CPack/DEB: Add CPACK_DEBIAN_COMPRESSION_LEVEL variable

Add a new variable `CPACK_DEBIAN_COMPRESSION_LEVEL` to control the compression level used when generating Debian packages. This complements the existing `CPACK_DEBIAN_COMPRESSION_TYPE` variable and allows finer control over the compression performance vs. size trade-off. Supported values correspond to the compression level accepted by the underlying compressor (e.g. gzip, xz, zstd, etc.).
2026-01-26 19:09:06 +00:00 · 2025-10-24 18:21:22 +00:00 · 2025-10-24 18:21:22 +00:00 · 07fe3f95ce
commit 07fe3f95ce
parent 70dcdffb1f
7 changed files with 78 additions and 9 deletions
--- a/Help/cpack_gen/deb.rst
+++ b/Help/cpack_gen/deb.rst
@ -306,6 +306,37 @@ List of CPack DEB generator specific variables:

    Zstandard compression

+.. variable:: CPACK_DEBIAN_COMPRESSION_LEVEL
+
+ .. versionadded:: 4.3
+
+ The compression level used for creating the Debian package.
+
+ :Mandatory: No
+ :Default: Automatically determined by the compression tool.
+
+ This variable allows fine-tuning of the compression ratio and speed for the
+ Debian package archive. It controls the numeric compression level passed to
+ the compressor defined by :variable:`CPACK_DEBIAN_COMPRESSION_TYPE`.
+ If ``CPACK_DEBIAN_COMPRESSION_LEVEL`` is not set, or is set to ``0``,
+ the default value will be used.
+
+ The valid range and interpretation depend on the selected compression type:
+
+  - ``gzip``  – level 1–9 (default 6)
+  - ``bzip2`` – level 1–9 (default 9)
+  - ``xz``    – level 1–9 (default 6)
+  - ``lzma``  – level 1–9 (default 6)
+  - ``zstd``  – level 1–19 (default 3)
+
+ Example usage:
+
+ .. code-block:: cmake
+
+   set(CPACK_DEBIAN_COMPRESSION_TYPE "xz")
+   set(CPACK_DEBIAN_COMPRESSION_LEVEL 9)
+
+   include(CPack)

 .. variable:: CPACK_DEBIAN_PACKAGE_PRIORITY
              CPACK_DEBIAN_<COMPONENT>_PACKAGE_PRIORITY
--- a/Help/release/dev/cpack-deb-compression-level.rst
+++ b/Help/release/dev/cpack-deb-compression-level.rst
@ -0,0 +1,6 @@
+cpack-deb-compression-level
+---------------------------
+
+* The :cpack_gen:`CPack DEB Generator` gained a new variable
+  :variable:`CPACK_DEBIAN_COMPRESSION_LEVEL` to control the
+  compression level used when creating Debian packages.
--- a/Modules/Internal/CPack/CPackDeb.cmake
+++ b/Modules/Internal/CPack/CPackDeb.cmake
@ -808,6 +808,10 @@ function(cpack_deb_prepare_package_vars)
    string(REGEX REPLACE "\.deb$" "-dbgsym.ddeb" CPACK_DBGSYM_OUTPUT_FILE_NAME "${CPACK_OUTPUT_FILE_NAME}")
  endif()

+  if(NOT DEFINED CPACK_DEBIAN_COMPRESSION_LEVEL)
+    set(CPACK_DEBIAN_COMPRESSION_LEVEL "0")
+  endif()
+
  # Print out some debug information if we were asked for that
  if(CPACK_DEBIAN_PACKAGE_DEBUG)
     message("CPackDeb:Debug: CPACK_TOPLEVEL_DIRECTORY          = '${CPACK_TOPLEVEL_DIRECTORY}'")
@ -820,6 +824,7 @@ function(cpack_deb_prepare_package_vars)
     message("CPackDeb:Debug: CPACK_TEMPORARY_PACKAGE_FILE_NAME = '${CPACK_TEMPORARY_PACKAGE_FILE_NAME}'")
     message("CPackDeb:Debug: CPACK_DEBIAN_PACKAGE_CONTROL_STRICT_PERMISSION = '${CPACK_DEBIAN_PACKAGE_CONTROL_STRICT_PERMISSION}'")
     message("CPackDeb:Debug: CPACK_DEBIAN_PACKAGE_SOURCE       = '${CPACK_DEBIAN_PACKAGE_SOURCE}'")
+     message("CPackDeb:Debug: CPACK_DEBIAN_COMPRESSION_LEVEL       = '${CPACK_DEBIAN_COMPRESSION_LEVEL}'")
  endif()

