[PATCH] testsuite: Fix mistransformed gcov

[Hans-Peter Nilsson <hp@axis.com>]

How was r13-2619-g34b9a03353d3fd "gcov: Respect triplet when looking
for gcov" tested?  I'm having a hard time believing it was tested with
a *cross-compiler* *in-build-tree*.  I think it was only tested for
the special-case of an installed cross-compiler; not even with a
native build exercising the false branch (see patch), considering that
a breaking typo ("}" vs "]") snuck by in the first revision, before
commit.

I guess reviewers forgot to ask that, but it's really on the
submitter; it's a general requirement for patches to say how it was
tested.  Usually no more is needed than "tested with a cross-compiler
for ..., no regressions" (implying running twice and comparing results
before and after the patch).

In this case, when adjusting test-framework bits, a little more care
and mentioned details about how it was tested, would have been in
order.  It's likely it'd have shown that an uninstalled in-tree cross
(an IMHO more expected case) wasn't tested, which that patch broke for
the one gcov invocation that the testsuite does for cross-builds
(IIUC).

It can be said like this: I tested *this* patch as follows (all
directory names below manually redacted), showing no regressions and
fixing the regression for the in-tree cross build;

For a native build (x86_64, Debian 11):
- In the gcc build directory:
 make check RUNTESTFLAGS=gcov.exp

- In an empty new directory after native installation in /pre.
/gccsrc/top/contrib/test_installed --prefix=/pre gcov.exp

- Also, for good measure (mentioned somewhere in the installation
documentation) native:
for tool in gcc g++ ; do env PATH=/pre/bin:$PATH runtest \
 --tool $tool --srcdir=/gccsrc/top/gcc/testsuite gcov.exp; done

For a cris-elf cross:
- In the gcc build directory:
make check 'RUNTESTFLAGS=--target_board=cris-sim gcov.exp'

- In an empty new directory after installation in /pre.
/gccsrc/top/contrib/test_installed --with-gcc=/pre/bin/cris-elf-gcc \
 --with-g++=/pre/bin/cris-elf-g++ --with-gfortran=/pre/bin/cris-elf-gfortran \
 --target=cris-elf --target_board=cris-sim gcov.exp

Ok to commit?

brgds, H-P
PS. Beware that the proc name may be up for bikeshedding.

---- 8< -------- 8< -------- 8< -------- 8< ----

In commit r13-2619-g34b9a03353d3fd, [transform] was applied to all
invocations of gcov, for both out-of-tree and in-tree testing.
For in-tree cross builds, this means gcov was called as
"/path/to/gccobj/gcc/target-tuple-gcov" gcov-pr94029.c which is
incorrect, as it's there "/path/to/gccobj/gcc/gcov" until it's
installed.  This caused a testsuite failure, like:

Running /x/gcc/gcc/testsuite/gcc.misc-tests/gcov.exp ...
FAIL: gcc.misc-tests/gcov-pr94029.c gcov failed: spawn failed

To avoid cumbersome conditionals, use a dedicated new helper function.

gcc/testsuite:
	* lib/gcc-dg.exp (gcc-transform-out-of-tree): New proc.
	* g++.dg/gcov/gcov.exp, gcc.misc-tests/gcov.exp: Call
	gcc-transform-out-of-tree instead of transform.
---
 gcc/testsuite/g++.dg/gcov/gcov.exp    |  4 ++--
 gcc/testsuite/gcc.misc-tests/gcov.exp |  4 ++--
 gcc/testsuite/lib/gcc-dg.exp          | 13 +++++++++++++
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/g++.dg/gcov/gcov.exp b/gcc/testsuite/g++.dg/gcov/gcov.exp
index 04e7a0164865..c9f20958836b 100644
--- a/gcc/testsuite/g++.dg/gcov/gcov.exp
+++ b/gcc/testsuite/g++.dg/gcov/gcov.exp
@@ -24,9 +24,9 @@ global GXX_UNDER_TEST
 
 # Find gcov in the same directory as $GXX_UNDER_TEST.
 if { ![is_remote host] && [string match "*/*" [lindex $GXX_UNDER_TEST 0]] } {
-    set GCOV [file dirname [lindex $GXX_UNDER_TEST 0]]/[transform gcov]
+    set GCOV [file dirname [lindex $GXX_UNDER_TEST 0]]/[gcc-transform-out-of-tree gcov]
 } else {
-    set GCOV [transform gcov]
+    set GCOV [gcc-transform-out-of-tree gcov]
 }
 
 # Initialize harness.
diff --git a/gcc/testsuite/gcc.misc-tests/gcov.exp b/gcc/testsuite/gcc.misc-tests/gcov.exp
index b8e9661aa537..90ceec46e0f0 100644
--- a/gcc/testsuite/gcc.misc-tests/gcov.exp
+++ b/gcc/testsuite/gcc.misc-tests/gcov.exp
@@ -24,9 +24,9 @@ global GCC_UNDER_TEST
 
 # For now find gcov in the same directory as $GCC_UNDER_TEST.
 if { ![is_remote host] && [string match "*/*" [lindex $GCC_UNDER_TEST 0]] } {
-    set GCOV [file dirname [lindex $GCC_UNDER_TEST 0]]/[transform gcov]
+    set GCOV [file dirname [lindex $GCC_UNDER_TEST 0]]/[gcc-transform-out-of-tree gcov]
 } else {
-    set GCOV [transform gcov]
+    set GCOV [gcc-transform-out-of-tree gcov]
 }
 
 # Initialize harness.
diff --git a/gcc/testsuite/lib/gcc-dg.exp b/gcc/testsuite/lib/gcc-dg.exp
index 23ec038f41eb..2910c9ce0998 100644
--- a/gcc/testsuite/lib/gcc-dg.exp
+++ b/gcc/testsuite/lib/gcc-dg.exp
@@ -1429,5 +1429,18 @@ proc scan-symbol-not { args } {
     }
 }
 
+# Transform a tool-name to its canonical-target-name by "transform"
+# (which may return the original name for native targets) but only if
+# testing out-of-tree.  When in-tree, the tool is expected to be found
+# by its original name, typically with some build-directory prefix
+# prepended by the caller.
+proc gcc-transform-out-of-tree { args } {
+    global TESTING_IN_BUILD_TREE
+    if { [info exists TESTING_IN_BUILD_TREE] } {
+	return $args;
+    }
+    return [transform $args]
+}
+
 set additional_prunes ""
 set dg_runtest_extra_prunes ""
-- 
2.30.2