llvm-config: Add --build-system option

[• tstellarAMD]

Summary

This can be used for distinguishing between cmake and autoconf builds.
Users may need this in order to handle inconsistencies between the
outputs of the two build systems.

[beanz]

LGTM. I suspect that behavioral differences between CMake and autoconf will probably exist until we remove the autoconf system, so this flag is probably an all-around good idea.

At the very least it will be potentially useful for debugging issues with distributed packages because llvm-config will be able to report which build system was used to generate the package.

Thanks,
-Chris

llvm/trunk/tools/llvm-config/BuildVariables.inc.in

 #define LLVM_CPPFLAGS "@LLVM_CPPFLAGS@"
 #define LLVM_CFLAGS "@LLVM_CFLAGS@"
 #define LLVM_LDFLAGS "@LLVM_LDFLAGS@"
 #define LLVM_CXXFLAGS "@LLVM_CXXFLAGS@"
 #define LLVM_BUILDMODE "@LLVM_BUILDMODE@"
 #define LLVM_LIBDIR_SUFFIX "@LLVM_LIBDIR_SUFFIX@"
 #define LLVM_TARGETS_BUILT "@LLVM_TARGETS_BUILT@"
 #define LLVM_SYSTEM_LIBS "@LLVM_SYSTEM_LIBS@"
+#define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"

llvm/trunk/tools/llvm-config/CMakeLists.txt

 get_property(COMPILE_FLAGS TARGET llvm-config PROPERTY COMPILE_FLAGS)
 
 # Use configure_file to create BuildVariables.inc.
 set(LLVM_SRC_ROOT ${LLVM_MAIN_SRC_DIR})
 set(LLVM_OBJ_ROOT ${LLVM_BINARY_DIR})
 set(LLVM_CPPFLAGS "${CMAKE_CPP_FLAGS} ${CMAKE_CPP_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
 set(LLVM_CFLAGS "${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
 set(LLVM_CXXFLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${COMPILE_FLAGS} ${LLVM_DEFINITIONS}")
+set(LLVM_BUILD_SYSTEM cmake)
+
 # Use the C++ link flags, since they should be a superset of C link flags.
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")
 set(LLVM_BUILDMODE ${CMAKE_BUILD_TYPE})
 set(LLVM_SYSTEM_LIBS ${SYSTEM_LIBS})
 string(REPLACE ";" " " LLVM_TARGETS_BUILT "${LLVM_TARGETS_TO_BUILD}")
 configure_file(${BUILDVARIABLES_SRCPATH} ${BUILDVARIABLES_OBJPATH} @ONLY)
 
 # Set build-time environment(s).

llvm/trunk/tools/llvm-config/Makefile

$(ObjDir)/BuildVariables.inc: $(BUILDVARIABLES_SRCPATH) Makefile $(ObjDir)/.dir
   $(Verb) $(ECHO) 's/@LLVM_BUILDMODE@/$(subst /,\/,$(BuildMode))/' \
     >> temp.sed
   $(Verb) $(ECHO) 's/@LLVM_LIBDIR_SUFFIX@//' \
     >> temp.sed
   $(Verb) $(ECHO) 's/@LLVM_SYSTEM_LIBS@/$(subst /,\/,$(LLVM_SYSTEM_LIBS))/' \
     >> temp.sed
   $(Verb) $(ECHO) 's/@LLVM_TARGETS_BUILT@/$(subst /,\/,$(TARGETS_TO_BUILD))/' \
     >> temp.sed
+  $(Verb) $(ECHO) 's/@LLVM_BUILD_SYSTEM@/autoconf/' \
+    >> temp.sed
   $(Verb) $(SED) -f temp.sed < $< > $@
   $(Verb) $(RM) temp.sed
 
 # When cross-compiling, install a version of llvm-config that runs on the host.
 ifeq ($(LLVM_CROSS_COMPILING),1)
 install:: $(DESTDIR)$(PROJ_bindir)
   $(Echo) Installing llvm-config-host
   $(Verb) $(ProgInstall) $(BuildLLVMToolDir)/llvm-config \
     $(DESTDIR)$(PROJ_bindir)/$(program_prefix)llvm-config-host
 endif

llvm/trunk/tools/llvm-config/llvm-config.cpp

Options:\n\
   --libs            Libraries needed to link against LLVM components.\n\
   --libnames        Bare library names for in-tree builds.\n\
   --libfiles        Fully qualified library filenames for makefile depends.\n\
   --components      List of all possible components.\n\
   --targets-built   List of all targets currently built.\n\
   --host-target     Target triple used to configure LLVM.\n\
   --build-mode      Print build mode of LLVM tree (e.g. Debug or Release).\n\
   --assertion-mode  Print assertion mode of LLVM tree (ON or OFF).\n\
+  --build-system    Print the build system used to build LLVM (autoconf or cmake).\n\
 Typical components:\n\
   all               All LLVM libraries (default).\n\
   engine            Either a native JIT or a bitcode interpreter.\n";
   exit(1);
 }
 
 /// \brief Compute the path to the main executable.
 std::string GetExecutablePath(const char *Argv0) {
if (Arg.startswith("-")) {
       } else if (Arg == "--build-mode") {
         OS << build_mode << '\n';
       } else if (Arg == "--assertion-mode") {
 #if defined(NDEBUG)
         OS << "OFF\n";
 #else
         OS << "ON\n";
 #endif
+      } else if (Arg == "--build-system") {
+        OS << LLVM_BUILD_SYSTEM << '\n';
       } else if (Arg == "--obj-root") {
         OS << ActivePrefix << '\n';
       } else if (Arg == "--src-root") {
         OS << LLVM_SRC_ROOT << '\n';
       } else {
         usage();
       }
     } else {