Cache more results of executing programs (compilers, etc)

3 files changed, 111 insertions, 55 deletions

diff --git a/libbuild2/bin/guess.cxx b/libbuild2/bin/guess.cxx
index 21936d9..9f15030 100644
--- a/libbuild2/bin/guess.cxx
+++ b/libbuild2/bin/guess.cxx
@@ -54,7 +54,7 @@ namespace build2
       {
         process_path r (
           run_try_search (prog,
-                          true        /* init */,
+                          false       /* init (cached) */,
                           dir_path () /* fallback */,
                           true        /* path_only */,
                           paths));
@@ -80,14 +80,33 @@ namespace build2
           dr << info << "use " << var << " to override";
         });
 
-      return run_search (prog, true, dir_path (), true);
+      return run_search (prog, false, dir_path (), true);
     }
 
-    ar_info
+    // Extracting ar/ranlib information requires running them which can become
+    // expensive if done repeatedly. So we cache the result.
+    //
+    static global_cache<ar_info> ar_cache;
+
+    const ar_info&
     guess_ar (const path& ar, const path* rl, const char* paths)
     {
       tracer trace ("bin::guess_ar");
 
+      // First check the cache.
+      //
+      string key;
+      {
+        sha256 cs;
+        cs.append (ar.string ());
+        if (rl != nullptr) cs.append (rl->string ());
+        if (paths != nullptr) cs.append (paths);
+        key = cs.string ();
+
+        if (const ar_info* r = ar_cache.find (key))
+          return *r;
+      }
+
       guess_result arr, rlr;
 
       process_path arp (search (ar, paths, "config.bin.ar"));
@@ -307,24 +326,43 @@ namespace build2
           fail << "unable to guess " << *rl << " signature";
       }
 
-      return ar_info {
-        move (arp),
-        move (arr.id),
-        move (arr.signature),
-        move (arr.checksum),
-        move (*arr.version),
-
-        move (rlp),
-        move (rlr.id),
-        move (rlr.signature),
-        move (rlr.checksum)};
+      return ar_cache.insert (move (key),
+                              ar_info {
+                                move (arp),
+                                move (arr.id),
+                                move (arr.signature),
+                                move (arr.checksum),
+                                move (*arr.version),
+
+                                move (rlp),
+                                move (rlr.id),
+                                move (rlr.signature),
+                                move (rlr.checksum)});
     }
 
-    ld_info
+    // Extracting ld information requires running it which can become
+    // expensive if done repeatedly. So we cache the result.
+    //
+    static global_cache<ld_info> ld_cache;
+
+    const ld_info&
     guess_ld (const path& ld, const char* paths)
     {
       tracer trace ("bin::guess_ld");
 
+      // First check the cache.
+      //
+      string key;
+      {
+        sha256 cs;
+        cs.append (ld.string ());
+        if (paths != nullptr) cs.append (paths);
+        key = cs.string ();
+
+        if (const ld_info* r = ld_cache.find (key))
+          return *r;
+      }
+
       guess_result r;
 
       process_path pp (search (ld, paths, "config.bin.ld"));
@@ -484,19 +522,38 @@ namespace build2
       if (r.empty ())
         fail << "unable to guess " << ld << " signature";
 
-      return ld_info {
-        move (pp),
-        move (r.id),
-        move (r.signature),
-        move (r.checksum),
-        move (r.version)};
+      return ld_cache.insert (move (key),
+                              ld_info {
+                                move (pp),
+                                move (r.id),
+                                move (r.signature),
+                                move (r.checksum),
+                                move (r.version)});
     }
 
-    rc_info
+    // Extracting rc information requires running it which can become
+    // expensive if done repeatedly. So we cache the result.
+    //
+    static global_cache<rc_info> rc_cache;
+
+    const rc_info&
     guess_rc (const path& rc, const char* paths)
     {
       tracer trace ("bin::guess_rc");
 
