[PATCH] gdb/testsuite: fix dw2-entry-pc.exp with ASLR

[Bratislav Filipovic <bfilipov@amd.com>]

Following Simon Marchi's fix for dw2-empty-inline-ranges.exp [1], this
test exhibits the same failure pattern when running in an environment
where GDB can't disable address space randomization (such as in a
container where that capability is removed) with a toolchain generating
position-independent executables.

The test does a first run to grab addresses of labels and function
boundaries (foo_middle, foo_start, foo_end, and range labels).  It then
crafts DWARF using these addresses across multiple test iterations.
When the executable is PIE and ASLR is active, the addresses in each
subsequent run don't match the addresses from the initial run.

The failure manifests in the 'maint info blocks' output comparisons,
where the expected addresses (from the first run) don't match the
actual addresses in the test runs.

The simplest fix, following Simon's approach, is to use "nopie" when
building the binaries.  This doesn't affect the effectiveness of the
test, which is exercising different ways DW_AT_entry_pc can be
expressed in DWARF.

Also, with a non-PIE executable, it is no longer necessary to run the
inferior before grabbing the addresses in the initial run, as they are
stable.  So remove that runto_main call.

[1] https://inbox.sourceware.org/gdb-patches/20260205204257.422150-1-simon.marchi@efficios.com/
---
 gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp b/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
index 441aa0fde1d..f7cc7f7c067 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
@@ -28,11 +28,7 @@ standard_testfile
 get_func_info foo
 
 if { [prepare_for_testing "failed to prepare" ${testfile} \
-	  [list ${srcfile}]] } {
-    return -1
-}
-
-if {![runto_main]} {
+	  [list ${srcfile}] {debug nopie}]} {
     return -1
 }
 
@@ -83,7 +79,7 @@ proc get_next_suffix {} {
 
 proc build_and_runto_main { suffix asm_file } {
     if {[prepare_for_testing "failed to prepare" "${::testfile}-${suffix}" \
-	     [list $::srcfile $asm_file] {nodebug}]} {
+	     [list $::srcfile $asm_file] {nodebug nopie}]} {
 	return false
     }
 
-- 
2.43.0