[libcxx-commits] [PATCH] D130214: [libc++][test] Fix infinite loop when mkstemp fails

[Ryan Prichard via Phabricator via libcxx-commits]

rprichard created this revision.
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mkstemp is guaranteed to make at least TMP_MAX attempts to create the
random file, and if it can't, it fails with EEXIST. get_temp_file_name
shouldn't call mkstemp again if it fails with anything other than
EEXIST. A single mkstemp call seems sufficient.

On Android, I've seen mkstemp fail with:

- EROFS (because cwd wasn't set to a writable filesystem)
- EACCES (because cwd pointed to a dir owned by root, but the test program was running as the shell user instead)

Previously, get_temp_file_name would run forever in these situations.

See D4962 <https://reviews.llvm.org/D4962> and "llvm-svn: 229035"


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130214

Files:
  libcxx/test/support/platform_support.h


Index: libcxx/test/support/platform_support.h
===================================================================
--- libcxx/test/support/platform_support.h
+++ libcxx/test/support/platform_support.h
@@ -75,16 +75,12 @@
         abort();
     }
 #else
-    std::string Name;
-    int FD = -1;
-    do {
-        Name = "libcxx.XXXXXX";
-        FD = mkstemp(&Name[0]);
-        if (FD == -1 && errno == EINVAL) {
-            perror("mkstemp");
-            abort();
-        }
-    } while (FD == -1);
+    std::string Name = "libcxx.XXXXXX";
+    int FD = mkstemp(&Name[0]);
+    if (FD == -1) {
+        perror("mkstemp");
+        abort();
+    }
     close(FD);
     return Name;
 #endif


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