Define intermediate build results file cache interface

11 files changed, 354 insertions, 48 deletions

diff --git a/libbuild2/algorithm.hxx b/libbuild2/algorithm.hxx
index aa1336c..90159d3 100644
--- a/libbuild2/algorithm.hxx
+++ b/libbuild2/algorithm.hxx
@@ -757,7 +757,7 @@ namespace build2
   // the prerequisites in the reverse order.
   //
   // You can also clean extra files derived from ad hoc group members that are
-  // "indexed" using using their target types (see add/find_adhoc_member() for
+  // "indexed" using their target types (see add/find_adhoc_member() for
   // details).
   //
   // Note that if the target path is empty then it is assumed "unreal" and is
diff --git a/libbuild2/build/script/parser.test.cxx b/libbuild2/build/script/parser.test.cxx
index 4a3e8cc..a277102 100644
--- a/libbuild2/build/script/parser.test.cxx
+++ b/libbuild2/build/script/parser.test.cxx
@@ -10,6 +10,7 @@
 #include <libbuild2/target.hxx>
 #include <libbuild2/context.hxx>
 #include <libbuild2/scheduler.hxx>
+#include <libbuild2/file-cache.hxx>
 
 #include <libbuild2/build/script/script.hxx> // line
 #include <libbuild2/build/script/parser.hxx>
@@ -179,7 +180,8 @@ namespace build2
         //
         scheduler sched (1);
         global_mutexes mutexes (1);
-        context ctx (sched, mutexes);
+        file_cache fcache (sched);
+        context ctx (sched, mutexes, fcache);
 
         try
         {
diff --git a/libbuild2/cc/compile-rule.cxx b/libbuild2/cc/compile-rule.cxx
index 116f67b..e394175 100644
--- a/libbuild2/cc/compile-rule.cxx
+++ b/libbuild2/cc/compile-rule.cxx
@@ -188,7 +188,7 @@ namespace build2
       bool touch = false;                   // Target needs to be touched.
       timestamp mt = timestamp_unknown;     // Target timestamp.
       prerequisite_member src;
-      auto_rmfile psrc;                     // Preprocessed source, if any.
+      file_cache::entry psrc;               // Preprocessed source, if any.
       path dd;                              // Dependency database path.
       size_t header_units = 0;              // Number of imported header units.
       module_positions modules = {0, 0, 0}; // Positions of imported modules.
@@ -1100,7 +1100,7 @@ namespace build2
         // If we have no #include directives (or header unit imports), then
         // skip header dependency extraction.
         //
-        pair<auto_rmfile, bool> psrc (auto_rmfile (), false);
+        pair<file_cache::entry, bool> psrc (file_cache::entry (), false);
         if (md.pp < preprocessed::includes)
         {
           // Note: trace is used in a test.
@@ -1292,22 +1292,33 @@ namespace build2
         {
           md.psrc = move (psrc.first);
 
+          // Now is also the right time to unpin the cache entry (we don't do
+          // it earlier because parse_unit() may need to read it).
+          //
+          md.psrc.unpin ();
+
           // Without modules keeping the (partially) preprocessed output
           // around doesn't buy us much: if the source/headers haven't changed
           // then neither will the object file. Modules make things more
           // interesting: now we may have to recompile an otherwise unchanged
-          // translation unit because a BMI it depends on has changed. In this
-          // case re-processing the translation unit would be a waste and
-          // compiling the original source would break distributed
+          // translation unit because a named module BMI it depends on has
+          // changed. In this case re-processing the translation unit would be
+          // a waste and compiling the original source would break distributed
           // compilation.
           //
           // Note also that the long term trend will (hopefully) be for
           // modularized projects to get rid of #include's which means the
           // need for producing this partially preprocessed output will
-          // (hopefully) gradually disappear.
+          // (hopefully) gradually disappear. Or not, most C headers will stay
+          // headers, and probably not importable.
+          //
+          // @@ TODO: no use keeping it if there are no named module imports
+          //          (but see also file_cache::create() hint, and
+          //          extract_headers() the cache case: there we just assume
+          //          it exists if modules is true).
           //
           if (modules)
-            md.psrc.active = false; // Keep.
+            md.psrc.temporary = false; // Keep.
         }
 