+      // First check the cache.
+      //
+      string key;
+      {
+        sha256 cs;
+        cs.append (rc.string ());
+        if (paths != nullptr) cs.append (paths);
+        key = cs.string ();
+
+        if (const rc_info* r = rc_cache.find (key))
+          return *r;
+      }
+
       guess_result r;
 
       process_path pp (search (rc, paths, "config.bin.rc"));
@@ -575,8 +632,12 @@ namespace build2
       if (r.empty ())
         fail << "unable to guess " << rc << " signature";
 
-      return rc_info {
-        move (pp), move (r.id), move (r.signature), move (r.checksum)};
+      return rc_cache.insert (move (key),
+                              rc_info {
+                                move (pp),
+                                move (r.id),
+                                move (r.signature),
+                                move (r.checksum)});
     }
   }
 }
diff --git a/libbuild2/bin/guess.hxx b/libbuild2/bin/guess.hxx
index 27bb5ed..9a63fa1 100644
--- a/libbuild2/bin/guess.hxx
+++ b/libbuild2/bin/guess.hxx
@@ -45,7 +45,7 @@ namespace build2
     // The ranlib path can be NULL, in which case no ranlib guessing will be
     // attemplated and the returned ranlib_* members will be left empty.
     //
-    ar_info
+    const ar_info&
     guess_ar (const path& ar, const path* ranlib, const char* paths);
 
     // ld information.
@@ -85,7 +85,7 @@ namespace build2
       optional<semantic_version> version;
     };
 
-    ld_info
+    const ld_info&
     guess_ld (const path& ld, const char* paths);
 
     // rc information.
@@ -110,7 +110,7 @@ namespace build2
       string checksum;
     };
 
-    rc_info
+    const rc_info&
     guess_rc (const path& rc, const char* paths);
   }
 }
diff --git a/libbuild2/bin/init.cxx b/libbuild2/bin/init.cxx
index 49ba518..6d2d2c2 100644
--- a/libbuild2/bin/init.cxx
+++ b/libbuild2/bin/init.cxx
@@ -683,7 +683,7 @@ namespace build2
                            nullptr,
                            config::save_default_commented)));
 
-        ar_info ari (guess_ar (ar, ranlib, pat.paths));
+        const ar_info& ari (guess_ar (ar, ranlib, pat.paths));
 
         // If this is a configuration with new values, then print the report
         // at verbosity level 2 and up (-v).
@@ -723,33 +723,28 @@ namespace build2
         }
 
         rs.assign<process_path_ex> ("bin.ar.path")   =
-          process_path_ex (move (ari.ar_path), "ar", ari.ar_checksum);
-        rs.assign<string>       ("bin.ar.id")        = move (ari.ar_id);
-        rs.assign<string>       ("bin.ar.signature") = move (ari.ar_signature);
-        rs.assign<string>       ("bin.ar.checksum")  = move (ari.ar_checksum);
+          process_path_ex (ari.ar_path, "ar", ari.ar_checksum);
+        rs.assign<string>       ("bin.ar.id")        = ari.ar_id;
+        rs.assign<string>       ("bin.ar.signature") = ari.ar_signature;
+        rs.assign<string>       ("bin.ar.checksum")  = ari.ar_checksum;
 
         {
-          semantic_version& v (ari.ar_version);
+          const semantic_version& v (ari.ar_version);
 
           rs.assign<string>   ("bin.ar.version")       = v.string ();
           rs.assign<uint64_t> ("bin.ar.version.major") = v.major;
           rs.assign<uint64_t> ("bin.ar.version.minor") = v.minor;
           rs.assign<uint64_t> ("bin.ar.version.patch") = v.patch;
-          rs.assign<string>   ("bin.ar.version.build") = move (v.build);
+          rs.assign<string>   ("bin.ar.version.build") = v.build;
         }
 
