Infer package name and version from URL (#220)

* Function to extract name and version from url. Some tests

* Rewrite. Previous version was not safe enough. More tests

* Allow underscore as a name-version separator (<name>_<ver>)

* CPMAddPackage can infer name and version from url

* Allow URL parse from single arg and uncomment tests

* Info about shorthand syntax in README

* Fix style

* Fixed typo

Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

* Explicit hash algorithm in shorthand URL example.
Also added tests which include a hash algorithm provided
We can't document a default until it's confirmed here: https://gitlab.kitware.com/cmake/cmake/-/issues/21859

Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

README.md

@@ -62,6 +62,17 @@ CPMAddPackage("uri@version#tag")
 
 In the shorthand syntax if the URI is of the form `gh:user/name`, it is interpreted as GitHub URI and converted to `https://github.com/user/name.git`. If the URI is of the form `gl:user/name`, it is interpreted as a [GitLab](https://gitlab.com/explore/) URI and coverted to `https://gitlab.com/user/name.git`. Otherwise the URI used verbatim as a git URL. All packages added using the shorthand syntax will be added using the [EXCLUDE_FROM_ALL](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) flag.
 
+The single-argument syntax also works for URLs:
+
+```cmake
+# An archive package from a given url. The version is inferred
+CPMAddPackage("https://example.com/my-package-1.2.3.zip")
+# An archive package from a given url with an MD5 hash provided
+CPMAddPackage("https://example.com/my-package-1.2.3.zip#MD5=68e20f674a48be38d60e129f600faf7d")
+# An archive package from a given url. The version is explicitly given
+CPMAddPackage("https://example.com/my-package.zip@1.2.3")
+```
+
 After calling `CPMAddPackage` or `CPMFindPackage`, the following variables are defined in the local scope, where `<dependency>` is the name of the dependency.
 
 - `<dependency>_SOURCE_DIR` is the path to the source of the dependency.

cmake/CPM.cmake

@@ -134,7 +134,7 @@ endif()
 include(FetchContent)
 include(CMakeParseArguments)
 
-# Infer package name from git repository uri (path or url)
+# Try to infer package name from git repository uri (path or url)
 function(cpm_package_name_from_git_uri URI RESULT)
   if("${URI}" MATCHES "([^/:]+)/?.git/?$")
     set(${RESULT}
@@ -146,6 +146,52 @@ function(cpm_package_name_from_git_uri URI RESULT)
   endif()
 endfunction()
 
+# Try to infer package name and version from a url
+function(cpm_package_name_and_ver_from_url url outName outVer)
+  if(url MATCHES "[/\\?]([a-zA-Z0-9_\\.-]+)\\.(tar|tar\\.gz|tar\\.bz2|zip|ZIP)(\\?|/|$)")
+    # We matched an archive
+    set(filename "${CMAKE_MATCH_1}")
+
+    if(filename MATCHES "([a-zA-Z0-9_\\.-]+)[_-]v?(([0-9]+\\.)*[0-9]+[a-zA-Z0-9]*)")
+      # We matched <name>-<version> (ie foo-1.2.3)
+      set(${outName}
+          "${CMAKE_MATCH_1}"
+          PARENT_SCOPE
+      )
+      set(${outVer}
+          "${CMAKE_MATCH_2}"
+          PARENT_SCOPE
+      )
+    elseif(filename MATCHES "(([0-9]+\\.)+[0-9]+[a-zA-Z0-9]*)")
+      # We couldn't find a name, but we found a version
+      #
+      # In many cases (which we don't handle here) the url would look something like
+      # `irrelevant/ACTUAL_PACKAGE_NAME/irrelevant/1.2.3.zip`. In such a case we can't possibly
+      # distinguish the package name from the irrelevant bits. Moreover if we try to match the
+      # package name from the filename, we'd get bogus at best.
+      unset(${outName} PARENT_SCOPE)
+      set(${outVer}
+          "${CMAKE_MATCH_1}"
+          PARENT_SCOPE
+      )
+    else()
+      # Boldly assume that the file name is the package name.
+      #
+      # Yes, something like `irrelevant/ACTUAL_NAME/irrelevant/download.zip` will ruin our day, but
+      # such cases should be quite rare. No popular service does this... we think.
+      set(${outName}
+          "${filename}"
+          PARENT_SCOPE
+      )
+      unset(${outVer} PARENT_SCOPE)
+    endif()
+  else()
+    # No ideas yet what to do with non-archives
+    unset(${outName} PARENT_SCOPE)
+    unset(${outVer} PARENT_SCOPE)
+  endif()
+endfunction()
+
 # Initialize logging prefix
 if(NOT CPM_INDENT)
   set(CPM_INDENT
@@ -274,11 +320,6 @@ function(cpm_parse_add_package_single_arg arg outArgs)
       set(out "GIT_REPOSITORY;${arg}")
       set(packageType "git")
     else()
-      # This error here is temporary. We can't provide URLs from here until we support inferring the
-      # package name from an url. When this is supported, remove this error as well as commented out
-      # tests in test/unit/parse_add_package_single_arg.cmake
-      message(FATAL_ERROR "CPM: Unsupported package type of '${arg}'")
-
       # Fall back to a URL
       set(out "URL;${arg}")
       set(packageType "archive")
@@ -349,7 +390,7 @@ function(CPMAddPackage)
       EXCLUDE_FROM_ALL
   )
 
-  set(multiValueArgs OPTIONS)
+  set(multiValueArgs URL OPTIONS)
 
   cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
 
@@ -397,6 +438,24 @@ function(CPMAddPackage)
     endif()
   endif()
 
