[llvm] annotate interfaces in llvm-c for DLL export #141701

andrurogerz · 2025-05-28T01:52:01Z

Purpose

This patch is one in a series of code-mods that annotate LLVM’s public interface for export. This patch annotates the llvm-c interface with a new LLVM_C_ABI annotation, which behaves like the LLVM_ABI. This annotation currently has no meaningful impact on the LLVM build; however, it is a prerequisite to support an LLVM Windows DLL (shared library) build.

Overview

Add a new llvm-c/Visibility.h header file that defines a new LLVM_C_ABI macro. The macro resolves to the proper DLL export/import annotation on Windows and a "default" visibility annotation elsewhere.
Add a new LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS #cmakedefine that is used to gate the definition of LLVM_C_ABI.
Remove the existing LLVM_C_ABI definition from llvm/Support/Compiler.h. Update the small number of LLVM_C_ABI references to get it from the new llvm-c/Visibility.h header.
Code-mod annotate the public llvm-c interface using the Interface Definition Scanner (IDS) tool.
Format the changes with clang-format.

Background

This effort is tracked in #109483. Additional context is provided in this discourse, and documentation for LLVM_ABI and related annotations is found in the LLVM repo here.

Validation

Local builds and tests to validate cross-platform compatibility. This included llvm, clang, and lldb on the following configurations:

Windows with MSVC
Windows with Clang
Linux with GCC
Linux with Clang
Darwin with Clang

llvm/include/llvm-c/Visibility.h

llvm/include/llvm-c/Remarks.h

llvmbot · 2025-06-24T21:16:28Z

@llvm/pr-subscribers-llvm-support
@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-debuginfo

Author: Andrew Rogers (andrurogerz)

Changes

Purpose

This patch is one in a series of code-mods that annotate LLVM’s public interface for export. This patch annotates the llvm-c interface with a new LLVM_C_ABI annotation, which behaves like the LLVM_ABI. This annotation currently has no meaningful impact on the LLVM build; however, it is a prerequisite to support an LLVM Windows DLL (shared library) build.

Overview

Add a new llvm-c/Visibility.h header file that defines a new LLVM_C_ABI macro. The macro resolves to the proper DLL export/import annotation on Windows and a "default" visibility annotation elsewhere.
Add a new LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS #cmakedefine that is used to gate the definition of LLVM_C_ABI.
Remove the existing LLVM_C_ABI definition from llvm/Support/Compiler.h. Update the small number of LLVM_C_ABI references to get it from the new llvm-c/Visibility.h header.
Code-mod annotate the public llvm-c interface using the Interface Definition Scanner (IDS) tool.
Format the changes with clang-format.

Background

This effort is tracked in #109483. Additional context is provided in this discourse, and documentation for LLVM_ABI and related annotations is found in the LLVM repo here.

Validation

Local builds and tests to validate cross-platform compatibility. This included llvm, clang, and lldb on the following configurations:

Windows with MSVC
Windows with Clang
Linux with GCC
Linux with Clang
Darwin with Clang

Patch is 370.12 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/141701.diff

34 Files Affected:

(modified) llvm/CMakeLists.txt (+4)
(modified) llvm/include/llvm-c/Analysis.h (+8-5)
(modified) llvm/include/llvm-c/BitReader.h (+25-19)
(modified) llvm/include/llvm-c/BitWriter.h (+6-5)
(modified) llvm/include/llvm-c/Comdat.h (+8-5)
(modified) llvm/include/llvm-c/Core.h (+1152-973)
(modified) llvm/include/llvm-c/DebugInfo.h (+194-234)
(modified) llvm/include/llvm-c/Disassembler.h (+16-17)
(modified) llvm/include/llvm-c/Error.h (+8-7)
(modified) llvm/include/llvm-c/ErrorHandling.h (+4-3)
(modified) llvm/include/llvm-c/ExecutionEngine.h (+72-66)
(modified) llvm/include/llvm-c/IRReader.h (+5-3)
(modified) llvm/include/llvm-c/LLJIT.h (+33-30)
(modified) llvm/include/llvm-c/LLJITUtils.h (+2-1)
(modified) llvm/include/llvm-c/Linker.h (+2-1)
(modified) llvm/include/llvm-c/Object.h (+53-50)
(modified) llvm/include/llvm-c/Orc.h (+108-97)
(modified) llvm/include/llvm-c/OrcEE.h (+4-3)
(modified) llvm/include/llvm-c/Remarks.h (+37-27)
(modified) llvm/include/llvm-c/Support.h (+6-5)
(modified) llvm/include/llvm-c/Target.h (+50-38)
(modified) llvm/include/llvm-c/TargetMachine.h (+69-55)
(modified) llvm/include/llvm-c/Transforms/PassBuilder.h (+45-32)
(added) llvm/include/llvm-c/Visibility.h (+44)
(modified) llvm/include/llvm-c/blake3.h (+19-17)
(modified) llvm/include/llvm/Config/llvm-config.h.cmake (+3)
(modified) llvm/include/llvm/Support/Compiler.h (-5)
(modified) llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp (+1)
(modified) llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp (+1)
(modified) llvm/lib/Target/X86/MCA/X86CustomBehaviour.cpp (+1)
(modified) llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp (+1)
(modified) llvm/lib/Target/X86/TargetInfo/X86TargetInfo.cpp (+1)
(modified) llvm/lib/Target/X86/X86AsmPrinter.cpp (+1)
(modified) llvm/lib/Target/X86/X86TargetMachine.cpp (+1)

diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index ec8db6f0733f2..5aa4b9efccb7e 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -949,6 +949,10 @@ if (LLVM_BUILD_LLVM_DYLIB OR LLVM_BUILD_SHARED_LIBS OR LLVM_ENABLE_PLUGINS)
   set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS ON)
 endif()
 
+# Because LLVM-C is built into the LLVM library, for now export its symbols
+# whenever LLVM symbols are exported.
+set(LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
+
 option(LLVM_OPTIMIZED_TABLEGEN "Force TableGen to be built with optimization" OFF)
 if(CMAKE_CROSSCOMPILING OR (LLVM_OPTIMIZED_TABLEGEN AND (LLVM_ENABLE_ASSERTIONS OR CMAKE_CONFIGURATION_TYPES)))
   set(LLVM_USE_HOST_TOOLS ON)
diff --git a/llvm/include/llvm-c/Analysis.h b/llvm/include/llvm-c/Analysis.h
index 270b145a4d27e..01e1667b5232b 100644
--- a/llvm/include/llvm-c/Analysis.h
+++ b/llvm/include/llvm-c/Analysis.h
@@ -21,6 +21,7 @@
 
 #include "llvm-c/ExternC.h"
 #include "llvm-c/Types.h"
+#include "llvm-c/Visibility.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
@@ -41,17 +42,19 @@ typedef enum {
 /* Verifies that a module is valid, taking the specified action if not.
    Optionally returns a human-readable description of any invalid constructs.
    OutMessage must be disposed with LLVMDisposeMessage. */
-LLVMBool LLVMVerifyModule(LLVMModuleRef M, LLVMVerifierFailureAction Action,
-                          char **OutMessage);
+LLVM_C_ABI LLVMBool LLVMVerifyModule(LLVMModuleRef M,
+                                     LLVMVerifierFailureAction Action,
+                                     char **OutMessage);
 
 /* Verifies that a single function is valid, taking the specified action. Useful
    for debugging. */
-LLVMBool LLVMVerifyFunction(LLVMValueRef Fn, LLVMVerifierFailureAction Action);
+LLVM_C_ABI LLVMBool LLVMVerifyFunction(LLVMValueRef Fn,
+                                       LLVMVerifierFailureAction Action);
 
 /* Open up a ghostview window that displays the CFG of the current function.
    Useful for debugging. */
-void LLVMViewFunctionCFG(LLVMValueRef Fn);
-void LLVMViewFunctionCFGOnly(LLVMValueRef Fn);
+LLVM_C_ABI void LLVMViewFunctionCFG(LLVMValueRef Fn);
+LLVM_C_ABI void LLVMViewFunctionCFGOnly(LLVMValueRef Fn);
 
 /**
  * @}
diff --git a/llvm/include/llvm-c/BitReader.h b/llvm/include/llvm-c/BitReader.h
index 088107468d4fb..9dcdbf436454f 100644
--- a/llvm/include/llvm-c/BitReader.h
+++ b/llvm/include/llvm-c/BitReader.h
@@ -21,6 +21,7 @@
 
 #include "llvm-c/ExternC.h"
 #include "llvm-c/Types.h"
+#include "llvm-c/Visibility.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
@@ -36,30 +37,33 @@ LLVM_C_EXTERN_C_BEGIN
    Optionally returns a human-readable error message via OutMessage.
 
