使用并行生成时PRE_TARGETDEPS失败

PRE_TARGETDEPS fails when using parallel builds

本文关键字：PRE TARGETDEPS 失败并行更新时间：2023-10-16

我正在使用自定义资源管理(代替qrc(，我正在尝试将其集成到QtCreaor中。

我有一个 Python 脚本，可以生成要编译的源文件。我使用QMAKE_EXTRA_TARGETS/PRE_TARGETDEPS告诉QMake必须在编译文件之前执行此脚本。所以我在我的专业文件中这样做：

CONFIG += ordered
generated_file.target   = my_custom_target
generated_file.commands = echo "Generating..." && d:/dev/vobs_ext_2015/tools_ext/python/Python34_light/python.exe $$PWD/pyc_res_generator.py -o $$PWD/generated/generated.cpp && echo "Generated!"
generated_file.depends  = FORCE
QMAKE_EXTRA_TARGETS            += generated_file
PRE_TARGETDEPS                 += my_custom_target
SOURCES                        += generated/generated.cpp
#DEPENDPATH = ./generated

pyc_res_generator.py只是：

#! /usr/bin/env python
# -*- coding: utf8 *-*
import argparse
parser = argparse.ArgumentParser(description="", formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument("-o", type=str, help="Output file name")
args = parser.parse_args()
with open(args.o, 'w') as output_file:
output_file.write( "// This is valid C++!" )

为了测试这一点，我在 generated .cpp 中编写了一些无效的C++(如fjkfkfk(。当我编译(目标是Android(时，我在日志中看到：

echo Generating... && python.exe pyc_res_generator.py -o generated/generated.cpp && echo Generated!
Generating... 
B:Androidandroid-ndk-r11b/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-g++ -c -Wno-psabi -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -ffunction-sections -funwind-tables -fstack-protector -fno-short-enums -DANDROID -Wa,--noexecstack -fno-builtin-memmove -std=c++11 -g -g -marm -O0 -fno-omit-frame-pointer -Wall -Wno-psabi -W -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I..TestQt -I. -IB:QtCreator5_6_15.6android_armv7include -IB:QtCreator5_6_15.6android_armv7includeQtWidgets -IB:QtCreator5_6_15.6android_armv7includeQtGui -IB:QtCreator5_6_15.6android_armv7includeQtCore -I. -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9include -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9libsarmeabi-v7ainclude -isystem B:Androidandroid-ndk-r11bplatformsandroid-9arch-armusrinclude -IB:QtCreator5_6_15.6android_armv7mkspecsandroid-g++ -o main.obj ..TestQtmain.cpp
B:Androidandroid-ndk-r11b/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-g++ -c -Wno-psabi -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -ffunction-sections -funwind-tables -fstack-protector -fno-short-enums -DANDROID -Wa,--noexecstack -fno-builtin-memmove -std=c++11 -g -g -marm -O0 -fno-omit-frame-pointer -Wall -Wno-psabi -W -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I..TestQt -I. -IB:QtCreator5_6_15.6android_armv7include -IB:QtCreator5_6_15.6android_armv7includeQtWidgets -IB:QtCreator5_6_15.6android_armv7includeQtGui -IB:QtCreator5_6_15.6android_armv7includeQtCore -I. -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9include -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9libsarmeabi-v7ainclude -isystem B:Androidandroid-ndk-r11bplatformsandroid-9arch-armusrinclude -IB:QtCreator5_6_15.6android_armv7mkspecsandroid-g++ -o dialog.obj ..TestQtdialog.cpp
B:Androidandroid-ndk-r11b/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-g++ -c -Wno-psabi -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -ffunction-sections -funwind-tables -fstack-protector -fno-short-enums -DANDROID -Wa,--noexecstack -fno-builtin-memmove -std=c++11 -g -g -marm -O0 -fno-omit-frame-pointer -Wall -Wno-psabi -W -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I..TestQt -I. -IB:QtCreator5_6_15.6android_armv7include -IB:QtCreator5_6_15.6android_armv7includeQtWidgets -IB:QtCreator5_6_15.6android_armv7includeQtGui -IB:QtCreator5_6_15.6android_armv7includeQtCore -I. -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9include -isystem B:Androidandroid-ndk-r11bsourcescxx-stlgnu-libstdc++4.9libsarmeabi-v7ainclude -isystem B:Androidandroid-ndk-r11bplatformsandroid-9arch-armusrinclude -IB:QtCreator5_6_15.6android_armv7mkspecsandroid-g++ -o generated.obj ..TestQtgeneratedgenerated.cpp
B:QtCreator5_6_15.6android_armv7binmoc.exe -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -IB:/QtCreator5_6_1/5.6/android_armv7/mkspecs/android-g++ -IC:/Users/jp225611/Documents/TestQt -IB:/QtCreator5_6_1/5.6/android_armv7/include -IB:/QtCreator5_6_1/5.6/android_armv7/include/QtWidgets -IB:/QtCreator5_6_1/5.6/android_armv7/include/QtGui -IB:/QtCreator5_6_1/5.6/android_armv7/include/QtCore -I. -IB:Androidandroid-ndk-r11b/sources/cxx-stl/gnu-libstdc++/4.9/include -IB:Androidandroid-ndk-r11b/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi-v7a/include -IB:Androidandroid-ndk-r11b/platforms/android-9/arch-arm//usr/include ..TestQtdialog.h -o moc_dialog.cpp
..TestQtgeneratedgenerated.cpp:1:1: error: 'fjkfkfk' does not name a type
// This is valid C++!
^
makefile:670: recipe for target 'generated.obj' failed
mingw32-make: *** [generated.obj] Error 1
mingw32-make: *** Waiting for unfinished jobs....
Generated!
13:59:08: Le processus "B:QtCreator5_6_1Toolsmingw492_32binmingw32-make.exe" s'est terminé avec le code 2.
Erreur lors de la compilation/déploiement du projet TestQt (kit : android_armeabi-v7a)
When executing step "Make"
13:59:08: Temps écoulé : 00:03.

