diff options
Diffstat (limited to 'pkgs/development/compilers/gcc/patches/12/mangle-NIX_STORE-in-__FILE__.patch')
| -rw-r--r-- | pkgs/development/compilers/gcc/patches/12/mangle-NIX_STORE-in-__FILE__.patch | 99 |
1 files changed, 0 insertions, 99 deletions
diff --git a/pkgs/development/compilers/gcc/patches/12/mangle-NIX_STORE-in-__FILE__.patch b/pkgs/development/compilers/gcc/patches/12/mangle-NIX_STORE-in-__FILE__.patch deleted file mode 100644 index 8a09af2183f1..000000000000 --- a/pkgs/development/compilers/gcc/patches/12/mangle-NIX_STORE-in-__FILE__.patch +++ /dev/null @@ -1,99 +0,0 @@ -From 30908556fece379ffd7c0da96c774d8bd297e459 Mon Sep 17 00:00:00 2001 -From: Sergei Trofimovich <siarheit@google.com> -Date: Fri, 22 Sep 2023 22:41:49 +0100 -Subject: [PATCH] gcc/file-prefix-map.cc: always mangle __FILE__ into invalid - store path - -Without the change `__FILE__` used in static inline functions in headers -embed paths to header files into executable images. For local headers -it's not a problem, but for headers in `/nix/store` this causes `-dev` -inputs to be retained in runtime closure. - -Typical examples are `nix` -> `nlohmann_json` and `pipewire` -> -`lttng-ust.dev`. - -For this reason we want to remove the occurrences of hashes in the -expansion of `__FILE__`. `nuke-references` does it by replacing hashes -by `eeeeee...`. It is handy to be able to invert the transformation to -go back to the original store path. The chosen solution is to make the -hash uppercase: -- it does not trigger runtime references (except for all digit hashes, - which are unlikely enough) -- it visually looks like a bogus store path -- it is easy to find the original store path if required - -Ideally we would like to use `-fmacro-prefix-map=` feature of `gcc` as: - - -fmacro-prefix-map=/nix/store/$hash1-nlohmann-json-ver=/nix/store/$HASH1-nlohmann-json-ver - -fmacro-prefix-map=/nix/... - -In practice it quickly exhausts argument length limit due to `gcc` -deficiency: https://gcc.gnu.org/PR111527 - -Until it's fixed let's hardcode header mangling if $NIX_STORE variable -is present in the environment. - -Tested as: - - $ printf "# 0 \"/nix/store/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-pppppp-vvvvvvv\" \nconst char * f(void) { return __FILE__; }" | NIX_STORE=/nix/store ./gcc/xgcc -Bgcc -x c - -S -o - - ... - .string "/nix/store/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-pppppp-vvvvvvv" - ... - -Mangled successfully. - -To reverse the effect of the mangle use new `NIX_GCC_DONT_MANGLE_PREFIX_MAP` -environment variable. It should not normally be needed. ---- a/gcc/file-prefix-map.cc -+++ b/gcc/file-prefix-map.cc -@@ -65,7 +65,7 @@ add_prefix_map (file_prefix_map *&maps, const char *arg, const char *opt) - remapping was performed. */ - - static const char * --remap_filename (file_prefix_map *maps, const char *filename) -+remap_filename (file_prefix_map *maps, const char *filename, bool mangle_nix_store = false) - { - file_prefix_map *map; - char *s; -@@ -76,7 +76,31 @@ remap_filename (file_prefix_map *maps, const char *filename) - if (filename_ncmp (filename, map->old_prefix, map->old_len) == 0) - break; - if (!map) -- return filename; -+ { -+ if (mangle_nix_store && getenv("NIX_GCC_DONT_MANGLE_PREFIX_MAP") == NULL) -+ { -+ /* Remap the 32 characters after $NIX_STORE/ to uppercase -+ * -+ * That way we avoid argument parameters explosion -+ * and still avoid embedding headers into runtime closure: -+ * https://gcc.gnu.org/PR111527 -+ */ -+ char * nix_store = getenv("NIX_STORE"); -+ size_t nix_store_len = nix_store ? strlen(nix_store) : 0; -+ const char * name = filename; -+ size_t name_len = strlen(name); -+ if (nix_store && name_len >= nix_store_len + 1 + 32 && memcmp(name, nix_store, nix_store_len) == 0) -+ { -+ s = (char *) ggc_alloc_atomic (name_len + 1); -+ memcpy(s, name, name_len + 1); -+ for (size_t i = nix_store_len + 1; i < nix_store_len + 1 + 32; i++) { -+ s[i] = TOUPPER(s[i]); -+ } -+ return s; -+ } -+ } -+ return filename; -+ } - name = filename + map->old_len; - name_len = strlen (name) + 1; - -@@ -129,7 +153,7 @@ add_profile_prefix_map (const char *arg) - const char * - remap_macro_filename (const char *filename) - { -- return remap_filename (macro_prefix_maps, filename); -+ return remap_filename (macro_prefix_maps, filename, true); - } - - /* Remap using -fdebug-prefix-map. Return the GC-allocated new name |