    This is deprecated. Use LLVMParseBitcode2. */
-LLVMBool LLVMParseBitcode(LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutModule,
-                          char **OutMessage);
+LLVM_C_ABI LLVMBool LLVMParseBitcode(LLVMMemoryBufferRef MemBuf,
+                                     LLVMModuleRef *OutModule,
+                                     char **OutMessage);
 
 /* Builds a module from the bitcode in the specified memory buffer, returning a
    reference to the module via the OutModule parameter. Returns 0 on success. */
-LLVMBool LLVMParseBitcode2(LLVMMemoryBufferRef MemBuf,
-                           LLVMModuleRef *OutModule);
+LLVM_C_ABI LLVMBool LLVMParseBitcode2(LLVMMemoryBufferRef MemBuf,
+                                      LLVMModuleRef *OutModule);
 
 /* This is deprecated. Use LLVMParseBitcodeInContext2. */
-LLVMBool LLVMParseBitcodeInContext(LLVMContextRef ContextRef,
-                                   LLVMMemoryBufferRef MemBuf,
-                                   LLVMModuleRef *OutModule, char **OutMessage);
+LLVM_C_ABI LLVMBool LLVMParseBitcodeInContext(LLVMContextRef ContextRef,
+                                              LLVMMemoryBufferRef MemBuf,
+                                              LLVMModuleRef *OutModule,
+                                              char **OutMessage);
 
-LLVMBool LLVMParseBitcodeInContext2(LLVMContextRef ContextRef,
-                                    LLVMMemoryBufferRef MemBuf,
-                                    LLVMModuleRef *OutModule);
+LLVM_C_ABI LLVMBool LLVMParseBitcodeInContext2(LLVMContextRef ContextRef,
+                                               LLVMMemoryBufferRef MemBuf,
+                                               LLVMModuleRef *OutModule);
 
 /** Reads a module from the specified path, returning via the OutMP parameter
     a module provider which performs lazy deserialization. Returns 0 on success.
     Optionally returns a human-readable error message via OutMessage.
     This is deprecated. Use LLVMGetBitcodeModuleInContext2. */
-LLVMBool LLVMGetBitcodeModuleInContext(LLVMContextRef ContextRef,
-                                       LLVMMemoryBufferRef MemBuf,
-                                       LLVMModuleRef *OutM, char **OutMessage);
+LLVM_C_ABI LLVMBool LLVMGetBitcodeModuleInContext(LLVMContextRef ContextRef,
+                                                  LLVMMemoryBufferRef MemBuf,
+                                                  LLVMModuleRef *OutM,
+                                                  char **OutMessage);
 
 /** Reads a module from the given memory buffer, returning via the OutMP
  * parameter a module provider which performs lazy deserialization.
@@ -68,15 +72,17 @@ LLVMBool LLVMGetBitcodeModuleInContext(LLVMContextRef ContextRef,
  *
  * Takes ownership of \p MemBuf if (and only if) the module was read
  * successfully. */
-LLVMBool LLVMGetBitcodeModuleInContext2(LLVMContextRef ContextRef,
-                                        LLVMMemoryBufferRef MemBuf,
-                                        LLVMModuleRef *OutM);
+LLVM_C_ABI LLVMBool LLVMGetBitcodeModuleInContext2(LLVMContextRef ContextRef,
+                                                   LLVMMemoryBufferRef MemBuf,
+                                                   LLVMModuleRef *OutM);
 
 /* This is deprecated. Use LLVMGetBitcodeModule2. */
-LLVMBool LLVMGetBitcodeModule(LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
-                              char **OutMessage);
+LLVM_C_ABI LLVMBool LLVMGetBitcodeModule(LLVMMemoryBufferRef MemBuf,
+                                         LLVMModuleRef *OutM,
+                                         char **OutMessage);
 
-LLVMBool LLVMGetBitcodeModule2(LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM);
+LLVM_C_ABI LLVMBool LLVMGetBitcodeModule2(LLVMMemoryBufferRef MemBuf,
+                                          LLVMModuleRef *OutM);
 
 /**
  * @}
diff --git a/llvm/include/llvm-c/BitWriter.h b/llvm/include/llvm-c/BitWriter.h
index ea84b6593d126..71d482b6be070 100644
--- a/llvm/include/llvm-c/BitWriter.h
+++ b/llvm/include/llvm-c/BitWriter.h
@@ -21,6 +21,7 @@
 
