[llvm][fatlto] Drop any CFI related instrumentation after emitting bitcode

clang/test/CodeGen/fat-lto-objects-cfi.cpp

@@ -0,0 +1,46 @@
+// REQUIRES: x86-registered-target
+
+// RUN: %clang_cc1 -triple x86_64-unknown-fuchsia -O2 -flto -ffat-lto-objects \
+// RUN:          -fsanitize=cfi-icall -fsanitize-trap=cfi-icall -fvisibility=hidden  -emit-llvm -o - %s \
+// RUN:   | FileCheck %s
+
+// CHECK: llvm.embedded.object
+// CHECK-SAME: section ".llvm.lto"
+
+// CHECK-LABEL: define hidden void @foo
+//      CHECK: entry:
+// CHECK-NEXT:   %cmp14.not = icmp eq i64 %len, 0
+// CHECK-NEXT:   br i1 %cmp14.not, label %for.end7, label %for.cond1.preheader.preheader
+//      CHECK: for.cond1.preheader.preheader:                    ; preds = %entry
+// CHECK-NEXT:   %arrayidx.1 = getelementptr inbounds nuw i8, ptr %ptr, i64 4
+// CHECK-NEXT:   br label %for.cond1.preheader
+
+// CHECK-NOT: @llvm.type.test
+
+// The code below is a reduced case from https://github.com/llvm/llvm-project/issues/112053
+#define __PRINTFLIKE(__fmt, __varargs) __attribute__((__format__(__printf__, __fmt, __varargs)))
+typedef void func(void* arg, const char* fmt, ...) __PRINTFLIKE(2, 3);
+typedef __SIZE_TYPE__ size_t;
+typedef unsigned long uintptr_t;
+
+extern "C"
+void foo(const void* ptr, size_t len, long disp_addr,
+                     func* printf_func, void* printf_arg) {
+  uintptr_t address = (uintptr_t)ptr;
+  size_t count;
+
+  for (count = 0; count < len; count += 16) {
+    union {
+      unsigned int buf[4];
+      unsigned char cbuf[16];
+    } u;
+    size_t s = 10;
+    size_t i;
+
+    for (i = 0; i < s / 4; i++) {
+      u.buf[i] = ((const unsigned int*)address)[i];
+      printf_func(printf_arg, "%08x ", static_cast<unsigned int>(u.buf[i]));
+    }
+  }
+}
+

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -1645,6 +1645,13 @@ PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level, bool ThinLTO,
     MPM.addPass(buildLTOPreLinkDefaultPipeline(Level));
   MPM.addPass(EmbedBitcodePass(ThinLTO, EmitSummary));
 
+  // If we're doing FatLTO w/ CFI enabled, we don't want the type tests in the
+  // object code, only in the bitcode section, so drop it before we run
+  // module optimization and generate machine code. If llvm.type.test() isn't in
+  // the IR, this won't do anything.
+  MPM.addPass(
+      LowerTypeTestsPass(nullptr, nullptr, lowertypetests::DropTestKind::All));
+
   // Use the ThinLTO post-link pipeline with sample profiling
   if (ThinLTO && PGOOpt && PGOOpt->Action == PGOOptions::SampleUse)
     MPM.addPass(buildThinLTODefaultPipeline(Level, /*ImportSummary=*/nullptr));