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[binutils-gdb/gdb-7.10-branch] PR18617 - Incorrect expression bytecode generated for narrowing conversions
- From: Pedro Alves <palves at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 8 Jul 2015 10:16:29 -0000
- Subject: [binutils-gdb/gdb-7.10-branch] PR18617 - Incorrect expression bytecode generated for narrowing conversions
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cc1259417e727c47e58cea1bb4a148974689ad8e
commit cc1259417e727c47e58cea1bb4a148974689ad8e
Author: Robert O'Callahan <robert@ocallahan.org>
Date: Wed Jul 8 11:11:22 2015 +0100
PR18617 - Incorrect expression bytecode generated for narrowing conversions
The existing code preserves 'from' bits, which is incorrect. E.g.
(gdb) maint agent-eval (char)255L
Scope: 0x4008d6
Reg mask: 00
0 const16 255
3 ext 64
5 end
'ext 64' should be 'ext 8'; this bytecode evaluates to 255 instead of
the correct result of -1. The fix is simple. I ran the entire test
suite on x86-64 and there were no new test failures.
gdb/ChangeLog:
2015-07-08 Robert O'Callahan <robert@ocallahan.org>
PR exp/18617
* ax-gdb.c (gen_conversion): Extend to 'to' bits, not 'from'.
gdb/testsuite/ChangeLog:
2015-07-08 Robert O'Callahan <robert@ocallahan.org>
PR exp/18617
* gdb.trace/ax.exp: Add test.
Diff:
---
gdb/ChangeLog | 5 +++++
gdb/ax-gdb.c | 2 +-
gdb/testsuite/ChangeLog | 5 +++++
gdb/testsuite/gdb.trace/ax.exp | 2 ++
4 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b3b5c59..b376ab8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-08 Robert O'Callahan <robert@ocallahan.org>
+
+ PR exp/18617
+ * ax-gdb.c (gen_conversion): Extend to 'to' bits, not 'from'.
+
2015-07-06 Joel Brobecker <brobecker@adacore.com>
* version.in: Set GDB version number to 7.9.90.DATE-cvs.
diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index 7a9d1e7..38dacac 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -885,7 +885,7 @@ gen_conversion (struct agent_expr *ax, struct type *from, struct type *to)
/* If we're converting to a narrower type, then we need to clear out
the upper bits. */
if (TYPE_LENGTH (to) < TYPE_LENGTH (from))
- gen_extend (ax, from);
+ gen_extend (ax, to);
/* If the two values have equal width, but different signednesses,
then we need to extend. */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 0a90fa9..e8651fa 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-08 Robert O'Callahan <robert@ocallahan.org>
+
+ PR exp/18617
+ * gdb.trace/ax.exp: Add test.
+
2015-06-30 Martin Galvan <martin.galvan@tallertechnologies.com>
* lib/gdb.exp (test_class_help): Remove the unneeded escaping of
diff --git a/gdb/testsuite/gdb.trace/ax.exp b/gdb/testsuite/gdb.trace/ax.exp
index e3d0479..d064475 100644
--- a/gdb/testsuite/gdb.trace/ax.exp
+++ b/gdb/testsuite/gdb.trace/ax.exp
@@ -80,6 +80,8 @@ gdb_test "maint agent &gdb_long_test == &gdb_short_test" "" "maint agent &gdb_lo
gdb_test "maint agent &gdb_long_test < &gdb_short_test" "" "maint agent &gdb_long_test < &gdb_short_test"
+gdb_test "maint agent (unsigned char)1L" ".*ext 8.*" "maint agent (unsigned char)1L"
+
# Now test eval version of agent expressions.
gdb_test "maint agent-eval 12" ".*const8 12.*end.*" "maint agent-eval 12"