Move most of HeaderSearch initialization to libDriver.

For example, adding the default system include paths in clients is now as
simple as

  InitHeaderSearch init(headers);
  init.AddDefaultSystemIncludePaths(langopts);
  init.Realize();



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55174 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/InitHeaderSearch.cpp b/lib/Driver/InitHeaderSearch.cpp
new file mode 100644
index 0000000..7fd36f8
--- /dev/null
+++ b/lib/Driver/InitHeaderSearch.cpp
@@ -0,0 +1,312 @@
+//===--- InitHeaderSearch.cpp - Initialize header search paths ----------*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the InitHeaderSearch class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Driver/InitHeaderSearch.h"
+
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/System/Path.h"
+
+#include <vector>
+
+using namespace clang;
+
+void InitHeaderSearch::AddPath(const std::string &Path, IncludeDirGroup Group,
+                               bool isCXXAware, bool isUserSupplied,
+                               bool isFramework) {
+  assert(!Path.empty() && "can't handle empty path here");
+  FileManager &FM = Headers.getFileMgr();
+  
+  // Compute the actual path, taking into consideration -isysroot.
+  llvm::SmallString<256> MappedPath;
+  
+  // Handle isysroot.
+  if (Group == System) {
+    // FIXME: Portability.  This should be a sys::Path interface, this doesn't
+    // handle things like C:\ right, nor win32 \\network\device\blah.
+    if (isysroot.size() != 1 || isysroot[0] != '/') // Add isysroot if present.
+      MappedPath.append(isysroot.begin(), isysroot.end());
+  }
+  
+  MappedPath.append(Path.begin(), Path.end());
+
+  // Compute the DirectoryLookup type.
+  DirectoryLookup::DirType Type;
+  if (Group == Quoted || Group == Angled)
+    Type = DirectoryLookup::NormalHeaderDir;
+  else if (isCXXAware)
+    Type = DirectoryLookup::SystemHeaderDir;
+  else
+    Type = DirectoryLookup::ExternCSystemHeaderDir;
+  
+  
+  // If the directory exists, add it.
+  if (const DirectoryEntry *DE = FM.getDirectory(&MappedPath[0], 
+                                                 &MappedPath[0]+
+                                                 MappedPath.size())) {
+    IncludeGroup[Group].push_back(DirectoryLookup(DE, Type, isUserSupplied,
+                                                  isFramework));
+    return;
+  }
+  
+  // Check to see if this is an apple-style headermap (which are not allowed to
+  // be frameworks).
+  if (!isFramework) {
+    if (const FileEntry *FE = FM.getFile(&MappedPath[0], 
+                                         &MappedPath[0]+MappedPath.size())) {
+      if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
+        // It is a headermap, add it to the search path.
+        IncludeGroup[Group].push_back(DirectoryLookup(HM, Type,isUserSupplied));
+        return;
+      }
+    }
+  }
+  
+  if (Verbose)
+    fprintf(stderr, "ignoring nonexistent directory \"%s\"\n", Path.c_str());
+}
+
+
+void InitHeaderSearch::AddEnvVarPaths(const char *Name) {
+  const char* at = getenv(Name);
+  if (!at)
+    return;
+
+  const char* delim = strchr(at, llvm::sys::PathSeparator);
+  while (delim != 0) {
+    if (delim-at == 0)
+      AddPath(".", Angled, false, true, false);
+    else
+      AddPath(std::string(at, std::string::size_type(delim-at)), Angled, false,
+            true, false);
+    at = delim + 1;
+    delim = strchr(at, llvm::sys::PathSeparator);
+  }
+  if (*at == 0)
+    AddPath(".", Angled, false, true, false);
+  else
+    AddPath(at, Angled, false, true, false);
+}
+
+
+void InitHeaderSearch::AddDefaultSystemIncludePaths(const LangOptions &Lang) {
+  // FIXME: temporary hack: hard-coded paths.
+  // FIXME: get these from the target?
