From f667ad5f984ec4ab0baccec5ddc57a2bda7a175c Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Sat, 26 Aug 2017 01:04:35 +0000 Subject: Add flag to request Clang is ABI-compatible with older versions of itself This patch adds a flag -fclang-abi-compat that can be used to request that Clang attempts to be ABI-compatible with some older version of itself. This is provided on a best-effort basis; right now, this can be used to undo the ABI change in r310401, reverting Clang to its prior C++ ABI for pass/return by value of class types affected by that change, and to undo the ABI change in r262688, reverting Clang to using integer registers rather than SSE registers for passing <1 x long long> vectors. The intent is that we will maintain this backwards compatibility path as we make ABI-breaking fixes in future. The reversion to the old behavior for r310401 is also applied to the PS4 target since that change is not part of its platform ABI (which is essentially to do whatever Clang 3.2 did). llvm-svn: 311823 --- clang/lib/Frontend/CompilerInvocation.cpp | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'clang/lib/Frontend/CompilerInvocation.cpp') diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index aea3af9..abf6b0b 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -573,6 +573,33 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, if (!Opts.ProfileInstrumentUsePath.empty()) setPGOUseInstrumentor(Opts, Opts.ProfileInstrumentUsePath); + if (Arg *A = Args.getLastArg(OPT_fclang_abi_compat_EQ)) { + Opts.setClangABICompat(CodeGenOptions::ClangABI::Latest); + + StringRef Ver = A->getValue(); + std::pair VerParts = Ver.split('.'); + unsigned Major, Minor = 0; + + // Check the version number is valid: either 3.x (0 <= x <= 9) or + // y or y.0 (4 <= y <= current version). + if (!VerParts.first.startswith("0") && + !VerParts.first.getAsInteger(10, Major) && + 3 <= Major && Major <= CLANG_VERSION_MAJOR && + (Major == 3 ? VerParts.second.size() == 1 && + !VerParts.second.getAsInteger(10, Minor) + : VerParts.first.size() == Ver.size() || + VerParts.second == "0")) { + // Got a valid version number. + if (Major == 3 && Minor <= 8) + Opts.setClangABICompat(CodeGenOptions::ClangABI::Ver3_8); + else if (Major <= 4) + Opts.setClangABICompat(CodeGenOptions::ClangABI::Ver4); + } else if (Ver != "latest") { + Diags.Report(diag::err_drv_invalid_value) + << A->getAsString(Args) << A->getValue(); + } + } + Opts.CoverageMapping = Args.hasFlag(OPT_fcoverage_mapping, OPT_fno_coverage_mapping, false); Opts.DumpCoverageMapping = Args.hasArg(OPT_dump_coverage_mapping); -- cgit v1.1