libctf: don't run tests requiring deduplicating linker unless one is in use

Before now, we were relying on gcc -B to repoint GCC at our freshly-built
linker, and assuming we could use this to run tests that do linker dedup.

This is, alas, not reliable (building --with-ld=/an/absolute/path bypasses
-B searches for the linker), and we would like the libctf tests in
particular to not fail if the compiler uses a linker that cannot deduplicate
(simply skipping such tests).

Add a new testsuite function that tries to link one of the lookup tests'
testcases (which is known to produce conflicting types, i.e. a dict with
per-translation-unit children) and then does an objdump and greps it for
signs of the per-translation-unit children.  If there are none, the linker
probably just concatenated the sections: i.e., it is not a linker that
can deduplicate CTF.

libctf/
	PR libctf/33162
	* testsuite/config/default.exp (objdump): Introduce.
	(OBJDUMPFLAGS): Likewise.
	* testsuite/lib/ctf-lib.exp (check_ctf_linker_dedup): New.
	* testsuite/libctf-lookup/lookup.exp: Use it.
	* testsuite/libctf-regression/libctf-repeat-cu.exp: Likewise.
	* testsuite/libctf-regression/regression.exp: Likewise.

diff --git a/libctf/testsuite/config/default.exp b/libctf/testsuite/config/default.exp
index f24482620b6c2d0f5c82b3585c432f0ccc1da14d..d5e51f418cadb0075e5001c51bde9d5d4278498b 100644 (file)
--- a/libctf/testsuite/config/default.exp
+++ b/libctf/testsuite/config/default.exp
@@ -34,6 +34,10 @@ if ![info exists as] then {
     set as [findfile $base_dir/../gas/as-new $base_dir/../gas/as-new [transform as]]
 }
 
+if ![info exists objdump] then {
+    set objdump [findfile $base_dir/../binutils/objdump]
+}
+
 remote_exec host "mkdir -p tmpdir"
 
 # Make symlinks from tmpdir/libctf to the linker and assembler in the
@@ -63,10 +67,12 @@ if {![info exists CFLAGS_FOR_TARGET]} {
 if ![info exists AR] then {
     set AR [findfile $base_dir/../binutils/ar]
 }
-
 if {![info exists OBJDUMP]} {
     set OBJDUMP [findfile $base_dir/../binutils/objdump]
 }
+if ![info exists OBJDUMPFLAGS] then {
+    set OBJDUMPFLAGS {}
+}
 
 # load the utility procedures
 load_lib ctf-lib.exp

diff --git a/libctf/testsuite/lib/ctf-lib.exp b/libctf/testsuite/lib/ctf-lib.exp
index 64d2a40ad9f219b1956451714a4690c151fe316f..4df6619606b99ee75b6d7ceb10b42f80b610b3bd 100644 (file)
--- a/libctf/testsuite/lib/ctf-lib.exp
+++ b/libctf/testsuite/lib/ctf-lib.exp
@@ -20,6 +20,51 @@
 
 load_file $srcdir/../../ld/testsuite/lib/ld-lib.exp
 
+# Returns true if the target linker deduplicates CTF.
+proc check_ctf_linker_dedup { } {
+    global ctf_linker_dedup_saved
+
+    if {![info exists ctf_linker_dedup_saved]} {
+       set ctf_linker_dedup_saved 0
+
+       if ([check_ctf_available]) {
+           global objdump srcdir
+
+           set basename "tmpdir/ctf_linker_dedups[pid]"
+           compile_one_cc $srcdir/libctf-lookup/ambiguous-struct-A.c ${basename}-A.o "-gctf -fPIC -c"
+           compile_one_cc $srcdir/libctf-lookup/ambiguous-struct-B.c ${basename}-B.o "-gctf -fPIC -c"
+           compile_one_cc "${basename}-A.o ${basename}-B.o" $basename.so "-gctf -fPIC -shared"
+           if {! [remote_file host exists $basename.so] } {
+               return 0
+           }
+
+           # Don't use run_host_cmd: it dumps the entire output into the log,
+           # even on success.
+           set cmdret [remote_exec host [concat sh -c [list "$objdump --ctf $basename.so >dump.out 2>dump.err"]] "" "/dev/null"]
+           set cmdret [lindex $cmdret 0]
+           remote_upload host "dump.out"
+           remote_upload host "dump.err"
+           set dump_out [prune_warnings [file_contents "dump.out"]]
+           set dump_err [prune_warnings [file_contents "dump.err"]]
+           remote_file host delete "dump.out" "dump.err"
+           remote_file build delete "dump.out" "dump.err"
+
+           if {$cmdret != 0} {
+               verbose -log "failed with $cmdret: stderr: $dump_err"
+               verbose -log "output: $dump_out"
+               return 0;
+           }
+
+           remote_file host delete $basename.so ${basename}-A.o ${basename}-B.o
+           if [regexp {CTF archive member: } $dump_out] {
+               set ctf_linker_dedup_saved 1
+           }
+       }
+    }
+    return $ctf_linker_dedup_saved
+}
+
+
 proc run_native_host_cmd { command } {
     global link_output
     global ld

diff --git a/libctf/testsuite/libctf-lookup/lookup.exp b/libctf/testsuite/libctf-lookup/lookup.exp
index a8b09c2df78ac916f242d6102d8d500f7d0f6005..d15c315729de991c58d1f54b1681290b6fc63027 100644 (file)
--- a/libctf/testsuite/libctf-lookup/lookup.exp
+++ b/libctf/testsuite/libctf-lookup/lookup.exp
@@ -28,6 +28,11 @@ if {![check_ctf_available]} {
     return 0
 }
 
+if {![check_ctf_linker_dedup]} {
+    unsupported "no CTF deduplication support in the linker"
+    return 0
+}
+
 if {[info exists env(LC_ALL)]} {
     set old_lc_all $env(LC_ALL)
 }

diff --git a/libctf/testsuite/libctf-regression/libctf-repeat-cu.exp b/libctf/testsuite/libctf-regression/libctf-repeat-cu.exp
index e29cf63fce95713b1c4177311c47f9484c4e6b91..7c19fe8f6a75a71374f70343850d66becd2d546b 100644 (file)
--- a/libctf/testsuite/libctf-regression/libctf-repeat-cu.exp
+++ b/libctf/testsuite/libctf-regression/libctf-repeat-cu.exp
@@ -37,6 +37,11 @@ if {![check_ctf_available]} {
     return 0
 }
 
+if {![check_ctf_linker_dedup]} {
+    unsupported "no CTF deduplication support in the linker"
+    return 0
+}
+
 if {[info exists env(LC_ALL)]} {
     set old_lc_all $env(LC_ALL)
 }

diff --git a/libctf/testsuite/libctf-regression/regression.exp b/libctf/testsuite/libctf-regression/regression.exp
index e4b63473691daeb9fa2fa650a5da61395dcc39f1..0270cca0cba2b960cfedcdb0ca6f104db82aec06 100644 (file)
--- a/libctf/testsuite/libctf-regression/regression.exp
+++ b/libctf/testsuite/libctf-regression/regression.exp
@@ -23,6 +23,11 @@ if {![check_ctf_available]} {
     return 0
 }
 
+if {![check_ctf_linker_dedup]} {
+    unsupported "no CTF deduplication support in the linker"
+    return 0
+}
+
 if ![is_elf_format] {
     unsupported "CTF needs bfd changes to be emitted on non-ELF"
     return 0