+  if (Lang.CPlusPlus) {
+    AddPath("/usr/include/c++/4.2.1", System, true, false, false);
+    AddPath("/usr/include/c++/4.2.1/i686-apple-darwin10", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.2.1/backward", System, true, false, false);
+
+    AddPath("/usr/include/c++/4.0.0", System, true, false, false);
+    AddPath("/usr/include/c++/4.0.0/i686-apple-darwin8", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.0.0/backward", System, true, false, false);
+
+    // Ubuntu 7.10 - Gutsy Gibbon
+    AddPath("/usr/include/c++/4.1.3", System, true, false, false);
+    AddPath("/usr/include/c++/4.1.3/i486-linux-gnu", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.1.3/backward", System, true, false, false);
+
+    // Fedora 8
+    AddPath("/usr/include/c++/4.1.2", System, true, false, false);
+    AddPath("/usr/include/c++/4.1.2/i386-redhat-linux", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.1.2/backward", System, true, false, false);
+
+    // Fedora 9
+    AddPath("/usr/include/c++/4.3.0", System, true, false, false);
+    AddPath("/usr/include/c++/4.3.0/i386-redhat-linux", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.3.0/backward", System, true, false, false);
+
+    // Arch Linux 2008-06-24
+    AddPath("/usr/include/c++/4.3.1", System, true, false, false);
+    AddPath("/usr/include/c++/4.3.1/i686-pc-linux-gnu", System, true, false,
+        false);
+    AddPath("/usr/include/c++/4.3.1/backward", System, true, false, false);
+    AddPath("/usr/include/c++/4.3.1/x86_64-unknown-linux-gnu", System, true,
+        false, false);
+  }
+
+  AddPath("/usr/local/include", System, false, false, false);
+
+  AddPath("/usr/lib/gcc/i686-apple-darwin10/4.2.1/include", System, 
+      false, false, false);
+  AddPath("/usr/lib/gcc/powerpc-apple-darwin10/4.2.1/include", 
+      System, false, false, false);
+
+  // leopard
+  AddPath("/usr/lib/gcc/i686-apple-darwin9/4.0.1/include", System, 
+      false, false, false);
+  AddPath("/usr/lib/gcc/powerpc-apple-darwin9/4.0.1/include", 
+      System, false, false, false);
+  AddPath("/usr/lib/gcc/powerpc-apple-darwin9/"
+      "4.0.1/../../../../powerpc-apple-darwin0/include", 
+      System, false, false, false);
+
+  // tiger
+  AddPath("/usr/lib/gcc/i686-apple-darwin8/4.0.1/include", System, 
+      false, false, false);
+  AddPath("/usr/lib/gcc/powerpc-apple-darwin8/4.0.1/include", 
+      System, false, false, false);
+  AddPath("/usr/lib/gcc/powerpc-apple-darwin8/"
+      "4.0.1/../../../../powerpc-apple-darwin8/include", 
+      System, false, false, false);
+
+  // Ubuntu 7.10 - Gutsy Gibbon
+  AddPath("/usr/lib/gcc/i486-linux-gnu/4.1.3/include", System,
+      false, false, false);
+
+  // Fedora 8
+  AddPath("/usr/lib/gcc/i386-redhat-linux/4.1.2/include", System,
+      false, false, false);
+
+  // Fedora 9
+  AddPath("/usr/lib/gcc/i386-redhat-linux/4.3.0/include", System,
+      false, false, false);
+
+  //Debian testing/lenny x86
+  AddPath("/usr/lib/gcc/i486-linux-gnu/4.2.3/include", System,
+      false, false, false);
+
+  //Debian testing/lenny amd64
+  AddPath("/usr/lib/gcc/x86_64-linux-gnu/4.2.3/include", System,
+      false, false, false);
+
+  // Arch Linux 2008-06-24
+  AddPath("/usr/lib/gcc/i686-pc-linux-gnu/4.3.1/include", System,
+      false, false, false);
+  AddPath("/usr/lib/gcc/i686-pc-linux-gnu/4.3.1/include-fixed", System,
+      false, false, false);
+  AddPath("/usr/lib/gcc/x86_64-unknown-linux-gnu/4.3.1/include", System,
+      false, false, false);
+  AddPath("/usr/lib/gcc/x86_64-unknown-linux-gnu/4.3.1/include-fixed",
+      System, false, false, false);
+
+  // Debian testing/lenny ppc32
+  AddPath("/usr/lib/gcc/powerpc-linux-gnu/4.2.3/include", System,
+      false, false, false);
+
+  // Gentoo x86 stable
+  AddPath("/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/include", System,
+      false, false, false);
+
+  AddPath("/usr/include", System, false, false, false);
+  AddPath("/System/Library/Frameworks", System, true, false, true);
+  AddPath("/Library/Frameworks", System, true, false, true);
+}
+
+void InitHeaderSearch::AddDefaultEnvVarPaths(const LangOptions &Lang) {
+  AddEnvVarPaths("CPATH");
+  if (Lang.CPlusPlus && Lang.ObjC1)
+    AddEnvVarPaths("OBJCPLUS_INCLUDE_PATH");
+  else if (Lang.CPlusPlus)
+    AddEnvVarPaths("CPLUS_INCLUDE_PATH");
+  else if (Lang.ObjC1)
+    AddEnvVarPaths("OBJC_INCLUDE_PATH");
+  else
+    AddEnvVarPaths("C_INCLUDE_PATH");
+}
+
+
+/// RemoveDuplicates - If there are duplicate directory entries in the specified
+/// search list, remove the later (dead) ones.
