PR#6: Manage /usr/bin/cc with update-alternatives - rpms/gcc

rpms / gcc

#6 Manage /usr/bin/cc with update-alternatives

Opened 4 years ago by tstellar. Modified 2 years ago

rpms/ tstellar/gcc cc-alternatives into rawhide

Manage /usr/bin/cc with update-alternatives

Tom Stellard • 4 years ago

7bbb787

gcc.spec

file modified

+33 -3

		`@@ -4,7 +4,7 @@`
		`%global gcc_major 10`
		`# Note, gcc_release must be integer, if you want to add suffixes to`
		`# %%{release}, append them after %%{gcc_release} on Release: line.`
		`- %global gcc_release 0.8`
		`+ %global gcc_release 0.9`
		`%global nvptx_tools_gitrev 5f6f343a302d620b0868edab376c00b15741e39e`
		`%global newlib_cygwin_gitrev 50e2a63b04bdd018484605fbb954fd1bd5147fa0`
		`%global _unpackaged_files_terminate_build 0`
		`@@ -244,6 +244,8 @@`
		`%endif`
		`Requires: libgcc >= %{version}-%{release}`
		`Requires: libgomp = %{version}-%{release}`
		`+ Requires(post): %{_sbindir}/alternatives`
		`+ Requires(preun): %{_sbindir}/alternatives`
		`%if !%{build_ada}`
		`Obsoletes: gcc-gnat < %{version}-%{release}`
		`%endif`
		`@@ -338,6 +340,8 @@`
		`Provides: gcc-g++ = %{version}-%{release}`
		`Provides: g++ = %{version}-%{release}`
		`Autoreq: true`
		`+ Requires(post): %{_sbindir}/alternatives`
		`+ Requires(preun): %{_sbindir}/alternatives`

		`%description c++`
		`This package adds C++ support to the GNU Compiler Collection.`
		`@@ -1906,6 +1910,12 @@`
		`# Help plugins find out nvra.`
		`echo gcc-%{version}-%{release}.%{_arch} > $FULLPATH/rpmver`

		`+ for f in cc c++; do`
		`+ rm %{buildroot}%{_bindir}/$f`
		`+ touch %{buildroot}%{_bindir}/$f`
		`+ done`
		`+`
		`+`
		`%check`
		`cd obj-%{gcc_target_platform}`

		`@@ -1927,6 +1937,12 @@`
		`\| uuencode testlogs-%{_target_platform}.tar.xz \|\| :`
		`rm -rf testlogs-%{_target_platform}-%{version}-%{release}`

		`+ %post`
		`+ %{_sbindir}/update-alternatives --install %{_bindir}/cc cc %{_bindir}/gcc 50`
		`+`
		`+ %post c++`
		`+ %{_sbindir}/update-alternatives --install %{_bindir}/c++ c++ %{_bindir}/g++ 50`
		`+`
		`%post go`
		`%{_sbindir}/update-alternatives --install \`
		`%{_prefix}/bin/go go %{_prefix}/bin/go.gcc 92 \`
		`@@ -1950,6 +1966,16 @@`
		`end`
		`end`

		`+ %postun`
		`+ if [ $1 -eq 0 ] ; then`
		`+ %{_sbindir}/update-alternatives --remove cc %{_bindir}/gcc`
		`+ fi`
		`+`
		`+ %postun c++`
		`+ if [ $1 -eq 0 ] ; then`
		`+ %{_sbindir}/update-alternatives --remove c++ %{_bindir}/g++`
		`+ fi`
		`+`
		`%postun -n libgcc -p <lua>`
		`if posix.access ("/sbin/ldconfig", "x") then`
		`local pid = posix.fork ()`
		`@@ -1993,7 +2019,7 @@`
		`%ldconfig_scriptlets -n libgo`

		`%files -f %{name}.lang`
		`- %{_prefix}/bin/cc`
		`+ %ghost %{_prefix}/bin/cc`
		`%{_prefix}/bin/c89`
		`%{_prefix}/bin/c99`
		`%{_prefix}/bin/gcc`
		`@@ -2331,7 +2357,7 @@`
		`%files c++`
		`%{_prefix}/bin/%{gcc_target_platform}-*++`
		`%{_prefix}/bin/g++`
		`- %{_prefix}/bin/c++`
		`+ %ghost %{_prefix}/bin/c++`
		`%{_mandir}/man1/g++.1*`
		`%dir %{_prefix}/lib/gcc`
		`%dir %{_prefix}/lib/gcc/%{gcc_target_platform}`
		`@@ -3003,6 +3029,10 @@`
		`%endif`

