Merge pull request #7348 from thufschmitt/dont-use-vlas

Remove the usage of VLAs in the code

(cherry picked from commit ac4431e9d016e62fb5dc9ae36833bd0c6cdadeec)
Change-Id: Ifbf5fbfc2e27122362a2aaea4b62c7cf3ca46b1a

1 files changed, 2 insertions, 7 deletions

diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 516cbef83..7c7273012 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -323,9 +323,7 @@ typedef std::unordered_map<Path, std::unordered_set<std::string>> UncheckedRoots
 
 static void readProcLink(const std::string & file, UncheckedRoots & roots)
 {
-    /* 64 is the starting buffer size gnu readlink uses... */
-    auto bufsiz = ssize_t{64};
-try_again:
+    constexpr auto bufsiz = PATH_MAX;
     char buf[bufsiz];
     auto res = readlink(file.c_str(), buf, bufsiz);
     if (res == -1) {
@@ -334,10 +332,7 @@ try_again:
         throw SysError("reading symlink");
     }
     if (res == bufsiz) {
-        if (SSIZE_MAX / 2 < bufsiz)
-            throw Error("stupidly long symlink");
-        bufsiz *= 2;
-        goto try_again;
+        throw Error("overly long symlink starting with '%1%'", std::string_view(buf, bufsiz));
     }
     if (res > 0 && buf[0] == '/')
         roots[std::string(static_cast<char *>(buf), res)]