[gcc r14-8733] testsuite, Objective-C++: Update link flags [PR112863].

[gcc r14-8733] testsuite, Objective-C++: Update link flags [PR112863].

[Iain D Sandoe]

https://gcc.gnu.org/g:bec7100445f07259d5df69c9f442ea72a90fc37e

commit r14-8733-gbec7100445f07259d5df69c9f442ea72a90fc37e
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Wed Jan 24 08:05:41 2024 +0000

    testsuite, Objective-C++: Update link flags [PR112863].
    
    These regressions are caused by missing or duplicate runpaths which
    now fire linker warnings.
    
    We need to add options to locate libobjc (and on Darwin libobjc-gnu)
    along with libstdc++.
    Usually '-L' options are added to point to the relevant directories for
    the uninstalled libraries.
    
    In cases where libraries are available as both shared and convenience
    some additional checks are made.
    
    For some targets -static-xxxx options are handled by specs substitution
    and need a '-B' option rather than '-L'.  For Darwin, when embedded
    runpaths are in use (the default for all versions after macOS 10.11),
    '-B' is also needed to provide the runpath.
    
    When '-B' is used, this results in a '-L' for each path that exists (so
    that appending a '-L' as well is a needless duplicate).  There are also
    cases where tools warn for duplicates, leading to spurious fails.
    
            PR target/112863
    
    gcc/testsuite/ChangeLog:
    
            * lib/obj-c++.exp: Decide on whether to present -B or -L to
            reference the paths to uninstalled libobjc/libobjc-gnu and
            libstdc++ and use that to generate the link flags.

Diff:
---
 gcc/testsuite/lib/obj-c++.exp | 69 ++++++++++++++++++++++++++-----------------
 1 file changed, 42 insertions(+), 27 deletions(-)

diff --git a/gcc/testsuite/lib/obj-c++.exp b/gcc/testsuite/lib/obj-c++.exp
index 397b70cb96ad..854dc264f9d0 100644
--- a/gcc/testsuite/lib/obj-c++.exp
+++ b/gcc/testsuite/lib/obj-c++.exp
@@ -110,34 +110,43 @@ proc obj-c++_link_flags { paths } {
     set shlib_ext [get_shlib_extension]
     verbose "shared lib extension: $shlib_ext"
 
+    # We need to add options to locate libobjc/libobjc-gnu and libstdc++
+    # Usually '-L' options are added to point to the relevant directories for
+    # the uninstalled libraries.
+
+    # In cases where libraries are available as both shared and convenience
+    # some additional checks are made.
+
+    # For some targets -static-xxxx options are handled by specs substitution
+    # and need a '-B' option rather than '-L'.  For Darwin, when embedded
+    # runpaths are in use (the default for all versions after macOS 10.11),
+    # '-B' is also needed to provide the runpath.
+    # When '-B' is used, this results in a '-L' for each path that exists (so
+    # that appending a '-L' as well is a needless duplicate).  There are also
+    # cases where tools warn for duplicates, leading to spurious fails.
+    # Therefore the objective of the code below is to add just one '-L' or
+    # '-B' for each of the libraries.
+
+    set target_wants_B_option 0
+    if { [istarget *-*-darwin9* ] || [istarget *-*-darwin\[12\]* ] } {
+      set target_wants_B_option 1
+    }
+
     if { $gccpath != "" } {
-      if [file exists "${gccpath}/lib/libstdc++.a"] {
-          append ld_library_path ":${gccpath}/lib"
-      }
-      if [file exists "${gccpath}/libg++/libg++.a"] {
-          append flags " -L${gccpath}/libg++ "
-          append ld_library_path ":${gccpath}/libg++"
-      }
-      if [file exists "${gccpath}/libstdc++/libstdc++.a"] {
-          append flags " -L${gccpath}/libstdc++ "
-          append ld_library_path ":${gccpath}/libstdc++"
-      }
-      if [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.a"] {
-          # Allow for %s spec substitutions
-          append flags " -B${gccpath}/libstdc++-v3/src/.libs "
-          append flags " -L${gccpath}/libstdc++-v3/src/.libs "
-          append ld_library_path ":${gccpath}/libstdc++-v3/src/.libs"
-      }
-      # Look for libstdc++.${shlib_ext}.
-      if [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.${shlib_ext}"] {
-	  # Allow for %s spec substitutions
-	  append flags " -B${gccpath}/libstdc++-v3/src/.libs "
-	  append flags " -L${gccpath}/libstdc++-v3/src/.libs "
-	  append ld_library_path ":${gccpath}/libstdc++-v3/src/.libs"
+      if { [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.a"] ||
+	  [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.${shlib_ext}"] } {
+		if { $target_wants_B_option } {
+		    append flags "-B${gccpath}/libstdc++-v3/src/.libs "
+		} else {
+		    append flags "-L${gccpath}/libstdc++-v3/src/.libs "
+		}
+		append ld_library_path ":${gccpath}/libstdc++-v3/src/.libs"
       }
+
       if [file exists "${gccpath}/libiberty/libiberty.a"] {
           append flags " -L${gccpath}/libiberty "
       }
+
       if [file exists "${gccpath}/librx/librx.a"] {
           append flags " -L${gccpath}/librx "
       }
@@ -159,9 +168,11 @@ proc obj-c++_link_flags { paths } {
 
       if { $libobjc_dir != "" } {
 	  set libobjc_dir [file dirname ${libobjc_dir}]
-	  # Allow for %s spec substitutions
-	  append flags " -B${libobjc_dir} "
-	  append flags " -L${libobjc_dir} "
+	  if { $target_wants_B_option } {
+	    append flags "-B${libobjc_dir} "
+	  } else {
+	    append flags "-L${libobjc_dir} "
+	  }
 	  append ld_library_path ":${libobjc_dir}"
       }
       append ld_library_path \
@@ -176,7 +187,11 @@ proc obj-c++_link_flags { paths } {
       }
       set libstdcpp [lookfor_file ${tool_root_dir} libstdc++];
       if { $libstdcpp != "" } {
-          append flags "-L${libstdcpp} ";
+	  if { $target_wants_B_option } {
+	    append flags "-B${libstdcpp} "
+	  } else {
+	    append flags "-L${libstdcpp} "
+	  }
           append ld_library_path ":${libstdcpp}"
       }
       set libiberty [lookfor_file ${tool_root_dir} libiberty];