In a fresh VCL application Compile and Build operation produce the same binary and map file (with minor differences at the end of .exe file even if "include version information in project" option is switched off - already discussed). Map file is the same byte to byte. But wen I add any third-party component the binary and map(!) file produced by Build and Compile are significantly different!
Tested on two versions of Delphi:
- Version 7.0 (Build 8.1)
- CodeGear™ RAD Studio 2007 Version 11.0.2902.10471 (+December 2007 Update)
Step to reproduce:
Create New VCL Application. Possibly add any native Delphi component (I try all components from Standart, Additional, Win32 and System tab).
Turn on Detailed Map file on Linker tab of the Project Options.
Build project.
Rename output .exe and .map file (for example: project1.exe to project1b.exe and project1.map to project1b.map).
Compile project.
Rename output .exe and .map file (for example: project1.exe to project1c.exe and project1.map to project1c.map).
Compare files from step 4 and 6. (I use WinMerge
2.12.4.0).
We have little different .exe files and fully identical .map files. Then if we repeat all steps again but use in the project third-party component (I try ODAC, DOA, DevExpress and selfmade) we get more different .exe and different .map files.
Why? Any suggestions?
UPDATE
Some information about how I found this and why it's interests me:
Project is build from simple script with MSBuild. When in the project was added translation thru ITE (dll with resources) I found that when project was Build (from script or from IDE) - translated version work wrong - some text on button, labels etc. got from wrong place (literally from another button, labels). When project Compiled from IDE - everything is ok. So I start compare Build and Compile output...
What you're seeing is simply an artifact of the built-in make logic of the compiler. When you do a build, it tells the compiler to build all available sources. So Delphi processes each source file and for each unit in the uses lists for which it finds source, it will then build that file. It does this recursively. When you do a compile, only the existing .dcu files are loaded and if they're found to be up-to-date, nothing is done. This can actually lead to a different order in which the units are discovered since each .dcu will effectively "flatten" the uses list. Since the units are discovered and loaded in a different order, they are in-turn, linked in a different order. This is why your map files look so different. Given the same sources, the map file should be the same if you do two builds in a row or two compiles in a row.
Other causes for differences are more mundane and include things like the PE header time stamp, and other bits of padding and alignments.
There is two parts to this answer I believe.
Part of the problem your seeing, IIRC, is that the compiler doesn't zero out memory before doing a compile/build. Thus anything left in uninitialized memory becomes filler in the output for alignment purposes.
I also seem to recall that there is a date time stamp included in the pe header information for the application. that will cause a difference every time.
I'm not the best person to confirm this but this is what I seem to recall from past discussions.
People like Allen Bauer or Barry Kelly would probably be able to give better/more accurate information on this.
If you use compiler defines in your project and just changed those, if you do a compile, you won't see any changes to the dcu's and the resulting module (exe or dll). If you do a full rebuild the compiler defines are used in the newly created dcu's and modules.
I have seen this in a large project group where we use modules in different projects with different defines and all dcu's are stored in the same directory.
Ergo: The compiler does not enforce the dependancies on the defines in this case.
Perhaps you did see the same issue.
Related
Compiling some old code, my application will no longer run. Newly compiled exe-file won't start "because qtintf70.dll is missing from your computer".
Strange thing: an older exe file compiled from exact same code runs just fine. Both exe files tested on same system, but compiled on different Delphi installations (both Delphi 7 running on VirtualBox).
Googling, someone suggested "You have pulled in Clx somehow. Clx apps require the QT library. Look for units in your uses clauses that start with Q." but again: this is the exact same code. I've checked and can't find anything.
Suggestions?
In D7, the only source code units which reference qtintf70.dll are QForms.Pas and Qt.Pas.
So, what you need to do is to
Move all instances of these two files and their corresponding .DCU files to somewhere not on your project's search paths. Use a utility like SwiftSearch to make sure you find all of them.
Do a full build of the project.
