Add support for CPATH and friends.

This moves the existing code for CPATH into the driver and adds the environment lookup and path splitting there.
The paths are then passed down to cc1 with -I options (CPATH), added after the normal user-specified include dirs.
Language specific paths are passed via -LANG-isystem and the actual filtering is performed in the frontend.

I tried to match GCC's behavior as close as possible

Fixes PR8971.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140341 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 84 insertions, 63 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 840e4c2734..c3c07f412f 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -183,6 +183,38 @@ static void addProfileRT(const ToolChain &TC, const ArgList &Args,
   CmdArgs.push_back(Args.MakeArgString(ProfileRT));
 }
 
+static void AddIncludeDirectoryList(const ArgList &Args,
+                                    ArgStringList &CmdArgs,
+                                    const char *ArgName,
+                                    const char *DirList) {
+  if (!DirList)
+    return; // Nothing to do.
+
+  StringRef Dirs(DirList);
+  if (Dirs.empty()) // Empty string should not add '.'.
+    return;
+
+  StringRef::size_type Delim;
+  while ((Delim = Dirs.find(llvm::sys::PathSeparator)) != StringRef::npos) {
+    if (Delim == 0) { // Leading colon.
+      CmdArgs.push_back(ArgName);
+      CmdArgs.push_back(".");
+    } else {
+      CmdArgs.push_back(ArgName);
+      CmdArgs.push_back(Args.MakeArgString(Dirs.substr(0, Delim)));
+    }
+    Dirs = Dirs.substr(Delim + 1);
+  }
+
+  if (Dirs.empty()) { // Trailing colon.
+    CmdArgs.push_back(ArgName);
+    CmdArgs.push_back(".");
+  } else { // Add the last path.
+    CmdArgs.push_back(ArgName);
+    CmdArgs.push_back(Args.MakeArgString(Dirs));
+  }
+}
+
 void Clang::AddPreprocessingOptions(const Driver &D,
                                     const ArgList &Args,
                                     ArgStringList &CmdArgs,
@@ -391,6 +423,23 @@ void Clang::AddPreprocessingOptions(const Driver &D,
   }
   
   Args.AddAllArgs(CmdArgs, options::OPT_fauto_module_import);
+
+  // Parse additional include paths from environment variables.
+  // CPATH - included following the user specified includes (but prior to
+  // builtin and standard includes).
+  AddIncludeDirectoryList(Args, CmdArgs, "-I", ::getenv("CPATH"));
+  // C_INCLUDE_PATH - system includes enabled when compiling C.
+  AddIncludeDirectoryList(Args, CmdArgs, "-c-isystem",
+                          ::getenv("C_INCLUDE_PATH"));
+  // CPLUS_INCLUDE_PATH - system includes enabled when compiling C++.
+  AddIncludeDirectoryList(Args, CmdArgs, "-cxx-isystem",
+                          ::getenv("CPLUS_INCLUDE_PATH"));
+  // OBJC_INCLUDE_PATH - system includes enabled when compiling ObjC.
+  AddIncludeDirectoryList(Args, CmdArgs, "-objc-isystem",
+                          ::getenv("OBJC_INCLUDE_PATH"));
+  // OBJCPLUS_INCLUDE_PATH - system includes enabled when compiling ObjC++.
+  AddIncludeDirectoryList(Args, CmdArgs, "-objcxx-isystem",
+                          ::getenv("OBJCPLUS_INCLUDE_PATH"));
 }
 
 /// getARMTargetCPU - Get the (LLVM) name of the ARM cpu we are targeting.
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 7cb707b966..e699261379 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -534,9 +534,21 @@ static void HeaderSearchOptsToArgs(const HeaderSearchOptions &Opts,
         Res.push_back(E.IsFramework? "-F" : "-I");
         break;
         
+      case frontend::CSystem:
+        Res.push_back("-c-isystem");
+        break;
+
       case frontend::CXXSystem:
         Res.push_back("-cxx-isystem");
         break;
+
+      case frontend::ObjCSystem:
+        Res.push_back("-objc-isystem");
+        break;
+
+      case frontend::ObjCXXSystem:
+        Res.push_back("-objcxx-isystem");
+        break;
         
       case frontend::Angled:
         Res.push_back(E.IsFramework ? "-F" : "-I");
@@ -551,26 +563,6 @@ static void HeaderSearchOptsToArgs(const HeaderSearchOptions &Opts,
     Res.push_back(E.Path);
   }
 
