[PATCH] BaseTools/tools_def: use separate PP definition for DTC

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Clang's preprocessor behaves differently from GCC's, and produces
intermediate device tree source that still contains #pragma pack()
and other directives that the device tree compiler chokes on.

For assembling device tree sources, it matters very little which
preprocessor is being used, so let's just use GNU CPP explicitly.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
We may need to revisit this in the future, but at present, it is highly
unlikely that someone has DTC installed but not GNU CPP, so for the time
being, this should be a sufficient fix.

 BaseTools/Conf/build_rule.template |  2 +-
 BaseTools/Conf/tools_def.template  | 10 +++-------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/BaseTools/Conf/build_rule.template b/BaseTools/Conf/build_rule.template
index 77ed282e0311..92482341ab11 100755
--- a/BaseTools/Conf/build_rule.template
+++ b/BaseTools/Conf/build_rule.template
@@ -278,7 +278,7 @@
         $(OUTPUT_DIR)(+)${s_dir}(+)${s_base}.dtb
 
     <Command.GCC>
-        "$(PP)" $(DTCPP_FLAGS) $(INC) ${src} > ${d_path}(+)${s_base}.i
+        "$(DTCPP)" $(DTCPP_FLAGS) $(INC) ${src} > ${d_path}(+)${s_base}.i
         "$(DTC)" $(DTC_FLAGS) -I dts -O dtb -o ${dst} ${d_path}(+)${s_base}.i
 
 [Visual-Form-Representation-File]
diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 427ad60b0e26..a5463797c330 100755
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -237,6 +237,7 @@ DEFINE IPHONE_TOOLS            = /Developer/Platforms/iPhoneOS.platform/Develope
 
 DEFINE SOURCERY_CYGWIN_TOOLS = /cygdrive/c/Program Files/CodeSourcery/Sourcery G++ Lite/bin
 
+DEFINE DTCPP_BIN               = ENV(DTCPP_PREFIX)cpp
 DEFINE DTC_BIN                 = ENV(DTC_PREFIX)dtc
 
 ####################################################################################
@@ -4499,6 +4500,8 @@ DEBUG_*_*_OBJCOPY_ADDDEBUGFLAG     = --add-gnu-debuglink=$(DEBUG_DIR)/$(MODULE_N
 RELEASE_*_*_OBJCOPY_ADDDEBUGFLAG   =
 NOOPT_*_*_OBJCOPY_ADDDEBUGFLAG     = --add-gnu-debuglink=$(DEBUG_DIR)/$(MODULE_NAME).debug
 *_*_*_DTC_FLAGS                    = -H epapr
+*_*_*_DTCPP_PATH                   = DEF(DTCPP_BIN)
+*_*_*_DTC_PATH                     = DEF(DTC_BIN)
 
 DEFINE GCC_ALL_CC_FLAGS            = -g -Os -fshort-wchar -fno-builtin -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -include AutoGen.h -fno-common
 DEFINE GCC_IA32_CC_FLAGS           = DEF(GCC_ALL_CC_FLAGS) -m32 -malign-double -freorder-blocks -freorder-blocks-and-partition -O2 -mno-stack-arg-probe
@@ -4912,7 +4915,6 @@ RELEASE_GCC45_X64_CC_FLAGS       = DEF(GCC45_X64_CC_FLAGS) -Os
 *_GCC46_*_MAKE_PATH                    = DEF(GCC46_IA32_PREFIX)make
 *_GCC46_*_*_DLL                        = ENV(GCC46_DLL)
 *_GCC46_*_ASL_PATH                     = DEF(UNIX_IASL_BIN)
-*_GCC46_*_DTC_PATH                     = DEF(DTC_BIN)
 
 *_GCC46_*_PP_FLAGS                     = DEF(GCC_PP_FLAGS)
 *_GCC46_*_ASLPP_FLAGS                  = DEF(GCC_ASLPP_FLAGS)
@@ -5023,7 +5025,6 @@ RELEASE_GCC46_ARM_CC_FLAGS       = DEF(GCC46_ARM_CC_FLAGS) -Wno-unused-but-set-v
 *_GCC47_*_MAKE_PATH                    = DEF(GCC47_IA32_PREFIX)make
 *_GCC47_*_*_DLL                        = ENV(GCC47_DLL)
 *_GCC47_*_ASL_PATH                     = DEF(UNIX_IASL_BIN)
-*_GCC47_*_DTC_PATH                     = DEF(DTC_BIN)
 