The build should grind to a halt somewhere with a complaint that the compiler can't find one or other of these units. The source unit that is being compiled at the time is the one which contains a reference to one or other of them.
When I open my project and I double click on a specific pas file in the Project Manager, bds.exe freezes and continues using 25% of the cpu. I have to kill the process through the Windows Task Manager. (1)
When I open my project and I press F12 on that exact same file, I see what I would have expected to see earlier, the contents of the pas file.
When I open my project and I compile it first, then double click on the file, everything is fine.
I'm trying to figure out how, what I assume to be a mismatched DCU file, snuck into my project and what the best way is to prevent a similar issue in the future. Can I force all DCU files to be rebuilt? Can I simply delete all dcu files and recompile or is that a dangerous thing to do? My DCU files are currently also stored in the same directory where I keep the pas and dfm files, that is a bit messy.
(1) our application also shows behaviour in production where it sometimes crashes while it continues to use a steady cpu usage or simply continues to work as expected but shows a steady cpu usage in the background. We have been unable to trigger it in a compiled version but see it popping up from time to time. We assume the dcu mismatch is at the source of this problem.
There are numerous issues in your question, some entirely unrelated, but the assumption that the problem is a "mismatched" DCU is unlikely to be correct (by which I presume you mean an "old" or otherwise incorrect DCU compiled in the past or with different source).
First your problems.
IDE Behaviour
The problem with the IDE locking up when double-clicking a unit in the Project Manager is unlikely to be anything to do with a "mismatched" DCU.
Do you have source files located on a network drive ? Is this unit such a file ? Is that network location available/valid ? i.e. is the path to the file using a network drive letter that is no longer mapped or otherwise not available ?
If there is no explicit path in the unit reference in the DPR, do you have network locations listed in your system, IDE or project PATH ?
Difficulty accessing file locations is the most likely explanation for the IDE appearing to lock up when trying to simply open a file.
As to why it should behave differently when using F12 rather than the Project Manager, unfortunately the Delphi IDE is notorious for using different mechanisms to achieve the same thing in different places so it isn't surprising that sometimes when one of these mechanisms breaks the others still work (and can give different results even when both work).
Runtime Behaviour of your App
If we work on the basis that you do indeed have a "mismatched" DCU then performing a full build of your project will resolve that mismatch, as long as you have the source for all the required DCU's and that the correct and appropriate source for each DCU is available.
However, even though the mismatch may be resolved, rebuilding may or may not fix the issue, depending on whether that issue remains in the source code for that unit itself when recompiled.
The simple fact of the DCU being "mismatched" cannot cause aberrant application behaviour. With the exception of OS or RTL bugs etc, if there are errors in the behaviour of an application then those errors will be the result of errors in the source code as compiled.
Simply recompiling source code containing an error will not remove that error.
As such, if there is such an error then far more information will be needed if anyone is to be able to give any assistance on that score (and this should be a separate question, once you have done some initial debugging and diagnostics yourself).
Runtime Packages
If you are using runtime packages then things get more complicated because with a runtime package, the DCU employed for any particular unit could be part of a package file. In that case, the DCU file on disk is produced when you compile the package itself but any project that uses that package will not use the DCU on disk but will instead use the version that has been compiled into the package.
So if you are using runtime packages then as well as rebuilding your project you need to also rebuild any and all runtime packages that may have changed.
Now, for your actual questions.
Q1: Can I Rebuild all The DCU's ?
Yes, of course. But see above w.r.t Runtime Packages, if your project uses them.
I would strongly recommend that you change your project settings to output DCU files to a specific location, separate from the source files.
For example, you could have a project specific DCU folder using a relative path. i.e. set your DCU output folder to something like ".\dcu" and create a dcu folder within the folder where your DPR is located.
For Delphi versions supporting multiple platforms and configurations it is best to include the environment variables for the platform and configuration in that path, so that you don't end up using units compiled for DEBUG in a RELEASE build.
e.g.
.\dcu\$(Platform)\$(Config)
or
.\$(Platform)\$(Config)\dcu
What Is Compiled in a Build ?
