llvm-config.cpp revision 50188c1f42c122640ab9ccac2134acf371c26b2c
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/PathV1.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                           bool IncludeNonInstalled) {
60  // Lookup the component.
61  AvailableComponent *AC = ComponentMap.lookup(Name);
62  assert(AC && "Invalid component name!");
63
64  // Add to the visited table.
65  if (!VisitedComponents.insert(AC).second) {
66    // We are done if the component has already been visited.
67    return;
68  }
69
70  // Only include non-installed components if requested.
71  if (!AC->IsInstalled && !IncludeNonInstalled)
72    return;
73
74  // Otherwise, visit all the dependencies.
75  for (unsigned i = 0; AC->RequiredLibraries[i]; ++i) {
76    VisitComponent(AC->RequiredLibraries[i], ComponentMap, VisitedComponents,
77                   RequiredLibs, IncludeNonInstalled);
78  }
79
80  // Add to the required library list.
81  if (AC->Library)
82    RequiredLibs.push_back(AC->Library);
83}
84
85/// \brief Compute the list of required libraries for a given list of
86/// components, in an order suitable for passing to a linker (that is, libraries
87/// appear prior to their dependencies).
88///
89/// \param Components - The names of the components to find libraries for.
90/// \param RequiredLibs [out] - On return, the ordered list of libraries that
91/// are required to link the given components.
92/// \param IncludeNonInstalled - Whether non-installed components should be
93/// reported.
94void ComputeLibsForComponents(const std::vector<StringRef> &Components,
95                              std::vector<StringRef> &RequiredLibs,
96                              bool IncludeNonInstalled) {
97  std::set<AvailableComponent*> VisitedComponents;
98
99  // Build a map of component names to information.
100  StringMap<AvailableComponent*> ComponentMap;
101  for (unsigned i = 0; i != array_lengthof(AvailableComponents); ++i) {
102    AvailableComponent *AC = &AvailableComponents[i];
103    ComponentMap[AC->Name] = AC;
104  }
105
106  // Visit the components.
107  for (unsigned i = 0, e = Components.size(); i != e; ++i) {
108    // Users are allowed to provide mixed case component names.
109    std::string ComponentLower = Components[i].lower();
110
111    // Validate that the user supplied a valid component name.
112    if (!ComponentMap.count(ComponentLower)) {
113      llvm::errs() << "llvm-config: unknown component name: " << Components[i]
114                   << "\n";
115      exit(1);
116    }
117
118    VisitComponent(ComponentLower, ComponentMap, VisitedComponents,
119                   RequiredLibs, IncludeNonInstalled);
120  }
121
122  // The list is now ordered with leafs first, we want the libraries to printed
123  // in the reverse order of dependency.
124  std::reverse(RequiredLibs.begin(), RequiredLibs.end());
125}
126
127/* *** */
128
129void usage() {
130  errs() << "\
131usage: llvm-config <OPTION>... [<COMPONENT>...]\n\
132\n\
133Get various configuration information needed to compile programs which use\n\
134LLVM.  Typically called from 'configure' scripts.  Examples:\n\
135  llvm-config --cxxflags\n\
136  llvm-config --ldflags\n\
137  llvm-config --libs engine bcreader scalaropts\n\
138\n\
139Options:\n\
140  --version         Print LLVM version.\n\
141  --prefix          Print the installation prefix.\n\
142  --src-root        Print the source root LLVM was built from.\n\
143  --obj-root        Print the object root used to build LLVM.\n\
144  --bindir          Directory containing LLVM executables.\n\
145  --includedir      Directory containing LLVM headers.\n\
146  --libdir          Directory containing LLVM libraries.\n\
147  --cppflags        C preprocessor flags for files that include LLVM headers.\n\
148  --cflags          C compiler flags for files that include LLVM headers.\n\
149  --cxxflags        C++ compiler flags for files that include LLVM headers.\n\
150  --ldflags         Print Linker flags.\n\
151  --libs            Libraries needed to link against LLVM components.\n\
152  --libnames        Bare library names for in-tree builds.\n\
153  --libfiles        Fully qualified library filenames for makefile depends.\n\
154  --components      List of all possible components.\n\
155  --targets-built   List of all targets currently built.\n\
156  --host-target     Target triple used to configure LLVM.\n\
157  --build-mode      Print build mode of LLVM tree (e.g. Debug or Release).\n\
158Typical components:\n\
159  all               All LLVM libraries (default).\n\
160  engine            Either a native JIT or a bitcode interpreter.\n";
161  exit(1);
162}
163
164/// \brief Compute the path to the main executable.
