diff --git a/BaseTools/Source/C/DevicePath/GNUmakefile b/BaseTools/Source/C/DevicePath/GNUmakefile
index 3afc7fc050..f61b1b2f17 100644
--- a/BaseTools/Source/C/DevicePath/GNUmakefile
+++ b/BaseTools/Source/C/DevicePath/GNUmakefile
@@ -14,8 +14,9 @@ OBJECTS = DevicePath.o UefiDevicePathLib.o DevicePathFromText.o  DevicePathUtili
 include $(MAKEROOT)/Makefiles/app.makefile
 
 GCCVERSION = $(shell $(CC) -dumpversion | awk -F'.' '{print $$1}')
+CLANG := $(shell $(CC) --version | grep clang)
 ifneq ("$(GCCVERSION)", "5")
-ifneq ($(CXX), llvm)
+ifeq ($(CLANG),)
 ifneq ($(DARWIN),Darwin)
 # gcc 12 trips over device path handling
 CFLAGS += -Wno-error=stringop-overflow
diff --git a/BaseTools/Source/C/Makefiles/header.makefile b/BaseTools/Source/C/Makefiles/header.makefile
index 0fb315a25a..bcc2791998 100644
--- a/BaseTools/Source/C/Makefiles/header.makefile
+++ b/BaseTools/Source/C/Makefiles/header.makefile
@@ -44,18 +44,19 @@ endif
 CYGWIN:=$(findstring CYGWIN, $(shell uname -s))
 LINUX:=$(findstring Linux, $(shell uname -s))
 DARWIN:=$(findstring Darwin, $(shell uname -s))
-ifeq ($(CXX), llvm)
+CLANG:=$(shell $(CC) --version | grep clang)
+ifneq ($(CLANG),)
 CC ?= $(CLANG_BIN)clang
 CXX ?= $(CLANG_BIN)clang++
 AS ?= $(CLANG_BIN)clang
 AR ?= $(CLANG_BIN)llvm-ar
 LD ?= $(CLANG_BIN)llvm-ld
-else
-CC ?= gcc
-CXX ?= g++
-AS ?= gcc
-AR ?= ar
-LD ?= ld
+else ifeq ($(origin CC),default)
+CC = gcc
+CXX = g++
+AS = gcc
+AR = ar
+LD = ld
 endif
 LINKER ?= $(CC)
 ifeq ($(HOST_ARCH), IA32)
@@ -91,7 +92,7 @@ ifeq ($(DARWIN),Darwin)
 CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -Wall -Werror \
 -Wno-deprecated-declarations -Wno-self-assign -Wno-unused-result -nostdlib -g
 else
-ifeq ($(CXX), llvm)
+ifneq ($(CLANG),)
 CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -fwrapv \
 -fno-delete-null-pointer-checks -Wall -Werror \
 -Wno-deprecated-declarations -Wno-self-assign \
@@ -103,7 +104,7 @@ CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -fwrapv \
 -Wno-unused-result -nostdlib -g
 endif
 endif
-ifeq ($(CXX), llvm)
+ifneq ($(CLANG),)
 LDFLAGS =
 CXXFLAGS = -Wno-deprecated-register -Wno-unused-result
 else
diff --git a/BaseTools/Source/C/VfrCompile/GNUmakefile b/BaseTools/Source/C/VfrCompile/GNUmakefile
index e227b10791..7d5976649d 100644
--- a/BaseTools/Source/C/VfrCompile/GNUmakefile
+++ b/BaseTools/Source/C/VfrCompile/GNUmakefile
@@ -16,7 +16,8 @@ TOOL_INCLUDE = -I Pccts/h
 #OBJECTS = VfrSyntax.o VfrServices.o DLGLexer.o EfiVfrParser.o ATokenBuffer.o DLexerBase.o AParser.o
 OBJECTS = AParser.o DLexerBase.o ATokenBuffer.o EfiVfrParser.o VfrLexer.o VfrSyntax.o \
           VfrFormPkg.o VfrError.o VfrUtilityLib.o VfrCompiler.o
-ifeq ($(CXX), llvm)
+CLANG:=$(shell $(CC) --version | grep clang)
+ifneq ($(CLANG),)
 VFR_CPPFLAGS = -Wno-deprecated-register -std=c++14 -DPCCTS_USE_NAMESPACE_STD $(CPPFLAGS)
 else
 VFR_CPPFLAGS = -DPCCTS_USE_NAMESPACE_STD $(CPPFLAGS)
diff --git a/BaseTools/Source/C/VfrCompile/Pccts/antlr/makefile b/BaseTools/Source/C/VfrCompile/Pccts/antlr/makefile
index 3bd9b6b1df..42b603571f 100644
--- a/BaseTools/Source/C/VfrCompile/Pccts/antlr/makefile
+++ b/BaseTools/Source/C/VfrCompile/Pccts/antlr/makefile
@@ -164,10 +164,10 @@ PCCTS_H=../h
 #
 #   UNIX  (default)
 #
-ifeq ($(CXX), llvm)
+ifneq ($(CLANG),)
 CC?=$(CLANG_BIN)clang
-else
-CC?=gcc
+else ifeq ($(origin CC),default)
+CC=gcc
 endif
 COPT=-O
 ANTLR=${BIN_DIR}/antlr
diff --git a/BaseTools/Source/C/VfrCompile/Pccts/dlg/makefile b/BaseTools/Source/C/VfrCompile/Pccts/dlg/makefile
index 61366185c1..e45ac98e04 100644
--- a/BaseTools/Source/C/VfrCompile/Pccts/dlg/makefile
+++ b/BaseTools/Source/C/VfrCompile/Pccts/dlg/makefile
@@ -114,10 +114,11 @@ PCCTS_H=../h
 #
 #   UNIX
 #
-ifeq ($(CXX), llvm)
-BUILD_CC?=$(CLANG_BIN)clang
-else
-BUILD_CC?=cc
+CLANG:=$(shell $(CC) --version | grep clang)
+ifneq ($(CLANG),)
+CC?=$(CLANG_BIN)clang
+else ifeq ($(origin CC),default)
+CC=gcc
 endif
 COPT=-O
 ANTLR=${BIN_DIR}/antlr