[gcc r11-11336] testsuite: Fix weak_undefined handling on Darwin

[Iain D Sandoe <iains@gcc.gnu.org>]

https://gcc.gnu.org/g:d79d1073c444ceb85b3cd2f55be7b4dfe598d287

commit r11-11336-gd79d1073c444ceb85b3cd2f55be7b4dfe598d287
Author: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
Date:   Tue Mar 28 10:40:05 2023 +0200

    testsuite: Fix weak_undefined handling on Darwin
    
    The patch that introduced the weak_undefined effective-target keyword
    and corresponding dg-add-options support
    
    commit 378ec7b87a5265dbe2d489c245fac98ef37fa638
    Author: Alexandre Oliva <oliva@adacore.com>
    Date:   Thu Mar 23 00:45:05 2023 -0300
    
        [testsuite] test for weak_undefined support and add options
    
    badly broke the affected tests on macOS like so:
    
    ERROR: gcc.dg/addr_equal-1.c: unknown dg option: 89 for " dg-add-options 5 weak_undefined "
    ERROR: gcc.dg/addr_equal-1.c: unknown dg option: 89 for " dg-add-options 5 weak_undefined "
    
    add_options_for_weak_undefined tries to call an non-existant proc "89".
    Even after fixing this by escaping the brackets, two tests still failed to
    link since they lacked the corresponding calls do dg-add-options
    weak_undefined.
    
    Tested on x86_64-apple-darwin20.6.0 and i386-pc-solaris2.11.
    
    2023-03-27  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
    
            gcc/testsuite:
            * lib/target-supports.exp (add_options_for_weak_undefined): Escape
            brackets.
            * gcc.dg/visibility-22.c: Add weak_undefined options.
    
    (cherry picked from commit 8443f42f05f9026dadad1236b9e44ec294c70337)

Diff:
---
 gcc/testsuite/gcc.dg/visibility-22.c  |  1 +
 gcc/testsuite/lib/target-supports.exp | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/visibility-22.c b/gcc/testsuite/gcc.dg/visibility-22.c
index e2b78d1c7fd..9123b350b2e 100644
--- a/gcc/testsuite/gcc.dg/visibility-22.c
+++ b/gcc/testsuite/gcc.dg/visibility-22.c
@@ -3,6 +3,7 @@
 /* { dg-require-visibility "" } */
 /* { dg-require-effective-target weak_undefined } */
 /* { dg-options "-O2 -fPIC" { target fpic } } */
+/* { dg-add-options weak_undefined } */
 
 extern void foo () __attribute__((weak,visibility("hidden")));
 int
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index a09606e4497..63a5f5579be 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -348,6 +348,18 @@ proc check_weak_available { } {
     }
 }
 
+# return options to add to enable weak undefined symbols.
+
+proc add_options_for_weak_undefined { flags } {
+    if { [istarget *-*-darwin*] } {
+	lappend flags "-Wl,-undefined,dynamic_lookup"
+	if { [istarget *-*-darwin\[89\]*] } {
+	    lappend flags "-Wl,-flat_namespace"
+	}
+    }
+    return $flags
+}
+
 # return 1 if weak undefined symbols are supported.
 
 proc check_effective_target_weak_undefined { } {