diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 1e17132f..dd7df011 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -16,6 +16,7 @@
 #include <sys/resource.h>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 
 #include <sys/resource.h>
 
@@ -349,7 +350,18 @@ EvalState::EvalState(const Strings & _searchPath, ref<Store> store)
 
 
 EvalState::~EvalState()
-{
+{ /*
+    std::cout << std::endl << "============= " << std::endl;
+    std::cout << "Maps summary: " << std::endl;
+    std::cout << "============= " << std::endl;
+    std::cout << "FuncMap:" << std::endl;
+    for(auto e: profState.funcMap) {
+        std::cout << e.first << ": " << e.second << std::endl;
+    }
+    std::cout << std::endl << "FileMap:" << std::endl;
+    for(auto e: profState.fileMap) {
+        std::cout << e.first << ": " << e.second << std::endl;
+    } */
 }
 
 
@@ -1178,6 +1190,26 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & po
     }
 
     nrFunctionCalls++;
+    /* Lo and behold.
+
+       There's no way to get the symbol name in the Symbol class.
+
+       That said, there's a ostream operator *WINK WINK*
+    */
+    if (settings.profileEvaluation && lambda.name.set()) {
+        std::ostringstream ossFunc;
+        ossFunc << lambda.name;
+        string functionName = ossFunc.str();
+        profState.registerFunction(functionName);
+
+       if (pos.file.set()) {
+           std::ostringstream ossFi;
+           ossFi << pos.file;
+           string fileName = ossFi.str();
+           profState.registerFile(fileName);
+           std::cout << "file: " << fileName << " funcName: " << functionName << " " << pos.line << ":" << pos.column << std::endl;
+       }
+    }
     if (countCalls) incrFunctionCall(&lambda);
 
     /* Evaluate the body.  This is conditional on showTrace, because
@@ -1978,5 +2010,39 @@ EvalSettings evalSettings;
 
 static GlobalConfig::Register r1(&evalSettings);
 
+/* Profiler stuff
+*****************
+*/
+
+ProfilerState::ProfilerState() {
+}
+
+CompressedFileId ProfilerState::registerFile(FileName& fName) {
+    CompressedFileId fid;
+    auto it = fileMap.find(fName);
+    if(it == fileMap.end()) {
+        fid = currentFuncId;
+        fileMap.insert({fName,currentFuncId});
+        currentFuncId++;
+    }
+    else {
+        fid = it->second;
+    }
+    return fid;
+}
+
+CompressedFuncId ProfilerState::registerFunction(FunctionName& fName) {
+    CompressedFuncId fid;
+    auto it = funcMap.find(fName);
+    if(it == funcMap.end()) {
+        fid = currentFuncId;
+        funcMap.insert({fName,currentFuncId});
+        currentFuncId++;
+    }
+    else {
+        fid = it->second;
+    }
+    return fid;
+}
 
 }
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 4997d139..92b5aa8a 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -20,6 +20,55 @@ class Store;
 class EvalState;
 enum RepairFlag : bool;
 
+/* Profiler-related operations.
+   [callGrindSpec]: TODO: add URL */
+
+typedef string FunctionName;
+typedef string FileName;
+typedef int CompressedFuncId;
+typedef int CompressedFileId;
+typedef int LineNumber;
+
+struct ProfFuncOcc {
+    CompressedFuncId funcId;
+    CompressedFileId fileId;
+};
+
+struct ProfFuncCall {
+    CompressedFuncId calledFunc;
+    CompressedFileId calledFile;
+    LineNumber calledFuncLineNb;
+    int cost;
+};
+
+struct ProfCostOcc {
+    CompressedFuncId funcId;
+    CompressedFileId fileId;
+    ProfFuncOcc funcOcc;
+    int selfCost;
+    std::vector<ProfFuncCall> calledFunctions;
+};
+
+class ProfilerState {
+
+public:
+    ProfilerState();
+    CompressedFileId registerFile(FileName& fName);
+    CompressedFuncId registerFunction(FunctionName& fName);
+    ProfCostOcc& getFuncOcc(FileName& fName, FunctionName& fnName);
+    void saveCost(ProfCostOcc& occCost);
+
+public:
+    std::vector<ProfCostOcc> stackedMeasurements;
+    string funcName;
+    /* We index every func and file to leverage Callgrind's string compression.
+       See section "3.1.6.�Subposition Compression" section from [callgrindSpec]. */
+    std::map<FunctionName,CompressedFuncId> funcMap;
+    std::map<FileName,CompressedFileId> fileMap;
+    CompressedFuncId currentFuncId;
+    CompressedFileId currentFileId;
+};
+
 
 typedef void (* PrimOpFun) (EvalState & state, const Pos & pos, Value * * args, Value & v);
 
@@ -315,7 +364,7 @@ private:
     friend void prim_getAttr(EvalState & state, const Pos & pos, Value * * args, Value & v);
 
     /* Profiler-related members */
-
+    ProfilerState profState;
 
 };