         // Above we may have ignored changes to the translation unit. The
@@ -3109,7 +3120,7 @@ namespace build2
     // header unit BMI is out-of-date, then we have to re-preprocess this
     // translation unit.
     //
-    pair<auto_rmfile, bool> compile_rule::
+    pair<file_cache::entry, bool> compile_rule::
     extract_headers (action a,
                      const scope& bs,
                      file& t,
@@ -3123,11 +3134,13 @@ namespace build2
     {
       tracer trace (x, "compile_rule::extract_headers");
 
+      context& ctx (t.ctx);
+
       otype ot (li.type);
 
       bool reprocess (cast_false<bool> (t[c_reprocess]));
 
-      auto_rmfile psrc;
+      file_cache::entry psrc;
       bool puse (true);
 
       // If things go wrong (and they often do in this area), give the user a
@@ -3346,6 +3359,8 @@ namespace build2
                         &so_map, this]
         (bool& gen) -> const path*
       {
+        context& ctx (t.ctx);
+
         const path* r (nullptr);
 
         if (args.empty ()) // First call.
@@ -3489,7 +3504,7 @@ namespace build2
                     // See if this path is inside a project with an out-of-
                     // tree build and is in the out directory tree.
                     //
-                    const scope& bs (t.ctx.scopes.find (d));
+                    const scope& bs (ctx.scopes.find (d));
                     if (bs.root_scope () != nullptr)
                     {
                       const dir_path& bp (bs.out_path ());
@@ -3580,16 +3595,16 @@ namespace build2
 
               msvc_sanitize_cl (args);
 
-              psrc = auto_rmfile (t.path () + x_pext);
+              psrc = ctx.fcache.create (t.path () + x_pext, !modules);
 
               if (fc)
               {
                 args.push_back ("/Fi:");
-                args.push_back (psrc.path.string ().c_str ());
+                args.push_back (psrc.path ().string ().c_str ());
               }
               else
               {
-                out = "/Fi" + psrc.path.string ();
+                out = "/Fi" + psrc.path ().string ();
                 args.push_back (out.c_str ());
               }
 
@@ -3724,9 +3739,9 @@ namespace build2
 
                 // Preprocessor output.
                 //
-                psrc = auto_rmfile (t.path () + x_pext);
+                psrc = ctx.fcache.create (t.path () + x_pext, !modules);
                 args.push_back ("-o");
-                args.push_back (psrc.path.string ().c_str ());
+                args.push_back (psrc.path ().string ().c_str ());
               }
               else
               {
@@ -4005,8 +4020,9 @@ namespace build2
               // around (see apply() for details).
               //
               return modules
-                ? make_pair (auto_rmfile (t.path () + x_pext, false), true)
-                : make_pair (auto_rmfile (), false);
+                ? make_pair (ctx.fcache.create_existing (t.path () + x_pext),
+                             true)
+                : make_pair (file_cache::entry (), false);
             }
 
             // This can be a header or a header unit (mapping).
@@ -4059,7 +4075,7 @@ namespace build2
 
               // Bail out early if we have deferred a failure.
               //
-              return make_pair (auto_rmfile (), false);
+              return make_pair (file_cache::entry (), false);
             }
           }
         }
@@ -4073,6 +4089,13 @@ namespace build2
             if (args.empty () || gen != args_gen)
               drmp = init_args (gen);
 
+            // If we are producing the preprocessed output, get its write
+            // handle.
+            //
+            file_cache::write psrcw (psrc
+                                     ? psrc.init_new ()
+                                     : file_cache::write ());
+
             if (verb >= 3)
               print_process (args.data ()); // Disable pipe mode.
 
@@ -4559,7 +4582,7 @@ namespace build2
                 if (md.deferred_failure)
                 {
                   is.close ();
-                  return make_pair (auto_rmfile (), false);
+                  return make_pair (file_cache::entry (), false);
                 }
 
                 // In case of VC, we are parsing stderr and if things go
@@ -4703,6 +4726,13 @@ namespace build2
             }
             else
               run_finish (args, pr); // Throws.
+
+            // Success.
+            //
+            assert (!restart);
+
+            if (psrc)
+              psrcw.close ();
           }
           catch (const process_error& e)
           {
@@ -4727,7 +4757,7 @@ namespace build2
       //
       dd.expect ("");
 
-      puse = puse && !reprocess && !psrc.path.empty ();
+      puse = puse && !reprocess && psrc;
       return make_pair (move (psrc), puse);
     }
 
