size)
+{
+  bfd_vma mask;
+  mask = (bfd_vma) 1 << (arch_size - 1);
+  return (((vma & ((mask << 1) - 1)) ^ mask) - mask);
+}
+
 /* Dump selected contents of ABFD.  */
 
 static void
 dump_bfd (bfd *abfd, bfd_boolean is_mainfile)
 {
+  const struct elf_backend_data * bed;
+
   if (bfd_big_endian (abfd))
     byte_get = byte_get_big_endian;
   else if (bfd_little_endian (abfd))
@@ -3784,6 +3798,18 @@ dump_bfd (bfd *abfd, bfd_boolean is_mainfile)
 	}
     }
 
+  /* Adjust user-specified start and stop limits for targets that use
+     signed addresses.  */
+  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
+      && (bed = get_elf_backend_data (abfd)) != NULL
+      && bed->sign_extend_vma)
+    {
+      start_address = sign_extend_address (abfd, start_address,
+					   bed->s->arch_size);
+      stop_address = sign_extend_address (abfd, stop_address,
+					  bed->s->arch_size);
+    }
+
   /* If we are adjusting section VMA's, change them all now.  Changing
      the BFD information is a hack.  However, we must do it, or
      bfd_find_nearest_line will not do the right thing.  */
diff --git a/binutils/testsuite/binutils-all/objdump.exp b/binutils/testsuite/binutils-all/objdump.exp
index 94ff015..f25946c 100644
--- a/binutils/testsuite/binutils-all/objdump.exp
+++ b/binutils/testsuite/binutils-all/objdump.exp
@@ -672,6 +672,60 @@ if {[is_elf_format]} then {
     test_follow_debuglink "--dwarf=follow-links --headers --wide" objdump.WK3
 }
 
+# Test objdump output with start and stop address limits for the specified
+# dump option
+
+proc test_objdump_limited { testfile dopt want start stop } {
+    global OBJDUMP
+    global OBJDUMPFLAGS
+
+    set got [binutils_run $OBJDUMP "$OBJDUMPFLAGS $dopt --start-address 0x$start --stop-address 0x$stop $testfile"]
+
+    if [regexp $want $got] then {
+	pass "objdump $dopt --start-address 0x$start --stop-address 0x$stop ($testfile)"
+    } else {
+	fail "objdump $dopt --start-address 0x$start --stop-address 0x$stop ($testfile)"
+    }
+}
+
+# Test objdump -d --start-address M --stop-address N
+
+proc test_objdump_disas_limited { testfile start stop } {
+    set want "$testfile:\[ 	\]*file format.*Disassembly of section .text:\n.*\[ \]*$start:.*"
+    test_objdump_limited $testfile -d $want $start $stop
+}
+
+# Test objdump -s --start-address M --stop-address N
+
+proc test_objdump_content_limited { testfile start stop } {
+    set want "$testfile:\[ 	\]*file format.*Contents of section .text:\n\[ \]*$start .*"
+    test_objdump_limited $testfile -s $want $start $stop
+}
+
+# Test objdump with --start-address and --stop-address options for higher
+# address ranges which may be sign-extended on targets that treat addresses
+# as signed.  We only check that objdump produces some dump output at the
+# specified start address as a proxy for correct enforcement of the
+# start/stop limits.
+
+if {[is_elf_format]} then {
+    # generate a copy of the test object with .text repositioned
+    if { [binutils_run $OBJCOPY "--change-section-address .text=0x80000000 tmpdir/bintest.o tmpdir/bintest_signed.o"] != "" } {
+	fail "Failed to reposition .text to 0x80000000 (tmpdir/bintest.o -> tmpdir/bintest_signed.o)"
+	return
+    }
+
+    if [is_remote host] {
+	set testfile3 [remote_download host tmpdir/bintest_signed.o]
+    } else {
+	set testfile3 tmpdir/bintest_signed.o
+    }
+
+    test_objdump_content_limited $testfile3 "80000004" "80000008"
+    test_objdump_disas_limited $testfile3 "80000004" "80000008"
+    remote_file host delete $testfile3
+}
+
 # Options which are not tested: -a -D -R -T -x -l --stabs
 # I don't see any generic way to test any of these other than -a.
 # Tests could be written for specific targets, and that should be done