When you do a Build on a project (as distinct from a "Compile"), all units referenced by that project will be recompiled, with the exception of any VCL/RTL units (i.e. those provided with Delphi). Those get special treatment.
At a minimum, rebuilding a project will forcibly recompile all units explicitly listed in the DPR, but will also recompile all other units that are used by those units (or units that they use etc etc).
NOTE: DCU's With Missing Source
A unit will only be recompiled if the source can be located.
If you have a DCU and the source file is missing or cannot be located on the project, IDE or system path, then the compiler will simply assume that you want to use the existing DCU.
This is the case even with a full "Build".
3rd Party DCU's
It may seem obvious but you should also be careful that you don't delete DCU's that may be your only copy of any 3rd party libraries you may be using for which you do not have the source.
This is highly inadvisable, but I guess we mustn't rule out the possibility that you may be in this situation.
Q2: Should I Delete all the DCU's ?
In general, yes. As noted above, even a full build will be successful if you are missing the source code for a unit that is referenced, as long as there is a DCU (or required package, if using runtime packages) that can be found.
So the only way to be sure that you have the current source for all DCU's is to first delete the DCU's that any previous builds may have used.
This is of course much easier when you have a specific, explicit location in which all your project DCU's are output.
It's slightly more involved if you are using Runtime Packages, though if you are organising your DCU's sensibly then the only real complication is that you need to repeat the same exercise for all the projects involved, working through starting each of the runtime packages that are used and finishing with the projects that in turn use them.
Yes, you can rebuild all DCU files in your project;
In the project group window, right click on the project and select Build.
It is OK to delete all DCUs in your project, but not necessary (or desirable in case you make a mistake...).
Note that this only builds DCUs explicitly in you project (as shown in your project tree) not any implicit ones imported as a result of your uses clauses.
Three things may be going on that have not been adressed in other answers.
Note that I only have experience with Delphi XE2 and Seattle 10, but they may apply to your version.
Delphi can be slow when switching from form to source view, especially if you have many components on your form. In migrating from XE2 to 10, we noticed an improvement here. We are talking seconds here, this does not seem to be your issue.
Delphi can be notoriously slow when switching between projects. After a switch the IDE can take a very long time (20-30 seconds) to respond. You cannot type anything; code completion takes a long time; initiating a project search with Alt-S-D waits a long time, then fails. In migrating from XE2 to 10, we noticed a large deterioration here.
Conditional compilation. If you have IFDEFs in your code compiling stuff for one project but not for another, your IDE can hang completely, and there's nothing else you can do then killing BDS.EXE. This happens in Delphi Seattle 10 if you switch projects and accidentally Compile instead of Build.
You may experience variations of these.
For over a decade, I have been stuck (lovingly) on Delphi 6 and have developed hundred of thousands of lines of code in a logical (to me) unit structure, where a project tends to be a few hundred lines of code referencing high-level work routines in my "library". In trying to migrate to XE5, I just can't find a way to have all my library units compiled in one place on the search path, and then just used by the project (and recompiled if necessary), but that the dcus are off with the library source rather than in with each individual project.
I'm just starting to accept that "hello world" takes 2.5Mb in XE5, and I can't stand the idea that each library unit has to be separately compiled into dcus at the project level. In the "old" days, these unit dcus would sit next to the pas files and not be recompiled if nothing changed in the source file.
The obvious place to look is the Project options, but I can't find the right setting to make the project stop keeping copies of each dcu.
I am vaguely aware that multi-platform development will cause restructuring, but I can't help feeling that there is some compromise position.
There must be something big I am missing.
Starting in Delphi XE2, Delphi supports compilation for multiple platforms, as well as different build configurations. Because of this, Delphi needs to create DCU files for each combination. For example, Win32, Win64, and OS-X DCU files are saved in separate folders by default. Otherwise, if it weren't like this, the DCU files would overwrite each other, which you should avoid (if you use different configurations/platforms).