@@ -4740,7 +4770,7 @@ namespace build2
                 file& t,
                 linfo li,
                 const file& src,
-                auto_rmfile& psrc,
+                file_cache::entry& psrc,
                 const match_data& md,
                 const path& dd,
                 unit& tu) const
@@ -4791,8 +4821,8 @@ namespace build2
         // may extend cc.reprocess to allow specifying where reprocessing is
         // needed).
         //
-        ps = !psrc.path.empty () && !reprocess;
-        sp = &(ps ? psrc.path : src.path ());
+        ps = psrc && !reprocess;
+        sp = &(ps ? psrc.path () : src.path ());
 
         // VC's preprocessed output, if present, is fully preprocessed.
         //
@@ -4931,11 +4961,16 @@ namespace build2
       for (;;) // Breakout loop.
       try
       {
-        // Disarm the removal of the preprocessed file in case of an error.
-        // We re-arm it below.
+        // If we are compiling the preprocessed output, get its read handle.
         //
-        if (ps)
-          psrc.active = false;
+        file_cache::read psrcr (ps ? psrc.open () : file_cache::read ());
+
+        // Temporarily disable the removal of the preprocessed file in case of
+        // an error. We re-enable it below.
+        //
+        bool ptmp (ps && psrc.temporary);
+        if (ptmp)
+          psrc.temporary = false;
 
         process pr;
 
@@ -4973,8 +5008,8 @@ namespace build2
 
           if (pr.wait ())
           {
-            if (ps)
-              psrc.active = true; // Re-arm.
+            if (ptmp)
+              psrc.temporary = true; // Re-enable.
 
             unit_type& ut (tu.type);
             module_info& mi (tu.module_info);
@@ -7045,14 +7080,14 @@ namespace build2
 
       // If we have the (partially) preprocessed output, switch to that.
       //
-      bool psrc (!md.psrc.path.empty ());
-      bool pact (md.psrc.active);
+      bool psrc (md.psrc);
+      bool ptmp (psrc && md.psrc.temporary);
       if (psrc)
       {
         args.pop_back (); // nullptr
         args.pop_back (); // sp
 
-        sp = &md.psrc.path;
+        sp = &md.psrc.path ();
 
         // This should match with how we setup preprocessing.
         //
@@ -7099,10 +7134,11 @@ namespace build2
 
         // Let's keep the preprocessed file in case of an error but only at
         // verbosity level 3 and up (when one actually sees it mentioned on
-        // the command line). We also have to re-arm on success (see below).
+        // the command line). We also have to re-enable on success (see
+        // below).
         //
-        if (pact && verb >= 3)
-          md.psrc.active = false;
+        if (ptmp && verb >= 3)
+          md.psrc.temporary = false;
       }
 
       if (verb >= 3)
@@ -7121,6 +7157,10 @@ namespace build2
       {
         try
         {
+          // If we are compiling the preprocessed output, get its read handle.
+          //
+          file_cache::read psrcr (psrc ? md.psrc.open () : file_cache::read ());
+
           // VC cl.exe sends diagnostics to stdout. It also prints the file
           // name being compiled as the first line. So for cl.exe we redirect
           // stdout to a pipe, filter that noise out, and send the rest to
@@ -7178,8 +7218,8 @@ namespace build2
 
       // Remove preprocessed file (see above).
       //
-      if (pact && verb >= 3)
-        md.psrc.active = true;
+      if (ptmp && verb >= 3)
+        md.psrc.temporary = true;
 
       // Clang's module compilation requires two separate compiler
       // invocations.
@@ -7251,14 +7291,21 @@ namespace build2
     {
       const file& t (xt.as<file> ());
 
+      // Compressed preprocessed file extension.
+      //
+      auto cpext = [this, &t, s = string ()] () mutable -> const char*
+      {
+        return (s = t.ctx.fcache.compressed_extension (x_pext)).c_str ();
+      };
+
       clean_extras extras;
 
       switch (ctype)
       {
-      case compiler_type::gcc:   extras = {".d", x_pext, ".t"};          break;
-      case compiler_type::clang: extras = {".d", x_pext};                break;
-      case compiler_type::msvc:  extras = {".d", x_pext, ".idb", ".pdb"};break;
-      case compiler_type::icc:   extras = {".d"};                        break;
+      case compiler_type::gcc:   extras = {".d", x_pext, cpext (), ".t"};          break;
+      case compiler_type::clang: extras = {".d", x_pext, cpext ()};                break;
+      case compiler_type::msvc:  extras = {".d", x_pext, cpext (), ".idb", ".pdb"};break;
+      case compiler_type::icc:   extras = {".d"};                                  break;
       }
 
