Index: clang/lib/Driver/ToolChains/Clang.cpp =================================================================== --- clang/lib/Driver/ToolChains/Clang.cpp +++ clang/lib/Driver/ToolChains/Clang.cpp @@ -580,16 +580,27 @@ static CodeGenOptions::FramePointerKind getFramePointerKind(const ArgList &Args, const llvm::Triple &Triple) { + // We have 4 states: + // + // 00) leaf retained, non-leaf retained + // 01) leaf retained, non-leaf omitted (this is invalid) + // 10) leaf omitted, non-leaf retained + // (what -momit-leaf-frame-pointer was designed for) + // 11) leaf omitted, non-leaf omitted + // + // "omit" options taking precedence over "no-omit" options is the only way + // to make 3 valid states representable Arg *A = Args.getLastArg(options::OPT_fomit_frame_pointer, options::OPT_fno_omit_frame_pointer); bool OmitFP = A && A->getOption().matches(options::OPT_fomit_frame_pointer); bool NoOmitFP = A && A->getOption().matches(options::OPT_fno_omit_frame_pointer); + bool KeepLeaf = + Args.hasFlag(options::OPT_momit_leaf_frame_pointer, + options::OPT_mno_omit_leaf_frame_pointer, Triple.isPS4CPU()); if (NoOmitFP || mustUseNonLeafFramePointerForTarget(Triple) || (!OmitFP && useFramePointerForTargetByDefault(Args, Triple))) { - if (Args.hasFlag(options::OPT_momit_leaf_frame_pointer, - options::OPT_mno_omit_leaf_frame_pointer, - Triple.isPS4CPU())) + if (KeepLeaf) return CodeGenOptions::FramePointerKind::NonLeaf; return CodeGenOptions::FramePointerKind::All; } Index: clang/test/Driver/frame-pointer-elim.c =================================================================== --- clang/test/Driver/frame-pointer-elim.c +++ clang/test/Driver/frame-pointer-elim.c @@ -1,5 +1,8 @@ +// KEEP-ALL-NOT: warning: // KEEP-ALL: "-mframe-pointer=all" +// KEEP-NON-LEAF-NOT: warning: // KEEP-NON-LEAF: "-mframe-pointer=non-leaf" +// KEEP-NONE-NOT: warning: // KEEP-NONE: "-mframe-pointer=none" // On Linux x86, omit frame pointer when optimization is enabled. @@ -25,6 +28,13 @@ // RUN: %clang -### -target i386-linux -S -O1 -momit-leaf-frame-pointer %s 2>&1 | \ // RUN: FileCheck --check-prefix=KEEP-NONE %s +// fno-no-omit-frame-pointer -momit-leaf-frame-pointer can be overwritten by +// fomit-frame-pointer later on the command without warning +// RUN: %clang -### -target i386-linux -S -O1 -fno-omit-frame-pointer -momit-leaf-frame-pointer -fomit-frame-pointer %s 2>&1 | \ +// RUN: FileCheck --check-prefix=KEEP-NONE %s + +// RUN: %clang -### -target i386-linux -S -O1 -fno-omit-frame-pointer -momit-leaf-frame-pointer %s 2>&1 | \ +// RUN: FileCheck --check-prefix=KEEP-NON-LEAF %s // Explicit or default -fomit-frame-pointer wins over -mno-omit-leaf-frame-pointer. // RUN: %clang -### -target i386 -S %s -fomit-frame-pointer -mno-omit-leaf-frame-pointer 2>&1 | \ // RUN: FileCheck --check-prefix=KEEP-NONE %s