[IR][sanitizer] Add module flag "frame-pointer" and set it for cc1 -mframe-pointer={non-leaf,all}

The Linux kernel objtool diagnostic `call without frame pointer save/setup`
arise in multiple instrumentation passes (asan/tsan/gcov). With the mechanism
introduced in D100251, it's trivial to respect the command line
-m[no-]omit-leaf-frame-pointer/-f[no-]omit-frame-pointer, so let's do it.

Fix: https://github.com/ClangBuiltLinux/linux/issues/1236 (tsan)
Fix: https://github.com/ClangBuiltLinux/linux/issues/1238 (asan)

Also document the function attribute "frame-pointer" which is long overdue.

Differential Revision: https://reviews.llvm.org/D101016

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index b5108f7..726ac6a 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -676,6 +676,16 @@ bool Module::getUwtable() const {
 
 void Module::setUwtable() { addModuleFlag(ModFlagBehavior::Max, "uwtable", 1); }
 
+FramePointerKind Module::getFramePointer() const {
+  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("frame-pointer"));
+  return static_cast<FramePointerKind>(
+      Val ? cast<ConstantInt>(Val->getValue())->getZExtValue() : 0);
+}
+
+void Module::setFramePointer(FramePointerKind Kind) {
+  addModuleFlag(ModFlagBehavior::Max, "frame-pointer", static_cast<int>(Kind));
+}
+
 void Module::setSDKVersion(const VersionTuple &V) {
   SmallVector<unsigned, 3> Entries;
   Entries.push_back(V.getMajor());