llvm-config: Replace with C++ version (was llvm-config-2).

 - Reapply of r144300, with lots of fixes/migration easement in between.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145449 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 335 insertions, 0 deletions

diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
new file mode 100644
index 0000000..fddd481
--- /dev/null
+++ b/tools/llvm-config/llvm-config.cpp
@@ -0,0 +1,335 @@
+//===-- 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/STLExtras.h"
+#include "llvm/ADT/StringMap.h"
+#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 <set>
+#include <vector>
+
+using namespace llvm;
+
+// Include the build time variables we can report to the user. This is generated
+// at build time from the BuildVariables.inc.in file by the build system.
+#include "BuildVariables.inc"
+
+// Include the component table. This creates an array of struct
+// AvailableComponent entries, which record the component name, library name,
+// and required components for all of the available libraries.
+//
+// Not all components define a library, we also use "library groups" as a way to
+// create entries for pseudo groups like x86 or all-targets.
+#include "LibraryDependencies.inc"
+
+/// \brief Traverse a single component adding to the topological ordering in
+/// \arg RequiredLibs.
+///
+/// \param Name - The component to traverse.
+/// \param ComponentMap - A prebuilt map of component names to descriptors.
+/// \param VisitedComponents [in] [out] - The set of already visited components.
+/// \param RequiredLibs [out] - The ordered list of required libraries.
+static void VisitComponent(StringRef Name,
+                           const StringMap<AvailableComponent*> &ComponentMap,
+                           std::set<AvailableComponent*> &VisitedComponents,
+                           std::vector<StringRef> &RequiredLibs) {
+  // Lookup the component.
+  AvailableComponent *AC = ComponentMap.lookup(Name);
+  assert(AC && "Invalid component name!");
+
+  // Add to the visited table.
+  if (!VisitedComponents.insert(AC).second) {
+    // We are done if the component has already been visited.
+    return;
+  }
+
+  // Otherwise, visit all the dependencies.
+  for (unsigned i = 0; AC->RequiredLibraries[i]; ++i) {
+    VisitComponent(AC->RequiredLibraries[i], ComponentMap, VisitedComponents,
+                   RequiredLibs);
+  }
+
+  // Add to the required library list.
+  if (AC->Library)
+    RequiredLibs.push_back(AC->Library);
+}
+
+/// \brief Compute the list of required libraries for a given list of
+/// components, in an order suitable for passing to a linker (that is, libraries
+/// appear prior to their dependencies).
+///
+/// \param Components - The names of the components to find libraries for.
+/// \param RequiredLibs [out] - On return, the ordered list of libraries that
+/// are required to link the given components.
+void ComputeLibsForComponents(const std::vector<StringRef> &Components,
+                              std::vector<StringRef> &RequiredLibs) {
+  std::set<AvailableComponent*> VisitedComponents;
+
+  // Build a map of component names to information.
+  StringMap<AvailableComponent*> ComponentMap;
+  for (unsigned i = 0; i != array_lengthof(AvailableComponents); ++i) {
+    AvailableComponent *AC = &AvailableComponents[i];
+    ComponentMap[AC->Name] = AC;
+  }
+
+  // Visit the components.
+  for (unsigned i = 0, e = Components.size(); i != e; ++i) {
+    // Users are allowed to provide mixed case component names.
+    std::string ComponentLower = Components[i].lower();
+
+    // Validate that the user supplied a valid component name.
+    if (!ComponentMap.count(ComponentLower)) {
+      llvm::errs() << "llvm-config: unknown component name: " << Components[i]
+                   << "\n";
+      exit(1);
+    }
+
+    VisitComponent(ComponentLower, ComponentMap, VisitedComponents,
+                   RequiredLibs);
+  }
+
+  // The list is now ordered with leafs first, we want the libraries to printed
+  // in the reverse order of dependency.
+  std::reverse(RequiredLibs.begin(), RequiredLibs.end());
+}
+
+/* *** */
+
+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);
+}
+
+/// \brief Compute the path to the main executable.
+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;
+  std::string ActiveObjRoot;
+
+  // 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;
+
+    // If we are in a development tree, then check if we are in a BuildTools
+    // directory. This indicates we are built for the build triple, but we
+    // always want to provide information for the host triple.
+    if (sys::path::filename(LLVM_OBJ_ROOT) == "BuildTools") {
+      ActiveObjRoot = sys::path::parent_path(LLVM_OBJ_ROOT);
+    } else {
+      ActiveObjRoot = LLVM_OBJ_ROOT;
+    }
+  } else if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/bin") {
+    IsInDevelopmentTree = true;
+    DevelopmentTreeLayoutIsCMakeStyle = true;
+    ActiveObjRoot = LLVM_OBJ_ROOT;
+  } 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 = ActiveObjRoot + "/include";
+      ActiveBinDir = ActiveObjRoot + "/bin/" + LLVM_BUILDMODE;
+      ActiveLibDir = ActiveObjRoot + "/lib/" + LLVM_BUILDMODE;
+    } else {
+      ActiveIncludeDir = ActiveObjRoot + "/include";
+      ActiveBinDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/bin";
+      ActiveLibDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/lib";
+    }
+
+    // We need to include files from both the source and object trees.
+    ActiveIncludeOption = ("-I" + ActiveIncludeDir + " " +
+                           "-I" + ActiveObjRoot + "/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 != array_lengthof(AvailableComponents); ++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 (PrintLibNames) {
+        OS << Lib;
+      } else if (PrintLibFiles) {
+        OS << ActiveLibDir << '/' << Lib;
+      } else if (PrintLibs) {
+        // 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;
+      }
+    }
+    OS << '\n';
+  } else if (!Components.empty()) {
+    errs() << "llvm-config: error: components given, but unused\n\n";
+    usage();
+  }
+
+  return 0;
+}