cmake: Ensure source and binary dirs are set

If only the source dir is provided, the binary dir is assumed
to be the working directory. If only the binary dir is provided
and it doesn't yet have a CMakeCache.txt to provide the
source dir, then the source dir is assumed to be the working
directory. This logic was not previously being handled
correctly when -S and/or -B options were involved.
Furthermore, when both were missing, no suitable error
message was provided and an empty string was used for
the build directory.

Fixes: #18707

Source/cmake.cxx

@@ -609,16 +609,13 @@ bool cmake::FindPackage(const std::vector<std::string>& args)
 }
 
 // Parse the args
-void cmake::SetArgs(const std::vector<std::string>& args,
-                    bool directoriesSetBefore)
+void cmake::SetArgs(const std::vector<std::string>& args)
 {
-  bool directoriesSet = directoriesSetBefore;
   bool haveToolset = false;
   bool havePlatform = false;
   for (unsigned int i = 1; i < args.size(); ++i) {
     std::string const& arg = args[i];
     if (arg.find("-H", 0) == 0 || arg.find("-S", 0) == 0) {
-      directoriesSet = true;
       std::string path = arg.substr(2);
       if (path.empty()) {
         ++i;
@@ -639,7 +636,6 @@ void cmake::SetArgs(const std::vector<std::string>& args,
     } else if (arg.find("-O", 0) == 0) {
       // There is no local generate anymore.  Ignore -O option.
     } else if (arg.find("-B", 0) == 0) {
-      directoriesSet = true;
       std::string path = arg.substr(2);
       if (path.empty()) {
         ++i;
@@ -801,16 +797,27 @@ void cmake::SetArgs(const std::vector<std::string>& args,
         this->SetGlobalGenerator(gen);
       }
     }
-    // no option assume it is the path to the source
+    // no option assume it is the path to the source or an existing build
     else {
-      directoriesSet = true;
       this->SetDirectoriesFromFile(arg.c_str());
     }
   }
-  if (!directoriesSet) {
-    this->SetHomeOutputDirectory(cmSystemTools::GetCurrentWorkingDirectory());
+
+  const bool haveSourceDir = !this->GetHomeDirectory().empty();
+  const bool haveBinaryDir = !this->GetHomeOutputDirectory().empty();
+
+  if (this->CurrentWorkingMode == cmake::NORMAL_MODE && !haveSourceDir &&
+      !haveBinaryDir) {
+    cmSystemTools::Error("No source or binary directory provided");
+    return;
+  }
+
+  if (!haveSourceDir) {
     this->SetHomeDirectory(cmSystemTools::GetCurrentWorkingDirectory());
   }
+  if (!haveBinaryDir) {
+    this->SetHomeOutputDirectory(cmSystemTools::GetCurrentWorkingDirectory());
+  }
 }
 
 void cmake::SetDirectoriesFromFile(const char* arg)

Source/cmake.h

@@ -275,8 +275,7 @@ public:
   int GetSystemInformation(std::vector<std::string>&);
 
   ///! Parse command line arguments
-  void SetArgs(const std::vector<std::string>&,
-               bool directoriesSetBefore = false);
+  void SetArgs(const std::vector<std::string>& args);
 
   ///! Is this cmake running as a result of a TRY_COMPILE command
   bool GetIsInTryCompile() const;

Tests/RunCMake/CommandLine/RunCMakeTest.cmake

@@ -4,17 +4,17 @@ include(RunCMake)
 
