several improvements to Path::getAbsolutePath() (#6542)

- fixed result on Linux if parts discarded by `..` do not exist - small adjustments to Windows implementation to match Linux one - throw from `getAbsolutePath()` if the given path does not exist
danmar · Dec 4, 2024 · 640f82d · 640f82d
1 parent 1b1fab7
commit 640f82d
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diff --git a/lib/path.cpp b/lib/path.cpp
@@ -359,16 +359,26 @@ bool Path::isHeader(const std::string &path)
 
 std::string Path::getAbsoluteFilePath(const std::string& filePath)
 {
+    if (filePath.empty())
+        return "";
+
     std::string absolute_path;
 #ifdef _WIN32
     char absolute[_MAX_PATH];
     if (_fullpath(absolute, filePath.c_str(), _MAX_PATH))
         absolute_path = absolute;
+    if (!absolute_path.empty() && absolute_path.back() == '\\')
+        absolute_path.pop_back();
 #elif defined(__linux__) || defined(__sun) || defined(__hpux) || defined(__GNUC__) || defined(__CPPCHECK__)
-    char * absolute = realpath(filePath.c_str(), nullptr);
+    // simplify the path since any non-existent part has to exist even if discarded by ".."
+    std::string spath = Path::simplifyPath(filePath);
+    char * absolute = realpath(spath.c_str(), nullptr);
     if (absolute)
         absolute_path = absolute;
     free(absolute);
+    // only throw on realpath() fialure to resolve a path when the given one was non-existent
+    if (!spath.empty() && absolute_path.empty() && !exists(spath))
+        throw std::runtime_error("path '" + filePath + "' does not exist");
 #else
 #error Platform absolute path function needed
 #endif
@@ -412,6 +422,12 @@ bool Path::isDirectory(const std::string &path)
     return file_type(path) == S_IFDIR;
 }
 
+bool Path::exists(const std::string &path)
+{
+    const auto type = file_type(path);
+    return type == S_IFREG || type == S_IFDIR;
+}
+
 std::string Path::join(const std::string& path1, const std::string& path2) {
     if (path1.empty() || path2.empty())
         return path1 + path2;

diff --git a/lib/path.h b/lib/path.h
@@ -190,6 +190,13 @@ class CPPCHECKLIB Path {
      */
     static bool isDirectory(const std::string &path);
 
+    /**
+     * @brief Checks if a given path exists (i.e. is a file or directory)
+     * @param path Path to be checked
+     * @return true if given path exists
+     */
+    static bool exists(const std::string &path);
+
     /**
      * join 2 paths with '/' separators
      */

diff --git a/test/testpath.cpp b/test/testpath.cpp
@@ -49,6 +49,8 @@ class TestPath : public TestFixture {
         TEST_CASE(identifyWithCppProbe);
         TEST_CASE(is_header);
         TEST_CASE(simplifyPath);
+        TEST_CASE(getAbsolutePath);
+        TEST_CASE(exists);
     }
 
