From 378c047ae30184bdcefdf767fb49538655ee2191 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <oliver@assarbad.net>
Date: Fri, 13 Nov 2020 22:27:45 +0100
Subject: Makefiles: Explicitly tell 'make' tool what Makefile name to use

CMake did not specify the filename of the Makefile generated by it.
Due to GNU make precedence rules this means that the presence of a
GNUmakefile or makefile would take precedence over the generated
Makefile.

This is only relevant for in-source builds and only whenever an
alternative makefile by the above mentioned names exists.

This patch adds the (seemingly universal) `-f` switch and the
(hardcoded) filename (it is now hardcoded separately in these two
files):

- cmLocalUnixMakefileGenerator3.cxx
- cmGlobalUnixMakefileGenerator3.cxx

Fixes: #21418
---
 Source/cmGlobalUnixMakefileGenerator3.cxx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Source/cmGlobalUnixMakefileGenerator3.cxx b/Source/cmGlobalUnixMakefileGenerator3.cxx
index c6c540b..9c3a533 100644
--- a/Source/cmGlobalUnixMakefileGenerator3.cxx
+++ b/Source/cmGlobalUnixMakefileGenerator3.cxx
@@ -589,6 +589,11 @@ cmGlobalUnixMakefileGenerator3::GenerateBuildCommand(
   }
   makeCommand.Add(this->SelectMakeProgram(makeProgram));
 
+  // Explicitly tell the make tool to use the Makefile written by
+  // cmLocalUnixMakefileGenerator3::WriteLocalMakefile
+  makeCommand.Add("-f");
+  makeCommand.Add("Makefile");
+
   if (jobs != cmake::NO_BUILD_PARALLEL_LEVEL) {
     if (jobs == cmake::DEFAULT_BUILD_PARALLEL_LEVEL) {
       makeCommand.Add("-j");
-- 
cgit v0.12


From cfce067b3facbd54275fd323a54e32e161717b8e Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Mon, 16 Nov 2020 11:33:58 -0500
Subject: Tests: Add RunCMake.Make case for conflicting Makefile names

Issue: #21418
---
 Tests/RunCMake/Make/MakefileConflict.cmake | 5 +++++
 Tests/RunCMake/Make/RunCMakeTest.cmake     | 8 ++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 Tests/RunCMake/Make/MakefileConflict.cmake

diff --git a/Tests/RunCMake/Make/MakefileConflict.cmake b/Tests/RunCMake/Make/MakefileConflict.cmake
new file mode 100644
index 0000000..6a8406f
--- /dev/null
+++ b/Tests/RunCMake/Make/MakefileConflict.cmake
@@ -0,0 +1,5 @@
+add_custom_target(Custom)
+
+# Write a file that GNU make will prefer over "Makefile"
+# if 'cmake --build' does not explicitly specify it.
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/GNUmakefile" "")
diff --git a/Tests/RunCMake/Make/RunCMakeTest.cmake b/Tests/RunCMake/Make/RunCMakeTest.cmake
index 5562aca..b66e30e 100644
--- a/Tests/RunCMake/Make/RunCMakeTest.cmake
+++ b/Tests/RunCMake/Make/RunCMakeTest.cmake
@@ -42,6 +42,14 @@ run_VerboseBuild()
 run_cmake(CustomCommandDepfile-ERROR)
 run_cmake(IncludeRegexSubdir)
 
+function(run_MakefileConflict)
+  run_cmake(MakefileConflict)
+  set(RunCMake_TEST_NO_CLEAN 1)
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/MakefileConflict-build)
+  run_cmake_command(MakefileConflict-build ${CMAKE_COMMAND} --build . --target Custom)
+endfunction()
+run_MakefileConflict()
+
 function(run_CMP0113 val)
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/CMP0113-${val}-build)
   run_cmake(CMP0113-${val})
-- 
cgit v0.12