  # For debian source packages:
@ -849,6 +854,7 @@ function(cpack_deb_prepare_package_vars)
  set(GEN_CPACK_DEBIAN_PACKAGE_DEPENDS "${CPACK_DEBIAN_PACKAGE_DEPENDS}" PARENT_SCOPE)
  set(GEN_CPACK_DEBIAN_ARCHIVE_TYPE "${CPACK_DEBIAN_ARCHIVE_TYPE}" PARENT_SCOPE)
  set(GEN_CPACK_DEBIAN_COMPRESSION_TYPE "${CPACK_DEBIAN_COMPRESSION_TYPE}" PARENT_SCOPE)
+  set(GEN_CPACK_DEBIAN_COMPRESSION_LEVEL "${CPACK_DEBIAN_COMPRESSION_LEVEL}" PARENT_SCOPE)
  set(GEN_CPACK_DEBIAN_PACKAGE_RECOMMENDS "${CPACK_DEBIAN_PACKAGE_RECOMMENDS}" PARENT_SCOPE)
  set(GEN_CPACK_DEBIAN_PACKAGE_SUGGESTS "${CPACK_DEBIAN_PACKAGE_SUGGESTS}" PARENT_SCOPE)
  set(GEN_CPACK_DEBIAN_PACKAGE_HOMEPAGE "${CPACK_DEBIAN_PACKAGE_HOMEPAGE}" PARENT_SCOPE)
--- a/Source/CPack/cmCPackDebGenerator.cxx
+++ b/Source/CPack/cmCPackDebGenerator.cxx
@ -32,8 +32,8 @@ class DebGenerator
 public:
  DebGenerator(cmCPackLog* logger, std::string outputName, std::string workDir,
               std::string topLevelDir, std::string temporaryDir,
-               cmValue debianCompressionType, cmValue numThreads,
-               cmValue debianArchiveType,
+               cmValue debianCompressionType, cmValue debianCompressionLevel,
+               cmValue numThreads, cmValue debianArchiveType,
               std::map<std::string, std::string> controlValues,
               bool genShLibs, std::string shLibsFilename, bool genPostInst,
               std::string postInst, bool genPostRm, std::string postRm,
@ -69,16 +69,18 @@ private:
  bool const PermissionStrictPolicy;
  std::vector<std::string> const PackageFiles;
  cmArchiveWrite::Compress TarCompressionType;
+  int CompressionLevel = 0;
 };

 DebGenerator::DebGenerator(
  cmCPackLog* logger, std::string outputName, std::string workDir,
  std::string topLevelDir, std::string temporaryDir,
-  cmValue debCompressionType, cmValue numThreads, cmValue debianArchiveType,
-  std::map<std::string, std::string> controlValues, bool genShLibs,
-  std::string shLibsFilename, bool genPostInst, std::string postInst,
-  bool genPostRm, std::string postRm, cmValue controlExtra,
-  bool permissionStrictPolicy, std::vector<std::string> packageFiles)
+  cmValue debCompressionType, cmValue debCompressionLevel, cmValue numThreads,
+  cmValue debianArchiveType, std::map<std::string, std::string> controlValues,
+  bool genShLibs, std::string shLibsFilename, bool genPostInst,
+  std::string postInst, bool genPostRm, std::string postRm,
+  cmValue controlExtra, bool permissionStrictPolicy,
+  std::vector<std::string> packageFiles)
  : Logger(logger)
  , OutputName(std::move(outputName))
  , WorkDir(std::move(workDir))
@ -135,6 +137,19 @@ DebGenerator::DebGenerator(
  } else {
    this->NumThreads = 1;
  }
+
+  if (debCompressionLevel) {
+    long compressionLevel;
+    if (!cmStrToLong(*debCompressionLevel, &compressionLevel)) {
+      compressionLevel = 0;
+      cmCPackLogger(cmCPackLog::LOG_ERROR,
+                    "Unrecognized compression level: " << debCompressionLevel
+                                                       << std::endl);
+    }
+    this->CompressionLevel = static_cast<int>(compressionLevel);
+  } else {
+    this->CompressionLevel = 0;
+  }
 }

