projinfo as library function (#4646)

* Move projinfo to be able to call it in the library

* calling projinfo with `--help` or `-?` produces a return code 0.

Author: jjimenezshaw

scripts/ci/emscripten/build_wasm.sh

@@ -248,23 +248,66 @@ else
 fi
 
 # --- 6.5 Create C Wrappers ---
-# Helper functions to extract some info from PROJ in C
+# Helper functions to extract some info from PROJ in C and C++
 log_step "6.5 Creating C Wrapper Functions"
 
-WRAPPER_FILE="${TEMP_BUILD_DIR}/proj_wrappers.c"
+WRAPPER_FILE="${TEMP_BUILD_DIR}/proj_wrappers.cpp"
 WRAPPER_OBJ_FILE="${TEMP_BUILD_DIR}/proj_wrappers.o"
 
 DDD=`date +"%Y-%m-%dT%H:%M:%S%z" -u`
 cat << EOF > ${WRAPPER_FILE}
 #include "proj.h"
 #include "math.h"
 
+#include "projapps_lib.h"
+
+#include <emscripten/bind.h>
+#include <emscripten/val.h>
+#include <vector>
+#include <string>
+
+void trampoline(PJ_PROJINFO_LOG_LEVEL level, const char *msg, void *user_data) {
+    if (!user_data) return;
+    const emscripten::val* js_callback = reinterpret_cast<const emscripten::val*>(user_data);
+    (*js_callback)(level, std::string(msg));
+}
+
+int projinfo_wrapper(uintptr_t ctx_ptr, emscripten::val jsArgs, emscripten::val jsCallback) {
+    std::vector<std::string> args = emscripten::vecFromJSArray<std::string>(jsArgs);
+    std::vector<char*> argv;
+    for (auto& s : args) {
+        argv.push_back(&s[0]);
+    }
+    PJ_CONTEXT *ctx = reinterpret_cast<PJ_CONTEXT *>(ctx_ptr);
+    return projinfo(ctx, args.size(), argv.data(), &trampoline, &jsCallback);
+}
+
+EMSCRIPTEN_BINDINGS(proj_module) {
+    emscripten::value_object<PJ_INFO>("PJ_INFO")
+        .field("major", &PJ_INFO::major)
+        .field("minor", &PJ_INFO::minor)
+        .field("patch", &PJ_INFO::patch)
+        .field("release", std::function<std::string(const PJ_INFO&)>([](const PJ_INFO& i) {
+                return std::string(i.release); }),
+            std::function<void(PJ_INFO&, std::string)>([](PJ_INFO& i, std::string v) {}))
+        .field("version", std::function<std::string(const PJ_INFO&)>([](const PJ_INFO& i) {
+                return std::string(i.version); }),
+            std::function<void(PJ_INFO&, std::string)>([](PJ_INFO& i, std::string v) {}));
+    emscripten::function("proj_info_ems", &proj_info);
+
+    emscripten::enum_<PJ_PROJINFO_LOG_LEVEL>("PJ_PROJINFO_LOG_LEVEL")
+        .value("INFO", PJ_PROJINFO_LOG_LEVEL_INFO)
+        .value("WARN", PJ_PROJINFO_LOG_LEVEL_WARN)
+        .value("ERR", PJ_PROJINFO_LOG_LEVEL_ERR);
+
+    emscripten::function("projinfo_ems", &projinfo_wrapper, emscripten::allow_raw_pointers());
+}
+
+extern "C" {
+
 const char* get_compilation_date() {
     return "$DDD" ;
 }
-
-int get_proj_info_sizeof() {
-    return sizeof(PJ_INFO);
 }
 EOF
 
@@ -290,6 +333,7 @@ FINAL_LIBS="${INSTALL_DIR}/lib/libproj.a \
 emcc -v ${FINAL_LIBS} \
     -o ${INSTALL_DIR}/projModule.js \
     -O3 \
+    -lembind \
     -s STACK_OVERFLOW_CHECK=1 \
     -s STACK_SIZE=5MB \
     -s NO_DISABLE_EXCEPTION_CATCHING \
@@ -303,7 +347,6 @@ emcc -v ${FINAL_LIBS} \
     -s ALLOW_MEMORY_GROWTH=1 \
     -s EXPORTED_RUNTIME_METHODS="[ccall, cwrap, FS, HEAPF64, stringToNewUTF8, UTF8ToString, getValue]" \
     -s EXPORTED_FUNCTIONS="[
-     _get_proj_info_sizeof,
      _get_compilation_date,
      _proj_info,
      _proj_context_errno_string,

scripts/reference_exported_symbols.txt

@@ -1083,6 +1083,7 @@ proj_grid_cache_set_ttl
 proj_grid_get_info_from_database
 proj_grid_info
 proj_identify
+projinfo
 proj_info
 proj_init_info
 proj_insert_object_session_create

src/CMakeLists.txt

@@ -2,6 +2,9 @@
 add_compile_options("$<$<COMPILE_LANGUAGE:C>:${PROJ_C_WARN_FLAGS}>")
 add_compile_options("$<$<COMPILE_LANGUAGE:CXX>:${PROJ_CXX_WARN_FLAGS}>")
 
+# 0: include the lib files for the apps.
+include(apps/lib_projapps.cmake)
+
 # First configure proj library
 include(lib_proj.cmake)
 add_subdirectory(apps)

src/apps/lib_projapps.cmake

@@ -0,0 +1,4 @@
+set(SRC_PROJAPPS_LIBS
+  apps/projinfo_lib.cpp
+)
+set(HEADERS_PROJAPPS_LIBS apps/projapps_lib.h)

src/apps/projapps_lib.h

@@ -0,0 +1,68 @@
+/******************************************************************************
+ *
+ * Project:  PROJ
+ * Purpose:  projinfo C API
+ * Author:   Javier Jimenez Shaw
+ *
+ ******************************************************************************
+ * Copyright (c) 2025  Javier Jimenez Shaw
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ ****************************************************************************/
+
+#if !defined(PROJAPPS_LIB_H)
+#define PROJAPPS_LIB_H
+
+#include "proj.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Level for the output given by projinfo in its callback.
+ */
+typedef enum {
+    PJ_PROJINFO_LOG_LEVEL_INFO = 1,
+    PJ_PROJINFO_LOG_LEVEL_WARN = 2,
+    PJ_PROJINFO_LOG_LEVEL_ERR = 3,
+} PJ_PROJINFO_LOG_LEVEL;
+
+typedef void (*projinfo_cb_t)(PJ_PROJINFO_LOG_LEVEL level, const char *msg,
+                              void *user_data);
+
+/*
+ * Internal C implementation of projinfo CLI application.
+ * See https://proj.org/apps/projinfo.html for more documentation.
+ * @param ctx context. It can be nullptr.
+ * @param argc number for parameters in argv.
+ * @param argv list of char* with the command parameters of projinfo.
+ *  It does not contain the program name as first parameter.
+ * @param cb callback that to get the output of projinfo.
+ *  It can be very fragmented, no necesarily by lines.
+ * @param user_data pointer for data passed to the callback.
+ */
+int PROJ_DLL projinfo(PJ_CONTEXT *ctx, int argc, char **argv, projinfo_cb_t cb,
+                      void *user_data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif