[llvm] [RISCV][Zicfilp] Codegen LPAD insns by looking at module flags (PR #152121)

[Craig Topper via llvm-commits]

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@@ -64,9 +67,25 @@ static void emitLpad(MachineBasicBlock &MBB, const RISCVInstrInfo *TII,
 bool RISCVIndirectBranchTracking::runOnMachineFunction(MachineFunction &MF) {
   const auto &Subtarget = MF.getSubtarget<RISCVSubtarget>();
   const RISCVInstrInfo *TII = Subtarget.getInstrInfo();
-  if (!Subtarget.hasStdExtZicfilp())
+
+  const Module *const M = MF.getFunction().getParent();
+  if (!M)
+    return false;
+  if (const Metadata *const Flag = M->getModuleFlag("cf-protection-branch");
+      !Flag || mdconst::extract<ConstantInt>(Flag)->isZero())
     return false;
 
+  StringRef CFBranchLabelScheme;
+  if (const Metadata *const MD = M->getModuleFlag("cf-branch-label-scheme"))
+    CFBranchLabelScheme = cast<MDString>(MD)->getString();
+  else
+    report_fatal_error("missing cf-branch-label-scheme module flag");
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topperc wrote:

Use `reportFatalUsageError` which won't generate a stack trace.

https://github.com/llvm/llvm-project/pull/152121