       return perform_clean_extra (a, t, extras);
diff --git a/libbuild2/cc/compile-rule.hxx b/libbuild2/cc/compile-rule.hxx
index edff1d8..917acd1 100644
--- a/libbuild2/cc/compile-rule.hxx
+++ b/libbuild2/cc/compile-rule.hxx
@@ -8,7 +8,7 @@
 #include <libbuild2/utility.hxx>
 
 #include <libbuild2/rule.hxx>
-#include <libbuild2/filesystem.hxx> // auto_rmfile
+#include <libbuild2/file-cache.hxx>
 
 #include <libbuild2/cc/types.hxx>
 #include <libbuild2/cc/common.hxx>
@@ -140,14 +140,14 @@ namespace build2
       optional<bool>
       inject_header (action, file&, const file&, timestamp, bool) const;
 
-      pair<auto_rmfile, bool>
+      pair<file_cache::entry, bool>
       extract_headers (action, const scope&, file&, linfo,
                        const file&, match_data&,
                        depdb&, bool&, timestamp, module_imports&) const;
 
       string
       parse_unit (action, file&, linfo,
-                  const file&, auto_rmfile&,
+                  const file&, file_cache::entry&,
                   const match_data&, const path&,
                   unit&) const;
 
diff --git a/libbuild2/context.cxx b/libbuild2/context.cxx
index df06aa8..e8f671d 100644
--- a/libbuild2/context.cxx
+++ b/libbuild2/context.cxx
@@ -58,6 +58,7 @@ namespace build2
   context::
   context (scheduler& s,
            global_mutexes& ms,
+           file_cache& fc,
            bool mo,
            bool nem,
            bool dr,
@@ -68,6 +69,7 @@ namespace build2
       : data_ (new data (*this)),
         sched (s),
         mutexes (ms),
+        fcache (fc),
         match_only (mo),
         no_external_modules (nem),
         dry_run_option (dr),
diff --git a/libbuild2/context.hxx b/libbuild2/context.hxx
index edbf780..f25db85 100644
--- a/libbuild2/context.hxx
+++ b/libbuild2/context.hxx
@@ -20,6 +20,7 @@
 
 namespace build2
 {
+  class file_cache;
   class loaded_modules_lock;
 
   class LIBBUILD2_SYMEXPORT run_phase_mutex
@@ -141,6 +142,7 @@ namespace build2
   public:
     scheduler& sched;
     global_mutexes& mutexes;
+    file_cache& fcache;
 
