Use path to executable when trying to load library (#5082)

* Use path to executable when trying to load library

* Fix function call, add support for more OS, add test

* Format

* Handle MacOS

* Amend

* Argument as fallback

* Use Path::getCurrentExecutablePath()

* Move to cmdlineparser.cpp

* Debug output

* Use argv[0] in Cygwin

* Revert "Debug output"

This reverts commit 5a68d71f1d27549c7b4a46363f3cd5cd912018e7.

* Use native python in Cygwin

.github/workflows/CI-cygwin.yml

@@ -23,6 +23,7 @@ jobs:
           - platform: 'x86_64'
             packages: |
               gcc-g++
+              python3
       fail-fast: false
 
     runs-on: ${{ matrix.os }}

cli/cmdlineparser.cpp

@@ -149,15 +149,7 @@ bool CmdLineParser::parseFromArgs(int argc, const char* const argv[])
     bool def = false;
     bool maxconfigs = false;
 
-    mSettings.exename = argv[0];
-#ifdef __linux__
-    // Executing cppcheck in PATH. argv[0] does not contain the path.
-    if (mSettings.exename.find_first_of("/\\") == std::string::npos) {
-        char buf[PATH_MAX] = {0};
-        if (FileLister::fileExists("/proc/self/exe") && readlink("/proc/self/exe", buf, sizeof(buf)-1) > 0)
-            mSettings.exename = buf;
-    }
-#endif
+    mSettings.exename = Path::getCurrentExecutablePath(argv[0]);
 
     for (int i = 1; i < argc; i++) {
         if (argv[i][0] == '-') {

cli/main.cpp

@@ -68,18 +68,6 @@
 #include <string>
 #endif
 
-#ifdef _WIN32
-#include <windows.h>
-
-static char exename[1024] = {0};
-#endif
-
-#if defined(__APPLE__)
-#include <mach-o/dyld.h>
-
-static char exename[1024] = {0};
-#endif
-
 /**
  * Main function of cppcheck
  *
@@ -95,15 +83,7 @@ int main(int argc, char* argv[])
 #endif
 
     CppCheckExecutor exec;
-#ifdef _WIN32
-    GetModuleFileNameA(nullptr, exename, sizeof(exename)/sizeof(exename[0])-1);
-    argv[0] = exename;
-#endif
-#if defined(__APPLE__)
-    uint32_t size = sizeof(exename);
-    _NSGetExecutablePath(exename, &size);
-    argv[0] = exename;
-#endif
+
 // *INDENT-OFF*
 #ifdef NDEBUG
     try {

lib/library.cpp

@@ -107,8 +107,9 @@ Library::Error Library::load(const char exename[], const char path[])
         cfgfolders.emplace_back(FILESDIR "/cfg");
 #endif
         if (exename) {
-            const std::string exepath(Path::fromNativeSeparators(Path::getPathFromFilename(exename)));
+            const std::string exepath(Path::fromNativeSeparators(Path::getPathFromFilename(Path::getCurrentExecutablePath(exename))));
             cfgfolders.push_back(exepath + "cfg");
+            cfgfolders.push_back(exepath + "../cfg");
             cfgfolders.push_back(exepath);
         }
 

lib/path.cpp

@@ -28,16 +28,21 @@
 #include <fstream>
 #include <utility>
 
+#include <simplecpp.h>
+
 #ifndef _WIN32
 #include <unistd.h>
 #else
 #include <direct.h>
+#include <windows.h>
 #endif
 #if defined(__CYGWIN__)
 #include <strings.h>
 #endif
+#if defined(__APPLE__)
+#include <mach-o/dyld.h>
+#endif
 
-#include <simplecpp.h>
 
 /** Is the filesystem case insensitive? */
 static bool caseInsensitiveFilesystem()
@@ -131,6 +136,29 @@ std::string Path::getCurrentPath()
     return "";
 }
 
+std::string Path::getCurrentExecutablePath(const char* fallback)
+{
+    char buf[4096] = {};
+    bool success{};
+#ifdef _WIN32
+    success = (GetModuleFileNameA(nullptr, buf, sizeof(buf)) < sizeof(buf));
+#elif defined(__APPLE__)
+    uint32_t size = sizeof(buf);
+    success = (_NSGetExecutablePath(buf, &size) == 0);
+#else
+    const char* procPath =
+#ifdef __SVR4 // Solaris
+        "/proc/self/path/a.out";
+#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+        "/proc/curproc/file";
+#else // Linux
+        "/proc/self/exe";
+#endif
+    success = (readlink(procPath, buf, sizeof(buf)) != -1);
+#endif
+    return success ? std::string(buf) : std::string(fallback);
+}
+
 bool Path::isAbsolute(const std::string& path)
 {
     const std::string& nativePath = toNativeSeparators(path);

lib/path.h

@@ -104,6 +104,12 @@ public:
      */
     static std::string getCurrentPath();
 
+    /**
+     * @brief Returns the absolute path to the current executable
+     * @return absolute path to the current executable
+     */
+    static std::string getCurrentExecutablePath(const char* fallback);
+
     /**
      * @brief Check if given path is absolute
      * @param path Path to check

test/testpath.cpp

@@ -32,6 +32,7 @@ private:
         TEST_CASE(removeQuotationMarks);
         TEST_CASE(acceptFile);
         TEST_CASE(getCurrentPath);
+        TEST_CASE(getCurrentExecutablePath);
         TEST_CASE(isAbsolute);
         TEST_CASE(getRelative);
         TEST_CASE(is_c);
@@ -72,6 +73,10 @@ private:
         ASSERT_EQUALS(true, Path::isAbsolute(Path::getCurrentPath()));
     }
 
+    void getCurrentExecutablePath() const {
+        ASSERT_EQUALS(false, Path::getCurrentExecutablePath("").empty());
+    }
+
     void isAbsolute() const {
 #ifdef _WIN32
         ASSERT_EQUALS(true, Path::isAbsolute("C:\\foo\\bar"));