llvm-config.cpp revision 2662c83a594b5df8deef2a540595a5faa72cfbdc
1//===-- llvm-config.cpp - LLVM project configuration utility --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This tool encapsulates information about an LLVM project configuration for
11// use by other project's build environments (to determine installed path,
12// available features, required libraries, etc.).
13//
14// Note that although this tool *may* be used by some parts of LLVM's build
15// itself (i.e., the Makefiles use it to compute required libraries when linking
16// tools), this tool is primarily designed to support external projects.
17//
18//===----------------------------------------------------------------------===//
19
20#include "llvm/ADT/STLExtras.h"
21#include "llvm/ADT/StringMap.h"
22#include "llvm/ADT/StringRef.h"
23#include "llvm/ADT/Twine.h"
24#include "llvm/Config/config.h"
25#include "llvm/Config/llvm-config.h"
26#include "llvm/Support/FileSystem.h"
27#include "llvm/Support/Path.h"
28#include "llvm/Support/TargetRegistry.h"
29#include "llvm/Support/raw_ostream.h"
30#include <cstdlib>
31#include <set>
32#include <vector>
33
34using namespace llvm;
35
36// Include the build time variables we can report to the user. This is generated
37// at build time from the BuildVariables.inc.in file by the build system.
38#include "BuildVariables.inc"
39
40// Include the component table. This creates an array of struct
41// AvailableComponent entries, which record the component name, library name,
42// and required components for all of the available libraries.
43//
44// Not all components define a library, we also use "library groups" as a way to
45// create entries for pseudo groups like x86 or all-targets.
46#include "LibraryDependencies.inc"
47
48/// \brief Traverse a single component adding to the topological ordering in
49/// \arg RequiredLibs.
50///
51/// \param Name - The component to traverse.
52/// \param ComponentMap - A prebuilt map of component names to descriptors.
53/// \param VisitedComponents [in] [out] - The set of already visited components.
54/// \param RequiredLibs [out] - The ordered list of required libraries.
55static void VisitComponent(StringRef Name,
56                           const StringMap<AvailableComponent*> &ComponentMap,
57                           std::set<AvailableComponent*> &VisitedComponents,
58                           std::vector<StringRef> &RequiredLibs) {
59  // Lookup the component.
60  AvailableComponent *AC = ComponentMap.lookup(Name);
61  assert(AC && "Invalid component name!");
62
63  // Add to the visited table.
64  if (!VisitedComponents.insert(AC).second) {
65    // We are done if the component has already been visited.
66    return;
67  }
68
69  // Otherwise, visit all the dependencies.
70  for (unsigned i = 0; AC->RequiredLibraries[i]; ++i) {
71    VisitComponent(AC->RequiredLibraries[i], ComponentMap, VisitedComponents,
72                   RequiredLibs);
73  }
74
75  // Add to the required library list.
76  if (AC->Library)
77    RequiredLibs.push_back(AC->Library);
78}
79
80/// \brief Compute the list of required libraries for a given list of
81/// components, in an order suitable for passing to a linker (that is, libraries
82/// appear prior to their dependencies).
83///
84/// \param Components - The names of the components to find libraries for.
85/// \param RequiredLibs [out] - On return, the ordered list of libraries that
86/// are required to link the given components.
87void ComputeLibsForComponents(const std::vector<StringRef> &Components,
88                              std::vector<StringRef> &RequiredLibs) {
89  std::set<AvailableComponent*> VisitedComponents;
90
91  // Build a map of component names to information.
92  StringMap<AvailableComponent*> ComponentMap;
93  for (unsigned i = 0; i != array_lengthof(AvailableComponents); ++i) {
94    AvailableComponent *AC = &AvailableComponents[i];
95    ComponentMap[AC->Name] = AC;
96  }
97
98  // Visit the components.
99  for (unsigned i = 0, e = Components.size(); i != e; ++i) {
100    // Users are allowed to provide mixed case component names.
101    std::string ComponentLower = Components[i].lower();
102
103    // Validate that the user supplied a valid component name.
104    if (!ComponentMap.count(ComponentLower)) {
105      llvm::errs() << "llvm-config: unknown component name: " << Components[i]
106                   << "\n";
107      exit(1);
108    }
109
110    VisitComponent(ComponentLower, ComponentMap, VisitedComponents,
111                   RequiredLibs);
112  }
113
114  // The list is now ordered with leafs first, we want the libraries to printed
115  // in the reverse order of dependency.
116  std::reverse(RequiredLibs.begin(), RequiredLibs.end());
117}
118
119/* *** */
120
121void usage() {
122  errs() << "\
123usage: llvm-config <OPTION>... [<COMPONENT>...]\n\
124\n\
125Get various configuration information needed to compile programs which use\n\
126LLVM.  Typically called from 'configure' scripts.  Examples:\n\
127  llvm-config --cxxflags\n\
128  llvm-config --ldflags\n\
129  llvm-config --libs engine bcreader scalaropts\n\
130\n\
131Options:\n\
132  --version         Print LLVM version.\n\
133  --prefix          Print the installation prefix.\n\
134  --src-root        Print the source root LLVM was built from.\n\
135  --obj-root        Print the object root used to build LLVM.\n\
136  --bindir          Directory containing LLVM executables.\n\
137  --includedir      Directory containing LLVM headers.\n\
138  --libdir          Directory containing LLVM libraries.\n\
139  --cppflags        C preprocessor flags for files that include LLVM headers.\n\
140  --cflags          C compiler flags for files that include LLVM headers.\n\
141  --cxxflags        C++ compiler flags for files that include LLVM headers.\n\
142  --ldflags         Print Linker flags.\n\
143  --libs            Libraries needed to link against LLVM components.\n\
144  --libnames        Bare library names for in-tree builds.\n\
145  --libfiles        Fully qualified library filenames for makefile depends.\n\
146  --components      List of all possible components.\n\
147  --targets-built   List of all targets currently built.\n\
148  --host-target     Target triple used to configure LLVM.\n\
149  --build-mode      Print build mode of LLVM tree (e.g. Debug or Release).\n\
150Typical components:\n\
151  all               All LLVM libraries (default).\n\
152  backend           Either a native backend or the C backend.\n\
153  engine            Either a native JIT or a bitcode interpreter.\n";
154  exit(1);
155}
156
157/// \brief Compute the path to the main executable.
158llvm::sys::Path GetExecutablePath(const char *Argv0) {
159  // This just needs to be some symbol in the binary; C++ doesn't
160  // allow taking the address of ::main however.
161  void *P = (void*) (intptr_t) GetExecutablePath;
162  return llvm::sys::Path::GetMainExecutable(Argv0, P);
163}
164
165int main(int argc, char **argv) {
166  std::vector<StringRef> Components;
167  bool PrintLibs = false, PrintLibNames = false, PrintLibFiles = false;
168  bool HasAnyOption = false;
169
170  // llvm-config is designed to support being run both from a development tree
171  // and from an installed path. We try and auto-detect which case we are in so
172  // that we can report the correct information when run from a development
173  // tree.
174  bool IsInDevelopmentTree, DevelopmentTreeLayoutIsCMakeStyle;
175  llvm::SmallString<256> CurrentPath(GetExecutablePath(argv[0]).str());
176  std::string CurrentExecPrefix;
177  std::string ActiveObjRoot;
178
179  // Create an absolute path, and pop up one directory (we expect to be inside a
180  // bin dir).
181  sys::fs::make_absolute(CurrentPath);
182  CurrentExecPrefix = sys::path::parent_path(
183    sys::path::parent_path(CurrentPath)).str();
184
185  // Check to see if we are inside a development tree by comparing to possible
186  // locations (prefix style or CMake style). This could be wrong in the face of
187  // symbolic links, but is good enough.
188  if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE) {
189    IsInDevelopmentTree = true;
190    DevelopmentTreeLayoutIsCMakeStyle = false;
191
192    // If we are in a development tree, then check if we are in a BuildTools
193    // directory. This indicates we are built for the build triple, but we
194    // always want to provide information for the host triple.
195    if (sys::path::filename(LLVM_OBJ_ROOT) == "BuildTools") {
196      ActiveObjRoot = sys::path::parent_path(LLVM_OBJ_ROOT);
197    } else {
198      ActiveObjRoot = LLVM_OBJ_ROOT;
199    }
200  } else if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/bin") {
201    IsInDevelopmentTree = true;
202    DevelopmentTreeLayoutIsCMakeStyle = true;
203    ActiveObjRoot = LLVM_OBJ_ROOT;
204  } else {
205    IsInDevelopmentTree = false;
206  }
207
208  // Compute various directory locations based on the derived location
209  // information.
210  std::string ActivePrefix, ActiveBinDir, ActiveIncludeDir, ActiveLibDir;
211  std::string ActiveIncludeOption;
212  if (IsInDevelopmentTree) {
213    ActivePrefix = CurrentExecPrefix;
214
215    // CMake organizes the products differently than a normal prefix style
216    // layout.
217    if (DevelopmentTreeLayoutIsCMakeStyle) {
218      ActiveIncludeDir = ActiveObjRoot + "/include";
219      ActiveBinDir = ActiveObjRoot + "/bin/" + LLVM_BUILDMODE;
220      ActiveLibDir = ActiveObjRoot + "/lib/" + LLVM_BUILDMODE;
221    } else {
222      ActiveIncludeDir = ActiveObjRoot + "/include";
223      ActiveBinDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/bin";
224      ActiveLibDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/lib";
225    }
226
227    // We need to include files from both the source and object trees.
