From e75bc53e06f58afa89b04c717f88b76648d53162 Mon Sep 17 00:00:00 2001
From: Wenkai Du <43822138+wenkaidu@users.noreply.github.com>
Date: Tue, 22 Jun 2021 13:29:08 -0700
Subject: [PATCH] Deduct ROCM_PATH from CXX unless specified (#400)

---
 CMakeLists.txt | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4757c07667..5d9989ea3a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,8 +7,6 @@ set( CMAKE_CXX_STANDARD 14 )
 # Without this line, it will add -std=gnu++14 instead, which has some issues.
 set( CMAKE_CXX_EXTENSIONS OFF )
 
-set(CMAKE_INSTALL_PREFIX "${ROCM_PATH}" CACHE PATH "")
-
 project(rccl CXX)
 
 include(cmake/Dependencies.cmake)
@@ -23,6 +21,14 @@ if( CMAKE_CXX_COMPILER MATCHES ".*/hipcc$" )
     string(REGEX MATCH ".mcode\-object\-version" TARGET_ID_SUPPORT ${CXX_OUTPUT})
 endif()
 
+if(NOT DEFINED ROCM_PATH)
+  get_filename_component(_real_path ${CMAKE_CXX_COMPILER} REALPATH)
+  get_filename_component(_new_path "${_real_path}" DIRECTORY)
+  get_filename_component(ROCM_PATH "${_new_path}/../.." REALPATH)
+endif()
+
+set(CMAKE_INSTALL_PREFIX "${ROCM_PATH}" CACHE PATH "")
+
 #Set the AMDGPU_TARGETS with backward compatiblity
 if(COMMAND rocm_check_target_ids)
    rocm_check_target_ids(DEFAULT_AMDGPU_TARGETS