llvm-config: Start stubbing out a C++ version of llvm-config (as llvm-config-2,

for now).

 - Mostly complete except for the data that needs to come from the build system
   or the dependencies.

 - Has some small improvements from current llvm-config:

   o Uses TargetRegistry directly to get some information.

   o Designed to work correctly when used from a CMake build tree (relatively
     untested currently) (although pcc fixed this recently for old llvm-config).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143616 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 283 insertions, 1 deletions

diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 49c73b718f..4269ae842b 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -19,6 +19,7 @@ if( NOT WIN32 OR MSYS OR CYGWIN )
   add_subdirectory(llvm-config)
 endif()
 
+add_subdirectory(llvm-config-2)
 add_subdirectory(opt)
 add_subdirectory(llvm-as)
 add_subdirectory(llvm-dis)
diff --git a/tools/Makefile b/tools/Makefile
index 2da3917781..278546bc16 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -34,7 +34,7 @@ PARALLEL_DIRS := opt llvm-as llvm-dis \
                  bugpoint llvm-bcanalyzer llvm-stub \
                  llvm-diff macho-dump llvm-objdump \
 	         llvm-rtdyld llvm-dwarfdump llvm-cov \
-	         llvm-size
+	         llvm-size llvm-config-2
 
 # Let users override the set of tools to build from the command line.
 ifdef ONLY_TOOLS
diff --git a/tools/llvm-config-2/CMakeLists.txt b/tools/llvm-config-2/CMakeLists.txt
new file mode 100644
index 0000000000..a1e083df08
--- /dev/null
+++ b/tools/llvm-config-2/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS support)
+
+add_llvm_tool(llvm-config-2
+  llvm-config.cpp
+  )
diff --git a/tools/llvm-config-2/Makefile b/tools/llvm-config-2/Makefile
new file mode 100644
index 0000000000..e0036a4062
--- /dev/null
+++ b/tools/llvm-config-2/Makefile
@@ -0,0 +1,17 @@
+##===- tools/llvm-config/Makefile---------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+LEVEL := ../..
+TOOLNAME := llvm-config-2
+LINK_COMPONENTS := support
+
+# This tool has no plugins, optimize startup time.
+TOOL_NO_EXPORTS := 1
+
+include $(LEVEL)/Makefile.common
diff --git a/tools/llvm-config-2/llvm-config.cpp b/tools/llvm-config-2/llvm-config.cpp
new file mode 100644
index 0000000000..35bda5026f
--- /dev/null
+++ b/tools/llvm-config-2/llvm-config.cpp
@@ -0,0 +1,259 @@
+//===-- llvm-config.cpp - LLVM project configuration utility --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tool encapsulates information about an LLVM project configuration for
+// use by other project's build environments (to determine installed path,
+// available features, required libraries, etc.).
+//
+// Note that although this tool *may* be used by some parts of LLVM's build
+// itself (i.e., the Makefiles use it to compute required libraries when linking
+// tools), this tool is primarily designed to support external projects.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Config/config.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstdlib>
+#include <vector>
+
+using namespace llvm;
+
+// FIXME: Need to get various bits of build time information.
+const char LLVM_SRC_ROOT[] = "FIXME";
+const char LLVM_OBJ_ROOT[] = "FIXME";
+const char LLVM_CPPFLAGS[] = "FIXME";
+const char LLVM_CFLAGS[] = "FIXME";
+const char LLVM_LDFLAGS[] = "FIXME";
+const char LLVM_CXXFLAGS[] = "FIXME";
+const char LLVM_BUILDMODE[] = "FIXME";
+const char LLVM_SYSTEM_LIBS[] = "FIXME";
+
+// FIXME: Include component table.
+struct AvailableComponent {
+  const char *Name;
+} AvailableComponents[1] = {};
+unsigned NumAvailableComponents = 0;
+
+void ComputeLibsForComponents(const std::vector<StringRef> &Components,
+                              std::vector<StringRef> &RequiredLibs) {
+  // FIXME: Implement.
