[PATCH] libgcc: Add support for --disable-libgcov

[PATCH] libgcc: Add support for --disable-libgcov

[Rasmus Villemoes]

When trying to build gcc 6.4.0 targeting VxWorks 5.5, I ran into libgcov
not building against the VxWorks system headers - there are multiple
issues such as

gcc-src/libgcc/../gcc/gcov-io.c:78:3: warning: implicit declaration of function 'getpid' [-Wimplicit-function-declaration]
   s_flock.l_pid = getpid ();
   ^

gcc-src/libgcc/libgcov.c:139:9: warning: implicit declaration of function 'access' [-Wimplicit-function-declaration]
         if (access (filename, F_OK) == -1
         ^
gcc-src/libgcc/libgcov.c:139:31: error: 'F_OK' undeclared (first use in this function)
         if (access (filename, F_OK) == -1
                               ^
Moreover, from the gcov documentation, it would seem to be cumbersome at
best to actually use it on VxWorks. So add an option for disabling build
and install of libgcov.

It would probably be most user-friendly if the resulting compiler would
reject --coverage and -fprofile-arcs, but I couldn't find an easy way to
do that.

2018-05-25  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>

libgcc/
        * Makefile.in: Honour @enable_libgcov@
        * configure.ac: Add --disable-libgcov option
        * configure: Regenerate.
---
 libgcc/Makefile.in  | 8 +++++++-
 libgcc/configure.ac | 5 +++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index dd8cee99fd3..22acc15e236 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -36,6 +36,7 @@ SHELL = @SHELL@
 
 cpu_type = @cpu_type@
 enable_shared = @enable_shared@
+enable_libgcov = @enable_libgcov@
 double_type_size = @double_type_size@
 long_double_type_size = @long_double_type_size@
 decimal_float = @decimal_float@
@@ -941,7 +942,10 @@ libgcc.a libgcov.a libunwind.a libgcc_eh.a:
 
 	$(RANLIB) $@
 
-all: libgcc.a libgcov.a
+all: libgcc.a
+ifeq ($(enable_libgcov),yes)
+all: libgcov.a
+endif
 
 ifneq ($(LIBUNWIND),)
 all: libunwind.a
@@ -1164,9 +1168,11 @@ install-leaf: $(install-shared) $(install-libunwind)
 	$(INSTALL_DATA) libgcc.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcc.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc.a
+ifeq ($(enable_libgcov),yes)
 	$(INSTALL_DATA) libgcov.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcov.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcov.a
+endif
 
 	parts="$(INSTALL_PARTS)";				\
 	for file in $$parts; do					\
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index b59aa746afc..a878c473f3d 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -68,6 +68,11 @@ AC_ARG_ENABLE(shared,
 ], [enable_shared=yes])
 AC_SUBST(enable_shared)
 
+AC_ARG_ENABLE(libgcov,
+[  --disable-libgcov       don't provide libgcov],
+[], [enable_libgcov=yes])
+AC_SUBST(enable_libgcov)
+
 AC_ARG_ENABLE(vtable-verify,
 [  --enable-vtable-verify    Enable vtable verification feature ],
 [case "$enableval" in
-- 
2.15.1

Re: [PATCH] libgcc: Add support for --disable-libgcov

[Joseph Myers]

A new configure option should be documented in install.texi.

-- 
Joseph S. Myers
joseph@codesourcery.com

[PATCH v2] libgcc: Add support for --disable-libgcov

[Rasmus Villemoes]

When trying to build gcc 6.4.0 targeting VxWorks 5.5, I ran into libgcov
not building against the VxWorks system headers - there are multiple
issues such as

gcc-src/libgcc/../gcc/gcov-io.c:78:3: warning: implicit declaration of function 'getpid' [-Wimplicit-function-declaration]
   s_flock.l_pid = getpid ();
   ^

gcc-src/libgcc/libgcov.c:139:9: warning: implicit declaration of function 'access' [-Wimplicit-function-declaration]
         if (access (filename, F_OK) == -1
         ^
gcc-src/libgcc/libgcov.c:139:31: error: 'F_OK' undeclared (first use in this function)
         if (access (filename, F_OK) == -1
                               ^
Moreover, from the gcov documentation, it would seem to be cumbersome at
best to actually use it on VxWorks. So add an option for disabling build
and install of libgcov.

It would probably be most user-friendly if the resulting compiler would
reject --coverage and -fprofile-arcs, but I couldn't find an easy way to
do that. Also, the similar --disable-libsanitizer does not make the
compiler complain about use of -fsanitize=xyz.