 #include "llvm-c/ExternC.h"
 #include "llvm-c/Types.h"
+#include "llvm-c/Visibility.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
@@ -34,18 +35,18 @@ LLVM_C_EXTERN_C_BEGIN
 /*===-- Operations on modules ---------------------------------------------===*/
 
 /** Writes a module to the specified path. Returns 0 on success. */
-int LLVMWriteBitcodeToFile(LLVMModuleRef M, const char *Path);
+LLVM_C_ABI int LLVMWriteBitcodeToFile(LLVMModuleRef M, const char *Path);
 
 /** Writes a module to an open file descriptor. Returns 0 on success. */
-int LLVMWriteBitcodeToFD(LLVMModuleRef M, int FD, int ShouldClose,
-                         int Unbuffered);
+LLVM_C_ABI int LLVMWriteBitcodeToFD(LLVMModuleRef M, int FD, int ShouldClose,
+                                    int Unbuffered);
 
 /** Deprecated for LLVMWriteBitcodeToFD. Writes a module to an open file
     descriptor. Returns 0 on success. Closes the Handle. */
-int LLVMWriteBitcodeToFileHandle(LLVMModuleRef M, int Handle);
+LLVM_C_ABI int LLVMWriteBitcodeToFileHandle(LLVMModuleRef M, int Handle);
 
 /** Writes a module to a new memory buffer and returns it. */
-LLVMMemoryBufferRef LLVMWriteBitcodeToMemoryBuffer(LLVMModuleRef M);
+LLVM_C_ABI LLVMMemoryBufferRef LLVMWriteBitcodeToMemoryBuffer(LLVMModuleRef M);
 
 /**
  * @}
diff --git a/llvm/include/llvm-c/Comdat.h b/llvm/include/llvm-c/Comdat.h
index 8002bc0581af7..cf13f8507440e 100644
--- a/llvm/include/llvm-c/Comdat.h
+++ b/llvm/include/llvm-c/Comdat.h
@@ -16,6 +16,7 @@
 
 #include "llvm-c/ExternC.h"
 #include "llvm-c/Types.h"
+#include "llvm-c/Visibility.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
@@ -43,35 +44,37 @@ typedef enum {
  *
  * @see llvm::Module::getOrInsertComdat()
  */
-LLVMComdatRef LLVMGetOrInsertComdat(LLVMModuleRef M, const char *Name);
+LLVM_C_ABI LLVMComdatRef LLVMGetOrInsertComdat(LLVMModuleRef M,
+                                               const char *Name);
 
 /**
  * Get the Comdat assigned to the given global object.
  *
  * @see llvm::GlobalObject::getComdat()
  */
-LLVMComdatRef LLVMGetComdat(LLVMValueRef V);
+LLVM_C_ABI LLVMComdatRef LLVMGetComdat(LLVMValueRef V);
 
 /**
  * Assign the Comdat to the given global object.
  *
  * @see llvm::GlobalObject::setComdat()
  */
-void LLVMSetComdat(LLVMValueRef V, LLVMComdatRef C);
+LLVM_C_ABI void LLVMSetComdat(LLVMValueRef V, LLVMComdatRef C);
 
 /*
  * Get the conflict resolution selection kind for the Comdat.
  *
  * @see llvm::Comdat::getSelectionKind()
  */
-LLVMComdatSelectionKind LLVMGetComdatSelectionKind(LLVMComdatRef C);
+LLVM_C_ABI LLVMComdatSelectionKind LLVMGetComdatSelectionKind(LLVMComdatRef C);
 
 /*
  * Set the conflict resolution selection kind for the Comdat.
  *
  * @see llvm::Comdat::setSelectionKind()
  */
-void LLVMSetComdatSelectionKind(LLVMComdatRef C, LLVMComdatSelectionKind Kind);
+LLVM_C_ABI void LLVMSetComdatSelectionKind(LLVMComdatRef C,
+                                           LLVMComdatSelectionKind Kind);
 
 /**
  * @}
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index 3f30ed92997b4..d645646289025 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -18,6 +18,7 @@
 #include "llvm-c/Deprecated.h"
 #include "llvm-c/ErrorHandling.h"
 #include "llvm-c/ExternC.h"
+#include "llvm-c/Visibility.h"
 
 #include "llvm-c/Types.h"
 
@@ -536,7 +537,7 @@ typedef unsigned LLVMGEPNoWrapFlags;
 /** Deallocate and destroy all ManagedStatic variables.
     @see llvm::llvm_shutdown
     @see ManagedStatic */
-void LLVMShutdown(void);
+LLVM_C_ABI void LLVMShutdown(void);
 
