One of the most common mistakes when working with the LLVM C API is to
mix functions that work on the global context and those that work on an
explicit context. This often results in seemingly nonsensical errors
because types from different contexts are mixed.
We have considered the APIs working on the global context to be obsolete
for a long time already, and do not add any new APIs using the global
context. However, the fact that these still exist (and have shorter
names) continues to cause issues.
This PR proposes to deprecate these APIs, with intent to remove them at
some point in the future.
RFC:
https://discourse.llvm.org/t/rfc-deprecate-c-api-functions-using-the-global-context/88639
/Users/jiefu/llvm-project/llvm/examples/OrcV2Examples/OrcV2CBindingsBasicUsage/OrcV2CBindingsBasicUsage.c:77:52: error: cast from 'char **' to 'const char **' must have all intermediate pointers const qualified to be safe [-Werror,-Wcast-qual]
LLVMParseCommandLineOptions(argc, (const char **)argv, "");
^
/Users/jiefu/llvm-project/llvm/examples/OrcV2Examples/OrcV2CBindingsAddObjectFile/OrcV2CBindingsAddObjectFile.c:63:52: error: cast from 'char **' to 'const char **' must have all intermediate pointers const qualified to be safe [-Werror,-Wcast-qual]
LLVMParseCommandLineOptions(argc, (const char **)argv, "");
^
/Users/jiefu/llvm-project/llvm/examples/OrcV2Examples/OrcV2CBindingsDumpObjects/OrcV2CBindingsDumpObjects.c:62:52: error: cast from 'char **' to 'const char **' must have all intermediate pointers const qualified to be safe [-Werror,-Wcast-qual]
LLVMParseCommandLineOptions(argc, (const char **)argv, "");
^
...
This patch breaks Orc.h up into Orc.h, LLJIT.h and OrcEE.h.
Orc.h contain core Orc utilities.
LLJIT.h contains LLJIT specific types and functions.
OrcEE.h contains types and functions that depend on ExecutionEngine.
The intent is that these headers should match future library divisions: Clients
who only use Orc.h should only need to link againt the Orc core libraries,
clients using LLJIT.h will also need to link against LLVM core, and clients
using OrcEE.h will also have to link against ExecutionEngine.
In addition to breaking up the Orc.h header this patch introduces functions to:
(1) Set the object linking layer creation function on LLJITBuilder.
(2) Create an RTDyldObjectLinkingLayer instance (particularly for use in (1)).
(3) Register JITEventListeners with an RTDyldObjectLinkingLayer.
Together (1), (2) and (3) can be used to force use of RTDyldObjectLinkingLayer
as the underlying JIT linker for LLJIT, rather than the platform default, and
to register event listeners with the RTDyldObjectLinkingLayer.
