https://github.com/lenary created https://github.com/llvm/llvm-project/pull/205202
This ensures that we can separate out multilibs that are or are not built with control flow protection enabled. The initial version of the patch claims all values of these flags are incompatible. It might be the case that we could make this logic more complex if some versions do become compatible. >From af9e7108c19f4580c009125a420e644be9ffe01d Mon Sep 17 00:00:00 2001 From: Sam Elliott <[email protected]> Date: Mon, 22 Jun 2026 14:45:24 -0700 Subject: [PATCH] [RISCV][clang] Use fcf-protection flag in Multilib Selection This ensures that we can separate out multilibs that are or are not built with control flow protection enabled. The initial version of the patch claims all values of these flags are incompatible. It might be the case that we could make this logic more complex if some versions do become compatible. --- clang/lib/Driver/ToolChain.cpp | 12 ++++++++++++ clang/test/Driver/print-multi-selection-flags.c | 13 +++++++++++++ 2 files changed, 25 insertions(+) diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp index 7d93e7f65daf5..328f4f8c8f420 100644 --- a/clang/lib/Driver/ToolChain.cpp +++ b/clang/lib/Driver/ToolChain.cpp @@ -445,6 +445,18 @@ static void getRISCVMultilibFlags(const Driver &D, const llvm::Triple &Triple, Result.push_back("-fsanitize=shadow-call-stack"); else Result.push_back("-fno-sanitize=shadow-call-stack"); + + const Arg *CFProtectionArg = + Args.getLastArgNoClaim(options::OPT_fcf_protection_EQ); + StringRef CFProtectionVal = + CFProtectionArg ? CFProtectionArg->getValue() : "none"; + Result.push_back(("-fcf-protection=" + CFProtectionVal).str()); + + if (CFProtectionVal == "branch" || CFProtectionVal == "full") { + if (const Arg *SchemeArg = + Args.getLastArgNoClaim(options::OPT_mcf_branch_label_scheme_EQ)) + Result.push_back(SchemeArg->getAsString(Args)); + } } Multilib::flags_list diff --git a/clang/test/Driver/print-multi-selection-flags.c b/clang/test/Driver/print-multi-selection-flags.c index ba7b325892f9c..e5a116234c321 100644 --- a/clang/test/Driver/print-multi-selection-flags.c +++ b/clang/test/Driver/print-multi-selection-flags.c @@ -154,3 +154,16 @@ // CHECK-OPT-OS: -Os // CHECK-OPT-NOT: -Oz // CHECK-OPT-NOT: -Os + +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf | FileCheck --check-prefix=CHECK-CF-PROTECTION-NONE --implicit-check-not="mcf-branch-label-scheme" %s +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fcf-protection=none | FileCheck --check-prefix=CHECK-CF-PROTECTION-NONE --implicit-check-not="mcf-branch-label-scheme" %s +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fcf-protection=return | FileCheck --check-prefix=CHECK-CF-PROTECTION-RETURN --implicit-check-not="mcf-branch-label-scheme" %s +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fcf-protection=branch -mcf-branch-label-scheme=unlabeled | FileCheck --check-prefix=CHECK-CF-PROTECTION-BRANCH %s +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fcf-protection=full -mcf-branch-label-scheme=unlabeled | FileCheck --check-prefix=CHECK-CF-PROTECTION-FULL %s +// RUN: %clang -multi-lib-config=%S/Inputs/multilib/empty.yaml -print-multi-flags-experimental --target=riscv64-none-elf -fcf-protection -mcf-branch-label-scheme=unlabeled | FileCheck --check-prefix=CHECK-CF-PROTECTION-FULL %s +// CHECK-CF-PROTECTION-NONE: -fcf-protection=none +// CHECK-CF-PROTECTION-RETURN: -fcf-protection=return +// CHECK-CF-PROTECTION-BRANCH: -fcf-protection=branch +// CHECK-CF-PROTECTION-BRANCH: -mcf-branch-label-scheme=unlabeled +// CHECK-CF-PROTECTION-FULL: -fcf-protection=full +// CHECK-CF-PROTECTION-FULL: -mcf-branch-label-scheme=unlabeled _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
