cmake: Fix dependency loops in custom targets (fixes #6632)

mesonbuild/cmake/interpreter.py

@@ -26,6 +26,7 @@ from ..mesonlib import MachineChoice, version_compare
 from ..compilers.compilers import lang_suffixes, header_suffixes, obj_suffixes, lib_suffixes, is_header
 from enum import Enum
 from functools import lru_cache
+from pathlib import Path
 import typing as T
 import os, re
 
@@ -659,23 +660,35 @@ class ConverterCustomTarget:
             self.outputs = [self.name + '.h']
 
         # Check dependencies and input files
+        root = Path(root_src_dir)
         for i in self.depends_raw:
             if not i:
                 continue
+            raw = Path(i)
             art = output_target_map.artifact(i)
             tgt = output_target_map.target(i)
             gen = output_target_map.generated(i)
 
-            if art:
+            rel_to_root = None
+            try:
+                rel_to_root = raw.relative_to(root)
+            except ValueError:
+                rel_to_root = None
+
+            # First check for existing files. Only then check for existing
+            # targets, etc. This reduces the chance of misdetecting input files
+            # as outputs from other targets.
+            # See https://github.com/mesonbuild/meson/issues/6632
+            if not raw.is_absolute() and (root / raw).exists():
+                self.inputs += [raw.as_posix()]
+            elif raw.is_absolute() and raw.exists() and rel_to_root is not None:
+                self.inputs += [rel_to_root.as_posix()]
+            elif art:
                 self.depends += [art]
             elif tgt:
                 self.depends += [tgt]
             elif gen:
                 self.inputs += [gen.get_ref(i)]
-            elif not os.path.isabs(i) and os.path.exists(os.path.join(root_src_dir, i)):
-                self.inputs += [i]
-            elif os.path.isabs(i) and os.path.exists(i) and os.path.commonpath([i, root_src_dir]) == root_src_dir:
-                self.inputs += [os.path.relpath(i, root_src_dir)]
 
     def process_inter_target_dependencies(self):
         # Move the dependencies from all transfer_dependencies_from to the target

test cases/cmake/8 custom command/subprojects/cmMod/CMakeLists.txt

@@ -89,7 +89,27 @@ add_custom_command(
   WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/s2_a_cpp"
 )
 
-add_library(cmModLib SHARED cmMod.cpp genTest.cpp cpyBase.cpp cpyBase.hpp cpyNext.cpp cpyNext.hpp)
+# cpyTest (copy file without renaming)
+add_custom_command(
+  OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/cpyTest.hpp"
+  COMMAND mycpy "${CMAKE_CURRENT_SOURCE_DIR}/cpyTest/cpyTest.hpp" "${CMAKE_CURRENT_BINARY_DIR}/cpyTest.hpp"
+  DEPENDS "cpyTest/cpyTest.hpp"
+)
+
+add_custom_command(
+  OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/cpyTest2.hpp"
+  COMMAND mycpy "${CMAKE_CURRENT_SOURCE_DIR}/cpyTest/cpyTest2.hpp" "${CMAKE_CURRENT_BINARY_DIR}/cpyTest2.hpp"
+  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/cpyTest/cpyTest2.hpp"
+)
+
+add_custom_command(
+  OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/cpyTest3.hpp"
+  COMMAND mycpy cpyTest3.hpp "${CMAKE_CURRENT_BINARY_DIR}/cpyTest3.hpp"
+  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/cpyTest/cpyTest3.hpp"
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/cpyTest"
+)
+
+add_library(cmModLib SHARED cmMod.cpp genTest.cpp cpyBase.cpp cpyBase.hpp cpyNext.cpp cpyNext.hpp cpyTest.cpp cpyTest.hpp cpyTest2.hpp cpyTest3.hpp)
 include(GenerateExportHeader)
 generate_export_header(cmModLib)
 
@@ -99,7 +119,7 @@ set(ARGS_TEST ${ARGS_TEST} arg2)
 add_executable(macro_name macro_name.cpp)
 add_executable(args_test args_test.cpp)
 add_custom_target(args_test_cmd
-  COMMAND args_test ARGS ${ARGS_TEST}
+  COMMAND args_test ${ARGS_TEST}
 )
 add_custom_target(macro_name_cmd COMMAND macro_name)
 

test cases/cmake/8 custom command/subprojects/cmMod/cmMod.cpp

@@ -2,6 +2,7 @@
 #include "genTest.hpp"
 #include "cpyBase.hpp"
 #include "cpyNext.hpp"
+#include "cpyTest.hpp"
 #include "cmModLib.hpp"
 
 #ifndef FOO
@@ -19,5 +20,5 @@ string cmModClass::getStr() const {
 }
 
 string cmModClass::getOther() const {
-  return "Srings:\n - " + getStrCpy() + "\n - " + getStrNext();
+  return "Srings:\n - " + getStrCpy() + "\n - " + getStrNext() + "\n - " + getStrCpyTest();
 }

test cases/cmake/8 custom command/subprojects/cmMod/cpyTest.cpp

@@ -0,0 +1,7 @@
+#include "cpyTest.hpp"
+#include "cpyTest2.hpp"
+#include "cpyTest3.hpp"
+
+std::string getStrCpyTest() {
+  return CPY_TEST_STR_2 CPY_TEST_STR_3;
+}

test cases/cmake/8 custom command/subprojects/cmMod/cpyTest/cpyTest.hpp

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <string>
+
+std::string getStrCpyTest();

test cases/cmake/8 custom command/subprojects/cmMod/cpyTest/cpyTest2.hpp

@@ -0,0 +1,3 @@
+#pragma once
+
+#define CPY_TEST_STR_2 "Hello "

test cases/cmake/8 custom command/subprojects/cmMod/cpyTest/cpyTest3.hpp

@@ -0,0 +1,3 @@
+#pragma once
+
+#define CPY_TEST_STR_3 "CopyFile"