+static void RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
+                             bool Verbose) {
+  llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
+  llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
+  llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
+  for (unsigned i = 0; i != SearchList.size(); ++i) {
+    if (SearchList[i].isNormalDir()) {
+      // If this isn't the first time we've seen this dir, remove it.
+      if (SeenDirs.insert(SearchList[i].getDir()))
+        continue;
+      
+      if (Verbose)
+        fprintf(stderr, "ignoring duplicate directory \"%s\"\n",
+                SearchList[i].getDir()->getName());
+    } else if (SearchList[i].isFramework()) {
+      // If this isn't the first time we've seen this framework dir, remove it.
+      if (SeenFrameworkDirs.insert(SearchList[i].getFrameworkDir()))
+        continue;
+      
+      if (Verbose)
+        fprintf(stderr, "ignoring duplicate framework \"%s\"\n",
+                SearchList[i].getFrameworkDir()->getName());
+      
+    } else {
+      assert(SearchList[i].isHeaderMap() && "Not a headermap or normal dir?");
+      // If this isn't the first time we've seen this headermap, remove it.
+      if (SeenHeaderMaps.insert(SearchList[i].getHeaderMap()))
+        continue;
+      
+      if (Verbose)
+        fprintf(stderr, "ignoring duplicate directory \"%s\"\n",
+                SearchList[i].getDir()->getName());
+    }
+    
+    // This is reached if the current entry is a duplicate.
+    SearchList.erase(SearchList.begin()+i);
+    --i;
+  }
+}
+
+
+void InitHeaderSearch::Realize() {
+  // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
+  std::vector<DirectoryLookup> SearchList;
+  SearchList = IncludeGroup[Angled];
+  SearchList.insert(SearchList.end(), IncludeGroup[System].begin(),
+                    IncludeGroup[System].end());
+  SearchList.insert(SearchList.end(), IncludeGroup[After].begin(),
+                    IncludeGroup[After].end());
+  RemoveDuplicates(SearchList, Verbose);
+  RemoveDuplicates(IncludeGroup[Quoted], Verbose);
+  
+  // Prepend QUOTED list on the search list.
+  SearchList.insert(SearchList.begin(), IncludeGroup[Quoted].begin(), 
+                    IncludeGroup[Quoted].end());
+  
+
+  bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
+  Headers.SetSearchPaths(SearchList, IncludeGroup[Quoted].size(),
+                         DontSearchCurDir);
+
+  // If verbose, print the list of directories that will be searched.
+  if (Verbose) {
+    fprintf(stderr, "#include \"...\" search starts here:\n");
+    unsigned QuotedIdx = IncludeGroup[Quoted].size();
+    for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
+      if (i == QuotedIdx)
+        fprintf(stderr, "#include <...> search starts here:\n");
+      const char *Name = SearchList[i].getName();
+      const char *Suffix;
+      if (SearchList[i].isNormalDir())
+        Suffix = "";
+      else if (SearchList[i].isFramework())
+        Suffix = " (framework directory)";
+      else {
+        assert(SearchList[i].isHeaderMap() && "Unknown DirectoryLookup");
+        Suffix = " (headermap)";
+      }
+      fprintf(stderr, " %s%s\n", Name, Suffix);
+    }
+    fprintf(stderr, "End of search list.\n");
+  }
+}
+