2018-05-25  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>

gcc/doc/
	* install.texi: Document --disable-libgcov.

libgcc/
        * Makefile.in: Honour @enable_libgcov@.
        * configure.ac: Add --disable-libgcov option.
        * configure: Regenerate.
---
 gcc/doc/install.texi | 4 ++++
 libgcc/Makefile.in   | 8 +++++++-
 libgcc/configure.ac  | 5 +++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 7c5cdc762d3..cf3496d37c6 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1673,6 +1673,10 @@ should not be built.
 Specify that the run-time libraries used by vtable verification
 should not be built.
 
+@item --disable-libgcov
+Specify that the run-time library used for coverage analysis
+should not be built.
+
 @item --with-dwarf2
 Specify that the compiler should
 use DWARF 2 debugging information as the default.
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index dd8cee99fd3..22acc15e236 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -36,6 +36,7 @@ SHELL = @SHELL@
 
 cpu_type = @cpu_type@
 enable_shared = @enable_shared@
+enable_libgcov = @enable_libgcov@
 double_type_size = @double_type_size@
 long_double_type_size = @long_double_type_size@
 decimal_float = @decimal_float@
@@ -941,7 +942,10 @@ libgcc.a libgcov.a libunwind.a libgcc_eh.a:
 
 	$(RANLIB) $@
 
-all: libgcc.a libgcov.a
+all: libgcc.a
+ifeq ($(enable_libgcov),yes)
+all: libgcov.a
+endif
 
 ifneq ($(LIBUNWIND),)
 all: libunwind.a
@@ -1164,9 +1168,11 @@ install-leaf: $(install-shared) $(install-libunwind)
 	$(INSTALL_DATA) libgcc.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcc.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc.a
+ifeq ($(enable_libgcov),yes)
 	$(INSTALL_DATA) libgcov.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcov.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcov.a
+endif
 
 	parts="$(INSTALL_PARTS)";				\
 	for file in $$parts; do					\
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index b59aa746afc..a878c473f3d 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -68,6 +68,11 @@ AC_ARG_ENABLE(shared,
 ], [enable_shared=yes])
 AC_SUBST(enable_shared)
 
+AC_ARG_ENABLE(libgcov,
+[  --disable-libgcov       don't provide libgcov],
+[], [enable_libgcov=yes])
+AC_SUBST(enable_libgcov)
+
 AC_ARG_ENABLE(vtable-verify,
 [  --enable-vtable-verify    Enable vtable verification feature ],
 [case "$enableval" in
-- 
2.15.1

Re: [PATCH v2] libgcc: Add support for --disable-libgcov

[Rasmus Villemoes]

On 2018-05-25 23:34, Rasmus Villemoes wrote:

[...]
> add an option for disabling build and install of libgcov.
> 
> 
> 2018-05-25  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>
> 
> gcc/doc/
> 	* install.texi: Document --disable-libgcov.

I see I messed up that Changelog fragment, is should have been "gcc/"
and "* doc/install.texi".

Anyway, thinking a bit more about this, it might be better to use
--disable-gcov and have that also disable building the gcov tools.
There's actually already comments like

  # Install gcov if it was compiled.

and associated logic in gcc/Makefile, but I don't see how gcov could not
be compiled: This is in the install-common target, which depends on
native, which depends on $(LANGUAGES), which unconditionally contains
gcov$(exeext) and friends.

Thoughts?

Rasmus

[PATCH v3] add support for --disable-gcov

[Rasmus Villemoes]

For some targets (in my case VxWorks 5.5), libgcov does not compile due
to missing functions and macros such as getpid() and F_OK.

Incidentally, gcc/Makefile.in already contains comments such as

# Install gcov if it was compiled.

but there is no logic in place to actually allow gcov to not be
compiled.

So add an option for disabling build and install of libgcov and the
related host tools.

2018-06-10  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>

gcc/
	* configure.ac: Add --disable-gcov option.
	* configure: Regenerate.
	* Makefile.in: Honour @enable_gcov@.
	* doc/install.texi: Document --disable-gcov.

libgcc/
	* configure.ac: Add --disable-gcov option.
	* configure: Regenerate.
	* Makefile.in: Honour @enable_gcov@.
---
 gcc/Makefile.in      | 6 ++++--
 gcc/configure.ac     | 5 +++++
 gcc/doc/install.texi | 4 ++++
 libgcc/Makefile.in   | 8 +++++++-
 libgcc/configure.ac  | 5 +++++
 5 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index d8f3e886118..1f38cacde7a 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -137,8 +137,10 @@ SUBDIRS =@subdirs@ build
 