 /*===-- Version query -----------------------------------------------------===*/
 
@@ -546,12 +547,13 @@ void LLVMShutdown(void);
  * The version components are returned via the function's three output
  * parameters or skipped if a NULL pointer was supplied.
  */
-void LLVMGetVersion(unsigned *Major, unsigned *Minor, unsigned *Patch);
+LLVM_C_ABI void LLVMGetVersion(unsigned *Major, unsigned *Minor,
+                               unsigned *Patch);
 
 /*===-- Error handling ----------------------------------------------------===*/
 
-char *LLVMCreateMessage(const char *Message);
-void LLVMDisposeMessage(char *Message);
+LLVM_C_ABI char *LLVMCreateMessage(const char *Message);
+LLVM_C_ABI void LLVMDisposeMessage(char *Message);
 
 /**
  * @defgroup LLVMCCoreContext Contexts
@@ -574,44 +576,46 @@ typedef void (*LLVMYieldCallback)(LLVMContextRef, void *);
  * Every call to this function should be paired with a call to
  * LLVMContextDispose() or the context will leak memory.
  */
-LLVMContextRef LLVMContextCreate(void);
+LLVM_C_ABI LLVMContextRef LLVMContextCreate(void);
 
 /**
  * Obtain the global context instance.
  */
-LLVMContextRef LLVMGetGlobalContext(void);
+LLVM_C_ABI LLVMContextRef LLVMGetGlobalContext(void);
 
 /**
  * Set the diagnostic handler for this context.
  */
-void LLVMContextSetDiagnosticHandler(LLVMContextRef C,
-                                     LLVMDiagnosticHandler Handler,
-                                     void *DiagnosticContext);
+LLVM_C_ABI void LLVMContextSetDiagnosticHandler(LLVMContextRef C,
+                                                LLVMDiagnosticHandler Handler,
+                                                void *DiagnosticContext);
 
 /**
  * Get the diagnostic handler of this context.
  */
-LLVMDiagnosticHandler LLVMContextGetDiagnosticHandler(LLVMContextRef C);
+LLVM_C_ABI LLVMDiagnosticHandler
+LLVMContextGetDiagnosticHandler(LLVMContextRef C);
 
 /**
  * Get the diagnostic context of this context.
  */
-void *LLVMContextGetDiagnosticContext(LLVMContextRef C);
+LLVM_C_ABI void *LLVMContextGetDiagnosticContext(LLVMContextRef C);
 
 /**
  * Set the yield callback function for this context.
  *
  * @see LLVMContext::setYieldCallback()
  */
-void LLVMContextSetYieldCallback(LLVMContextRef C, LLVMYieldCallback Callback,
-                                 void *OpaqueHandle);
+LLVM_C_ABI void LLVMContextSetYieldCallback(LLVMContextRef C,
+                                            LLVMYieldCallback Callback,
+                                            void *OpaqueHandle);
 
 /**
  * Retrieve whether the given context is set to discard all value names.
  *
  * @see LLVMContext::shouldDiscardValueNames()
  */
-LLVMBool LLVMContextShouldDiscardValueNames(LLVMContextRef C);
+LLVM_C_ABI LLVMBool LLVMContextShouldDiscardValueNames(LLVMContextRef C);
 
 /**
  * Set whether the given context discards all value names.
@@ -621,7 +625,8 @@ LLVMBool LLVMContextShouldDiscardValueNames(LLVMContextRef C);
  *
  * @see LLVMContext::setDiscardValueNames()
  */
-void LLVMContextSetDiscardValueNames(LLVMContextRef C, LLVMBool Discard);
+LLVM_C_ABI void LLVMContextSetDiscardValueNames(LLVMContextRef C,
+                                                LLVMBool Discard);
 
 /**
  * Destroy a context instance.
@@ -629,7 +634,7 @@ void LLVMContextSetDiscardValueNames(LLVMContextRef C, LLVMBool Discard);
  * This should be called for every call to LLVMContextCreate() or memory
  * will be leaked.
  */
-void LLVMContextDispose(LLVMContextRef C);
+LLVM_C_ABI void LLVMContextDispose(LLVMContextRef C);
 
 /**
  * Return a string representation of the DiagnosticInfo. Use
@@ -637,23 +642,25 @@ void LLVMContextDispose(LLVMContextRef C);
  *
  * @see DiagnosticInfo::print()
  */
-char *LLVMGetDiagInfoDescription(LLVMDiagnosticInfoRef DI);
+LLVM_C_ABI char *LLVMGetDiagInfoDescription(LLVMDiagnosticInfoRef DI);
 