     void removeQuotationMarks() const {
@@ -437,6 +439,101 @@ class TestPath : public TestFixture {
         ASSERT_EQUALS("//home/file.cpp", Path::simplifyPath("\\\\home\\test\\..\\file.cpp"));
         ASSERT_EQUALS("//file.cpp", Path::simplifyPath("\\\\home\\..\\test\\..\\file.cpp"));
     }
+
+    void getAbsolutePath() const {
+        const std::string cwd = Path::getCurrentPath();
+
+        ScopedFile file("testabspath.txt", "");
+        std::string expected = Path::toNativeSeparators(Path::join(cwd, "testabspath.txt"));
+
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath("testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath("./testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath(".\\testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath("test/../testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath("test\\..\\testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath("./test/../testabspath.txt"));
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath(".\\test\\../testabspath.txt"));
+
+        ASSERT_EQUALS(expected, Path::getAbsoluteFilePath(Path::join(cwd, "testabspath.txt")));
+
+        std::string cwd_up = Path::getPathFromFilename(cwd);
+        cwd_up.pop_back(); // remove trailing slash
+        ASSERT_EQUALS(cwd_up, Path::getAbsoluteFilePath(Path::join(cwd, "..")));
+        ASSERT_EQUALS(cwd_up, Path::getAbsoluteFilePath(Path::join(cwd, "../")));
+        ASSERT_EQUALS(cwd_up, Path::getAbsoluteFilePath(Path::join(cwd, "..\\")));
+        ASSERT_EQUALS(cwd_up, Path::getAbsoluteFilePath(Path::join(cwd, "./../")));
+        ASSERT_EQUALS(cwd_up, Path::getAbsoluteFilePath(Path::join(cwd, ".\\..\\")));
+
+        ASSERT_EQUALS(cwd, Path::getAbsoluteFilePath("."));
+#ifndef _WIN32
+        TODO_ASSERT_EQUALS(cwd, "", Path::getAbsoluteFilePath("./"));
+        TODO_ASSERT_EQUALS(cwd, "", Path::getAbsoluteFilePath(".\\"));
+#else
+        ASSERT_EQUALS(cwd, Path::getAbsoluteFilePath("./"));
+        ASSERT_EQUALS(cwd, Path::getAbsoluteFilePath(".\\"));
+#endif
+
+        ASSERT_EQUALS("", Path::getAbsoluteFilePath(""));
+
+#ifndef _WIN32
+        // the underlying realpath() call only returns something if the path actually exists
+        ASSERT_THROW_EQUALS_2(Path::getAbsoluteFilePath("testabspath2.txt"), std::runtime_error, "path 'testabspath2.txt' does not exist");
+#else
+        ASSERT_EQUALS(Path::toNativeSeparators(Path::join(cwd, "testabspath2.txt")), Path::getAbsoluteFilePath("testabspath2.txt"));
+#endif
+
+#ifdef _WIN32
+        // determine an existing drive letter
+        std::string drive = Path::getCurrentPath().substr(0, 2);
+        ASSERT_EQUALS(drive + "", Path::getAbsoluteFilePath(drive + "\\"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "\\path"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "\\path\\"));
+        ASSERT_EQUALS(drive + "\\path\\files.txt", Path::getAbsoluteFilePath(drive + "\\path\\files.txt"));
+        ASSERT_EQUALS(drive + "", Path::getAbsoluteFilePath(drive + "//"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "//path"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "//path/"));
+        ASSERT_EQUALS(drive + "\\path\\files.txt", Path::getAbsoluteFilePath(drive + "//path/files.txt"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "\\\\path"));
+        ASSERT_EQUALS(drive + "", Path::getAbsoluteFilePath(drive + "/"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "/path"));
+
+        drive[0] = static_cast<char>(toupper(drive[0]));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "\\path"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "/path"));
+
+        drive[0] = static_cast<char>(tolower(drive[0]));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "\\path"));
+        ASSERT_EQUALS(drive + "\\path", Path::getAbsoluteFilePath(drive + "/path"));
+
+        ASSERT_EQUALS("1:\\path\\files.txt", Path::getAbsoluteFilePath("1:\\path\\files.txt")); // treated as valid drive
+        ASSERT_EQUALS(
+            Path::toNativeSeparators(Path::join(Path::getCurrentPath(), "CC:\\path\\files.txt")),
+            Path::getAbsoluteFilePath("CC:\\path\\files.txt")); // treated as filename
+        ASSERT_EQUALS("1:\\path\\files.txt", Path::getAbsoluteFilePath("1:/path/files.txt")); // treated as valid drive
+        ASSERT_EQUALS(
+            Path::toNativeSeparators(Path::join(Path::getCurrentPath(), "CC:\\path\\files.txt")),
+            Path::getAbsoluteFilePath("CC:/path/files.txt")); // treated as filename
+#endif
+
+#ifndef _WIN32
+        ASSERT_THROW_EQUALS_2(Path::getAbsoluteFilePath("C:\\path\\files.txt"), std::runtime_error, "path 'C:\\path\\files.txt' does not exist");
+#endif
+
+        // TODO: test UNC paths
+        // TODO: test with symlinks
+    }
+
+    void exists() const {
+        ScopedFile file("testpath.txt", "", "testpath");
+        ScopedFile file2("testpath2.txt", "");
+        ASSERT_EQUALS(true, Path::exists("testpath"));
+        ASSERT_EQUALS(true, Path::exists("testpath/testpath.txt"));
+        ASSERT_EQUALS(true, Path::exists("testpath2.txt"));
+
+        ASSERT_EQUALS(false, Path::exists("testpath2"));
+        ASSERT_EQUALS(false, Path::exists("testpath/testpath2.txt"));
+        ASSERT_EQUALS(false, Path::exists("testpath.txt"));
+    }
 };
 
 REGISTER_TEST(TestPath)