 bool DebGenerator::generate() const
@ -192,7 +207,7 @@ bool DebGenerator::generateDataTar() const
    return false;
  }
  cmArchiveWrite data_tar(fileStream_data_tar, this->TarCompressionType,
-                          this->DebianArchiveType, 0,
+                          this->DebianArchiveType, this->CompressionLevel,
                          static_cast<int>(this->NumThreads));
  if (!data_tar.Open()) {
    cmCPackLogger(cmCPackLog::LOG_ERROR,
@ -324,7 +339,7 @@ bool DebGenerator::generateControlTar(std::string const& md5Filename) const
    return false;
  }
  cmArchiveWrite control_tar(fileStream_control_tar, this->TarCompressionType,
-                             this->DebianArchiveType);
+                             this->DebianArchiveType, this->CompressionLevel);
  if (!control_tar.Open()) {
    cmCPackLogger(cmCPackLog::LOG_ERROR,
                  "Error opening the archive \""
@ -846,6 +861,7 @@ bool cmCPackDebGenerator::createDeb()
    this->GetOption("CPACK_TOPLEVEL_DIRECTORY"),
    this->GetOption("CPACK_TEMPORARY_DIRECTORY"),
    this->GetOption("GEN_CPACK_DEBIAN_COMPRESSION_TYPE"),
+    this->GetOption("GEN_CPACK_DEBIAN_COMPRESSION_LEVEL"),
    this->GetOption("CPACK_THREADS"),
    this->GetOption("GEN_CPACK_DEBIAN_ARCHIVE_TYPE"), controlValues, gen_shibs,
    shlibsfilename, this->IsOn("GEN_CPACK_DEBIAN_GENERATE_POSTINST"), postinst,
@ -901,6 +917,7 @@ bool cmCPackDebGenerator::createDbgsymDDeb()
    this->GetOption("CPACK_TOPLEVEL_DIRECTORY"),
    this->GetOption("CPACK_TEMPORARY_DIRECTORY"),
    this->GetOption("GEN_CPACK_DEBIAN_COMPRESSION_TYPE"),
+    this->GetOption("GEN_CPACK_DEBIAN_COMPRESSION_LEVEL"),
    this->GetOption("CPACK_THREADS"),
    this->GetOption("GEN_CPACK_DEBIAN_ARCHIVE_TYPE"), controlValues, false, "",
    false, "", false, "", nullptr,
--- a/Tests/RunCMake/CPack_DEB/Basic-verify-stdout.txt
+++ b/Tests/RunCMake/CPack_DEB/Basic-verify-stdout.txt
@ -11,4 +11,8 @@ d[rwx-]+ root/root         0 [0-9-]+ [0-9:]+ \./usr/share/
 d[rwx-]+ root/root         0 [0-9-]+ [0-9:]+ \./usr/share/doc/
 d[rwx-]+ root/root         0 [0-9-]+ [0-9:]+ \./usr/share/doc/basic/
 -[rwx-]+ root/root         0 [0-9-]+ [0-9:]+ \./usr/share/doc/basic/basic\.txt
+-- ar t
+debian-binary
+control\.tar\.xz
+data\.tar\.xz
 --
--- a/Tests/RunCMake/CPack_DEB/verify.cmake
+++ b/Tests/RunCMake/CPack_DEB/verify.cmake
@ -2,3 +2,5 @@ message(STATUS "dpkg-deb --info")
 execute_process(COMMAND dpkg-deb --info ${CMAKE_ARGV4})
 message(STATUS "dpkg-deb --contents")
 execute_process(COMMAND dpkg-deb --contents ${CMAKE_ARGV4})
+message(STATUS "ar t")
+execute_process(COMMAND ar t ${CMAKE_ARGV4})
--- a/Tests/RunCMake/RunCPack/Basic/CMakeLists.txt
+++ b/Tests/RunCMake/RunCPack/Basic/CMakeLists.txt
@ -3,5 +3,8 @@ project(Basic LANGUAGES NONE VERSION "1.2.3")

 install(FILES basic.txt DESTINATION share/doc/basic)

+set(CPACK_DEBIAN_COMPRESSION_TYPE "xz")
+set(CPACK_DEBIAN_COMPRESSION_LEVEL "4")
+
 set(CPACK_PACKAGE_CONTACT "somebody@cmake.org")
 include(CPack)