         if (ranlib != nullptr)
         {
           rs.assign<process_path_ex> ("bin.ranlib.path")   =
-            process_path_ex (move (ari.ranlib_path),
-                             "ranlib",
-                             ari.ranlib_checksum);
-          rs.assign<string>       ("bin.ranlib.id")        =
-            move (ari.ranlib_id);
-          rs.assign<string>       ("bin.ranlib.signature") =
-            move (ari.ranlib_signature);
-          rs.assign<string>       ("bin.ranlib.checksum") =
-            move (ari.ranlib_checksum);
+            process_path_ex (ari.ranlib_path, "ranlib", ari.ranlib_checksum);
+          rs.assign<string>       ("bin.ranlib.id")        = ari.ranlib_id;
+          rs.assign<string>       ("bin.ranlib.signature") = ari.ranlib_signature;
+          rs.assign<string>       ("bin.ranlib.checksum")  = ari.ranlib_checksum;
         }
       }
 
@@ -826,7 +821,7 @@ namespace build2
                            path (apply_pattern (ld_d, pat.pattern)),
                            config::save_default_commented)));
 
-        ld_info ldi (guess_ld (ld, pat.paths));
+        const ld_info& ldi (guess_ld (ld, pat.paths));
 
         // If this is a configuration with new values, then print the report
         // at verbosity level 2 and up (-v).
@@ -859,20 +854,20 @@ namespace build2
         }
 
         rs.assign<process_path_ex> ("bin.ld.path")   =
-          process_path_ex (move (ldi.path), "ld", ldi.checksum);
-        rs.assign<string>       ("bin.ld.id")        = move (ldi.id);
-        rs.assign<string>       ("bin.ld.signature") = move (ldi.signature);
-        rs.assign<string>       ("bin.ld.checksum")  = move (ldi.checksum);
+          process_path_ex (ldi.path, "ld", ldi.checksum);
+        rs.assign<string>       ("bin.ld.id")        = ldi.id;
+        rs.assign<string>       ("bin.ld.signature") = ldi.signature;
+        rs.assign<string>       ("bin.ld.checksum")  = ldi.checksum;
 
         if (ldi.version)
         {
-          semantic_version& v (*ldi.version);
+          const semantic_version& v (*ldi.version);
 
           rs.assign<string>   ("bin.ld.version")       = v.string ();
           rs.assign<uint64_t> ("bin.ld.version.major") = v.major;
           rs.assign<uint64_t> ("bin.ld.version.minor") = v.minor;
           rs.assign<uint64_t> ("bin.ld.version.patch") = v.patch;
-          rs.assign<string>   ("bin.ld.version.build") = move (v.build);
+          rs.assign<string>   ("bin.ld.version.build") = v.build;
         }
       }
 
@@ -979,7 +974,7 @@ namespace build2
                            path (apply_pattern (rc_d, pat.pattern)),
                            config::save_default_commented)));
 
-        rc_info rci (guess_rc (rc, pat.paths));
+        const rc_info& rci (guess_rc (rc, pat.paths));
 
         // If this is a configuration with new values, then print the report
         // at verbosity level 2 and up (-v).
@@ -994,10 +989,10 @@ namespace build2
         }
 
         rs.assign<process_path_ex> ("bin.rc.path")   =
-          process_path_ex (move (rci.path), "rc", rci.checksum);
-        rs.assign<string>       ("bin.rc.id")        = move (rci.id);
-        rs.assign<string>       ("bin.rc.signature") = move (rci.signature);
-        rs.assign<string>       ("bin.rc.checksum")  = move (rci.checksum);
+          process_path_ex (rci.path, "rc", rci.checksum);
+        rs.assign<string>       ("bin.rc.id")        = rci.id;
+        rs.assign<string>       ("bin.rc.signature") = rci.signature;
+        rs.assign<string>       ("bin.rc.checksum")  = rci.checksum;
       }
 
       return true;