		`%changelog`
		`+ * Mon Feb 24 2020 Tom Stellard <tstellar@redhat.com> 10.0.1-0.9`
		`+ - Manage /usr/bin/cc with update-alternatives`
		`+ - https://fedoraproject.org/wiki/Changes/Use-Update-Alternatives-For-usr-bin-cc`
		`+`
		`* Sun Feb 16 2020 Jakub Jelinek <jakub@redhat.com> 10.0.1-0.8`
		`- update from trunk`
		`- PRs analyzer/93212, analyzer/93288, analyzer/93350, analyzer/93356,`

tests/cc-alternative/hello.c

file added

		`@@ -0,0 +1,5 @@`
		`+ #include <stdio.h>`
		`+`
		`+ int main() {`
		`+ printf("Hello world\n");`
		`+ }`

tests/cc-alternative/hello.cpp

file added

		`@@ -0,0 +1,5 @@`
		`+ #include <iostream>`
		`+`
		`+ int main() {`
		`+ std::cout << "Hello world\n";`
		`+ }`

tests/cc-alternative/runtest.sh

file added

+36

		`@@ -0,0 +1,36 @@`
		`+ #!/bin/bash`
		`+`
		`+ # This test assumes gcc and gcc-c++ are already installed.`
		`+`
		`+ set -exo pipefail`
		`+`
		`+ # Verify that /usr/bin/cc points to gcc.`
		`+ ls -l /etc/alternatives/cc \| grep gcc`
		`+`
		`+ # Verify that /usr/bin/c++ points to g++`
		`+ ls -l /etc/alternatives/c++ \| grep g++`
		`+`
		`+ # Run cc and verify it invokes gcc`
		`+ /usr/bin/cc --version \| grep 'cc (GCC)'`
		`+`
		`+ # Run c++ and verify it invokes g++`
		`+ /usr/bin/c++ --version \| grep 'c++ (GCC)'`
		`+`
		`+ # Compile a C program`
		`+ /usr/bin/cc -o hello-c hello.c`
		`+ ./hello-c \| grep 'Hello world'`
		`+`
		`+ # Compile a C++ program`
		`+ /usr/bin/c++ -o hello-cpp hello.cpp`
		`+ ./hello-cpp \| grep 'Hello world'`
		`+`
		`+ # Uninstall gcc and verify that cc and c++ are gone.`
		`+ dnf remove -y gcc gcc-c++`
		`+`
		`+ test ! -h /etc/alternatives/cc`
		`+`
		`+ test ! -h /etc/alternatives/c++`
		`+`
		`+ test ! -e /usr/bin/cc`
		`+`
		`+ test ! -e /usr/bin/c++`

tests/tests-cc-alternative.yml

file added

+14

		`@@ -0,0 +1,14 @@`
		`+ # The cc-alternative test uninstalls gcc, so it needs to be run by`
		`+ # itself in a separate .yml file so it doesn't modify the test`
		`+ # environment for other tests.`
		`+`
		`+ - hosts: localhost`
		`+ roles:`
		`+ - role: standard-test-basic`
		`+ tags:`
		`+ - classic`
		`+ required_packages:`
		`+ - gcc`
		`+ - gcc-c++`
		`+ tests:`
		`+ - cc-alternative`

tstellar commented 4 years ago

https://fedoraproject.org/wiki/Changes/Use-Update-Alternatives-For-usr-bin-cc

rebased onto 6d16d466f041d3512352bc2c63192957f7dbae72

4 years ago

rebased onto 95ce5038f2795d720ba9e5f22303641f91cdf88a

4 years ago

rebased onto 7bbb787

4 years ago

pkarakal commented 2 years ago

is this change abandoned or planned for another release? it would be super useful to have it as currently usr/bin/c++ cannot be changed contrary to usr/bin/cc and it can be a chore maintaining multiple compiler and compiler versions (unless messing with environment variables or make it a part of your of build script. both are not as clean as changing the alternative)