-  if (!Opts.EnvIncPath.empty()) {
-    // FIXME: Provide an option for this, and move env detection to driver.
-    llvm::report_fatal_error("Not yet implemented!");
-  }
-  if (!Opts.CEnvIncPath.empty()) {
-    // FIXME: Provide an option for this, and move env detection to driver.
-    llvm::report_fatal_error("Not yet implemented!");
-  }
-  if (!Opts.ObjCEnvIncPath.empty()) {
-    // FIXME: Provide an option for this, and move env detection to driver.
-    llvm::report_fatal_error("Not yet implemented!");
-  }
-  if (!Opts.CXXEnvIncPath.empty()) {
-    // FIXME: Provide an option for this, and move env detection to driver.
-    llvm::report_fatal_error("Not yet implemented!");
-  }
-  if (!Opts.ObjCXXEnvIncPath.empty()) {
-    // FIXME: Provide an option for this, and move env detection to driver.
-    llvm::report_fatal_error("Not yet implemented!");
-  }
   if (!Opts.ResourceDir.empty()) {
     Res.push_back("-resource-dir");
     Res.push_back(Opts.ResourceDir);
@@ -1424,14 +1416,25 @@ static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
   for (arg_iterator it = Args.filtered_begin(OPT_iquote),
          ie = Args.filtered_end(); it != ie; ++it)
     Opts.AddPath((*it)->getValue(Args), frontend::Quoted, true, false, false);
-  for (arg_iterator it = Args.filtered_begin(OPT_cxx_isystem, OPT_isystem,
+  for (arg_iterator it = Args.filtered_begin(OPT_isystem,
          OPT_iwithsysroot), ie = Args.filtered_end(); it != ie; ++it)
-    Opts.AddPath((*it)->getValue(Args),
-                 ((*it)->getOption().matches(OPT_cxx_isystem) ?
-                   frontend::CXXSystem : frontend::System),
-                 true, false, !(*it)->getOption().matches(OPT_iwithsysroot));
-  
-  // FIXME: Need options for the various environment variables!
+    Opts.AddPath((*it)->getValue(Args), frontend::System, true, false,
+                 !(*it)->getOption().matches(OPT_iwithsysroot));
+
+  // Add the paths for the various language specific isystem flags.
+  for (arg_iterator it = Args.filtered_begin(OPT_c_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::CSystem, true, false, true);
+  for (arg_iterator it = Args.filtered_begin(OPT_cxx_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::CXXSystem, true, false, true);
+  for (arg_iterator it = Args.filtered_begin(OPT_objc_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::ObjCSystem, true, false,true);
+  for (arg_iterator it = Args.filtered_begin(OPT_objcxx_isystem),
+       ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::ObjCXXSystem, true, false,
+                 true);
 }
 
 void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index 08af532267..089ded19ce 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -81,10 +81,6 @@ public:
   void AddMinGW64CXXPaths(StringRef Base,
                           StringRef Version);
 
-  /// AddDelimitedPaths - Add a list of paths delimited by the system PATH
-  /// separator. The processing follows that of the CPATH variable for gcc.
-  void AddDelimitedPaths(StringRef String);
-
   // AddDefaultCIncludePaths - Add paths that should always be searched.
   void AddDefaultCIncludePaths(const llvm::Triple &triple,
                                const HeaderSearchOptions &HSOpts);
@@ -167,26 +163,6 @@ void InitHeaderSearch::AddPath(const Twine &Path,
                  << MappedPathStr << "\"\n";
 }
 
-
-void InitHeaderSearch::AddDelimitedPaths(StringRef at) {
-  if (at.empty()) // Empty string should not add '.' path.
-    return;
-
-  StringRef::size_type delim;
-  while ((delim = at.find(llvm::sys::PathSeparator)) != StringRef::npos) {
-    if (delim == 0)
-      AddPath(".", Angled, false, true, false);
-    else
-      AddPath(at.substr(0, delim), Angled, false, true, false);
-    at = at.substr(delim + 1);
-  }
-
-  if (at.empty())
-    AddPath(".", Angled, false, true, false);
-  else
-    AddPath(at, Angled, false, true, false);
-}
-
 void InitHeaderSearch::AddGnuCPlusPlusIncludePaths(StringRef Base,
                                                    StringRef ArchDir,
                                                    StringRef Dir32,
@@ -1094,7 +1070,11 @@ void InitHeaderSearch::Realize(const LangOptions &Lang) {
 
   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
        it != ie; ++it) {
-    if (it->first == System || (Lang.CPlusPlus && it->first == CXXSystem))
+    if (it->first == System ||
+        (!Lang.ObjC1 && !Lang.CPlusPlus && it->first == CSystem)    ||
+        (!Lang.ObjC1 && Lang.CPlusPlus  && it->first == CXXSystem)  ||
+        (Lang.ObjC1  && !Lang.CPlusPlus && it->first == ObjCSystem) ||
+        (Lang.ObjC1  && Lang.CPlusPlus  && it->first == ObjCXXSystem))
       SearchList.push_back(it->second);
   }
 
@@ -1147,17 +1127,6 @@ void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
                  E.IgnoreSysRoot);
   }
 
-  // Add entries from CPATH and friends.
-  Init.AddDelimitedPaths(HSOpts.EnvIncPath);
-  if (Lang.CPlusPlus && Lang.ObjC1)
-    Init.AddDelimitedPaths(HSOpts.ObjCXXEnvIncPath);
-  else if (Lang.CPlusPlus)
-    Init.AddDelimitedPaths(HSOpts.CXXEnvIncPath);
-  else if (Lang.ObjC1)
-    Init.AddDelimitedPaths(HSOpts.ObjCEnvIncPath);
-  else
-    Init.AddDelimitedPaths(HSOpts.CEnvIncPath);
-
   if (HSOpts.UseStandardIncludes)
     Init.AddDefaultSystemIncludePaths(Lang, Triple, HSOpts);