//===- Config.h -------------------------------------------------*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef LLD_WASM_CONFIG_H #define LLD_WASM_CONFIG_H #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringRef.h" #include "llvm/ADT/StringSet.h" #include "llvm/ADT/Twine.h" #include "llvm/BinaryFormat/Wasm.h" #include "llvm/Support/CachePruning.h" #include namespace llvm { enum class CodeGenOptLevel; } // namespace llvm namespace lld::wasm { class InputFile; class StubFile; class ObjFile; class SharedFile; class BitcodeFile; class InputTable; class InputGlobal; class InputFunction; class Symbol; class DefinedData; class GlobalSymbol; class DefinedFunction; class UndefinedGlobal; class TableSymbol; // For --unresolved-symbols. enum class UnresolvedPolicy { ReportError, Warn, Ignore, ImportDynamic }; // For --build-id. enum class BuildIdKind { None, Fast, Sha1, Hexstring, Uuid }; // This struct contains the global configuration for the linker. // Most fields are direct mapping from the command line options // and such fields have the same name as the corresponding options. // Most fields are initialized by the driver. struct Config { bool allowMultipleDefinition; bool bsymbolic; bool checkFeatures; bool compressRelocations; bool demangle; bool disableVerify; bool experimentalPic; bool emitRelocs; bool exportAll; bool exportDynamic; bool exportTable; bool extendedConst; bool growableTable; bool gcSections; llvm::StringSet<> keepSections; std::optional> memoryImport; std::optional memoryExport; bool sharedMemory; bool importTable; bool importUndefined; std::optional is64; bool mergeDataSegments; bool noinhibitExec; bool pie; bool printGcSections; bool relocatable; bool saveTemps; bool shared; bool shlibSigCheck; bool stripAll; bool stripDebug; bool stackFirst; // Because dyamanic linking under Wasm is still experimental we default to // static linking bool isStatic = true; bool thinLTOEmitImportsFiles; bool thinLTOEmitIndexFiles; bool thinLTOIndexOnly; bool trace; uint64_t globalBase; uint64_t initialHeap; uint64_t initialMemory; uint64_t maxMemory; bool noGrowableMemory; // The table offset at which to place function addresses. We reserve zero // for the null function pointer. This gets set to 1 for executables and 0 // for shared libraries (since they always added to a dynamic offset at // runtime). uint64_t tableBase; uint64_t zStackSize; uint64_t pageSize; unsigned ltoPartitions; unsigned ltoo; llvm::CodeGenOptLevel ltoCgo; unsigned optimize; bool ltoDebugPassManager; UnresolvedPolicy unresolvedSymbols; BuildIdKind buildId = BuildIdKind::None; llvm::StringRef entry; llvm::StringRef ltoObjPath; llvm::StringRef mapFile; llvm::StringRef outputFile; llvm::StringRef soName; llvm::StringRef thinLTOCacheDir; llvm::StringRef thinLTOJobs; llvm::StringRef thinLTOIndexOnlyArg; std::pair thinLTOObjectSuffixReplace; llvm::StringRef thinLTOPrefixReplaceOld; llvm::StringRef thinLTOPrefixReplaceNew; llvm::StringRef thinLTOPrefixReplaceNativeObject; llvm::StringRef whyExtract; llvm::StringSet<> allowUndefinedSymbols; llvm::StringSet<> exportedSymbols; std::vector requiredExports; llvm::SmallVector searchPaths; llvm::SmallVector rpath; llvm::CachePruningPolicy thinLTOCachePolicy; std::optional> features; std::optional> extraFeatures; llvm::SmallVector buildIdVector; }; // The Ctx object hold all other (non-configuration) global state. struct Ctx { Config arg; llvm::SmallVector objectFiles; llvm::SmallVector stubFiles; llvm::SmallVector sharedFiles; llvm::SmallVector bitcodeFiles; llvm::SmallVector lazyBitcodeFiles; llvm::SmallVector syntheticFunctions; llvm::SmallVector syntheticGlobals; llvm::SmallVector syntheticTables; // linker-generated symbols struct WasmSym { // __global_base // Symbol marking the start of the global section. DefinedData *globalBase; // __stack_pointer/__stack_low/__stack_high // Global that holds current value of stack pointer and data symbols marking // the start and end of the stack region. stackPointer is initialized to // stackHigh and grows downwards towards stackLow GlobalSymbol *stackPointer; DefinedData *stackLow; DefinedData *stackHigh; // __tls_base // Global that holds the address of the base of the current thread's // TLS block. GlobalSymbol *tlsBase; // __tls_size // Symbol whose value is the size of the TLS block. GlobalSymbol *tlsSize; // __tls_size // Symbol whose value is the alignment of the TLS block. GlobalSymbol *tlsAlign; // __data_end // Symbol marking the end of the data and bss. DefinedData *dataEnd; // __heap_base/__heap_end // Symbols marking the beginning and end of the "heap". It starts at the end // of the data, bss and explicit stack, and extends to the end of the linear // memory allocated by wasm-ld. This region of memory is not used by the // linked code, so it may be used as a backing store for `sbrk` or `malloc` // implementations. DefinedData *heapBase; DefinedData *heapEnd; // __wasm_first_page_end // A symbol whose address is the end of the first page in memory (if any). DefinedData *firstPageEnd; // __wasm_init_memory_flag // Symbol whose contents are nonzero iff memory has already been // initialized. DefinedData *initMemoryFlag; // __wasm_init_memory // Function that initializes passive data segments during instantiation. DefinedFunction *initMemory; // __wasm_call_ctors // Function that directly calls all ctors in priority order. DefinedFunction *callCtors; // __wasm_call_dtors // Function that calls the libc/etc. cleanup function. DefinedFunction *callDtors; // __wasm_apply_global_relocs // Function that applies relocations to wasm globals post-instantiation. // Unlike __wasm_apply_data_relocs this needs to run on every thread. DefinedFunction *applyGlobalRelocs; // __wasm_apply_tls_relocs // Like __wasm_apply_data_relocs but for TLS section. These must be // delayed until __wasm_init_tls. DefinedFunction *applyTLSRelocs; // __wasm_apply_global_tls_relocs // Like applyGlobalRelocs but for globals that hold TLS addresses. These // must be delayed until __wasm_init_tls. DefinedFunction *applyGlobalTLSRelocs; // __wasm_init_tls // Function that allocates thread-local storage and initializes it. DefinedFunction *initTLS; // Pointer to the function that is to be used in the start section. // (normally an alias of initMemory, or applyGlobalRelocs). DefinedFunction *startFunction; // __dso_handle // Symbol used in calls to __cxa_atexit to determine current DLL DefinedData *dsoHandle; // __table_base // Used in PIC code for offset of indirect function table UndefinedGlobal *tableBase; DefinedData *definedTableBase; // __memory_base // Used in PIC code for offset of global data UndefinedGlobal *memoryBase; DefinedData *definedMemoryBase; // __indirect_function_table // Used as an address space for function pointers, with each function that // is used as a function pointer being allocated a slot. TableSymbol *indirectFunctionTable; }; WasmSym sym; // True if we are creating position-independent code. bool isPic = false; // True if we have an MVP input that uses __indirect_function_table and which // requires it to be allocated to table number 0. bool legacyFunctionTable = false; // Will be set to true if bss data segments should be emitted. In most cases // this is not necessary. bool emitBssSegments = false; // A tuple of (reference, extractedFile, sym). Used by --why-extract=. llvm::SmallVector, 0> whyExtractRecords; Ctx(); void reset(); }; extern Ctx ctx; void errorOrWarn(const llvm::Twine &msg); } // namespace lld::wasm #endif