 *_GCC47_*_PP_FLAGS                     = DEF(GCC_PP_FLAGS)
 *_GCC47_*_ASLPP_FLAGS                  = DEF(GCC_ASLPP_FLAGS)
@@ -5163,7 +5164,6 @@ RELEASE_GCC47_AARCH64_CC_FLAGS   = DEF(GCC47_AARCH64_CC_FLAGS) -Wno-unused-but-s
 *_GCC48_*_MAKE_PATH                    = DEF(GCC48_IA32_PREFIX)make
 *_GCC48_*_*_DLL                        = ENV(GCC48_DLL)
 *_GCC48_*_ASL_PATH                     = DEF(UNIX_IASL_BIN)
-*_GCC48_*_DTC_PATH                     = DEF(DTC_BIN)
 
 *_GCC48_*_PP_FLAGS                     = DEF(GCC_PP_FLAGS)
 *_GCC48_*_ASLPP_FLAGS                  = DEF(GCC_ASLPP_FLAGS)
@@ -5303,7 +5303,6 @@ RELEASE_GCC48_AARCH64_CC_FLAGS   = DEF(GCC48_AARCH64_CC_FLAGS) -Wno-unused-but-s
 *_GCC49_*_MAKE_PATH                    = DEF(GCC49_IA32_PREFIX)make
 *_GCC49_*_*_DLL                        = ENV(GCC49_DLL)
 *_GCC49_*_ASL_PATH                     = DEF(UNIX_IASL_BIN)
-*_GCC49_*_DTC_PATH                     = DEF(DTC_BIN)
 
 *_GCC49_*_PP_FLAGS                     = DEF(GCC_PP_FLAGS)
 *_GCC49_*_ASLPP_FLAGS                  = DEF(GCC_ASLPP_FLAGS)
@@ -5449,7 +5448,6 @@ RELEASE_GCC49_AARCH64_DLINK_FLAGS  = DEF(GCC49_AARCH64_DLINK_FLAGS)
 *_GCC5_*_MAKE_PATH               = DEF(GCC5_IA32_PREFIX)make
 *_GCC5_*_*_DLL                   = ENV(GCC5_DLL)
 *_GCC5_*_ASL_PATH                = DEF(UNIX_IASL_BIN)
-*_GCC5_*_DTC_PATH                = DEF(DTC_BIN)
 
 *_GCC5_*_PP_FLAGS                = DEF(GCC_PP_FLAGS)
 *_GCC5_*_ASLPP_FLAGS             = DEF(GCC_ASLPP_FLAGS)
@@ -5606,7 +5604,6 @@ RELEASE_GCC5_AARCH64_DLINK_FLAGS = DEF(GCC5_AARCH64_DLINK_FLAGS) -flto -Os -L$(W
 *_CLANG35_*_MAKE_PATH            = make
 *_CLANG35_*_*_DLL                = ENV(CLANG35_DLL)
 *_CLANG35_*_ASL_PATH             = DEF(UNIX_IASL_BIN)
-*_CLANG35_*_DTC_PATH             = DEF(DTC_BIN)
 
 *_CLANG35_*_PP_FLAGS             = DEF(GCC_PP_FLAGS)
 *_CLANG35_*_ASLCC_FLAGS          = DEF(GCC_ASLCC_FLAGS)
@@ -5684,7 +5681,6 @@ RELEASE_CLANG35_AARCH64_CC_FLAGS = DEF(CLANG35_AARCH64_CC_FLAGS) $(ARCHCC_FLAGS)
 *_CLANG38_*_MAKE_PATH               = make
 *_CLANG38_*_*_DLL                   = ENV(CLANG38_DLL)
 *_CLANG38_*_ASL_PATH                = DEF(UNIX_IASL_BIN)
-*_CLANG38_*_DTC_PATH                = DEF(DTC_BIN)
 
 *_CLANG38_*_APP_FLAGS               =
 *_CLANG38_*_ASL_FLAGS               = DEF(IASL_FLAGS)
-- 
2.11.0