     // Match only flag (see --match-only but also dist).
     //
@@ -490,6 +492,7 @@ namespace build2
     explicit
     context (scheduler&,
              global_mutexes&,
+             file_cache&,
              bool match_only = false,
              bool no_external_modules = false,
              bool dry_run = false,
diff --git a/libbuild2/file-cache.hxx b/libbuild2/file-cache.hxx
new file mode 100644
index 0000000..4486307
--- /dev/null
+++ b/libbuild2/file-cache.hxx
@@ -0,0 +1,209 @@
+// file      : libbuild2/file-cache.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBUILD2_FILE_CACHE_HXX
+#define LIBBUILD2_FILE_CACHE_HXX
+
+#include <libbuild2/types.hxx>
+#include <libbuild2/forward.hxx>
+#include <libbuild2/utility.hxx>
+
+#include <libbuild2/export.hxx>
+
+namespace build2
+{
+  // We sometimes have intermediate build results that must be stored and
+  // accessed as files (for example, partially-preprocessed C/C++ translation
+  // units; those .i/.ii files). These files can be quite large which can lead
+  // to excessive disk usage (for example, the .ii files can be several MB
+  // each and can end up dominating object file sizes in a build with debug
+  // information). These files are also often temporary which means writing
+  // them to disk is really a waste.
+  //
+  // The file cache attempts to address this by still presenting a file-like
+  // entry (which can be a real file or a named pipe) but potentially storing
+  // the file contents in memory and/or compressed.
+  //
+  // Each cache entry is identified by the filesystem entry path that will be
+  // written to or read from. The file cache reserves a filesystem entry path
+  // that is derived by adding a compression extension to the main entry path
+  // (for example, .ii.lz4). When cleaning intermediate build results that are
+  // managed by the cache, the rule must clean such a reserved path in
+  // addition to the main entry path (see compressed_extension() below).
+  //
+  // While the cache is MT-safe (that is, we can insert multiple entries
+  // concurrently), each entry is expected to be accessed serially by a single
+  // thread. Furthermore, each entry can either be written to or read from at
+  // any give time and it can only be read from by a single reader at a time.
+  // In other words, there meant to be a single cache entry for any given path
+  // and it is not meant to be shared.
+  //
+  // The underlying filesystem entry can be either temporary or permanent. A
+  // temporary entry only exists during the build, normally between the match
+  // and execute phases. A permanent entry exists across builds. Note,
+  // however, that a permanent entry is often removed in cases of an error and
+  // sometimes a temporary entry is left behind for diagnostics. It is also
+  // possible that the distinction only becomes known some time after the
+  // entry has been created. As a result, all entries by default start as
+  // temporary and can later be made permanent if desired.
+  //
+  // A cache entry can be pinned or unpinned. A cache entry is created pinned.
+  // A cache entry being written to or read from remains pinned.
+  //
+  // An unpinned entry can be preempted. Preempting a cache entry can mean any
+  // of the following:
+  //
+  //   - An in-memory content is compressed (but stays in memory).
+  //
+  //   - An in-memory content (compressed or not) is flushed to disk (with or
+  //     without compression).
+  //
+  //   - An uncompressed on-disk content is compressed.
+  //
+  // Naturally, any of the above degrees of preemption make accessing the
+  // contents of a cache entry slower. Note also that pinned/unpinned and
+  // temporary/permanent are independent and a temporary entry does not need
+  // to be unpinned to be removed.
+  //
+  // After creation, a cache entry must be initialized by either writing new
+  // contents to the filesystem entry or by using an existing (permanent)
+  // filesystem entry. Once initialized, an entry can be opened for reading,
+  // potentially multiple times.
+  //
+  // Note also that a noop implementation of this caching semantics (that is,
+  // one that simply saves the file on disk) is file_cache::entry that is just
+  // auto_rmfile.
+  //
+  class /*LIBBUILD2_SYMEXPORT*/ file_cache
+  {
+  public:
+
+    // A cache entry write handle. During the lifetime of this object the
+    // filesystem entry can be opened for writing and written to.
+    //
+    // A successful write must be terminated with an explicit call to close()
+    // (similar semantics to ofdstream). A write handle that is destroyed
+    // without a close() call is treated as an unsuccessful write and the
+    // initialization can be attempted again.
+    //
+    struct write
+    {
+      void close () {}
+    };
+
+    // A cache entry read handle. During the lifetime of this object the
+    // filesystem entry can be opened for reading and read from.
+    //
+    struct read
+    {
+    };
+
+    // A cache entry handle. When it is destroyed, a temporary entry is
+    // automatically removed from the filesystem.
+    //
+    struct entry
+    {
+      using path_type = build2::path;
+
+      bool temporary;
+
+      // The returned reference is valid and stable for the lifetime of the
+      // entry handle.
+      //
+      const path_type&
+      path () const {return path_;}
+
+      // Initialization.
+      //
+      write
+      init_new ()
+      {
+        return write ();
+      }
+
+      void
+      init_existing () {}
+
+      // Reading.
+      //
+      read
+      open ()
+      {
+        return read ();
+      }
+
+      // Pinning.
+      //
+      void
+      pin () {}
+
+      void
+      unpin () {}
+
+      // NULL entry handle.
+      //
+      entry () = default;
+
+      explicit operator bool () const
+      {
+        return !path_.empty ();
+      }
+
+      // Move-to-NULL-entry-only type.
+      //
+      entry (entry&&);
+      entry (const entry&) = delete;
+      entry& operator= (entry&&);
+      entry& operator= (const entry&) = delete;
+
+      // Implementation details.
+      //
+      entry (path_type, bool);
+      ~entry ();
+
+      path_type path_;
+    };
+
+    // Create a cache entry corresponding to the specified filesystem path.
+    // The path must be absolute and normalized. The temporary argument may be
+    // used to hint whether the entry is likely to be temporary or permanent.
+    //
+    entry
+    create (path f, optional<bool> /*temporary*/)
+    {
+      return entry (move (f), true /* temporary */);
+    };
+
+    // A shortcut for creating and initializing an existing permanent entry.
+    //
+    entry
+    create_existing (path f)
+    {
+      entry e (move (f), false /* temporary */);
+      e.init_existing ();
+      return e;
+    };
+
+    // Return the compressed filesystem entry extension (with the leading dot)
+    // or empty string if no compression is used by this cache implementation.
+    //
+    // If the passed extension is not NULL, then it is included as a first-
+    // level extension into the returned value (useful to form extensions for
+    // clean_extra()).
+    //
+    string
+    compressed_extension (const char* = nullptr)
+    {
+      return string ();
+    }
+
+    explicit
+    file_cache (scheduler&)
+    {
+    }
+  };
+}
+
+#include <libbuild2/file-cache.ixx>
+
+#endif // LIBBUILD2_FILE_CACHE_HXX
diff --git a/libbuild2/file-cache.ixx b/libbuild2/file-cache.ixx
new file mode 100644
index 0000000..259d348
--- /dev/null
+++ b/libbuild2/file-cache.ixx
@@ -0,0 +1,38 @@
+// file      : libbuild2/file-cache.ixx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#include <libbuild2/filesystem.hxx> // try_rmfile()
+
+namespace build2
+{
+  inline file_cache::entry::
+  entry (path_type p, bool t)
+      : temporary (t), path_ (move (p))
+  {
+  }
+
+  inline file_cache::entry::
+  ~entry ()
+  {
+    if (!path_.empty () && temporary)
+      try_rmfile (path_, true /* ignore_errors */);
+  }
+
+  inline file_cache::entry::
+  entry (entry&& e)
+      : temporary (e.temporary), path_ (move (e.path_))
+  {
+  }
+
+  inline file_cache::entry& file_cache::entry::
+  operator= (entry&& e)
+  {
+    if (this != &e)
+    {
+      assert (path_.empty ());
+      temporary = e.temporary;
+      path_ = move (e.path_);
+    }
+    return *this;
+  }
+}
diff --git a/libbuild2/function.test.cxx b/libbuild2/function.test.cxx
index f8a2c16..7aa1a50 100644
--- a/libbuild2/function.test.cxx
+++ b/libbuild2/function.test.cxx
@@ -12,6 +12,7 @@
 #include <libbuild2/scheduler.hxx>
 #include <libbuild2/function.hxx>
 #include <libbuild2/variable.hxx>
+#include <libbuild2/file-cache.hxx>
 #include <libbuild2/diagnostics.hxx>
 