+  RequiredLibs = Components;
+}
+
+/* *** */
+
+void usage() {
+  errs() << "\
+usage: llvm-config <OPTION>... [<COMPONENT>...]\n\
+\n\
+Get various configuration information needed to compile programs which use\n\
+LLVM.  Typically called from 'configure' scripts.  Examples:\n\
+  llvm-config --cxxflags\n\
+  llvm-config --ldflags\n\
+  llvm-config --libs engine bcreader scalaropts\n\
+\n\
+Options:\n\
+  --version         Print LLVM version.\n\
+  --prefix          Print the installation prefix.\n\
+  --src-root        Print the source root LLVM was built from.\n\
+  --obj-root        Print the object root used to build LLVM.\n\
+  --bindir          Directory containing LLVM executables.\n\
+  --includedir      Directory containing LLVM headers.\n\
+  --libdir          Directory containing LLVM libraries.\n\
+  --cppflags        C preprocessor flags for files that include LLVM headers.\n\
+  --cflags          C compiler flags for files that include LLVM headers.\n\
+  --cxxflags        C++ compiler flags for files that include LLVM headers.\n\
+  --ldflags         Print Linker flags.\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\
+Typical components:\n\
+  all               All LLVM libraries (default).\n\
+  backend           Either a native backend or the C backend.\n\
+  engine            Either a native JIT or a bitcode interpreter.\n";
+  exit(1);
+}
+
+llvm::sys::Path GetExecutablePath(const char *Argv0) {
+  // This just needs to be some symbol in the binary; C++ doesn't
+  // allow taking the address of ::main however.
+  void *P = (void*) (intptr_t) GetExecutablePath;
+  return llvm::sys::Path::GetMainExecutable(Argv0, P);
+}
+
+int main(int argc, char **argv) {
+  std::vector<StringRef> Components;
+  bool PrintLibs = false, PrintLibNames = false, PrintLibFiles = false;
+  bool HasAnyOption = false;
+
+  // llvm-config is designed to support being run both from a development tree
+  // and from an installed path. We try and auto-detect which case we are in so
+  // that we can report the correct information when run from a development
+  // tree.
+  bool IsInDevelopmentTree, DevelopmentTreeLayoutIsCMakeStyle;
+  llvm::SmallString<256> CurrentPath(GetExecutablePath(argv[0]).str());
+  std::string CurrentExecPrefix;
+
+  // Create an absolute path, and pop up one directory (we expect to be inside a
+  // bin dir).
+  sys::fs::make_absolute(CurrentPath);
+  CurrentExecPrefix = sys::path::parent_path(
+    sys::path::parent_path(CurrentPath)).str();
+
+  // Check to see if we are inside a development tree by comparing to possible
+  // locations (prefix style or CMake style). This could be wrong in the face of
+  // symbolic links, but is good enough.
+  if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE) {
+    IsInDevelopmentTree = true;
+    DevelopmentTreeLayoutIsCMakeStyle = false;
+  } else if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/bin") {
+    IsInDevelopmentTree = true;
+    DevelopmentTreeLayoutIsCMakeStyle = true;
+  } else {
+    IsInDevelopmentTree = false;
+  }
+
+  // Compute various directory locations based on the derived location
+  // information.
+  std::string ActivePrefix, ActiveBinDir, ActiveIncludeDir, ActiveLibDir;
+  std::string ActiveIncludeOption;
+  if (IsInDevelopmentTree) {
+    ActivePrefix = CurrentExecPrefix;
+
+    // CMake organizes the products differently than a normal prefix style
+    // layout.
+    if (DevelopmentTreeLayoutIsCMakeStyle) {
+      ActiveIncludeDir = std::string(LLVM_OBJ_ROOT) + "/include";
+      ActiveBinDir = std::string(LLVM_OBJ_ROOT) + "/bin/" + LLVM_BUILDMODE;
+      ActiveLibDir = std::string(LLVM_OBJ_ROOT) + "/lib/" + LLVM_BUILDMODE;
+    } else {
+        ActiveIncludeDir = std::string(LLVM_OBJ_ROOT) + "/include";