These settings can be changed in the Project Options in the very first section Delphi Compiler by modifying the Unit output directory. This is by default .\$(Platform)\$(Config) which creates a subfolder for the platform, then another subfolder for the config, for example \Win32\Debug\. Careful for the Target at the very top, which by default is set to your current platform/config. You would typically want to first change it to All Configurations. If you clear this field completely from the options, it will produce your default behavior from older versions.
It sounds like you should create a Package. This would allow you to group all your "library" units together in one place (BPL). This package can then be installed into your IDE, and if you have any components, those components can then be installed into your component pallet.
Or you can do without a package too. All the units from all these different projects should be moved to this central place though - a single folder containing all your "library" units. This way it's less maintenance, and you can just add that one folder to your global library path.
If you put your files in a central folder, and use those files from a project, the DCU files for both the project and this "library" will be saved for that project. Delphi doesn't know that these files are a "library", it just knows that you're using them, and since it can't find an already compiled version of those units, it creates one in your project. If you want the DCU files to be saved only once and in this central place, then you would need a package.
First, let me thank all the respondents to this question - all provided useful insight. I experimented with the various suggestions (including breaking XE5 so badly that I had to reinstall -- at least I learned some areas not to mess with.)
Important to me, but a known bad coding practice, is having individual projects edit shared library units (only my own units - I do not mess with code belonging to Delphi or 3-rd party). This is critical to having multiple applications working on the same data, but in bite-sized pieces. the shared code lets me make high-level pieces of an app available to other projects. There might be better ways (I would love to hear about them), but this has worked for me for a long time.
The multi-platform model really requires the dcu structure used by default, so I will adapt to it. Share the source code, but accept multiple compilations to individual projects. A good suggestion by JensG is just to clean up the dcus when the project is not actively being worked on. Should be straight-forward utility program.
The D6 -> XE5 migration (which will take months for some of the less used areas) requires me to know which units compile successfully, so I will maintain one project whose function is to include all units and recompile them all. This will make it practical to map library unit pas files to dcu files.
The AnsiString/AnsiChar <-> String/Char problem is the major migration problem area. Simply making edit-level changes may get the code past the compiler, but there is no guarantee that the code still works the same way. Especially troubling is at interface points to Windows calls and such. My answer will be to make the units compilable first, but then write test code for trouble areas. This is what will take the months - I need to get on with new stuff, as well as fixing the old. I REALLY don't know yet if I will be able to substitute the XE5 compatible code back into Delphi 6 without another layer of testing. I THINK it should work, but it will take careful checking.
A second major migration problem is 3rd party code such as VCLZip. XE5 has its own zip support, but I have a lot of places where I use VCLzip and the conversion will not be trivial. For this specific library, it may be possible to find XE5-level source and simply work it in. There are other pieces of code gotten from the internet that I used, but never needed to truly understand which will cause significant hassles.
Again - thank you to all. This has been an interesting 24 hours. Howard
I need to know if is there any option to compile a delphi project only if the source or any used unit, package etc has been changed.
If this is not possible, second alternative : Is there any option to generate exactly the same binary compiling two times the same project.
Thanks.
Edit: The usage is for a hash based WebUpdate.
A Delphi "compile" will compile only changed units. But as said, unit have data so the compiler can check which needs updating and which not. And the executable can change because the build process can rearrange the exe. Your web updates should not use a file hash, it should use version information to decide what to update and what not. That's the way installers check which files should be replaced.
Delphi compiles only changed units on a compile, and compiles all units regardless of change-status on a build.
Exe's are never the same, on a binary level. Just built a project twice, renamed the exe's to have a txt extension and compared them with Beyond Compare: it shows differences.
One (hard) solution: Make your exes using a Makefile! A makefile allows you to say "this exe is made from those files, using those commands". Make will only run "those commands" if at least one of the files you list as making up your exe is newer then your exe.
