When cross-compiling, `cfg!(target_os)` and friends will be the
configuration for the host rather than the target, since the build
script runs on the host. Cargo provides the target's configuration via
environment variables, so use those.

If we fail because there seems to be something wrong with library names,
provide more output on what's expected and what we found. This should
make cross-compilation related errors easier to spot, including Windows
target-env mismatches as in #24 (which was user error but not easy to
determine).

Be smarter about target-env

See merge request taricorp/llvm-sys.rs!13

I'm not sure why I thought these didn't exist, since on examination
upstream it seems the AsmPrinter has been implemented from very early in
the RISC-V backend's life; assume the others were too.

orc2: Make struct fields public

See merge request taricorp/llvm-sys.rs!14

orc2: Derive standard traits for enum types

See merge request taricorp/llvm-sys.rs!16

Fixed LLVMOrcGenericIRModuleOperationFunction parameter order.

See merge request taricorp/llvm-sys.rs!19

Add LLVMBuildPtrDiff2

See merge request taricorp/llvm-sys.rs!21

Before this change, installing llvm-sys was sometimes failing with the
"Could not determine LLVM version from llvm-config" error, which was
occuring because of lack of straightforward error on non-existing
llvm-config binary call.

Fixes: #33

build: Return an error when the output of llvm-config is empty

Closes #33

See merge request taricorp/llvm-sys.rs!22

On Alpine Linux, old LLVM versions have binaries named llvm${major}-blah.

Support for Alpine Linux llvm-config naming

See merge request taricorp/llvm-sys.rs!24

This includes the following API changes:

* New BLAKE3 API:
  * Structs:
    * `llvm_blake3_chunk_state`
    * `llvm_blake3_hasher`.
  * Functions:
    * `llvm_blake3_version`
    * `llvm_blake3_hasher_init`
    * `llvm_blake3_hasher_init_keyed`
    * `llvm_blake3_hasher_init_derive_key`
    * `llvm_blake3_hasher_init_derive_key_raw`
    * `llvm_blake3_hasher_update`
    * `llvm_blake3_hasher_finalize`
    * `llvm_blake3_hasher_finalize_seek`
    * `llvm_blake3_hasher_reset`
* New functionns for interaction with opaque pointers:
  * `LLVMContextSetOpaquePointers`
  * `LLVMPointerTypeIsOpaque`
  * `LLVMPointerTypeInContext`
* Change of signature of `LLVMOpInfoCallback` function type:
  * New arguments `OpSize` and `InstSize`.
  * Removal of `Size` argument.
* New RMW atomic operations:
  * `LLVMAtomicRMWBinOpFMax`
  * `LLVMAtomicRMWBinOpFMin`
* New LLVM binary type:
  * `LLVMBinaryTypeOffload` - offloading fatbinary.
* New JIT symbol generic flag:
  * `LLVMJITSymbolGenericFlagsNone`
* Renaming of `LLVMJITCSymbolMapPair` to `LLVMOrcCSymbolMapPair`.
* New struct and type for JITDylib search order:
  * `LLVMOrcCJITDylibSearchOrderElement`
  * `LLVMOrcCJITDylibSearchOrder`
* New ORC function types:
  * `LLVMOrcDisposeCAPIDefinitionGeneratorFunction`
  * `LLVMOrcExecutionSessionLookupHandleResultFunction`
* New ORC functions:
  * `LLVMOrcExecutionSessionLookup`
  * `LLVMOrcLookupStateContinueLookup`
* Change of signature of `LLVMOrcCreateCustomCAPIDefinitionGenerator`:
  * New `Dispose` argument.
* Removal of `coroutines` header, which included functions:
  * `LLVMAddCoroEarlyPass`
  * `LLVMAddCoroSplitPass`
  * `LLVMAddCoroElidePass`
  * `LLVMAddCoroCleanupPass`
  * `LLVMPassManagerBuilderAddCoroutinePassesToExtensionPoints`
* Removal of IPO functions:
  * `LLVMAddArgumentPromotionPass`
  * `LLVMPassManagerBuilderPopulateLTOPassManager`
* Removal of one calar function:
  * `LLVMAddLoopUnswitchPass`
* New `LLVMGetCastOpcode` function to aid users of `LLVMBuildCast` in
  resolving the best cast operation given a source value and
  destination type. This function is a direct wrapper of
  `CastInst::getCastOpcode`.
* New `LLVMGetAggregateElement` function as a wrapper for
  `Constant::getAggregateElement`, which can be used to fetch an element
  of a constant struct, array or vector, independently of the underlying
  representation. The `LLVMGetElementAsConstant` function is deprecated
  in favor of the new function, which works on all constant aggregates,
  rather than only instances of `ConstantDataSequential`.
* Removal of the following functions for creating constant expressions,
  because the underlying constant expressions are nno longer supported.
  Instead, an instruction should be created using the `LLVMBuildXYZ`
  APIs, which will constant fold the operands if possible and create an
  instruction otherwise:
  * `LLVMConstExtractValue`
  * `LLVMConstInsertValue`
  * `LLVMConstUDiv`
  * `LLVMConstExactUDiv`
  * `LLVMConstSDiv`
  * `LLVMConstExactSDiv`
  * `LLVMConstURem`
  * `LLVMConstSRem`
  * `LLVMConstFAdd`
  * `LLVMConstFSub`
  * `LLVMConstFMul`
  * `LLVMConstFDiv`
  * `LLVMConstFRem`
* New `LLVMDeleteInstruction` function which allows deleting
  instructions that are not inserted into a basic block.

Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>

In the C API that struct is public because it's embedded in the public
llvm_blake3_hasher struct, but Rust allows us to make that type private.

On Arch Linux, we get the string '/usr/lib/libzstd.so.1.5.2' in
llvm-config's output. The library name is just `zstd` so we need to trim
the shared object version from the name as well as the `lib` prefix.

This only changes handling of system libraries so LLVM 15 works on Arch
Linux.

The `ID` parameter was missing

This should fix #39, where library paths can sometimes appear on Mac like
they do on other unix systems, but there are some quirks.

macOS: handle linking .dylib files by path

Closes #39

See merge request taricorp/llvm-sys.rs!26

This includes the following API changes:

* Core:
  * New functions:
    * `LLVMGetVersion`
    * `LLVMTargetExtTypeInContext`
  * Removed functions:
    * `LLVMConstFNeg`
    * `LLVMConstGEP`
    * `LLVMConstInBoundsGEP`
    * `LLVMAddAlias`
    * `LLVMBuildInvoke`
    * `LLVMBuildLoad`
    * `LLVMBuildGEP`
    * `LLVMBuildInBoundsGEP`
    * `LLVMBuildStructGEP`
    * `LLVMBuildCall`
    * `LLVMBuildPtrDiff`
  * New type kind:
    * `LLVMTargetExtTypeKind`
  * New value kind:
    * `LLVMConstantTargetNoneValueKind`
* Debug info:
  * New source languages known by DWARF:
    * `LLVMDWARFSourceLanguageKotlin`
    * `LLVMDWARFSourceLanguageZig`
    * `LLVMDWARFSourceLanguageCrystal`
    * `LLVMDWARFSourceLanguageC_plus_plus_17`
    * `LLVMDWARFSourceLanguageC_plus_plus_20`
    * `LLVMDWARFSourceLanguageC17`
    * `LLVMDWARFSourceLanguageFortran18`
    * `LLVMDWARFSourceLanguageAda2005`
    * `LLVMDWARFSourceLanguageAda2012`
  * New kind of metadata nodes:
    * `LLVMDIAssignIDMetadataKind`
* Initializaton:
  * Removed functions:
    * `LLVMInitializeObjCARCOpts`
    * `LLVMInitializeAggressiveInstCombiner`
    * `LLVMInitializeInstrumentation`
* Transforms:
  * Removed transforms:
    * `AggressiveInstCombine`
  * IPO:
    * Removed function:
      * `LLVMAddPruneEHPass`
* OrcV2:
  * New function types:
    * `LLVMMemoryManagerCreateContextCallback`
    * `LLVMMemoryManagerNotifyTerminatingCallback`
  * New function:
    * `LLVMOrcCreateRTDyldObjectLinkingLayerWithMCJITMemoryManagerLikeCallbacks`

Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>

Update to LLVM 16

See merge request taricorp/llvm-sys.rs!28

This causes warnings when building and running examples, which aren't
useful. Using MaybeUninit is safer overall, and while we're at it we can
make the example a little easier to follow.

(cherry picked from commit 64b66ade4366050932be13daa8ff9831d2dd79b0)
(cherry picked from commit 5bf37cb5eaa0fa47644e961b590f904fc8ef987e)

Alex Z authored Jul 14, 2022 and Peter Marheine committed Feb 04, 2023

(cherry picked from commit a2c1146c3a7e99c2f500135ecc6078f9f14cf270)
(cherry picked from commit c2c8e429cff4a09b058b37eddbf78d13138fbd6e)
(cherry picked from commit 0e762772)