Cpp runtime under MSYS

[ggabbiani]

Hi all,

I'm writing a C++ based project using ANTLR4 Cpp runtime, following the latest documentation.

The project successfully builds and executes under Linux and macOS but fails under Windows when trying to link the executables with the antlr4_static library receiving the following message:

[build] [13/14  92% :: 4.005] Linking CXX executable bin\orthodocs.exe
[build] FAILED: bin/orthodocs.exe 
[build] cmd.exe /C "cd . && C:\msys64\mingw64\bin\g++.exe -O3 -DNDEBUG  CMakeFiles/orthodocs.dir/src/analyzer.cpp.obj CMakeFiles/orthodocs.dir/src/main.cpp.obj -o bin\orthodocs.exe -Wl,--out-implib,lib\liborthodocs.dll.a -Wl,--major-image-version,0,--minor-image-version,0  lib/libfactories.a  lib/libCppSCAD.a  lib/libMarkdown.a  lib/libcommons.a  lib/libspdlog.a  lib/libCppSPDX.a  antlr4_runtime/src/antlr4_runtime/runtime/Cpp/dist/libantlr4-runtime.a  -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && cd ."
[build] C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: cannot find antlr4_runtime/src/antlr4_runtime/runtime/Cpp/dist/libantlr4-runtime.a: No such file or directory
[build] collect2.exe: error: ld returned 1 exit status
[build] ninja: build stopped: subcommand failed.

Environment:

Windows: Windows 10 Pro
MSYS2: MINGW64_NT-10.0-19045 version 3.4.3.x86_64 (runneradmin@fv-az269-587) (gcc version 11.3.0 (GCC) ) 2023-01-17 21:17 UTC
CMake: v3.24.1
ANTLR4 Cpp: v4.12.0

What I found so far:

It seems like a mismatch between the Cpp runtime build runtime/CMakeLists.txt and the client code build cmake/ExternalAntlr4Cpp.cmake.

CMake recognizes MINGW compiler and set the library prefix/suffix accordingly

WIN32="1"
MINGW="1"
MVSC=""
CMAKE_FIND_LIBRARY_PREFIXES="lib;"
CMAKE_FIND_LIBRARY_SUFFIXES=".dll.a;.a;.lib"

Cpp runtime build (runtime/CMakeLists.txt) tests WIN32 to set the static_lib_suffix to '-static' hence producing libantlr4-runtime-static.a.

set(static_lib_suffix "")

if (WIN32)
  set(static_lib_suffix "-static")
  ...
endif()
...
if (TARGET antlr4_static)
  set_target_properties(antlr4_static
                        PROPERTIES VERSION   ${ANTLR_VERSION}
                                   SOVERSION ${ANTLR_VERSION}
                                   OUTPUT_NAME "antlr4-runtime${static_lib_suffix}"
                                   COMPILE_PDB_NAME "antlr4-runtime${static_lib_suffix}"
                                   COMPILE_FLAGS "${disabled_compile_warnings} ${extra_static_compile_flags}")
endif()

Client code (cmake/ExternalAntlr4Cpp.cmake) evaluates MVSC for managing the static library name so searches for libantlr4-runtime.a.:

if(MSVC)
  ...
else()
  set(ANTLR4_STATIC_LIBRARIES
      ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.a)
  ...
endif()

this explains the mismatch.

What I do not understand is ... which of the two behaviors is the wrong one?

Personally I solved modifying cmake/ExternalAntlr4Cpp.cmake in this manner:

diff --git a/antlr4/cmake/ExternalAntlr4Cpp.cmake b/antlr4/cmake/ExternalAntlr4Cpp.cmake
index 54f874b..648b84a 100644
--- a/antlr4/cmake/ExternalAntlr4Cpp.cmake
+++ b/antlr4/cmake/ExternalAntlr4Cpp.cmake
@@ -27,16 +27,21 @@ else()
   set(ANTLR4_OUTPUT_DIR ${ANTLR4_ROOT}/runtime/Cpp/dist)
 endif()

+set(static_lib_suffix "")
+if (WIN32)
+  set(static_lib_suffix "-static")
+endif()
+
 if(MSVC)
   set(ANTLR4_STATIC_LIBRARIES
-      ${ANTLR4_OUTPUT_DIR}/antlr4-runtime-static.lib)
+      ${ANTLR4_OUTPUT_DIR}/antlr4-runtime${static_lib_suffix}.lib)
   set(ANTLR4_SHARED_LIBRARIES
       ${ANTLR4_OUTPUT_DIR}/antlr4-runtime.lib)
   set(ANTLR4_RUNTIME_LIBRARIES
       ${ANTLR4_OUTPUT_DIR}/antlr4-runtime.dll)
 else()
   set(ANTLR4_STATIC_LIBRARIES
-      ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.a)
+      ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime${static_lib_suffix}.a)
   if(MINGW)
     set(ANTLR4_SHARED_LIBRARIES
         ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.dll.a)

In this manner it builds and executes correctly but is this the correct way to solve or am I missing something?

Many thanks in advance

Giampiero