From 595971e195e2147205b0b6fda019b112c795315d Mon Sep 17 00:00:00 2001
From: Michael Bishop <cleverca22@gmail.com>
Date: Wed, 4 Mar 2020 22:22:20 -0400
Subject: [PATCH] log all ifd

---
 src/libexpr/eval.hh    |  5 ++++-
 src/libexpr/primops.cc | 19 +++++++++++--------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 1485dc7fe299..169d9bb93bce 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -286,7 +286,7 @@ public:
     /* Print statistics. */
     void printStats();
 
-    void realiseContext(const PathSet & context);
+    void realiseContext(const PathSet & context, const Pos &pos, const string reason);
 
 private:
 
@@ -369,6 +369,9 @@ struct EvalSettings : Config
 
     Setting<bool> traceFunctionCalls{this, false, "trace-function-calls",
         "Emit log messages for each function entry and exit at the 'vomit' log level (-vvvv)."};
+
+    Setting<bool> logAllIFD{this, false, "log-all-ifd",
+        "Emit log messages for all IFD at 'info' log level"};
 };
 
 extern EvalSettings evalSettings;
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index fc6c8296b4a9..1740e4430633 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -45,7 +45,7 @@ std::pair<string, string> decodeContext(const string & s)
 InvalidPathError::InvalidPathError(const Path & path) :
     EvalError("path '%s' is not valid", path), path(path) {}
 
-void EvalState::realiseContext(const PathSet & context)
+void EvalState::realiseContext(const PathSet & context, const Pos &pos, const string reason)
 {
     std::vector<StorePathWithOutputs> drvs;
 
@@ -56,6 +56,9 @@ void EvalState::realiseContext(const PathSet & context)
             throw InvalidPathError(store->printStorePath(ctx));
         if (!decoded.second.empty() && ctx.isDerivation()) {
             drvs.push_back(StorePathWithOutputs{ctx.clone(), {decoded.second}});
+            if (evalSettings.logAllIFD) {
+              printInfo(format("%1% importing from derivation %2% via %3%") % pos % decoded.first % reason);
+            }
 
             /* Add the output of this derivation to the allowed
                paths. */
@@ -91,7 +94,7 @@ static void prim_scopedImport(EvalState & state, const Pos & pos, Value * * args
     Path path = state.coerceToPath(pos, *args[1], context);
 
     try {
-        state.realiseContext(context);
+        state.realiseContext(context, pos, "scopedImport");
     } catch (InvalidPathError & e) {
         throw EvalError(format("cannot import '%1%', since path '%2%' is not valid, at %3%")
             % path % e.path % pos);
@@ -168,7 +171,7 @@ void prim_importNative(EvalState & state, const Pos & pos, Value * * args, Value
     Path path = state.coerceToPath(pos, *args[0], context);
 
     try {
-        state.realiseContext(context);
+        state.realiseContext(context, pos, "importNative");
     } catch (InvalidPathError & e) {
         throw EvalError(format("cannot import '%1%', since path '%2%' is not valid, at %3%")
             % path % e.path % pos);
@@ -215,7 +218,7 @@ void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v)
         commandArgs.emplace_back(state.coerceToString(pos, *elems[i], context, false, false));
     }
     try {
-        state.realiseContext(context);
+        state.realiseContext(context, pos, "exec");
     } catch (InvalidPathError & e) {
         throw EvalError(format("cannot execute '%1%', since path '%2%' is not valid, at %3%")
             % program % e.path % pos);
@@ -831,7 +834,7 @@ static void prim_pathExists(EvalState & state, const Pos & pos, Value * * args,
     PathSet context;
     Path path = state.coerceToPath(pos, *args[0], context);
     try {
-        state.realiseContext(context);
+        state.realiseContext(context, pos, "pathExists");
     } catch (InvalidPathError & e) {
         throw EvalError(format(
                 "cannot check the existence of '%1%', since path '%2%' is not valid, at %3%")
@@ -876,7 +879,7 @@ static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Va
     PathSet context;
     Path path = state.coerceToPath(pos, *args[0], context);
     try {
-        state.realiseContext(context);
+        state.realiseContext(context, pos, "readFile");
     } catch (InvalidPathError & e) {
         throw EvalError(format("cannot read '%1%', since path '%2%' is not valid, at %3%")
             % path % e.path % pos);
@@ -913,7 +916,7 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va
         string path = state.coerceToString(pos, *i->value, context, false, false);
 
         try {
-            state.realiseContext(context);
+            state.realiseContext(context, pos, "findFile");
         } catch (InvalidPathError & e) {
             throw EvalError(format("cannot find '%1%', since path '%2%' is not valid, at %3%")
                 % path % e.path % pos);
@@ -947,7 +950,7 @@ static void prim_readDir(EvalState & state, const Pos & pos, Value * * args, Val
     PathSet ctx;
     Path path = state.coerceToPath(pos, *args[0], ctx);
     try {
-        state.realiseContext(ctx);
+        state.realiseContext(ctx, pos, "readDir");
     } catch (InvalidPathError & e) {
         throw EvalError(format("cannot read '%1%', since path '%2%' is not valid, at %3%")
             % path % e.path % pos);