228    ActiveIncludeOption = ("-I" + ActiveIncludeDir + " " +
229                           "-I" + ActiveObjRoot + "/include");
230  } else {
231    ActivePrefix = CurrentExecPrefix;
232    ActiveIncludeDir = ActivePrefix + "/include";
233    ActiveBinDir = ActivePrefix + "/bin";
234    ActiveLibDir = ActivePrefix + "/lib";
235    ActiveIncludeOption = "-I" + ActiveIncludeDir;
236  }
237
238  raw_ostream &OS = outs();
239  for (int i = 1; i != argc; ++i) {
240    StringRef Arg = argv[i];
241
242    if (Arg.startswith("-")) {
243      HasAnyOption = true;
244      if (Arg == "--version") {
245        OS << PACKAGE_VERSION << '\n';
246      } else if (Arg == "--prefix") {
247        OS << ActivePrefix << '\n';
248      } else if (Arg == "--bindir") {
249        OS << ActiveBinDir << '\n';
250      } else if (Arg == "--includedir") {
251        OS << ActiveIncludeDir << '\n';
252      } else if (Arg == "--libdir") {
253        OS << ActiveLibDir << '\n';
254      } else if (Arg == "--cppflags") {
255        OS << ActiveIncludeOption << ' ' << LLVM_CPPFLAGS << '\n';
256      } else if (Arg == "--cflags") {
257        OS << ActiveIncludeOption << ' ' << LLVM_CFLAGS << '\n';
258      } else if (Arg == "--cxxflags") {
259        OS << ActiveIncludeOption << ' ' << LLVM_CXXFLAGS << '\n';
260      } else if (Arg == "--ldflags") {
261        OS << "-L" << ActiveLibDir << ' ' << LLVM_LDFLAGS
262           << ' ' << LLVM_SYSTEM_LIBS << '\n';
263      } else if (Arg == "--libs") {
264        PrintLibs = true;
265      } else if (Arg == "--libnames") {
266        PrintLibNames = true;
267      } else if (Arg == "--libfiles") {
268        PrintLibFiles = true;
269      } else if (Arg == "--components") {
270        for (unsigned j = 0; j != array_lengthof(AvailableComponents); ++j) {
271          OS << ' ';
272          OS << AvailableComponents[j].Name;
273        }
274        OS << '\n';
275      } else if (Arg == "--targets-built") {
276        bool First = true;
277        for (TargetRegistry::iterator I = TargetRegistry::begin(),
278               E = TargetRegistry::end(); I != E; First = false, ++I) {
279          if (!First)
280            OS << ' ';
281          OS << I->getName();
282        }
283        OS << '\n';
284      } else if (Arg == "--host-target") {
285        OS << LLVM_DEFAULT_TARGET_TRIPLE << '\n';
286      } else if (Arg == "--build-mode") {
287        OS << LLVM_BUILDMODE << '\n';
288      } else if (Arg == "--obj-root") {
289        OS << LLVM_OBJ_ROOT << '\n';
290      } else if (Arg == "--src-root") {
291        OS << LLVM_SRC_ROOT << '\n';
292      } else {
293        usage();
294      }
295    } else {
296      Components.push_back(Arg);
297    }
298  }
299
300  if (!HasAnyOption)
301    usage();
302
303  if (PrintLibs || PrintLibNames || PrintLibFiles) {
304    // Construct the list of all the required libraries.
305    std::vector<StringRef> RequiredLibs;
306    ComputeLibsForComponents(Components, RequiredLibs);
307
308    for (unsigned i = 0, e = RequiredLibs.size(); i != e; ++i) {
309      StringRef Lib = RequiredLibs[i];
310      if (i)
311        OS << ' ';
312
313      if (PrintLibNames) {
314        OS << Lib;
315      } else if (PrintLibFiles) {
316        OS << ActiveLibDir << '/' << Lib;
317      } else if (PrintLibs) {
318        // If this is a typical library name, include it using -l.
319        if (Lib.startswith("lib") && Lib.endswith(".a")) {
320          OS << "-l" << Lib.slice(3, Lib.size()-2);
321          continue;
322        }
323
324        // Otherwise, print the full path.
325        OS << ActiveLibDir << '/' << Lib;
326      }
327    }
328    OS << '\n';
329  } else if (!Components.empty()) {
330    errs() << "llvm-config: error: components given, but unused\n\n";
331    usage();
332  }
333
334  return 0;
335}
336