[lldb][test] 2 - Allow multiple precompiled headers in API tests via PCH_CXX_SOURCE

[Michael137]

Summary

Currently we only allow a single PCH file to be
specified in an API test since Clang's -include
option doesn't accept multple arguments. Instead
add a include-pch prefix to each input PCH file.

Drive-by change:

• Rename PCH_CXX_SOURCE to PCH_CXX_SOURCES to make the variable's usage clearer

Testing:

• Confirmed that the dwarfdump with and without the patch are identical for the only API test in the test-suite that uses PCH_CXX_SOURCE

[Michael137]

Actually realised this isn't necessary...abandoning

lldb/packages/Python/lldbsuite/test/make/Makefile.rules

 DYLIB_OBJECTS +=$(strip $(DYLIB_OBJC_SOURCES:.m=.o))
 ifneq "$(strip $(DYLIB_CXX_SOURCES))" ""
   DYLIB_OBJECTS +=$(strip $(patsubst %.mm, %.o, $(DYLIB_CXX_SOURCES:.cpp=.o)))
   CXX = $(call cxx_compiler,$(CC))
   LD = $(call cxx_linker,$(CC))
 endif
 
 #----------------------------------------------------------------------
-# Check if we have a precompiled header
+# Check if we have a precompiled headers
 #----------------------------------------------------------------------
-ifneq "$(strip $(PCH_CXX_SOURCE))" ""
-  PCH_OUTPUT = $(PCH_CXX_SOURCE:.h=.h.pch)
-  PCHFLAGS = -include $(PCH_CXX_SOURCE)
+ifneq "$(strip $(PCH_CXX_SOURCES))" ""
+  PCH_OUTPUT = $(PCH_CXX_SOURCES:.h=.h.pch)
+  PCHFLAGS = $(addprefix -include-pch , $(PCH_OUTPUT))
 endif
 
 #----------------------------------------------------------------------
 # Check if we have any C source files
 #----------------------------------------------------------------------
 ifneq "$(strip $(C_SOURCES))" ""
   OBJECTS +=$(strip $(C_SOURCES:.c=.o))
 endif
else
   $(LD) $(DYLIB_OBJECTS) $(LDFLAGS) -shared -o "$(DYLIB_FILENAME)"
 ifeq "$(SPLIT_DEBUG_SYMBOLS)" "YES"
   $(OBJCOPY) --only-keep-debug "$(DYLIB_FILENAME)" "$(DYLIB_FILENAME).debug"
   $(OBJCOPY) --strip-debug --add-gnu-debuglink="$(DYLIB_FILENAME).debug" "$(DYLIB_FILENAME)" "$(DYLIB_FILENAME)"
 endif
 endif
 
 #----------------------------------------------------------------------
-# Make the precompiled header and compile C++ sources against it
+# Make the precompiled headers and compile C++ sources against it
 #----------------------------------------------------------------------
 
 ifneq "$(PCH_OUTPUT)" ""
-$(PCH_OUTPUT) : $(PCH_CXX_SOURCE)
+$(PCH_OUTPUT) : $(PCH_CXX_SOURCES)
   $(CXX) $(CXXFLAGS) -x c++-header -o $@ $<
 endif
 
 %.o: %.c %.d
   $(CC) $(CFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<
 
 %.o: %.cpp %.d $(PCH_OUTPUT)
   $(CXX) $(PCHFLAGS) $(CXXFLAGS) -MT $@ -MD -MP -MF $*.d -c -o $@ $<

lldb/test/API/lang/cpp/gmodules/basic/Makefile

-PCH_CXX_SOURCE = pch.h
+PCH_CXX_SOURCES = pch.h
 CXX_SOURCES = main.cpp
 CFLAGS_EXTRAS := $(MODULE_DEBUG_INFO_FLAGS)
 
 include Makefile.rules