[hip][cuda] Fix the extended lambda name mangling issue.

Summary:
- HIP/CUDA host side needs to use device kernel symbol name to match the
  device side binaries. Without a consistent naming between host- and
  device-side compilations, it's risky that wrong device binaries are
  executed. Consistent naming is usually not an issue until unnamed
  types are used, especially the lambda. In this patch, the consistent
  name mangling is addressed for the extended lambdas, i.e. the lambdas
  annotated with `__device__`.
- In [Itanium C++ ABI][1], the mangling of the lambda is generally
  unspecified unless, in certain cases, ODR rule is required to ensure
  consisent naming cross TUs. The extended lambda is such a case as its
  name may be part of a device kernel function, e.g., the extended
  lambda is used as a template argument and etc. Thus, we need to force
  ODR for extended lambdas as they are referenced in both device- and
  host-side TUs. Furthermore, if a extended lambda is nested in other
  (extended or not) lambdas, those lambdas are required to follow ODR
  naming as well. This patch revises the current lambda mangle numbering
  to force ODR from an extended lambda to all its parent lambdas.
- On the other side, the aforementioned ODR naming should not change
  those lambdas' original linkages, i.e., we cannot replace the original
  `internal` with `linkonce_odr`; otherwise, we may violate ODR in
  general. This patch introduces a new field `HasKnownInternalLinkage`
  in lambda data to decouple the current linkage calculation based on
  mangling number assigned.

[1]: https://itanium-cxx-abi.github.io/cxx-abi/abi.html

Reviewers: tra, rsmith, yaxunl, martong, shafik

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68818

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375309 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 0 deletions

diff --git a/test/CodeGenCUDA/unnamed-types.cu b/test/CodeGenCUDA/unnamed-types.cu
new file mode 100644
index 0000000000..81557817e4
--- /dev/null
+++ b/test/CodeGenCUDA/unnamed-types.cu
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -std=c++11 -x hip -triple x86_64-linux-gnu -aux-triple amdgcn-amd-amdhsa -emit-llvm %s -o - | FileCheck %s --check-prefix=HOST
+// RUN: %clang_cc1 -std=c++11 -x hip -triple amdgcn-amd-amdhsa -fcuda-is-device -emit-llvm %s -o - | FileCheck %s --check-prefix=DEVICE
+
+#include "Inputs/cuda.h"
+
+// HOST: @0 = private unnamed_addr constant [43 x i8] c"_Z2k0IZZ2f1PfENKUlS0_E_clES0_EUlfE_EvS0_T_\00", align 1
+
+__device__ float d0(float x) {
+  return [](float x) { return x + 2.f; }(x);
+}
+
+__device__ float d1(float x) {
+  return [](float x) { return x * 2.f; }(x);
+}
+
+// DEVICE: amdgpu_kernel void @_Z2k0IZZ2f1PfENKUlS0_E_clES0_EUlfE_EvS0_T_(
+template <typename F>
+__global__ void k0(float *p, F f) {
+  p[0] = f(p[0]) + d0(p[1]) + d1(p[2]);
+}
+
+void f0(float *p) {
+  [](float *p) {
+    *p = 1.f;
+  }(p);
+}
+
+// The inner/outer lambdas are required to be mangled following ODR but their
+// linkages are still required to keep the original `internal` linkage.
+
+// HOST: define internal void @_ZZ2f1PfENKUlS_E_clES_(
+// DEVICE: define internal float @_ZZZ2f1PfENKUlS_E_clES_ENKUlfE_clEf(
+void f1(float *p) {
+  [](float *p) {
+    k0<<<1,1>>>(p, [] __device__ (float x) { return x + 1.f; });
+  }(p);
+}
+// HOST: @__hip_register_globals
+// HOST: __hipRegisterFunction{{.*}}@_Z2k0IZZ2f1PfENKUlS0_E_clES0_EUlfE_EvS0_T_{{.*}}@0