PowerPC: fix for gdb.base/eh_return.exp

Disable the Traceback Table generation on PowerPC for this test.  The
Traceback Table consists of a series of bit fields to indicate things like
the Traceback Table version, language, and specific information about the
function.  The Traceback Table is generated following the end of the code
for every function by default.  The Traceback Table is defined in the
PowerPC ELF ABI and is intended to support debuggers and exception
handlers.  The Traceback Table is displayed in the disassembly of functions
by default and is part of the function length.  The table is typically
interpreted by the disassembler as data represented by .long xxx entries.

Generation of the Traceback Table is disabled in this test using the
PowerPC specific gcc compiler option -mtraceback=no, the xlc option
additional_flags-qtable=none and the clang optons
 -mllvm -xcoff-traceback-table=false.  Disabling the Traceback Table
generation in this test results in the gdb_test_multiple statement
correctly locating the address of the bclr instruction before the statement
"End of assembler dump." in the disassembly output.

1 files changed, 35 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.base/eh_return.exp b/gdb/testsuite/gdb.base/eh_return.exp
index df55dbc..6e4b9bd 100644
--- a/gdb/testsuite/gdb.base/eh_return.exp
+++ b/gdb/testsuite/gdb.base/eh_return.exp
@@ -18,8 +18,42 @@
 
 standard_testfile
 
+# Set compiler flags.
+if {[istarget "powerpc*"]} then {
+    # PowerPC generates a Traceback Table, as defined in the PPC64 ABI,
+    # following each function by default.  The Traceback Table information is
+    # typically interpreted by the disassembler as data represented with
+    # .long xxxx following the last instruction in the function.  For example:
+    #
+    #   Dump of assembler code for function eh2:
+    #   0x00000000100009e0 <+0>:     lis     r2,4098
+    #   ...
+    #   0x0000000010000b04 <+292>:   add     r1,r1,r10
+    #   0x0000000010000b08 <+296>:   blr
+    #   0x0000000010000b0c <+300>:   .long 0x0
+    #   0x0000000010000b10 <+304>:   .long 0x1000000
+    #   0x0000000010000b14 <+308>:   .long 0x1000180
+    #   End of assembler dump.
+    #
+    # Disable the Traceback Table generation, using the PowerPC specific
+    # compiler option, so the test gdb_test_multiple "disassemble eh2" will
+    # locate the address of the blr instruction not the last .long statement.
+    if { [test_compiler_info "gcc-*"] } {
+	set compile_flags {debug nopie additional_flags=-mtraceback=no}
+    } elseif { [test_compiler_info "xlc-*"] } {
+	set compile_flags {debug nopie additional_flags=-qtbtable=none}
+    } elseif { [test_compiler_info "clang-*"] } {
+	set compile_flags [list debug nopie additional_flags=-mllvm \
+			       additional_flags=-xcoff-traceback-table=false]
+    } else {
+	set compile_flags {debug nopie }
+    }
+} else {
+    set compile_flags {debug nopie}
+}
+
 if {[prepare_for_testing "failed to prepare" $testfile $srcfile \
-	 {debug nopie}]} {
+	 $compile_flags]} {
     return -1
 }