From a186c1aff61fdedd2ef8d544c9f31c739daaa896 Mon Sep 17 00:00:00 2001
From: Kyle Edwards <kyle.edwards@kitware.com>
Date: Fri, 15 Jul 2022 15:29:20 -0400
Subject: Ninja Multi-Config: Deduplicate compile_commands.json for cross
 configs

compile_commands.json was being written for every permutation of
cross configurations. Deduplicate so only one command is output
for each configuration.

Fixes: #23733
---
 Source/cmNinjaTargetGenerator.cxx                  |  8 ++++---
 .../NinjaMultiConfig/CompileCommands-check.cmake   | 28 ++++++++++++++++++++++
 .../NinjaMultiConfig/CompileCommands.cmake         |  3 +++
 Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake |  5 ++++
 4 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 Tests/RunCMake/NinjaMultiConfig/CompileCommands-check.cmake
 create mode 100644 Tests/RunCMake/NinjaMultiConfig/CompileCommands.cmake

diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 86ae45d..a4080d8 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -1343,9 +1343,11 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
     }
   }
 
-  this->ExportObjectCompileCommand(
-    language, sourceFilePath, objectDir, objectFileName, objectFileDir,
-    vars["FLAGS"], vars["DEFINES"], vars["INCLUDES"], config);
+  if (firstForConfig) {
+    this->ExportObjectCompileCommand(
+      language, sourceFilePath, objectDir, objectFileName, objectFileDir,
+      vars["FLAGS"], vars["DEFINES"], vars["INCLUDES"], config);
+  }
 
   objBuild.Outputs.push_back(objectFileName);
   if (firstForConfig) {
diff --git a/Tests/RunCMake/NinjaMultiConfig/CompileCommands-check.cmake b/Tests/RunCMake/NinjaMultiConfig/CompileCommands-check.cmake
new file mode 100644
index 0000000..a1ae6ac
--- /dev/null
+++ b/Tests/RunCMake/NinjaMultiConfig/CompileCommands-check.cmake
@@ -0,0 +1,28 @@
+set(expected_compile_commands
+[==[^\[
+{
+  "directory": "[^
+]*(/Tests/RunCMake/NinjaMultiConfig/CompileCommands-build|\\\\Tests\\\\RunCMake\\\\NinjaMultiConfig\\\\CompileCommands-build)",
+  "command": "[^
+]*Debug[^
+]*",
+  "file": "[^
+]*(/Tests/RunCMake/NinjaMultiConfig/main\.c|\\\\Tests\\\\RunCMake\\\\NinjaMultiConfig\\\\main\.c)"
+},
+{
+  "directory": "[^
+]*(/Tests/RunCMake/NinjaMultiConfig/CompileCommands-build|\\\\Tests\\\\RunCMake\\\\NinjaMultiConfig\\\\CompileCommands-build)",
+  "command": "[^
+]*Release[^
+]*",
+  "file": "[^
+]*(/Tests/RunCMake/NinjaMultiConfig/main\.c|\\\\Tests\\\\RunCMake\\\\NinjaMultiConfig\\\\main\.c)"
+}
+]$]==])
+
+file(READ "${RunCMake_TEST_BINARY_DIR}/compile_commands.json" actual_compile_commands)
+if(NOT actual_compile_commands MATCHES "${expected_compile_commands}")
+  string(REPLACE "\n" "\n  " expected_compile_commands_formatted "${expected_compile_commands}")
+  string(REPLACE "\n" "\n  " actual_compile_commands_formatted "${actual_compile_commands}")
+  string(APPEND RunCMake_TEST_FAILED "Expected compile_commands.json to match:\n  ${expected_compile_commands_formatted}\nActual compile_commands.json:\n  ${actual_compile_commands_formatted}\n")
+endif()
diff --git a/Tests/RunCMake/NinjaMultiConfig/CompileCommands.cmake b/Tests/RunCMake/NinjaMultiConfig/CompileCommands.cmake
new file mode 100644
index 0000000..fc44d5a
--- /dev/null
+++ b/Tests/RunCMake/NinjaMultiConfig/CompileCommands.cmake
@@ -0,0 +1,3 @@
+enable_language(C)
+
+add_executable(exe main.c)
diff --git a/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake b/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
index 738bc6c..c040e8f 100644
--- a/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
+++ b/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
@@ -453,6 +453,11 @@ run_cmake_command(NoUnusedVariables ${CMAKE_COMMAND} ${CMAKE_CURRENT_LIST_DIR}
   "-DCMAKE_DEFAULT_BUILD_TYPE=Debug"
   "-DCMAKE_DEFAULT_CONFIGS=all"
   )
+unset(RunCMake_TEST_BINARY_DIR)
+
+set(RunCMake_TEST_OPTIONS "-DCMAKE_CONFIGURATION_TYPES=Debug\\;Release;-DCMAKE_CROSS_CONFIGS=all;-DCMAKE_EXPORT_COMPILE_COMMANDS=ON")
+run_cmake(CompileCommands)
+unset(RunCMake_TEST_OPTIONS)
 
 # CudaSimple uses separable compilation, which is currently only supported on NVCC.
 if(CMake_TEST_CUDA)
-- 
cgit v0.12