diff --git a/gcc/testsuite/g++.dg/asan/asan.exp b/gcc/testsuite/g++.dg/asan/asan.exp
index 9297bb55eb1..f078bc37800 100644
--- a/gcc/testsuite/g++.dg/asan/asan.exp
+++ b/gcc/testsuite/g++.dg/asan/asan.exp
@@ -22,7 +22,8 @@ load_lib asan-dg.exp
 
 # Initialize `dg'.
 dg-init
-asan_init
+# libasan uses libstdc++ but we assume that's added by the g++ impl.
+asan_init 0
 
 # Main loop.
 if [check_effective_target_fsanitize_address] {
diff --git a/gcc/testsuite/g++.dg/hwasan/hwasan.exp b/gcc/testsuite/g++.dg/hwasan/hwasan.exp
index 597033e01d5..12a7a3570a0 100644
--- a/gcc/testsuite/g++.dg/hwasan/hwasan.exp
+++ b/gcc/testsuite/g++.dg/hwasan/hwasan.exp
@@ -22,7 +22,8 @@ load_lib hwasan-dg.exp
 
 # Initialize `dg'.
 dg-init
-hwasan_init
+# libhwasan uses libstdc++ but we assume that's added by the g++ impl.
+hwasan_init 0
 
 # Main loop.
 if [check_effective_target_fsanitize_hwaddress] {
diff --git a/gcc/testsuite/gcc.dg/asan/asan.exp b/gcc/testsuite/gcc.dg/asan/asan.exp
index 10c69731fbf..6b8ebf07eae 100644
--- a/gcc/testsuite/gcc.dg/asan/asan.exp
+++ b/gcc/testsuite/gcc.dg/asan/asan.exp
@@ -24,7 +24,8 @@ load_lib asan-dg.exp
 
 # Initialize `dg'.
 dg-init
-asan_init
+# libasan uses libstdc++ so make sure we provide paths for it.
+asan_init 1
 
 # Main loop.
 if [check_effective_target_fsanitize_address] {
diff --git a/gcc/testsuite/gcc.dg/hwasan/hwasan.exp b/gcc/testsuite/gcc.dg/hwasan/hwasan.exp
index 802f1712296..88327d3b223 100644
--- a/gcc/testsuite/gcc.dg/hwasan/hwasan.exp
+++ b/gcc/testsuite/gcc.dg/hwasan/hwasan.exp
@@ -24,7 +24,8 @@ load_lib hwasan-dg.exp
 
 # Initialize `dg'.
 dg-init
-hwasan_init
+# libhwasan uses libstdc++ so make sure we provide paths for it.
+hwasan_init 1
 
 # Main loop.
 if [check_effective_target_fsanitize_hwaddress] {
diff --git a/gcc/testsuite/gdc.dg/asan/asan.exp b/gcc/testsuite/gdc.dg/asan/asan.exp
index 72b36696c4d..89c6bf35ae4 100644
--- a/gcc/testsuite/gdc.dg/asan/asan.exp
+++ b/gcc/testsuite/gdc.dg/asan/asan.exp
@@ -20,7 +20,8 @@ load_lib asan-dg.exp
 
 # Initialize `dg'.
 dg-init
-asan_init
+# libasan uses libstdc++ so make sure we provide paths for it.
+asan_init 1
 
 # Main loop.
 if [check_effective_target_fsanitize_address] {
diff --git a/gcc/testsuite/gfortran.dg/asan/asan.exp b/gcc/testsuite/gfortran.dg/asan/asan.exp
index 25cd19f6133..a1576381e61 100644
--- a/gcc/testsuite/gfortran.dg/asan/asan.exp
+++ b/gcc/testsuite/gfortran.dg/asan/asan.exp
@@ -27,7 +27,8 @@ load_lib asan-dg.exp
 
 # Initialize `dg'.
 dg-init
-asan_init
+# libasan uses libstdc++ so make sure we provide paths for it.
+asan_init 1
 
 # Main loop.
 if [check_effective_target_fsanitize_address] {
diff --git a/gcc/testsuite/lib/asan-dg.exp b/gcc/testsuite/lib/asan-dg.exp
index beb49e500eb..6bd3c211611 100644
--- a/gcc/testsuite/lib/asan-dg.exp
+++ b/gcc/testsuite/lib/asan-dg.exp
@@ -61,7 +61,7 @@ proc asan_include_flags {} {
 # (originally from g++.exp)
 #
 