165std::string GetExecutablePath(const char *Argv0) {
166  // This just needs to be some symbol in the binary; C++ doesn't
167  // allow taking the address of ::main however.
168  void *P = (void*) (intptr_t) GetExecutablePath;
169  return llvm::sys::fs::getMainExecutable(Argv0, P);
170}
171
172int main(int argc, char **argv) {
173  std::vector<StringRef> Components;
174  bool PrintLibs = false, PrintLibNames = false, PrintLibFiles = false;
175  bool HasAnyOption = false;
176
177  // llvm-config is designed to support being run both from a development tree
178  // and from an installed path. We try and auto-detect which case we are in so
179  // that we can report the correct information when run from a development
180  // tree.
181  bool IsInDevelopmentTree;
182  enum { MakefileStyle, CMakeStyle, CMakeBuildModeStyle } DevelopmentTreeLayout;
183  llvm::SmallString<256> CurrentPath(GetExecutablePath(argv[0]));
184  std::string CurrentExecPrefix;
185  std::string ActiveObjRoot;
186
187  // Create an absolute path, and pop up one directory (we expect to be inside a
188  // bin dir).
189  sys::fs::make_absolute(CurrentPath);
190  CurrentExecPrefix = sys::path::parent_path(
191    sys::path::parent_path(CurrentPath)).str();
192
193  // Check to see if we are inside a development tree by comparing to possible
194  // locations (prefix style or CMake style).
195  if (sys::fs::equivalent(CurrentExecPrefix,
196                          Twine(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE)) {
197    IsInDevelopmentTree = true;
198    DevelopmentTreeLayout = MakefileStyle;
199
200    // If we are in a development tree, then check if we are in a BuildTools
201    // directory. This indicates we are built for the build triple, but we
202    // always want to provide information for the host triple.
203    if (sys::path::filename(LLVM_OBJ_ROOT) == "BuildTools") {
204      ActiveObjRoot = sys::path::parent_path(LLVM_OBJ_ROOT);
205    } else {
206      ActiveObjRoot = LLVM_OBJ_ROOT;
207    }
208  } else if (sys::fs::equivalent(CurrentExecPrefix, LLVM_OBJ_ROOT)) {
209    IsInDevelopmentTree = true;
210    DevelopmentTreeLayout = CMakeStyle;
211    ActiveObjRoot = LLVM_OBJ_ROOT;
212  } else if (sys::fs::equivalent(CurrentExecPrefix,
213                                 Twine(LLVM_OBJ_ROOT) + "/bin")) {
214    IsInDevelopmentTree = true;
215    DevelopmentTreeLayout = CMakeBuildModeStyle;
216    ActiveObjRoot = LLVM_OBJ_ROOT;
217  } else {
218    IsInDevelopmentTree = false;
219    DevelopmentTreeLayout = MakefileStyle; // Initialized to avoid warnings.
220  }
221
222  // Compute various directory locations based on the derived location
223  // information.
224  std::string ActivePrefix, ActiveBinDir, ActiveIncludeDir, ActiveLibDir;
225  std::string ActiveIncludeOption;
226  if (IsInDevelopmentTree) {
227    ActiveIncludeDir = std::string(LLVM_SRC_ROOT) + "/include";
228    ActivePrefix = CurrentExecPrefix;
229
230    // CMake organizes the products differently than a normal prefix style
231    // layout.
232    switch (DevelopmentTreeLayout) {
233    case MakefileStyle:
234      ActiveBinDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/bin";
235      ActiveLibDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/lib";
236      break;
237    case CMakeStyle:
238      ActiveBinDir = ActiveObjRoot + "/bin";
239      ActiveLibDir = ActiveObjRoot + "/lib";
240      break;
241    case CMakeBuildModeStyle:
242      ActiveBinDir = ActiveObjRoot + "/bin/" + LLVM_BUILDMODE;
243      ActiveLibDir = ActiveObjRoot + "/lib/" + LLVM_BUILDMODE;
244      break;
245    }
246
247    // We need to include files from both the source and object trees.
