[gcc r14-8522] testsuite, GDC: Update link flags [PR112861].

[gcc r14-8522] testsuite, GDC: Update link flags [PR112861].

[Iain D Sandoe]

https://gcc.gnu.org/g:d1d144d80f27f7a027ec8a05758555e7aa45462f

commit r14-8522-gd1d144d80f27f7a027ec8a05758555e7aa45462f
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Wed Jan 24 08:05:01 2024 +0000

    testsuite, GDC: Update link flags [PR112861].
    
    The regressions here are because we do not generate a runpath for
    the uninstalled libstdc++.  This patch updates the link flags handling
    to simplify it.
    
    We need to add options to locate both libgphobos 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 is to add a single -B/-L option for each needed
    path.
    
            PR target/112861
    
    gcc/testsuite/ChangeLog:
    
            * lib/gdc.exp: Decide on whether to present -B or -L to reference
            the paths to uninstalled libphobos and libstdc++ and use that to
            generate the link flags.

Diff:
---
 gcc/testsuite/lib/gdc.exp | 40 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/gcc/testsuite/lib/gdc.exp b/gcc/testsuite/lib/gdc.exp
index 3045aa82918e..3c284229609a 100644
--- a/gcc/testsuite/lib/gdc.exp
+++ b/gcc/testsuite/lib/gdc.exp
@@ -133,6 +133,28 @@ proc gdc_link_flags { paths } {
 	set include_cxx_flags 0
     }
 
+    # We need to add options to locate libgphobos 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 { $gccpath != "" } {
 	# Path to libgphobos.spec.
 	append flags "-B${gccpath}/libphobos/src "
@@ -143,7 +165,11 @@ proc gdc_link_flags { paths } {
 
 	if { [file exists "${gccpath}/libphobos/src/.libs/libgphobos.a"] \
 	     || [file exists "${gccpath}/libphobos/src/.libs/libgphobos.${shlib_ext}"] } {
-	    append flags "-L${gccpath}/libphobos/src/.libs "
+	    if { $target_wants_B_option } {
+		append flags "-B${gccpath}/libphobos/src/.libs "
+	    } else {
+		append flags "-L${gccpath}/libphobos/src/.libs "
+	    }
 	    append ld_library_path ":${gccpath}/libphobos/src/.libs"
 	}
 	# Static linking is default. If only the shared lib is available adjust
@@ -163,7 +189,11 @@ proc gdc_link_flags { paths } {
 	if $include_cxx_flags {
 	    if { [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.a"] \
 		 || [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.${shlib_ext}"] } {
-		append flags "-L${gccpath}/libstdc++-v3/src/.libs "
+		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"
 	    }
 	}
@@ -173,7 +203,11 @@ proc gdc_link_flags { paths } {
 
 	set libphobos [lookfor_file ${tool_root_dir} libgphobos]
 	if { $libphobos != "" } {
-	    append flags "-B${libphobos} -L${libphobos} "
+	    if { $target_wants_B_option } {
+	      append flags "-B${libphobos} "
+	    } else { 
+	      append flags " -L${libphobos} "
+	    }
 	    append ld_library_path ":${libphobos}"
 	}
 	set libiberty [lookfor_file ${tool_root_dir} libiberty]