[docs] Coverage: Clarify return value of __llvm_profile_write_file

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@272215 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/SourceBasedCodeCoverage.rst b/docs/SourceBasedCodeCoverage.rst
index 4425bdeb02caed4b7ddf236028e1223128bafd76..ff43c931ea2fb338835e03cefab21087342e8978 100644 (file)
--- a/docs/SourceBasedCodeCoverage.rst
+++ b/docs/SourceBasedCodeCoverage.rst
@@ -206,8 +206,9 @@ without using static initializers, do this manually:
   to ``__llvm_profile_write_file``.
 
 * Forward-declare ``int __llvm_profile_write_file(void)`` and call it to write
-  out a profile. Calling this function multiple times appends profile data to
-  an existing on-disk raw profile.
+  out a profile. This function returns 0 when it succeeds, and a non-zero value
+  otherwise. Calling this function multiple times appends profile data to an
+  existing on-disk raw profile.
 
 Drawbacks and limitations
 =========================