+      ActiveBinDir = std::string(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE + "/bin";
+      ActiveLibDir = std::string(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE + "/lib";
+    }
+
+    // We need to include files from both the source and object trees.
+    ActiveIncludeOption = ("-I" + ActiveIncludeDir + " " +
+                           "-I" + LLVM_OBJ_ROOT + "/include");
+  } else {
+    ActivePrefix = CurrentExecPrefix;
+    ActiveIncludeDir = ActivePrefix + "/include";
+    ActiveBinDir = ActivePrefix + "/bin";
+    ActiveLibDir = ActivePrefix + "/lib";
+    ActiveIncludeOption = "-I" + ActiveIncludeDir;
+  }
+
+  raw_ostream &OS = outs();
+  for (int i = 1; i != argc; ++i) {
+    StringRef Arg = argv[i];
+
+    if (Arg.startswith("-")) {
+      HasAnyOption = true;
+      if (Arg == "--version") {
+        OS << PACKAGE_VERSION << '\n';
+      } else if (Arg == "--prefix") {
+        OS << ActivePrefix << '\n';
+      } else if (Arg == "--bindir") {
+        OS << ActiveBinDir << '\n';
+      } else if (Arg == "--includedir") {
+        OS << ActiveIncludeDir << '\n';
+      } else if (Arg == "--libdir") {
+        OS << ActiveLibDir << '\n';
+      } else if (Arg == "--cppflags") {
+        OS << ActiveIncludeOption << ' ' << LLVM_CPPFLAGS << '\n';
+      } else if (Arg == "--cflags") {
+        OS << ActiveIncludeOption << ' ' << LLVM_CFLAGS << '\n';
+      } else if (Arg == "--cxxflags") {
+        OS << ActiveIncludeOption << ' ' << LLVM_CXXFLAGS << '\n';
+      } else if (Arg == "--ldflags") {
+        OS << "-L" << ActiveLibDir << ' ' << LLVM_LDFLAGS
+           << ' ' << LLVM_SYSTEM_LIBS << '\n';
+      } else if (Arg == "--libs") {
+        PrintLibs = true;
+      } else if (Arg == "--libnames") {
+        PrintLibNames = true;
+      } else if (Arg == "--libfiles") {
+        PrintLibFiles = true;
+      } else if (Arg == "--components") {
+        for (unsigned j = 0; j != NumAvailableComponents; ++j) {
+          if (j)
+            OS << ' ';
+          OS << AvailableComponents[j].Name;
+        }
+        OS << '\n';
+      } else if (Arg == "--targets-built") {
+        bool First = true;
+        for (TargetRegistry::iterator I = TargetRegistry::begin(),
+               E = TargetRegistry::end(); I != E; First = false, ++I) {
+          if (!First)
+            OS << ' ';
+          OS << I->getName();
+        }
+        OS << '\n';
+      } else if (Arg == "--host-target") {
+        OS << LLVM_DEFAULT_TARGET_TRIPLE << '\n';
+      } else if (Arg == "--build-mode") {
+        OS << LLVM_BUILDMODE << '\n';
+      } else if (Arg == "--obj-root") {
+        OS << LLVM_OBJ_ROOT << '\n';
+      } else if (Arg == "--src-root") {
+        OS << LLVM_SRC_ROOT << '\n';
+      } else {
+        usage();
+      }
+    } else {
+      Components.push_back(Arg);
+    }
+  }
+
+  if (!HasAnyOption)
+    usage();
+
+  if (PrintLibs || PrintLibNames || PrintLibFiles) {
+    // Construct the list of all the required libraries.
+    std::vector<StringRef> RequiredLibs;
+    ComputeLibsForComponents(Components, RequiredLibs);
+
+    for (unsigned i = 0, e = RequiredLibs.size(); i != e; ++i) {
+      StringRef Lib = RequiredLibs[i];
+      if (i)
+        OS << ' ';
+
+      if (PrintLibs) {
+        OS << Lib;
+      } else if (PrintLibFiles) {
+        OS << ActiveLibDir << Lib;
+      } else if (PrintLibNames) {
+        // If this is a typical library name, include it using -l.
+        if (Lib.startswith("lib") && Lib.endswith(".a")) {
+          OS << "-l" << Lib.slice(3, Lib.size()-2);
+          continue;
+        }
+        
+        // Otherwise, print the full path.
+        OS << ActiveLibDir << Lib;
+      }
+    }
+  } else if (!Components.empty()) {
+    errs() << "llvm-config: error: components given, but unused\n\n";
+    usage();
+  }
+
+  return 0;
+}