From ace186d47aa03fdef613e60d013f594c74ddcbd4 Mon Sep 17 00:00:00 2001 From: Kevin Buettner Date: Fri, 27 Apr 2007 22:34:56 +0000 Subject: [PATCH] * dwarf2expr.c (unsigned_address_type): Add forward declaration. (dwarf2_read_address): Sign extend return address as required by target architecture. --- gdb/ChangeLog | 6 ++++++ gdb/dwarf2expr.c | 33 ++++++++++++++++++++++++++++++--- 2 files changed, 36 insertions(+), 3 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index fc66469..8799fa6 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,11 @@ 2007-04-27 Kevin Buettner + * dwarf2expr.c (unsigned_address_type): Add forward declaration. + (dwarf2_read_address): Sign extend return address as required by + target architecture. + +2007-04-27 Kevin Buettner + * solib-frv.c (lm_base): Bail out if the main executable has not been relocated. diff --git a/gdb/dwarf2expr.c b/gdb/dwarf2expr.c index 8464f3b..ad259f4 100644 --- a/gdb/dwarf2expr.c +++ b/gdb/dwarf2expr.c @@ -33,6 +33,7 @@ static void execute_stack_op (struct dwarf_expr_context *, gdb_byte *, gdb_byte *); +static struct type *unsigned_address_type (void); /* Create a new context for the expression evaluator. */ @@ -205,9 +206,35 @@ dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, int *bytes_read) error (_("dwarf2_read_address: Corrupted DWARF expression.")); *bytes_read = TARGET_ADDR_BIT / TARGET_CHAR_BIT; - /* NOTE: cagney/2003-05-22: This extract is assuming that a DWARF 2 - address is always unsigned. That may or may not be true. */ - result = extract_unsigned_integer (buf, TARGET_ADDR_BIT / TARGET_CHAR_BIT); + + /* For most architectures, calling extract_unsigned_integer() alone + is sufficient for extracting an address. However, some + architectures (e.g. MIPS) use signed addresses and using + extract_unsigned_integer() will not produce a correct + result. Turning the unsigned integer into a value and then + decomposing that value as an address will cause + gdbarch_integer_to_address() to be invoked for those + architectures which require it. Thus, using value_as_address() + will produce the correct result for both types of architectures. + + One concern regarding the use of values for this purpose is + efficiency. Obviously, these extra calls will take more time to + execute and creating a value takes more space, space which will + have to be garbage collected at a later time. If constructing + and then decomposing a value for this purpose proves to be too + inefficient, then gdbarch_integer_to_address() can be called + directly. + + The use of `unsigned_address_type' in the code below refers to + the type of buf and has no bearing on the signedness of the + address being returned. */ + + result = value_as_address (value_from_longest + (unsigned_address_type (), + extract_unsigned_integer + (buf, + TARGET_ADDR_BIT / TARGET_CHAR_BIT))); + return result; } -- 2.7.4