 using namespace std;
@@ -46,7 +47,8 @@ namespace build2
     //
     scheduler sched (1);
     global_mutexes mutexes (1);
-    context ctx (sched, mutexes);
+    file_cache fcache (sched);
+    context ctx (sched, mutexes, fcache);
 
     auto& functions (ctx.functions);
 
diff --git a/libbuild2/module.cxx b/libbuild2/module.cxx
index 9a7975d..eb4395d 100644
--- a/libbuild2/module.cxx
+++ b/libbuild2/module.cxx
@@ -80,6 +80,7 @@ namespace build2
     ctx.module_context_storage->reset (
       new context (ctx.sched,
                    ctx.mutexes,
+                   ctx.fcache,
                    false,                    /* match_only */
                    false,                    /* no_external_modules */
                    false,                    /* dry_run */
diff --git a/libbuild2/test/script/parser.test.cxx b/libbuild2/test/script/parser.test.cxx
index dbdeb57..df91586 100644
--- a/libbuild2/test/script/parser.test.cxx
+++ b/libbuild2/test/script/parser.test.cxx
@@ -10,6 +10,7 @@
 #include <libbuild2/target.hxx>
 #include <libbuild2/context.hxx>
 #include <libbuild2/scheduler.hxx>
+#include <libbuild2/file-cache.hxx>
 
 #include <libbuild2/test/target.hxx>
 
@@ -165,7 +166,8 @@ namespace build2
         //
         scheduler sched (1);
         global_mutexes mutexes (1);
-        context ctx (sched, mutexes);
+        file_cache fcache (sched);
+        context ctx (sched, mutexes, fcache);
 
         bool scope (false);
         bool id (false);