 /**
  * Return an enum LLVMDiagnosticSeverity.
  *
  * @see DiagnosticInfo::getSeverity()
  */
-LLVMDiagnosticSeverity LLVMGetDiagInfoSeverity(LLVMDiagnosticInfoRef DI);
+LLVM_C_ABI LLVMDiagnosticSeverity
+LLVMGetDiagInfoSeverity(LLVMDiagnosticInfoRef DI);
 
-unsigned LLVMGetMDKindIDInContext(LLVMContextRef C, const char *Name,
-                                  unsigned SLen);
-unsigned LLVMGetMDKindID(const char *Name, unsigned SLen);
+LLVM_C_ABI unsigned LLVMGetMDKindIDInContext(LLVMContextRef C, const char *Name,
+                                             unsigned SLen);
+LLVM_C_ABI unsigned LLVMGetMDKindID(const char *Name, unsigned SLen);
 
 /**
  * Maps a synchronization scope name to a ID unique within this context.
  */
-unsigned LLVMGetSyncScopeID(LLVMContextRef C, const char *Name, size_t SLen);
+LLVM_C_ABI unsigned LLVMGetSyncScopeID(LLVMContextRef C, const char *Name,
+                                       size_t SLen);
 
 /**
  * Return an unique id given the name of a enum attribute,
@@ -666,36 +673,39 @@ unsigned LLVMGetSyncScopeID(LLVMContextRef C, const char *Name, size_t SLen);
  * NB: Attribute names and/or id are subject to change without
  * going through the C API deprecation cycle.
  */
-unsigned LLVMGetEnumAttributeKindForName(const char *Name, size_t SLen);
-unsigned LLVMGetLastEnumAttributeKind(void);
+LLVM_C_ABI unsigned LLVMGetEnumAttributeKindForName(const char *Name,
+                                                    size_t SLen);
+LLVM_C_ABI unsigned LLVMGetLastEnumAttributeKind(void);
 
 /**
  * Create an enum attribute.
  */
-LLVMAttributeRef LLVMCreateEnumAttribute(LLVMContextRef C, unsigned KindID,
-                                         uint64_t Val);
+LLVM_C_ABI LLVMAttributeRef LLVMCreateEnumAttribute(LLVMContextRef C,
+                                                    unsigned KindID,
+                                                    uint64_t Val);
 
 /**
  * Get the unique id corresponding to the enum attribute
  * passed as argument.
  */
-unsigned LLVMGetEnumAttributeKind(LLVMAttributeRef A);
+LLVM_C_ABI unsigned LLVMGetEnumAttributeKind(LLVMAttributeRef A);
 
 /**
  * Get the enum attribute's value. 0 is returned if none exists.
  */
-uint64_t LLVMGetEnumAttributeValue(LLVMAttributeRef A);
+LLVM_C_ABI uint64_t LLVMGetEnumAttributeValue(LLVMAttributeRef A);
 
 /**
  * Create a type attribute
  */
-LLVMAttributeRef LLVMCreateTypeAttribute(LLVMContextRef C, unsigned KindID,
-                                         LLVMTypeRef type_ref);
+LLVM_C_ABI LLVMAttributeRef LLVMCreateTypeAttribute(LLVMContextRef C,
+                                                    unsigned KindID,
+                                                    LLVMTypeRef type_ref);
 
 /**
  * Get the type attribute's value.
  */
-LLVMTypeRef LLVMGetTypeAttributeValue(LLVMAttributeRef A);
+LLVM_C_ABI LLVMTypeRef LLVMGetTypeAttributeValue(LLVMAttributeRef A);
 
 /**
  * Create a ConstantRange attribute.
@@ -703,40 +713,42 @@ LLVMTypeRef LLVMGetTypeAttributeValue(LLVMAttributeRef A);
  * LowerWords and UpperWords need to be NumBits divided by 64 rounded up
  * elements long.
  */
-LLVMAttributeRef LLVMCreateConstantRangeAttribute(LLVMContextRef C,
-                                                  unsigned KindID,
-                                                  unsigned NumBits,
-                                                  const uint64_t LowerWords[],
-                                                  const uint64_t UpperWords[]);
+LLVM_C_ABI LLVMAttributeRef LLVMCreateConstantRangeAttribute(
+    LLVMContextRef C, unsigned KindID, unsigned NumBits,
+    const uint64_t LowerWords[], const uint64_t UpperWords[]);
 