248    ActiveIncludeOption = ("-I" + ActiveIncludeDir + " " +
249                           "-I" + ActiveObjRoot + "/include");
250  } else {
251    ActivePrefix = CurrentExecPrefix;
252    ActiveIncludeDir = ActivePrefix + "/include";
253    ActiveBinDir = ActivePrefix + "/bin";
254    ActiveLibDir = ActivePrefix + "/lib";
255    ActiveIncludeOption = "-I" + ActiveIncludeDir;
256  }
257
258  raw_ostream &OS = outs();
259  for (int i = 1; i != argc; ++i) {
260    StringRef Arg = argv[i];
261
262    if (Arg.startswith("-")) {
263      HasAnyOption = true;
264      if (Arg == "--version") {
265        OS << PACKAGE_VERSION << '\n';
266      } else if (Arg == "--prefix") {
267        OS << ActivePrefix << '\n';
268      } else if (Arg == "--bindir") {
269        OS << ActiveBinDir << '\n';
270      } else if (Arg == "--includedir") {
271        OS << ActiveIncludeDir << '\n';
272      } else if (Arg == "--libdir") {
273        OS << ActiveLibDir << '\n';
274      } else if (Arg == "--cppflags") {
275        OS << ActiveIncludeOption << ' ' << LLVM_CPPFLAGS << '\n';
276      } else if (Arg == "--cflags") {
277        OS << ActiveIncludeOption << ' ' << LLVM_CFLAGS << '\n';
278      } else if (Arg == "--cxxflags") {
279        OS << ActiveIncludeOption << ' ' << LLVM_CXXFLAGS << '\n';
280      } else if (Arg == "--ldflags") {
281        OS << "-L" << ActiveLibDir << ' ' << LLVM_LDFLAGS
282           << ' ' << LLVM_SYSTEM_LIBS << '\n';
283      } else if (Arg == "--libs") {
284        PrintLibs = true;
285      } else if (Arg == "--libnames") {
286        PrintLibNames = true;
287      } else if (Arg == "--libfiles") {
288        PrintLibFiles = true;
289      } else if (Arg == "--components") {
290        for (unsigned j = 0; j != array_lengthof(AvailableComponents); ++j) {
291          // Only include non-installed components when in a development tree.
292          if (!AvailableComponents[j].IsInstalled && !IsInDevelopmentTree)
293            continue;
294
295          OS << ' ';
296          OS << AvailableComponents[j].Name;
297        }
298        OS << '\n';
299      } else if (Arg == "--targets-built") {
300        OS << LLVM_TARGETS_BUILT << '\n';
301      } else if (Arg == "--host-target") {
302        OS << LLVM_DEFAULT_TARGET_TRIPLE << '\n';
303      } else if (Arg == "--build-mode") {
304        OS << LLVM_BUILDMODE << '\n';
305      } else if (Arg == "--obj-root") {
306        OS << LLVM_OBJ_ROOT << '\n';
307      } else if (Arg == "--src-root") {
308        OS << LLVM_SRC_ROOT << '\n';
309      } else {
310        usage();
311      }
312    } else {
313      Components.push_back(Arg);
314    }
315  }
316
317  if (!HasAnyOption)
318    usage();
319
320  if (PrintLibs || PrintLibNames || PrintLibFiles) {
321    // If no components were specified, default to "all".
322    if (Components.empty())
323      Components.push_back("all");
324
325    // Construct the list of all the required libraries.
326    std::vector<StringRef> RequiredLibs;
327    ComputeLibsForComponents(Components, RequiredLibs,
328                             /*IncludeNonInstalled=*/IsInDevelopmentTree);
329
330    for (unsigned i = 0, e = RequiredLibs.size(); i != e; ++i) {
331      StringRef Lib = RequiredLibs[i];
332      if (i)
333        OS << ' ';
334
335      if (PrintLibNames) {
336        OS << Lib;
337      } else if (PrintLibFiles) {
338        OS << ActiveLibDir << '/' << Lib;
339      } else if (PrintLibs) {
340        // If this is a typical library name, include it using -l.
341        if (Lib.startswith("lib") && Lib.endswith(".a")) {
342          OS << "-l" << Lib.slice(3, Lib.size()-2);
343          continue;
344        }
345
346        // Otherwise, print the full path.
347        OS << ActiveLibDir << '/' << Lib;
348      }
349    }
350    OS << '\n';
351  } else if (!Components.empty()) {
352    errs() << "llvm-config: error: components given, but unused\n\n";
353    usage();
354  }
355
356  return 0;
357}
358