[PATCH 4/4] testsuite, gdb.btrace: fix 32-bit PIE false positives

[Markus Metzger via Gdb-patches <gdb-patches@sourceware.org>]

For 32-bit position independent executables, GCC generates an extra call to

    __x86.get_pc_thunk.<reg>

which appears in the function call history.  It is correct to appear there
but this confuses the tests, which check for an expected sequence of
functions.

Build with -no-pie -fno-pie to avoid this complication.

gdb/testsuite/ChangeLog:
2020-12-04  Markus Metzger  <markus.t.metzger@intel.com>

	* gdb.btrace/exception.exp: Build with -no-pie -fno-pie.
	* gdb.btrace/function_call_history.exp: Likewise.
	* gdb.btrace/unknown_functions.exp: Likewise.
---
 gdb/testsuite/gdb.btrace/exception.exp             | 5 ++++-
 gdb/testsuite/gdb.btrace/function_call_history.exp | 5 ++++-
 gdb/testsuite/gdb.btrace/unknown_functions.exp     | 9 ++++++---
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/gdb/testsuite/gdb.btrace/exception.exp b/gdb/testsuite/gdb.btrace/exception.exp
index 0d242227938..b515de87b01 100755
--- a/gdb/testsuite/gdb.btrace/exception.exp
+++ b/gdb/testsuite/gdb.btrace/exception.exp
@@ -22,8 +22,11 @@ if { [skip_btrace_tests] } {
     return -1
 }
 
+# We expect a specific function call history.  This gets messed up with
+# PIE on 32-bit.
 standard_testfile exception.cc
-if [prepare_for_testing "failed to prepare" $testfile $srcfile {c++ debug}] {
+if [prepare_for_testing "failed to prepare" $testfile $srcfile \
+	{additional_flags=-fno-pie ldflags=-no-pie c++ debug}] {
     return -1
 }
 
diff --git a/gdb/testsuite/gdb.btrace/function_call_history.exp b/gdb/testsuite/gdb.btrace/function_call_history.exp
index 51536ff6035..ea22692bb47 100644
--- a/gdb/testsuite/gdb.btrace/function_call_history.exp
+++ b/gdb/testsuite/gdb.btrace/function_call_history.exp
@@ -22,8 +22,11 @@ if { [skip_btrace_tests] } {
     return -1
 }
 
+# We expect a specific function call history.  This gets messed up with
+# PIE on 32-bit.
 standard_testfile
-if [prepare_for_testing "failed to prepare" $testfile {} {debug}] {
+if [prepare_for_testing "failed to prepare" $testfile {} \
+	{additional_flags=-fno-pie ldflags=-no-pie debug}] {
     return -1
 }
 
diff --git a/gdb/testsuite/gdb.btrace/unknown_functions.exp b/gdb/testsuite/gdb.btrace/unknown_functions.exp
index 4db9c70f496..76803319d9f 100644
--- a/gdb/testsuite/gdb.btrace/unknown_functions.exp
+++ b/gdb/testsuite/gdb.btrace/unknown_functions.exp
@@ -24,9 +24,12 @@ if { [skip_btrace_tests] } {
 
 standard_testfile
 
-# discard local symbols
-set ldflags "additional_flags=-Wl,-x"
-if [prepare_for_testing "failed to prepare" $testfile $srcfile $ldflags] {
+# We expect a specific function call history.  This gets messed up with
+# PIE on 32-bit.
+#
+# Also discard local symbols.
+if [prepare_for_testing "failed to prepare" $testfile $srcfile \
+	{additional_flags=-fno-pie additional_flags=-Wl,-x ldflags=-no-pie}] {
     return -1
 }
 
-- 
2.26.2

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