 /**
  * Create a string attribute.
  */
-LLVMAttributeRef LLVMCreateStringAttribute(LLVMContextRef C,
-                                           const char *K, unsigned KLength,
-                                           const char *V, unsigned VLength);
+LLVM_C_ABI LLVMAttributeRef LLVMCreateStringAttribute(LLVMContextRef C,
+                                                      const char *K,
+                                                      unsigned KLength,
+                                                      const char *V,
+                                                      unsigned VLength);
 
 /**
  * Get the string attribute's kind.
  */
-const char *LLVMGetStringAttributeKind(LLVMAttributeRef A, unsigned *Length);
+LLVM_C_ABI const char *LLVMGetStringAttributeKind(LLVMAttributeRef A,
+                                                  unsigned *Length);
 
 /**
  * Get the string attribute's value.
  */
-const char *LLVMGetStringAttributeValue(LLVMAttributeRef A, unsigned *Length);
+LLVM_C_ABI const char *LLVMGetStringAttributeValue(LLVMAttributeRef A,
+                                                   unsigned *Length);
 
 /**
  * Check for the different types of attributes.
  */
-LLVMBool LLVMIsEnumAttribute(LLVMAttributeRef A);
-LLVMBool LLVMIsStringAttribute(LLVMAttributeRef A);
-LLVMBool LLVMIsTypeAttribute(LLVMAttributeRef A);
+LLVM_C_ABI LLVMBool LLVMIsEnumAttribute(LLVMAttributeRef A);
+LLVM_C_ABI LLVMBool LLVMIsStringAttribute(LLVMAttributeRef A);
+LLVM_C_ABI LLVMBool LLVMIsTypeAttribute(LLVMAttributeRef A);
 
 /**
  * Obtain a Type from a context by its registered name.
  */
-LLVMTypeRef LLVMGetTypeByName2(LLVMContextRef C, const char *Name);
+LLVM_C_ABI LLVMTypeRef LLVMGetTypeByName2(LLVMContextRef C, const char *Name);
 
 /**
  * @}
@@ -761,7 +773,7 @@ LLVMTypeRef LLVMGetTypeByName2(LLVMContextRef C, const char *Name);
  * Every invocation should be paired with LLVMDisposeModule() or memory
  * will be leaked.
  */
-LLVMModuleRef LLVMModuleCreateWithName(const char *ModuleID);
+LLVM_C_ABI LLVMModuleRef LLVMModuleCreateWithName(const char *ModuleID);
 
 /**
  * Create a new, empty module in a specific context.
@@ -769,12 +781,12 @@ LLVMModuleRef LLVMModuleCreateWithName(const char *ModuleID);
  * Every invocation should be paired with LLVMDisposeModule() or memory
  * will be leaked.
  */
-LLVMModuleRef LLVMModuleCreateWithNameInContext(const char *ModuleID,
-                       ...
[truncated]

llvm/include/llvm-c/Visibility.h

llvm/include/llvm-c/Remarks.h

andrurogerz · 2025-07-07T18:29:36Z

@compnerd I would like to revisit the LLVMRemarkVersion annotation in a follow-up if you're OK with that.

## Purpose This patch is one in a series of code-mods that annotate LLVM’s public interface for export. This patch annotates the `Demangle` interface with a new `DEMANGLE_ABI` annotation, which behaves like the `LLVM_ABI`. This annotation currently has no meaningful impact on the LLVM build; however, it is a prerequisite to support an LLVM Windows DLL (shared library) build. ## Overview 1. Add a new `Demangle/Visibility.h` header file that defines a new `DEMANGLE_ABI` macro. The macro resolves to the proper DLL export/import annotation on Windows and a "default" visibility annotation elsewhere. 2. Add a new `LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS ` `#cmakedefine` that is used to gate the definition of `DEMANGLE_ABI`. 3. Code-mod annotate the public `Demangle` interface using the [Interface Definition Scanner (IDS)](https://github.com/compnerd/ids) tool. 4. Manually fix-up `#include` statements for consistency. 5. Format the changes with `clang-format`. 6. Add a "stub" version of `Visibility.h` under `libcxxabi/src/demangle` that always defines `DEMANGLE_ABI` to nothing. 7. Update the canonical `libcxxabi/src/demangle/ItaniumDemangle.h` instead of the llvm copy, and run `cp-to-llvm.sh` to ensure the llvm copy matches. NOTE: we rely on `ccp-to-llvm.sh` not copying `Visibillity.h` as is already the case for `DemangleConfig.h`. ## Background This PR follows the pattern established with the `llvm-c` changes made in #141701. This effort is tracked in #109483. Additional context is provided in [this discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307), and documentation for `LLVM_ABI` and related annotations is found in the LLVM repo [here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst). ## Validation Local builds and tests to validate cross-platform compatibility. This included llvm, clang, and lldb on the following configurations: - Windows with MSVC - Windows with Clang - Linux with GCC - Linux with Clang - Darwin with Clang --------- Co-authored-by: Louis Dionne <[email protected]>

## Purpose This patch is one in a series of code-mods that annotate LLVM’s public interface for export. This patch annotates the `Demangle` interface with a new `DEMANGLE_ABI` annotation, which behaves like the `LLVM_ABI`. This annotation currently has no meaningful impact on the LLVM build; however, it is a prerequisite to support an LLVM Windows DLL (shared library) build. ## Overview 1. Add a new `Demangle/Visibility.h` header file that defines a new `DEMANGLE_ABI` macro. The macro resolves to the proper DLL export/import annotation on Windows and a "default" visibility annotation elsewhere. 2. Add a new `LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS ` `#cmakedefine` that is used to gate the definition of `DEMANGLE_ABI`. 3. Code-mod annotate the public `Demangle` interface using the [Interface Definition Scanner (IDS)](https://github.com/compnerd/ids) tool. 4. Manually fix-up `#include` statements for consistency. 5. Format the changes with `clang-format`. 6. Add a "stub" version of `Visibility.h` under `libcxxabi/src/demangle` that always defines `DEMANGLE_ABI` to nothing. 7. Update the canonical `libcxxabi/src/demangle/ItaniumDemangle.h` instead of the llvm copy, and run `cp-to-llvm.sh` to ensure the llvm copy matches. NOTE: we rely on `ccp-to-llvm.sh` not copying `Visibillity.h` as is already the case for `DemangleConfig.h`. ## Background This PR follows the pattern established with the `llvm-c` changes made in llvm#141701. This effort is tracked in llvm#109483. Additional context is provided in [this discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307), and documentation for `LLVM_ABI` and related annotations is found in the LLVM repo [here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst). ## Validation Local builds and tests to validate cross-platform compatibility. This included llvm, clang, and lldb on the following configurations: - Windows with MSVC - Windows with Clang - Linux with GCC - Linux with Clang - Darwin with Clang --------- Co-authored-by: Louis Dionne <[email protected]>

andrurogerz force-pushed the llvmdll-lib-llvm-c branch 2 times, most recently from 4c219aa to 29dbd9e Compare May 28, 2025 15:33

compnerd reviewed May 28, 2025

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andrurogerz force-pushed the llvmdll-lib-llvm-c branch 2 times, most recently from d478b2b to 1cf4a9d Compare June 4, 2025 14:07

compnerd reviewed Jun 9, 2025

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andrurogerz force-pushed the llvmdll-lib-llvm-c branch 3 times, most recently from a2e900b to cbf727c Compare June 24, 2025 19:12

andrurogerz marked this pull request as ready for review June 24, 2025 21:15

llvmbot added backend:X86 debuginfo llvm:support labels Jun 24, 2025

andrurogerz requested a review from compnerd June 24, 2025 21:16

compnerd reviewed Jun 24, 2025

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andrurogerz added 4 commits July 7, 2025 09:50

[llvm] define LLVM_C_ABI in a new llvm-c/Visibility.h header

dbd91d7

[llvm] IDS auto codemod for llvm-c library

5db0ca1

[llvm] manual fix-ups to llvm-c codemod of IR library

69a7ea0

[llvm] clang-format changes to llvm-c library

e10f4f8

andrurogerz force-pushed the llvmdll-lib-llvm-c branch from cbf727c to e10f4f8 Compare July 7, 2025 18:13

andrurogerz requested a review from compnerd July 7, 2025 18:19

compnerd approved these changes Jul 7, 2025

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compnerd merged commit 0580563 into llvm:main Jul 8, 2025
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andrurogerz mentioned this pull request Jul 8, 2025

[llvm] annotate interfaces in Demangle for DLL export #147564

Merged

andrurogerz deleted the llvmdll-lib-llvm-c branch July 23, 2025 19:41

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