而且我看到generatedgenerated.cpp是由pyc_res_generator.py正确生成的(它现在包含// This is valid C++!(......但显然太晚了，因为编译器看到了fjkfkfk...... 如您所见，输出报告：

Generating...
B:Androidandroid-ndk-r11b/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-g++ .... ..TestQtgeneratedgenerated.cpp
Generated...

虽然人们会期望：

Generating...
Generated...
B:Androidandroid-ndk-r11b/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-g++ .... ..TestQtgeneratedgenerated.cpp

这仅在启用并行构建时发生(我将环境变量设置为MAKEFLAGS-j8"(

看起来我的自定义命令generated_file是在编译generatedgenerated.cpp之前启动的，但是系统不会等到它结束才实际编译generatedgenerated.cpp。

我做错了什么吗？

PRE_TARGETDEPS(自定义目标(在这里不是好方法，因为generated_file.target必须与Makefile目标名称完全匹配，该名称可能因不同的选项而异：

是否启用了影子构建
主机平台(使用斜杠或反斜杠作为文件夹分隔符(
可能是目标编译器/平台

但是，自定义编译器显然效果更好。这就是移动文件的方式。自定义编译器可以生成要编译的新文件(然后系统在编译文件之前等待文件生成，即使在执行并行构建时也是如此(。

# Set fuiles to be generated in a variable
TO_GENERATE = $$PWD/generated/generated.cpp
# Specify custom command output file:
custom_generator.output  = $$PWD/generated/generated.cpp
# Specify custom command:
custom_generator.commands = 'echo "Generating..." && python $$PWD/pyc_res_generator.py -o $$PWD/generated/generated.cpp && echo "Generated..."'
# dependency:
custom_generator.depends = FORCE
# link to input file variable
custom_generator.input = TO_GENERATE
# link to variable to store generated file to
custom_generator.variable_out = SOURCES
# add to qmake:
QMAKE_EXTRA_COMPILERS += custom_generator

