diff options
Diffstat (limited to 'libbuild2/cc')
| -rw-r--r-- | libbuild2/cc/compile-rule.cxx | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/libbuild2/cc/compile-rule.cxx b/libbuild2/cc/compile-rule.cxx index 36276f9..8526308 100644 --- a/libbuild2/cc/compile-rule.cxx +++ b/libbuild2/cc/compile-rule.cxx @@ -7069,6 +7069,46 @@ namespace build2 { append_options (args, cmode); + // Clang 15 introduced the unqualified-std-cast-call warning which + // warns about unqualified calls to std::move() and std::forward() + // (because they can be "hijacked" via ADL). Surprisingly, this + // warning is enabled by default, as opposed to with -Wextra or at + // least -Wall. It has also proven to be quite disruptive, causing a + // large number of warnings in a large number of packages. So we are + // going to "remap" it to -Wextra for now and in the future may + // "relax" it to -Wall and potentially to being enabled by default. + // See GitHub issue #259 for background and details. + // + if (x_lang == lang::cxx && + ctype == compiler_type::clang && + cmaj >= 15) + { + bool w (false); // Seen -W[no-]unqualified-std-cast-call + optional<bool> extra; // Seen -W[no-]extra + + for (const char* s: reverse_iterate (args)) + { + if (s != nullptr) + { + if (strcmp (s, "-Wunqualified-std-cast-call") == 0 || + strcmp (s, "-Wno-unqualified-std-cast-call") == 0) + { + w = true; + break; + } + + if (!extra) // Last seen option wins. + { + if (strcmp (s, "-Wextra") == 0) extra = true; + else if (strcmp (s, "-Wno-extra") == 0) extra = false; + } + } + } + + if (!w && (!extra || !*extra)) + args.push_back ("-Wno-unqualified-std-cast-call"); + } + if (md.pp != preprocessed::all) append_sys_hdr_options (args); // Extra system header dirs (last). |