 run_cmake_command(NoArgs ${CMAKE_COMMAND})
 run_cmake_command(Wizard ${CMAKE_COMMAND} -i)
-run_cmake_command(C-no-arg ${CMAKE_COMMAND} -C)
-run_cmake_command(C-no-file ${CMAKE_COMMAND} -C nosuchcachefile.txt)
-run_cmake_command(Cno-file ${CMAKE_COMMAND} -Cnosuchcachefile.txt)
+run_cmake_command(C-no-arg ${CMAKE_COMMAND} -B DummyBuildDir -C)
+run_cmake_command(C-no-file ${CMAKE_COMMAND} -B DummyBuildDir -C nosuchcachefile.txt)
+run_cmake_command(Cno-file ${CMAKE_COMMAND} -B DummyBuildDir -Cnosuchcachefile.txt)
 run_cmake_command(cache-no-file ${CMAKE_COMMAND} nosuchsubdir/CMakeCache.txt)
 run_cmake_command(lists-no-file ${CMAKE_COMMAND} nosuchsubdir/CMakeLists.txt)
-run_cmake_command(D-no-arg ${CMAKE_COMMAND} -D)
-run_cmake_command(D-no-src ${CMAKE_COMMAND} -D VAR=VALUE)
-run_cmake_command(Dno-src ${CMAKE_COMMAND} -DVAR=VALUE)
-run_cmake_command(U-no-arg ${CMAKE_COMMAND} -U)
-run_cmake_command(U-no-src ${CMAKE_COMMAND} -U VAR)
-run_cmake_command(Uno-src ${CMAKE_COMMAND} -UVAR)
+run_cmake_command(D-no-arg ${CMAKE_COMMAND} -B DummyBuildDir -D)
+run_cmake_command(D-no-src ${CMAKE_COMMAND} -B DummyBuildDir -D VAR=VALUE)
+run_cmake_command(Dno-src ${CMAKE_COMMAND} -B DummyBuildDir -DVAR=VALUE)
+run_cmake_command(U-no-arg ${CMAKE_COMMAND} -B DummyBuildDir -U)
+run_cmake_command(U-no-src ${CMAKE_COMMAND} -B DummyBuildDir -U VAR)
+run_cmake_command(Uno-src ${CMAKE_COMMAND} -B DummyBuildDir -UVAR)
 run_cmake_command(E-no-arg ${CMAKE_COMMAND} -E)
 run_cmake_command(E_capabilities ${CMAKE_COMMAND} -E capabilities)
 run_cmake_command(E_capabilities-arg ${CMAKE_COMMAND} -E capabilities --extra-arg)
@@ -32,8 +32,8 @@ run_cmake_command(E___run_co_compile-bad-iwyu ${CMAKE_COMMAND} -E __run_co_compi
 run_cmake_command(E___run_co_compile-no--- ${CMAKE_COMMAND} -E __run_co_compile --iwyu=iwyu-does-not-exist command-does-not-exist)
 run_cmake_command(E___run_co_compile-no-cc ${CMAKE_COMMAND} -E __run_co_compile --iwyu=iwyu-does-not-exist --)
 
-run_cmake_command(G_no-arg ${CMAKE_COMMAND} -G)
-run_cmake_command(G_bad-arg ${CMAKE_COMMAND} -G NoSuchGenerator)
+run_cmake_command(G_no-arg ${CMAKE_COMMAND} -B DummyBuildDir -G)
+run_cmake_command(G_bad-arg ${CMAKE_COMMAND} -B DummyBuildDir -G NoSuchGenerator)
 run_cmake_command(P_no-arg ${CMAKE_COMMAND} -P)
 run_cmake_command(P_no-file ${CMAKE_COMMAND} -P nosuchscriptfile.cmake)
 
@@ -59,6 +59,7 @@ function(run_ExplicitDirs)
 
   file(REMOVE_RECURSE "${binary_dir}")
   file(MAKE_DIRECTORY "${binary_dir}")
+  run_cmake_command(no-S-B ${CMAKE_COMMAND} -DFOO=BAR)
   run_cmake_command(S-arg ${CMAKE_COMMAND} -S ${source_dir} ${binary_dir})
   run_cmake_command(S-arg-reverse-order ${CMAKE_COMMAND} ${binary_dir} -S${source_dir} )
   run_cmake_command(S-no-arg ${CMAKE_COMMAND} -S )
@@ -328,9 +329,9 @@ set(RunCMake_TEST_OPTIONS -Wdev -Wno-dev)
 run_cmake(Wno-dev)
 unset(RunCMake_TEST_OPTIONS)
 
-run_cmake_command(W_bad-arg1 ${CMAKE_COMMAND} -W)
-run_cmake_command(W_bad-arg2 ${CMAKE_COMMAND} -Wno-)
-run_cmake_command(W_bad-arg3 ${CMAKE_COMMAND} -Werror=)
+run_cmake_command(W_bad-arg1 ${CMAKE_COMMAND} -B DummyBuildDir -W)
+run_cmake_command(W_bad-arg2 ${CMAKE_COMMAND} -B DummyBuildDir -Wno-)
+run_cmake_command(W_bad-arg3 ${CMAKE_COMMAND} -B DummyBuildDir -Werror=)
 
 set(RunCMake_TEST_OPTIONS --debug-output)
 run_cmake(debug-output)

Tests/RunCMake/CommandLine/no-S-B-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CommandLine/no-S-B-stderr.txt

@@ -0,0 +1 @@
+CMake Error: No source or binary directory provided