 # Selection of languages to be made.
 CONFIG_LANGUAGES = @all_selected_languages@
-LANGUAGES = c gcov$(exeext) gcov-dump$(exeext) gcov-tool$(exeext) \
-            $(CONFIG_LANGUAGES)
+LANGUAGES = c $(CONFIG_LANGUAGES)
+ifeq (@enable_gcov@,yes)
+LANGUAGES += gcov$(exeext) gcov-dump$(exeext) gcov-tool$(exeext)
+endif
 
 # Default values for variables overridden in Makefile fragments.
 # CFLAGS is for the user to override to, e.g., do a cross build with -O2.
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 010ecd2ccf6..4fc851c644e 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -921,6 +921,11 @@ AC_ARG_ENABLE(shared,
 ], [enable_shared=yes])
 AC_SUBST(enable_shared)
 
+AC_ARG_ENABLE(gcov,
+[  --disable-gcov          don't provide libgcov and related host tools],
+[], [enable_gcov=yes])
+AC_SUBST(enable_gcov)
+
 AC_ARG_WITH(specs,
   [AS_HELP_STRING([--with-specs=SPECS],
                   [add SPECS to driver command-line processing])],
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 7c5cdc762d3..03eaeed4e87 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1044,6 +1044,10 @@ virtual calls in verifiable mode at all.  However the libvtv library will
 still be built (see @option{--disable-libvtv} to turn off building libvtv).
 @option{--disable-vtable-verify} is the default.
 
+@item --disable-gcov
+Specify that the run-time library used for coverage analysis
+and associated host tools should not be built.
+
 @item --disable-multilib
 Specify that multiple target
 libraries to support different target variants, calling
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index dd8cee99fd3..b7f20557214 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -36,6 +36,7 @@ SHELL = @SHELL@
 
 cpu_type = @cpu_type@
 enable_shared = @enable_shared@
+enable_gcov = @enable_gcov@
 double_type_size = @double_type_size@
 long_double_type_size = @long_double_type_size@
 decimal_float = @decimal_float@
@@ -941,7 +942,10 @@ libgcc.a libgcov.a libunwind.a libgcc_eh.a:
 
 	$(RANLIB) $@
 
-all: libgcc.a libgcov.a
+all: libgcc.a
+ifeq ($(enable_gcov),yes)
+all: libgcov.a
+endif
 
 ifneq ($(LIBUNWIND),)
 all: libunwind.a
@@ -1164,9 +1168,11 @@ install-leaf: $(install-shared) $(install-libunwind)
 	$(INSTALL_DATA) libgcc.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcc.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc.a
+ifeq ($(enable_libgcov),yes)
 	$(INSTALL_DATA) libgcov.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcov.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcov.a
+endif
 
 	parts="$(INSTALL_PARTS)";				\
 	for file in $$parts; do					\
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index b59aa746afc..9d0bbcaba86 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -68,6 +68,11 @@ AC_ARG_ENABLE(shared,
 ], [enable_shared=yes])
 AC_SUBST(enable_shared)
 
+AC_ARG_ENABLE(gcov,
+[  --disable-gcov          don't provide libgcov and related host tools],
+[], [enable_gcov=yes])
+AC_SUBST(enable_gcov)
+
 AC_ARG_ENABLE(vtable-verify,
 [  --enable-vtable-verify    Enable vtable verification feature ],
 [case "$enableval" in
-- 
2.16.4

Re: [PATCH v3] add support for --disable-gcov

[Jeff Law]

On 06/11/2018 01:25 AM, Rasmus Villemoes wrote:
> For some targets (in my case VxWorks 5.5), libgcov does not compile due
> to missing functions and macros such as getpid() and F_OK.
> 
> Incidentally, gcc/Makefile.in already contains comments such as
> 
> # Install gcov if it was compiled.
> 
> but there is no logic in place to actually allow gcov to not be
> compiled.
I think in the past folks would do things like

make LANGUAGES="c c++"

Which would skip building gcov.



> 
> So add an option for disabling build and install of libgcov and the
> related host tools.
> 
> 2018-06-10  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>
> 
> gcc/
> 	* configure.ac: Add --disable-gcov option.
> 	* configure: Regenerate.
> 	* Makefile.in: Honour @enable_gcov@.
> 	* doc/install.texi: Document --disable-gcov.
> 
> libgcc/
> 	* configure.ac: Add --disable-gcov option.
> 	* configure: Regenerate.
> 	* Makefile.in: Honour @enable_gcov@.
OK.  Presumably you're going through the process to get write access.
Once that's wrapped up you can install this patch.

