[llvm] fa90a0a - [llvm-exegesis] Improve error handling for shm_open calls

[Aiden Grossman via llvm-commits]

Author: Aiden Grossman
Date: 2024-03-27T13:25:44-07:00
New Revision: fa90a0aa0e12aaf657d0f6f7626e05f90ba6f999

URL: https://github.com/llvm/llvm-project/commit/fa90a0aa0e12aaf657d0f6f7626e05f90ba6f999
DIFF: https://github.com/llvm/llvm-project/commit/fa90a0aa0e12aaf657d0f6f7626e05f90ba6f999.diff

LOG: [llvm-exegesis] Improve error handling for shm_open calls

This patch adds error handling for shm_open failures in one case where
they were not handled before and also makes an error handler in another
case report the value of errno for diagnosis.

Added: 
    

Modified: 
    llvm/tools/llvm-exegesis/lib/SubprocessMemory.cpp

Removed: 
    


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diff  --git a/llvm/tools/llvm-exegesis/lib/SubprocessMemory.cpp b/llvm/tools/llvm-exegesis/lib/SubprocessMemory.cpp
index 1fd81bd407becb..0a947f6e206fef 100644
--- a/llvm/tools/llvm-exegesis/lib/SubprocessMemory.cpp
+++ b/llvm/tools/llvm-exegesis/lib/SubprocessMemory.cpp
@@ -63,6 +63,10 @@ Error SubprocessMemory::addMemoryDefinition(
     SharedMemoryNames.push_back(SharedMemoryName);
     int SharedMemoryFD =
         shm_open(SharedMemoryName.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+    if (SharedMemoryFD == -1)
+      return make_error<Failure>(
+          "Failed to create shared memory object for memory definition: " +
+          Twine(strerror(errno)));
     if (ftruncate(SharedMemoryFD, MemVal.SizeBytes) != 0) {
       return make_error<Failure>("Truncating a memory definiton failed: " +
                                  Twine(strerror(errno)));
@@ -100,7 +104,8 @@ Expected<int> SubprocessMemory::setupAuxiliaryMemoryInSubprocess(
       shm_open(AuxiliaryMemoryName.c_str(), O_RDWR, S_IRUSR | S_IWUSR);
   if (AuxiliaryMemoryFileDescriptor == -1)
     return make_error<Failure>(
-        "Getting file descriptor for auxiliary memory failed");
+        "Getting file descriptor for auxiliary memory failed: " +
+        Twine(strerror(errno)));
   // set up memory value file descriptors
   int *AuxiliaryMemoryMapping =
       (int *)mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED,