From 331733cd4e2f2fe76c0b7b6fdd81e54724572354 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Wed, 24 Jun 2020 23:18:19 +0100 Subject: [PATCH] W/ Clang, compile C/C++ testcases with -Wno-unknown-warning-option Some C/C++ testcases unconditionally pass -Wno-foo as additional options to disable some warning. That is OK with GCC, because GCC accepts -Wno-foo silently even if it doesn't support -Wfoo. This is a feature which allows disabling warnings with newer compilers without breaking builds with older compilers. Clang however warns about unknown -Wno-foo by default, unless you pass -Wno-unknown-warning-option as well: $ gcc -Wno-foo test.c * nothing, compiles successfuly * $ clang -Wno-foo test.c warning: unknown warning option '-Wno-foo [-Wunknown-warning-option] This commit adds -Wunknown-warning-option centrally in gdb_compile, so that individual testcases don't have to worry about breaking older Clangs. IOW, this avoids this problematic scenario: #1 - A testcase compiles successfully with Clang version X. #2 - Clang version "X + 1" adds a new warning, enabled by default, which breaks the test. #3 - We add -Wno-newwarning to the testcase, fixing the testcase with clang "X + 1". #4 - Now building the test with Clang version X no longer works, due to "unknown warning option". gdb/testsuite/ChangeLog: 2020-06-24 Pedro Alves * lib/gdb.exp (gdb_compile): Update intro comment. If C/C++ with Clang, add "-Wno-unknown-warning-option" to the options. --- gdb/testsuite/ChangeLog | 5 +++++ gdb/testsuite/lib/gdb.exp | 20 +++++++++++++++++++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 26284dabb25..6f4d99d3902 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-06-24 Pedro Alves + + * lib/gdb.exp (gdb_compile): Update intro comment. If C/C++ with + Clang, add "-Wno-unknown-warning-option" to the options. + 2020-06-23 Andrew Burgess * gdb.xml/tdesc-reload.c: New file. diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp index 7b243f5fff3..6b4f71be588 100644 --- a/gdb/testsuite/lib/gdb.exp +++ b/gdb/testsuite/lib/gdb.exp @@ -3826,7 +3826,8 @@ set gdb_saved_set_unbuffered_mode_obj "" # - ldflags=flag: Add FLAG to the linker flags. # - incdir=path: Add PATH to the searched include directories. # - libdir=path: Add PATH to the linker searched directories. -# - ada, c++, f77: Compile the file as Ada, C++ or Fortran. +# - ada, c++, f77, f90, go, rust: Compile the file as Ada, C++, +# Fortran 77, Fortran 90, Go or Rust. # - debug: Build with debug information. # - optimize: Build with optimization. @@ -3850,6 +3851,23 @@ proc gdb_compile {source dest type options} { set new_options [universal_compile_options] } + # Some C/C++ testcases unconditionally pass -Wno-foo as additional + # options to disable some warning. That is OK with GCC, because + # by design, GCC accepts any -Wno-foo option, even if it doesn't + # support -Wfoo. Clang however warns about unknown -Wno-foo by + # default, unless you pass -Wno-unknown-warning-option as well. + # We do that here, so that individual testcases don't have to + # worry about it. + if {[lsearch -exact $options getting_compiler_info] == -1 + && [lsearch -exact $options rust] == -1 + && [lsearch -exact $options ada] == -1 + && [lsearch -exact $options f77] == -1 + && [lsearch -exact $options f90] == -1 + && [lsearch -exact $options go] == -1 + && [test_compiler_info "clang-*"]} { + lappend new_options "additional_flags=-Wno-unknown-warning-option" + } + # Place (and look for) Fortran `.mod` files in the output # directory for this specific test. if {[lsearch -exact $options f77] != -1 \ -- 2.30.2