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| author | Sanjoy Das <sanjoy@playingwithpointers.com> | 2017-02-13 23:19:07 +0000 |
|---|---|---|
| committer | Sanjoy Das <sanjoy@playingwithpointers.com> | 2017-02-13 23:19:07 +0000 |
| commit | 5be2e8415c473b16bc618f9c9a4da7fe076a69fa (patch) | |
| tree | c1304c8981b6d1b421a2391f2a62bb963abc9d58 | |
| parent | a3ff9942684abd60ec56d5a3a724de1eab54b5cd (diff) | |
| download | bcm5719-llvm-5be2e8415c473b16bc618f9c9a4da7fe076a69fa.tar.gz bcm5719-llvm-5be2e8415c473b16bc618f9c9a4da7fe076a69fa.zip | |
[LangRef] Explicitly allow readnone and reaodnly functions to unwind
Summary:
This change edits the language reference to explicitly allow the
existence of readnone and readonly functions that can throw. Full
discussion at
http://lists.llvm.org/pipermail/llvm-dev/2017-January/108637.html
Reviewers: dberlin, chandlerc, hfinkel, majnemer
Reviewed By: majnemer
Subscribers: majnemer, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D28740
llvm-svn: 295000
| -rw-r--r-- | llvm/docs/LangRef.rst | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst index 068fb6bde61..ce8b6f04ee0 100644 --- a/llvm/docs/LangRef.rst +++ b/llvm/docs/LangRef.rst @@ -1474,8 +1474,10 @@ example: any mutable state (e.g. memory, control registers, etc) visible to caller functions. It does not write through any pointer arguments (including ``byval`` arguments) and never changes any state visible - to callers. This means that it cannot unwind exceptions by calling - the ``C++`` exception throwing methods. + to callers. This means while it cannot unwind exceptions by calling + the ``C++`` exception throwing methods (since they write to memory), there may + be non-``C++`` mechanisms that throw exceptions without writing to LLVM + visible memory. On an argument, this attribute indicates that the function does not dereference that pointer argument, even though it may read or write the @@ -1487,9 +1489,10 @@ example: caller functions. It may dereference pointer arguments and read state that may be set in the caller. A readonly function always returns the same value (or unwinds an exception identically) when - called with the same set of arguments and global state. It cannot - unwind an exception by calling the ``C++`` exception throwing - methods. + called with the same set of arguments and global state. This means while it + cannot unwind exceptions by calling the ``C++`` exception throwing methods + (since they write to memory), there may be non-``C++`` mechanisms that throw + exceptions without writing to LLVM visible memory. On an argument, this attribute indicates that the function does not write through this pointer argument, even though it may write to the memory that |
