Improve error handling for SmallVector programming errors

This patch changes errors in `SmallVector::grow` that are independent of
memory capacity to be reported using report_fatal_error or
std::length_error instead of report_bad_alloc_error, which falsely signals
an OOM.

It also cleans up a few related things:
- makes report_bad_alloc_error to print the failure reason passed
  to it.
- fixes the documentation to indicate that report_bad_alloc_error
  calls `abort()` not "an assertion"
- uses a consistent name for the size/capacity argument to `grow`
  and `grow_pod`

Reviewed By: mehdi_amini, MaskRay

Differential Revision: https://reviews.llvm.org/D86892

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Support/ErrorHandling.cpp b/llvm/lib/Support/ErrorHandling.cpp
index e962657..23b9f96 100644
--- a/llvm/lib/Support/ErrorHandling.cpp
+++ b/llvm/lib/Support/ErrorHandling.cpp
@@ -168,9 +168,11 @@ void llvm::report_bad_alloc_error(const char *Reason, bool GenCrashDiag) {
 #else
   // Don't call the normal error handler. It may allocate memory. Directly write
   // an OOM to stderr and abort.
-  char OOMMessage[] = "LLVM ERROR: out of memory\n";
-  ssize_t written = ::write(2, OOMMessage, strlen(OOMMessage));
-  (void)written;
+  const char *OOMMessage = "LLVM ERROR: out of memory\n";
+  const char *Newline = "\n";
+  (void)::write(2, OOMMessage, strlen(OOMMessage));
+  (void)::write(2, Reason, strlen(Reason));
+  (void)::write(2, Newline, strlen(Newline));
   abort();
 #endif
 }