[llvm] 08efca9 - [LLVM][Cygwin] Fix shared library name (#136599)

[via llvm-commits]

Author: jeremyd2019
Date: 2025-04-24T23:51:34+03:00
New Revision: 08efca9c2c2b9005a0390965a2bad9ef208e4db4

URL: https://github.com/llvm/llvm-project/commit/08efca9c2c2b9005a0390965a2bad9ef208e4db4
DIFF: https://github.com/llvm/llvm-project/commit/08efca9c2c2b9005a0390965a2bad9ef208e4db4.diff

LOG: [LLVM][Cygwin] Fix shared library name (#136599)

Treat Cygwin like WIN32 in llvm-shlib for naming the library.

Don't create shlib symlinks on Cygwin, they don't help anything there,
but teach llvm_install_library_symlink that Cygwin's shared libraries
live in BINDIR like WIN32.

Add a new variable to llvm-config's BuildVariables to have CMake's
shared library prefix, to avoid having to patch between "cyg" and
"msys-" on MSYS2.

Added: 
    

Modified: 
    llvm/cmake/modules/AddLLVM.cmake
    llvm/tools/llvm-config/BuildVariables.inc.in
    llvm/tools/llvm-config/CMakeLists.txt
    llvm/tools/llvm-config/llvm-config.cpp
    llvm/tools/llvm-shlib/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 39f0e28a249d3..52bf7ca0906a3 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -750,7 +750,7 @@ function(llvm_add_library name)
       set(library_name ${output_name}-${LLVM_VERSION_MAJOR}${LLVM_VERSION_SUFFIX})
       set(api_name ${output_name}-${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}${LLVM_VERSION_SUFFIX})
       set_target_properties(${name} PROPERTIES OUTPUT_NAME ${library_name})
-      if(UNIX)
+      if(UNIX AND NOT CYGWIN)
         llvm_install_library_symlink(${api_name} ${library_name} SHARED
           COMPONENT ${name})
         llvm_install_library_symlink(${output_name} ${library_name} SHARED
@@ -2259,7 +2259,7 @@ function(llvm_install_library_symlink name dest type)
   endif()
 
   set(output_dir lib${LLVM_LIBDIR_SUFFIX})
-  if(WIN32 AND "${type}" STREQUAL "SHARED")
+  if((WIN32 OR CYGWIN) AND "${type}" STREQUAL "SHARED")
     set(output_dir "${CMAKE_INSTALL_BINDIR}")
   endif()
 

diff  --git a/llvm/tools/llvm-config/BuildVariables.inc.in b/llvm/tools/llvm-config/BuildVariables.inc.in
index 370005cd8d7d0..e4e1d449bf4d7 100644
--- a/llvm/tools/llvm-config/BuildVariables.inc.in
+++ b/llvm/tools/llvm-config/BuildVariables.inc.in
@@ -35,3 +35,4 @@
 #define LLVM_DYLIB_COMPONENTS "@LLVM_DYLIB_COMPONENTS_expanded@"
 #define LLVM_DYLIB_VERSION "@LLVM_DYLIB_VERSION@"
 #define LLVM_TOOLS_INSTALL_DIR "@LLVM_TOOLS_INSTALL_DIR@"
+#define LLVM_SHARED_LIBRARY_PREFIX "@LLVM_SHARED_LIBRARY_PREFIX@"

diff  --git a/llvm/tools/llvm-config/CMakeLists.txt b/llvm/tools/llvm-config/CMakeLists.txt
index 02c2532dba77a..3a8f40b9c6fea 100644
--- a/llvm/tools/llvm-config/CMakeLists.txt
+++ b/llvm/tools/llvm-config/CMakeLists.txt
@@ -65,6 +65,7 @@ set(LLVM_CXXFLAGS "${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION} ${L
 set(LLVM_BUILD_SYSTEM cmake)
 set(LLVM_HAS_RTTI ${LLVM_CONFIG_HAS_RTTI})
 set(LLVM_DYLIB_VERSION "${LLVM_VERSION_MAJOR}${LLVM_VERSION_SUFFIX}")
+set(LLVM_SHARED_LIBRARY_PREFIX "${CMAKE_SHARED_LIBRARY_PREFIX}")
 
 # Use the C++ link flags, since they should be a superset of C link flags.
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")

diff  --git a/llvm/tools/llvm-config/llvm-config.cpp b/llvm/tools/llvm-config/llvm-config.cpp
index d5b76b1bb6c16..a54538bb534ad 100644
--- a/llvm/tools/llvm-config/llvm-config.cpp
+++ b/llvm/tools/llvm-config/llvm-config.cpp
@@ -390,7 +390,7 @@ int main(int argc, char **argv) {
     SharedExt = "dll";
     SharedVersionedExt = LLVM_DYLIB_VERSION ".dll";
     if (HostTriple.isOSCygMing()) {
-      SharedPrefix = "lib";
+      SharedPrefix = LLVM_SHARED_LIBRARY_PREFIX;
       StaticExt = "a";
       StaticPrefix = "lib";
     } else {
@@ -454,7 +454,7 @@ int main(int argc, char **argv) {
   /// extension. Returns true if Lib is in a recognized format.
   auto GetComponentLibraryNameSlice = [&](const StringRef &Lib,
                                           StringRef &Out) {
-    if (Lib.starts_with("lib")) {
+    if (Lib.starts_with(StaticPrefix) || Lib.starts_with(SharedPrefix)) {
       unsigned FromEnd;
       if (Lib.ends_with(StaticExt)) {
         FromEnd = StaticExt.size() + 1;
@@ -465,7 +465,10 @@ int main(int argc, char **argv) {
       }
 
       if (FromEnd != 0) {
-        Out = Lib.slice(3, Lib.size() - FromEnd);
+        unsigned FromStart = Lib.starts_with(SharedPrefix)
+                                 ? SharedPrefix.size()
+                                 : StaticPrefix.size();
+        Out = Lib.slice(FromStart, Lib.size() - FromEnd);
         return true;
       }
     }

diff  --git a/llvm/tools/llvm-shlib/CMakeLists.txt b/llvm/tools/llvm-shlib/CMakeLists.txt
index a5b0cab0f1ce5..4968c4e24e15b 100644
--- a/llvm/tools/llvm-shlib/CMakeLists.txt
+++ b/llvm/tools/llvm-shlib/CMakeLists.txt
@@ -33,7 +33,7 @@ if(LLVM_BUILD_LLVM_DYLIB)
   if (LLVM_LINK_LLVM_DYLIB)
     set(INSTALL_WITH_TOOLCHAIN INSTALL_WITH_TOOLCHAIN)
   endif()
-  if (WIN32)
+  if (WIN32 OR CYGWIN)
     add_llvm_library(LLVM SHARED DISABLE_LLVM_LINK_LLVM_DYLIB SONAME ${INSTALL_WITH_TOOLCHAIN} ${SOURCES})
   else()
     add_llvm_library(LLVM SHARED DISABLE_LLVM_LINK_LLVM_DYLIB OUTPUT_NAME LLVM ${INSTALL_WITH_TOOLCHAIN} ${SOURCES})