llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-driver Author: Daniel Paoliello (dpaoliello) <details> <summary>Changes</summary> There is no way in Arm64 Windows to indicate that a given function has used the Frame Pointer as a General Purpose Register, as such stack walks will always assume that the frame chain is valid and will follow whatever value has been saved for the Frame Pointer (even if it is pointing to data, etc.). This change makes the Frame Pointer always reserved when building for Arm64 Windows to avoid this issue. We will be updating the official Windows ABI documentation to reflect this requirement, and I will provide a link once it's available. cc @<!-- -->pmsjt --- Full diff: https://github.com/llvm/llvm-project/pull/146582.diff 2 Files Affected: - (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+13-2) - (modified) clang/test/Driver/frame-pointer-elim.c (+6) ``````````diff diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 070901f037823..2fcf9b28dc746 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -174,7 +174,13 @@ static bool mustUseNonLeafFramePointerForTarget(const llvm::Triple &Triple) { // even if new frame records are not created. static bool mustMaintainValidFrameChain(const llvm::opt::ArgList &Args, const llvm::Triple &Triple) { - if (Triple.isARM() || Triple.isThumb()) { + switch (Triple.getArch()) { + default: + return false; + case llvm::Triple::arm: + case llvm::Triple::armeb: + case llvm::Triple::thumb: + case llvm::Triple::thumbeb: // For 32-bit Arm, the -mframe-chain=aapcs and -mframe-chain=aapcs+leaf // options require the frame pointer register to be reserved (or point to a // new AAPCS-compilant frame record), even with -fno-omit-frame-pointer. @@ -183,8 +189,13 @@ static bool mustMaintainValidFrameChain(const llvm::opt::ArgList &Args, return V != "none"; } return false; + + case llvm::Triple::aarch64: + // Arm64 Windows requires that the frame chain is valid, as there is no + // way to indicate during a stack walk that a frame has used the frame + // pointer as a general purpose register. + return Triple.isOSWindows(); } - return false; } // True if a target-specific option causes -fno-omit-frame-pointer to also diff --git a/clang/test/Driver/frame-pointer-elim.c b/clang/test/Driver/frame-pointer-elim.c index f64ff6efc7261..0dd7eb0c738db 100644 --- a/clang/test/Driver/frame-pointer-elim.c +++ b/clang/test/Driver/frame-pointer-elim.c @@ -4,6 +4,8 @@ // KEEP-NON-LEAF: "-mframe-pointer=non-leaf" // KEEP-NONE-NOT: warning: argument unused // KEEP-NONE: "-mframe-pointer=none" +// KEEP-RESERVED-NOT: warning: argument unused +// KEEP-RESERVED: "-mframe-pointer=reserved" // On Linux x86, omit frame pointer when optimization is enabled. // RUN: %clang -### --target=i386-linux -S -fomit-frame-pointer %s 2>&1 | \ @@ -215,5 +217,9 @@ // RUN: %clang -### --target=aarch64-none-elf -S -O1 -fno-omit-frame-pointer %s 2>&1 | \ // RUN: FileCheck --check-prefix=KEEP-NON-LEAF %s +// AArch64 Windows requires that the frame pointer be reserved +// RUN: %clang -### --target=aarch64-pc-windows-msvc -S -fomit-frame-pointer %s 2>&1 | \ +// RUN: FileCheck --check-prefix=KEEP-RESERVED %s + void f0() {} void f1() { f0(); } `````````` </details> https://github.com/llvm/llvm-project/pull/146582 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