-proc asan_link_flags_1 { paths lib } {
+proc asan_link_flags_1 { paths lib need_stdcxx} {
     global srcdir
     global ld_library_path
     global shlib_ext
@@ -73,6 +73,10 @@ proc asan_link_flags_1 { paths lib } {
     set shlib_ext [get_shlib_extension]
     set ${lib}_saved_library_path $ld_library_path
 
+    # Providing -B instead of -L means that it works for targets that use
+    # spec substitution for handling -static-xxxxx, it also works for targets
+    # the use the startfile paths to provide a runpath for uninstalled test.
+    # Each -B option will produce a -L on the link line (for paths that exist).
     if { $gccpath != "" } {
       if { [file exists "${gccpath}/libsanitizer/${lib}/.libs/lib${lib}.a"]
 	   || [file exists "${gccpath}/libsanitizer/${lib}/.libs/lib${lib}.${shlib_ext}"] } {
@@ -81,6 +85,12 @@ proc asan_link_flags_1 { paths lib } {
 	  append flags " -B${gccpath}/libsanitizer/${lib}/.libs "
 	  append ld_library_path ":${gccpath}/libsanitizer/${lib}/.libs"
       }
+      # libasan links to libstdc++, so we must include it for C testcases.
+      if { $need_stdcxx && ( [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.a"]
+	   || [file exists "${gccpath}/libstdc++-v3/src/.libs/libstdc++.${shlib_ext}"] ) } {
+	append flags " -B${gccpath}/libstdc++-v3/src/.libs "
+	append ld_library_path ":${gccpath}/libstdc++-v3/src/.libs"
+      }      
     } else {
       global tool_root_dir
 
@@ -96,8 +106,8 @@ proc asan_link_flags_1 { paths lib } {
     return "$flags"
 }
 
-proc asan_link_flags { paths } {
-    return [asan_link_flags_1 $paths asan]
+proc asan_link_flags { paths need_stdcxx } {
+    return [asan_link_flags_1 $paths asan $need_stdcxx]
 }
 
 #
@@ -113,12 +123,13 @@ proc asan_init { args } {
 
     setenv ASAN_OPTIONS "color=never"
 
+    set needs_cxx [lindex $args 0]
     set link_flags ""
     if ![is_remote host] {
 	if [info exists TOOL_OPTIONS] {
-	    set link_flags "[asan_link_flags [get_multilibs ${TOOL_OPTIONS}]]"
+	    set link_flags "[asan_link_flags [get_multilibs ${TOOL_OPTIONS}] $needs_cxx]"
 	} else {
-	    set link_flags "[asan_link_flags [get_multilibs]]"
+	    set link_flags "[asan_link_flags [get_multilibs] $needs_cxx]"
 	}
     }
 
diff --git a/gcc/testsuite/lib/hwasan-dg.exp b/gcc/testsuite/lib/hwasan-dg.exp
index 8d66b4db3e3..33c9a7ce274 100644
--- a/gcc/testsuite/lib/hwasan-dg.exp
+++ b/gcc/testsuite/lib/hwasan-dg.exp
@@ -100,8 +100,8 @@ proc hwasan_include_flags {} {
 # (implementation in asan-dg.exp)
 #
 
-proc hwasan_link_flags { paths } {
-    return [asan_link_flags_1 $paths hwasan]
+proc hwasan_link_flags { paths needs_cxx } {
+    return [asan_link_flags_1 $paths hwasan $needs_cxx]
 }
 
 #
@@ -114,6 +114,7 @@ proc hwasan_init { args } {
     global TOOL_OPTIONS
     global hwasan_saved_TEST_ALWAYS_FLAGS
     global hwasan_saved_ALWAYS_CXXFLAGS
+    set needs_cxx [lindex $args 0]
 
     setenv HWASAN_OPTIONS "random_tags=0"
 
@@ -126,9 +127,9 @@ proc hwasan_init { args } {
     set link_flags ""
     if ![is_remote host] {
 	if [info exists TOOL_OPTIONS] {
-	    set link_flags "[hwasan_link_flags [get_multilibs ${TOOL_OPTIONS}]]"
+	    set link_flags "[hwasan_link_flags [get_multilibs ${TOOL_OPTIONS}] $needs_cxx]"
 	} else {
-	    set link_flags "[hwasan_link_flags [get_multilibs]]"
+	    set link_flags "[hwasan_link_flags [get_multilibs] $needs_cxx]"
 	}
     }
 
