From e5210aea7b4dd88d5edc598783d2f05d8a73ce24 Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Mon, 8 Apr 2024 09:40:33 +0100
Subject: [PATCH] flake: add a dev shell that has frame pointers

Helps tremendously with getting stack trace from ASan, etc.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 flake.lock | 18 +++++++++---------
 flake.nix  | 28 +++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/flake.lock b/flake.lock
index 4e570b88..a6a77dc6 100644
--- a/flake.lock
+++ b/flake.lock
@@ -5,11 +5,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1705309234,
-        "narHash": "sha256-uNRRNRKmJyCRC/8y1RqBkqWBLM034y4qN7EprSdmgyA=",
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "1ef2e671c3b0c19053962c07dbda38332dcebf26",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
         "type": "github"
       },
       "original": {
@@ -25,11 +25,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1703887061,
-        "narHash": "sha256-gGPa9qWNc6eCXT/+Z5/zMkyYOuRZqeFZBDbopNZQkuY=",
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
         "owner": "hercules-ci",
         "repo": "gitignore.nix",
-        "rev": "43e1aa1308018f37118e34d3a9cb4f5e75dc11d5",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
         "type": "github"
       },
       "original": {
@@ -41,11 +41,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1705856552,
-        "narHash": "sha256-JXfnuEf5Yd6bhMs/uvM67/joxYKoysyE3M2k6T3eWbg=",
+        "lastModified": 1712517181,
+        "narHash": "sha256-NfHaSxL89kX39s1V1/EnnIqBX8LXcc/7ow5fzfCwPrM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "612f97239e2cc474c13c9dafa0df378058c5ad8d",
+        "rev": "6507feebbd146188300681ca26bac5da3c12b9f1",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 10244ef8..221a1a91 100644
--- a/flake.nix
+++ b/flake.nix
@@ -38,15 +38,17 @@
         inherit system overlays;
         config.allowBroken = true;
       };
+      profilePkgs = import nixpkgs {
+        inherit system;
+        overlays = overlays ++ [
+          (final: prev: {
+            stdenv = prev.withCFlags "-fno-omit-frame-pointer" prev.stdenv;
+          })
+        ];
+      };
 
       overlays = [overlay];
-    in rec {
-      inherit
-        overlay
-        overlays
-        ;
-      defaultPackage = pkgs.picom;
-      devShells.default = defaultPackage.overrideAttrs (o: {
+      mkDevShell = p: p.overrideAttrs (o: {
         nativeBuildInputs = o.nativeBuildInputs ++ (with pkgs; [
           clang-tools_17
           llvmPackages_17.clang-unwrapped.python
@@ -59,8 +61,20 @@
           export LD_LIBRARY_PATH+=":/run/opengl-driver/lib"
         '';
       });
+    in rec {
+      inherit
+        overlay
+        overlays
+        ;
+      defaultPackage = pkgs.picom;
+      devShells.default = mkDevShell defaultPackage;
       devShells.useClang = devShells.default.override {
         inherit (pkgs.llvmPackages_17) stdenv;
       };
+      # build picom and all dependencies with frame pointer, making profiling/debugging easier.
+      # WARNING! many many rebuilds
+      devShells.useClangProfile = (mkDevShell profilePkgs.picom).override {
+        stdenv = profilePkgs.withCFlags "-fno-omit-frame-pointer" profilePkgs.llvmPackages_17.stdenv;
+      };
     });
 }