Thanks,
jeff

Re: [PATCH v3] add support for --disable-gcov

[Rainer Orth]

[-- Attachment #1: Type: text/plain, Size: 1473 bytes --]

Hi Jeff,

>> So add an option for disabling build and install of libgcov and the
>> related host tools.
>> 
>> 2018-06-10  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>
>> 
>> gcc/
>> 	* configure.ac: Add --disable-gcov option.
>> 	* configure: Regenerate.
>> 	* Makefile.in: Honour @enable_gcov@.
>> 	* doc/install.texi: Document --disable-gcov.
>> 
>> libgcc/
>> 	* configure.ac: Add --disable-gcov option.
>> 	* configure: Regenerate.
>> 	* Makefile.in: Honour @enable_gcov@.
> OK.  Presumably you're going through the process to get write access.
> Once that's wrapped up you can install this patch.

this patch badly broke all -fprofile-generate/-fprofile-use tests in the
default case like this:

UNRESOLVED: g++.dg/bprob/g++-bprob-1.C compilation,  -O0  -fbranch-probabilities
FAIL: g++.dg/bprob/g++-bprob-1.C compilation,  -O0  -fprofile-arcs

ld: fatal: library -lgcov: not found
collect2: error: ld returned 1 exit status
compiler exited with status 1
FAIL: g++.dg/bprob/g++-bprob-1.C compilation,  -g  -fprofile-arcs

libgcov.a is not copied over from libgcc to gcc due to a typo in
libgcc/Makefile.in.  Fixed as follows; will install as obvious once
bootstrap has finished.

	Rainer

-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University


2018-06-27  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	* Makefile.in (install_leaf): Use enable_gcov instead of
	enable_libgcov.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: libgcc-enable_gcov.patch --]
[-- Type: text/x-patch, Size: 613 bytes --]

# HG changeset patch
# Parent  5c87d0c29765b05d7da38622b0c67a4931fe47ce
Fix typo in Makefile.in

diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -1168,7 +1168,7 @@ install-leaf: $(install-shared) $(instal
 	$(INSTALL_DATA) libgcc.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcc.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcc.a
-ifeq ($(enable_libgcov),yes)
+ifeq ($(enable_gcov),yes)
 	$(INSTALL_DATA) libgcov.a $(DESTDIR)$(inst_libdir)/
 	chmod 644 $(DESTDIR)$(inst_libdir)/libgcov.a
 	$(RANLIB) $(DESTDIR)$(inst_libdir)/libgcov.a

Re: [PATCH v3] add support for --disable-gcov

[Rasmus Villemoes]

On 2018-06-27 21:22, Rainer Orth wrote:
> Hi Jeff,
> 
>>> So add an option for disabling build and install of libgcov and the
>>> related host tools.
>>>
>>> 2018-06-10  Rasmus Villemoes  <rasmus.villemoes@prevas.dk>
>>>
>>> gcc/
>>> 	* configure.ac: Add --disable-gcov option.
>>> 	* configure: Regenerate.
>>> 	* Makefile.in: Honour @enable_gcov@.
>>> 	* doc/install.texi: Document --disable-gcov.
>>>
>>> libgcc/
>>> 	* configure.ac: Add --disable-gcov option.
>>> 	* configure: Regenerate.
>>> 	* Makefile.in: Honour @enable_gcov@.
>> OK.  Presumably you're going through the process to get write access.
>> Once that's wrapped up you can install this patch.
> 
> this patch badly broke all -fprofile-generate/-fprofile-use tests in the
> default case like this:
> 
> UNRESOLVED: g++.dg/bprob/g++-bprob-1.C compilation,  -O0  -fbranch-probabilities
> FAIL: g++.dg/bprob/g++-bprob-1.C compilation,  -O0  -fprofile-arcs
> 
> ld: fatal: library -lgcov: not found
> collect2: error: ld returned 1 exit status
> compiler exited with status 1
> FAIL: g++.dg/bprob/g++-bprob-1.C compilation,  -g  -fprofile-arcs
> 
> libgcov.a is not copied over from libgcc to gcc due to a typo in
> libgcc/Makefile.in.  Fixed as follows; will install as obvious once
> bootstrap has finished.
> 

I'm terribly sorry about that! I was sure I had tested all of
--enable-gcov, --disable-gcov and none of those, and convinced myself
that the default behaviour was unchanged. Thanks for spotting the
problem and fixing it. I will try to be much more careful in the future.

Rasmus