Ninja: Fix regression with a large number of subdirectories
Since commit f50fb77a4f (Ninja: Regenerate when test or install scripts
are missing, 2024-10-29, v4.0.0-rc1~516^2) the list of paths we pass to
`ninja -t restat` scales with the number of project subdirectories.
Run it in blocks to avoid "command line too long" errors, particularly
on Windows.
Fixes: #26738
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index ce96c26..fe07b92 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -7,11 +7,11 @@
#include <cctype>
#include <cstdio>
#include <functional>
+#include <iterator>
#include <sstream>
#include <type_traits>
#include <utility>
-#include <cm/iterator>
#include <cm/memory>
#include <cm/optional>
#include <cm/string_view>
@@ -663,6 +663,7 @@
void cmGlobalNinjaGenerator::CleanMetaData()
{
+ constexpr size_t ninja_tool_arg_size = 8; // 2 `-_` flags and 4 separators
auto run_ninja_tool = [this](std::vector<char const*> const& args) {
std::vector<std::string> command;
command.push_back(this->NinjaCommand);
@@ -705,19 +706,27 @@
run_ninja_tool({ "recompact" });
}
if (this->NinjaSupportsRestatTool && this->OutputPathPrefix.empty()) {
- // XXX(ninja): We only list `build.ninja` entry files here because CMake
- // *always* rewrites these files on a reconfigure. If CMake ever gets
- // smarter about this, all CMake-time created/edited files listed as
- // outputs for the reconfigure build statement will need to be listed here.
cmNinjaDeps outputs;
this->AddRebuildManifestOutputs(outputs);
- std::vector<char const*> args;
- args.reserve(outputs.size() + 1);
- args.push_back("restat");
- for (auto const& output : outputs) {
- args.push_back(output.c_str());
+ auto output_it = outputs.begin();
+ size_t static_arg_size = ninja_tool_arg_size + this->NinjaCommand.size() +
+ this->GetCMakeInstance()->GetHomeOutputDirectory().size();
+ // The Windows command-line length limit is 32768. Leave plenty.
+ constexpr size_t maximum_arg_size = 30000;
+ while (output_it != outputs.end()) {
+ size_t total_arg_size = static_arg_size;
+ std::vector<char const*> args;
+ args.reserve(std::distance(output_it, outputs.end()) + 1);
+ args.push_back("restat");
+ total_arg_size += 7; // restat + 1
+ while (output_it != outputs.end() &&
+ total_arg_size + output_it->size() + 1 < maximum_arg_size) {
+ args.push_back(output_it->c_str());
+ total_arg_size += output_it->size() + 1;
+ ++output_it;
+ }
+ run_ninja_tool(args);
}
- run_ninja_tool(args);
}
}
diff --git a/Tests/RunCMake/Configure/RerunCMakeNinja.cmake b/Tests/RunCMake/Configure/RerunCMakeNinja.cmake
index da0131f..35e11d4 100644
--- a/Tests/RunCMake/Configure/RerunCMakeNinja.cmake
+++ b/Tests/RunCMake/Configure/RerunCMakeNinja.cmake
@@ -2,3 +2,15 @@
set(stamp ${CMAKE_CURRENT_BINARY_DIR}/stamp.txt)
file(READ ${input} content)
file(WRITE ${stamp} "${content}")
+
+# Add enough subdirectories to make the total list of paths to 'cmake_install.cmake'
+# files exceed the Windows command-line length limit.
+set(length 0)
+foreach(i RANGE 1 1000)
+ if(length GREATER_EQUAL 32678)
+ break()
+ endif()
+ add_subdirectory(RerunCMakeNinja RerunCMakeNinja${i})
+ string(LENGTH "${CMAKE_CURRENT_BINARY_DIR}/RerunCMakeNinja${i}/cmake_install.cmake" subdir_length)
+ math(EXPR length "${length} + ${subdir_length}")
+endforeach()
diff --git a/Tests/RunCMake/Configure/RerunCMakeNinja/CMakeLists.txt b/Tests/RunCMake/Configure/RerunCMakeNinja/CMakeLists.txt
new file mode 100644
index 0000000..d77c363
--- /dev/null
+++ b/Tests/RunCMake/Configure/RerunCMakeNinja/CMakeLists.txt
@@ -0,0 +1 @@
+# Empty subdirectory, but it has a 'cmake_install.cmake'.