The hard part in this is setting up the list of files that make up your exe: You can easily get the list of files listed in the DPR/DPROJ, but you'll also need to identify all the linked resources ($R), all the included files ($INCLUDE), all the files that are implictelly compiled by Delphi because they're used in the "uses" clauses and are found on the Library Path.
Generating a Makefile for the general case is very difficult, but for one particular project it might work. For example you might consider your file dependent on only the files listed in the DPR files and then make sure you add all the relevant files to the DPR.
It's easy enough to find all your external dependencies. Just run the program and open up the Modules info window. But how can I find all my internal dependencies? I know the program keeps a list of all the units, because I've traced my way through the initialization code a time or two. But is there any easy way to access this list from the debugger?
The Delphi debugger can show you which units were compiled into a module (exe, dll or package). You can see this in the Modules view (View | Debug Windows | Modules). Click on a module in the upper left pane, and the lower left pane will show all the compilation units that were built into that module. If a particular compilation unit was made up of multiple source files (i.e a .pas and a .inc file), that will be shown too (when you expand the comp unit).
Alternatively, you can have the Delphi compiler show you a list of used .dcus by passing --depends when you compile a project. It will output a .d file with a list of the .dcus (and .dcps) that were required.
Another, but rather cumbersome way, is to generate a map file, it contains a list of all units used in a program.
see also this answer:
How can I find all the units in my Delphi app?
I use the GExperts Project Dependencies.
With the "Used By...", you can see units included but not used by anyone.
But you can't see unit included in uses clauses that could be removed when they don't have any code actually called.
Here's the help:
Project Dependencies
The project dependency expert enables you to see what units a particular unit uses, and in turn what units use a particular unit. When this expert is activated, it parses all of the current project's source code for uses clauses and builds up a list of dependencies. To view the dependency information for a particular unit, click on it in the left pane. The right pane will contain the dependency information. Indirect dependencies are units that are used by used units of a particular unit.
You can refresh the dependency information at any time by clicking the refresh button on the toolbar and you can sort the file listing by clicking on the column headers.
(source: gexperts.org)
OTOH, you can also use free Peganza's ICARUS as a more detailed reporting tool but less interactive...
Have you looked at Pascal Analyzer or the free limited version, Icarus, from Peganza Software? They will create "uses reports" telling you what module uses what others, so that should give you the info you're after.
Marc
GExperts has a Project Dependencies tool. I have used it before when trying to track down used units. You can't search in it but you can export the list to a CSV file and search there. This also only lists what is in the uses section. If you have a module included that is not being used it will still show up.
I know of at least two ways you could try to get a view of all the units used in your project
CTRL-SHIFT-B opens the object browser. If I'm not mistaken, here you can get a view of used units. I'm not entirely sure about this method and don't have Delphi available to verify it.
Use Modelmaker; Modelmaker can give you a tree like view of all your unit dependancies. Look at the Visualizing existing code section for more information.
The easiest way is to compile program and check which .dcu was created by compiler. Make sure to setup compiler to create .dcu in a separate directory, for example c:\dcu. I have created simple utility that searches .pas for every .dcu file in directories that are in a compiler search path (that can be read from .cfg, .dof or .bdsproject file).
You can use a MAP file in conjunction with MapFileStats, this will not just give you all your dependencies, but the amount of code (and resources) they contribute in the final executable.
Useful to spot units you have dependencies to, but use little of, as well as spotting "fat hog" units, which take everything plus the kitchen sink with them.
FWIW, reducing dependencies and eliminating hogs isn't just beneficial to executable size, it's also beneficial down the road when it'll be time to upgrade to a new version.
There is a (rather old) utility called UsgParse. It builds a treeview of all units referenced by a project.
I found a copy on the NexusDB site via
http://coding.derkeiler.com/Archive/Delphi/borland.public.delphi.thirdpartytools.general/2004-03/0231.html
source: http://www.nexusdb.com/downloads/USGParse/USGParse_src.zip
binary: http://www.nexusdb.com/downloads/USGParse/USGParse.zip