+  if(DEFINED CPM_ARGS_URL)
+    # If a name or version aren't provided, try to infer them from the URL
+    list(GET CPM_ARGS_URL 0 firstUrl)
+    cpm_package_name_and_ver_from_url(${firstUrl} nameFromUrl verFromUrl)
+    # If we fail to obtain name and version from the first URL, we could try other URLs if any.
+    # However multiple URLs are expected to be quite rare, so for now we won't bother.
+
+    # If the caller provided their own name and version, they trump the inferred ones.
+    if(NOT DEFINED CPM_ARGS_NAME)
+      set(CPM_ARGS_NAME ${nameFromUrl})
+    endif()
+    if(NOT DEFINED CPM_ARGS_VERSION)
+      set(CPM_ARGS_VERSION ${verFromUrl})
+    endif()
+
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS URL "${CPM_ARGS_URL}")
+  endif()
+
   # Check for required arguments
 
   if(NOT DEFINED CPM_ARGS_NAME)

test/unit/package_name_and_ver_from_url.cmake

@@ -0,0 +1,60 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+include(${CPM_PATH}/CPM.cmake)
+include(${CPM_PATH}/testing.cmake)
+
+cpm_package_name_and_ver_from_url("https://example.com/coolpack-1.2.3.zip" name ver)
+assert_equal("coolpack" ${name})
+assert_equal("1.2.3" ${ver})
+
+cpm_package_name_and_ver_from_url("https://example.com/cool-pack-v1.3.tar.gz" name ver)
+assert_equal("cool-pack" ${name})
+assert_equal("1.3" ${ver})
+
+cpm_package_name_and_ver_from_url(
+  "https://subd.zip.com/download.php?Cool.Pack-v1.2.3rc0.tar" name ver
+)
+assert_equal("Cool.Pack" ${name})
+assert_equal("1.2.3rc0" ${ver})
+
+cpm_package_name_and_ver_from_url(
+  "http://evil-1.2.tar.gz.com/Plan9_1.2.3a.tar.bz2?download" name ver
+)
+assert_equal("Plan9" ${name})
+assert_equal("1.2.3a" ${ver})
+
+cpm_package_name_and_ver_from_url(
+  "http://evil-1.2.tar.gz.com/Plan_9-1.2.3a.tar.bz2?download" name ver
+)
+assert_equal("Plan_9" ${name})
+assert_equal("1.2.3a" ${ver})
+
+cpm_package_name_and_ver_from_url(
+  "http://evil-1.2.tar.gz.com/Plan-9_1.2.3a.tar.bz2?download" name ver
+)
+assert_equal("Plan-9" ${name})
+assert_equal("1.2.3a" ${ver})
+
+cpm_package_name_and_ver_from_url("https://sf.com/distrib/SFLib-0.999.4.tar.gz/download" name ver)
+assert_equal("SFLib" ${name})
+assert_equal("0.999.4" ${ver})
+
+cpm_package_name_and_ver_from_url("https://example.com/coolpack/v5.6.5rc44.zip" name ver)
+assert_not_defined(name)
+assert_equal("5.6.5rc44" ${ver})
+
+cpm_package_name_and_ver_from_url("evil-1.3.zip.com/coolpack/release999.000beta.ZIP" name ver)
+assert_not_defined(name)
+assert_equal("999.000beta" ${ver})
+
+cpm_package_name_and_ver_from_url("https://example.com/Foo55.tar.gz" name ver)
+assert_equal("Foo55" ${name})
+assert_not_defined(ver)
+
+cpm_package_name_and_ver_from_url("https://example.com/foo" name ver)
+assert_not_defined(name)
+assert_not_defined(ver)
+
+cpm_package_name_and_ver_from_url("example.zip.com/foo" name ver)
+assert_not_defined(name)
+assert_not_defined(ver)

test/unit/parse_add_package_single_arg.cmake

@@ -47,18 +47,19 @@ assert_equal(
   "${args}"
 )
 
-# The following test cases are to be used in the future, once single-argument archives are supported
+cpm_parse_add_package_single_arg("https://example.org/foo.tar.gz" args)
+assert_equal("URL;https://example.org/foo.tar.gz" "${args}")
 
-# cpm_parse_add_package_single_arg("https://example.org/foo.tar.gz" args)
+cpm_parse_add_package_single_arg("https://example.org/foo.tar.gz#baadf00d@1.2.0" args)
+assert_equal("URL;https://example.org/foo.tar.gz;URL_HASH;baadf00d;VERSION;1.2.0" "${args}")
 
-# assert_equal("URL;https://example.org/foo.tar.gz" "${args}")
+cpm_parse_add_package_single_arg("https://example.org/foo.tar.gz#MD5=baadf00d" args)
+assert_equal("URL;https://example.org/foo.tar.gz;URL_HASH;MD5=baadf00d" "${args}")
 
-# cpm_parse_add_package_single_arg("https://example.org/foo.tar.gz#baadf00d@1.2.0" args)
+cpm_parse_add_package_single_arg("https://example.org/Foo.zip#SHA3_512=1337" args)
+assert_equal("URL;https://example.org/Foo.zip;URL_HASH;SHA3_512=1337" "${args}")
 
-# assert_equal("URL;https://example.org/foo.tar.gz;URL_HASH;baadf00d;VERSION;1.2.0" "${args}")
-
-# cpm_parse_add_package_single_arg("ftp://user:password@server/pathname.zip#fragment#0ddb411@0"
-# args)
-
-# assert_equal("URL;ftp://user:password@server/pathname.zip#fragment;URL_HASH;0ddb411;VERSION;0"
-# "${args}")
+cpm_parse_add_package_single_arg("ftp://user:pass@server/pathname.zip#fragment#0ddb411@0" args)
+assert_equal(
+  "URL;ftp://user:pass@server/pathname.zip#fragment;URL_HASH;0ddb411;VERSION;0" "${args}"
+)