然后，您甚至不需要指定SOURCES += $$PWD/generated/generated.cpp.而且，$$PWD/generated/generated.cpp在清理后被删除！

这完全符合预期！

您需要将目标的名称设置为它生成的文件的名称。这是一个对我有用的完整项目文件(qmake 3.1，Qt 5.10.1(：

# Filename relative to the *build* directory.
generated_file.target   = generated/generated.cpp
generated_file.commands = 'echo "Generating..." && mkdir -p generated && echo "int main() {}" > generated/generated.cpp'
generated_file.depends  = FORCE
QMAKE_EXTRA_TARGETS     += generated_file
# Filename relative to the *source* directory.
SOURCES                 += $$OUT_PWD/generated/generated.cpp

原因是generated_file.target成为Makefile中目标的名称，因此当需要generated.cpp时，将执行您的自定义规则来创建文件。

您也可以将其从PRE_TARGETDEPS中删除，因为您已经将生成的文件添加到SOURCES instead中，从而创建了正确的依赖项。

请注意，此方法在构建目录中生成文件，而不是在源目录中生成文件。这就是为什么在将其添加到SOURCES时需要指定$$OUT_PWD：默认情况下，qmake似乎假定SOURCES相对于源目录。

如果你想在源目录中生成它，你可能会认为你只是在任何地方都$$PWD前缀，但是 qmake 有时使用绝对路径，有时使用相对路径，一切都失败了。您可能可以使用$$absolute_path($$PWD)解决此问题，但我还没有尝试过。

生成的Makefile中的相关部分(评论是我的(：

# How to create generated/generated.cpp.
# Depending on FORCE to make it always stale (fails if you create a file named FORCE :)).
generated/generated.cpp: FORCE
echo "Generating..." && mkdir -p generated && echo "int main() {}" > generated/generated.cpp
# generated.o depends on generated/generated.cpp.
# Note that it's not in the same directory; we don't care.
generated.o: generated/generated.cpp 
$(CXX) -c $(CXXFLAGS) $(INCPATH) -o generated.o generated/generated.cpp
# The final executable depends on the compiled generated.o.
OBJECTS = generated.o
$(TARGET):  $(OBJECTS)  
$(LINK) $(LFLAGS) -o $(TARGET) $(OBJECTS) $(OBJCOMP) $(LIBS)

qmake 文档对此非常模糊，只说明target应该是"自定义构建目标的名称"。但是，该示例显示他们将其设置为输出文件的名称。(作为奖励，它还显示了如何在commands中不重复该名称。

另一种选择依赖于 TEMPLATE=subdirs，以遵循 libname.depends 在并行构建环境中。每个应用程序文件夹中需要两个 .pro 文件。还有一个在共享库文件夹中。开发区域中使用 TEMPLATE=subdirs 的任何其他文件夹都需要兼容。

例如，使用LibLarry的TestApp。

文件夹测试应用有 bld.pro 和 TestApp.pro。

TestApp.pro：

#This is a TEMPLATE=subdirs, which gmake will interpret;  
# making sure the build dependencies are respected
TEMPLATE = subdirs
SUBDIRS += bld  mylib
bld.file = bld.pro
bld.depends = mylib # force library to be built first.
mylib.file = $${PATH_TO_LIB_LARRY}/liblarry.pro

bld.pro：

TARGET=TestApp
SOURCES+=TestApp.cpp
PRE_TARGETDEPS+=$${PATH_TO_LIB_LARRY}/liblarry.a
#boilerplate...
QT -= gui
CONFIG = ...
include ($${PATH_TO_LIB_LARRY}/liblarry.pri) # contains include file info
CONFIG += link_prl # allow lib larry to specify its position in the linker input command.

文件夹 LibLarry 有 LibLarry.pro 含

LibLarry.pro：

TARGET=larry
TEMPLATE=lib
CONFIG+=staticlib 
CONFIG+=create_prl # export information, so apps can link correctly
SOURCES+=my_shared_function.cpp
include (liblarry.pri)

liblarry.pri：

HEADERS += $$PWD/my_shared_function.h
INCLUDEPATH += $$PWD