I downloaded the latest beta release of Saxon/C but I can't quite figure out how to use the compile stylesheet functionality. There's a function in the class XsltProcessor.h :-
void compile(const char* stylesheet);
that claims to compile a stylesheet but I can't see anything that would apply this compiled stylesheet to an actual source file.
The compile method allows you to supply the stylesheet as a string representation which is then compiled and cached internally for later use.
To execute the stylesheet call the method xslt->xsltApplyStylesheet("sample.xml", NULL) but supply NULL in the argument where you would pass the file name.
You could also supply the source document as a string using the methods parseXmlString and setSourceValue. In the xsltApplyStylesheet you pass NULL for the source file argument.
We will make the usability better in next release.
Have you tried the sample code here? It uses XsltProcessor.xsltApplyStylesheet(), which is documented here.
The sample code seems to have a typo in that it says test->xsltApplyStylesheet() when it means xslt->xsltApplyStylesheet().
I'm not sure what the compile() method does with its results, or how to use them.
Related
I want to get loopinfo in each function by iterating through functions in Module Pass. My code is as follows:
for (auto &F:M) {
if(!F.isDeclaration()){
LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>(F).getLoopInfo();
}
}
However, there is an error, I think my variable Settings should conform to the first function definition, how should I resolve.
clang-12: /llvmtest/llvm/lib/IR/LegacyPassManager.cpp:1645: virtual
std::tuple<llvm::Pass*, bool>
{anonymous}::MPPassManager::getOnTheFlyPass(llvm::Pass*,
llvm::AnalysisID, llvm::Function&): Assertion `FPP && “Unable to find
on the fly pass”’ failed. PLEASE submit a bug report to
https://bugs.llvm.org/ and include the crash backtrace, preprocessed
source, and associated run script.
You can not do this with the legacy pass manager. In the legacy pass manager, every pass could only get info from same-scoped passes -- module from module, function from function, loop from loop, plus one exception allowing function passes to get data from module passes.
With the new pass manager, you'd create a LoopAnalysisManager and add the analysis pass you want and run it. See https://llvm.org/docs/NewPassManager.html#using-analyses .
Note that most of LLVM is presently written to support both pass managers at once. If you do this, you'll need to write your pass differently from most of LLVM's passes, you can't use the types with names like "WrapperPass" that exist to support both legacy and new pass managers.
It seems trivial, but I've searched far and wide.
I'm using this resource to make v8 run with ES Modules and I'm trying to implement my own search/load algorithm. Thus far, I've managed to make a simple system which loads a file from a known location, however I'd like to implement external modules. This means that the known location is actually unknown throughout the application. Take the following directory tree as an example:
~/
- index.js
import 'module1_index'; // This is successfully resolved to /libs/module1/module1_index.js
/libs/module1/
- module1_index.js
export * from './lib.js' // This import fails because it is looking for ./lib.js in ~/source
- lib.js
export /* literally anything */
The above example begins by executing the index.js file from ~. When module1_index.js is executed, lib.js is looked for from ~ and consequently fails. In order to address this, the files must be looked for relative to the file being executed at the moment, however I have not found a means to do this.
First Attempt
I'm given the opportunity to look for the file in the callResolve method (main.cpp:280):
v8::MaybeLocal<v8::Module> callResolve(v8::Local<v8::Context> context, v8::Local<v8::String> specifier, v8::Local<v8::Module> referrer)
or in loadModule (main.cpp:197)
v8::MaybeLocal<v8::Module> loadModule(char code[], char name[], v8::Local<v8::Context> cx)
however, as mentioned, I have found no function by which to extract the ScriptOrigin from the module. I should mention, when files are successfully resolved, the ScriptOrigin is initiated with the exact path to the file, and is reliable.
Second Attempt
I set up a stack, which keeps track of the current file being executed. Every import which is made is pushed onto the stack. Once the file has finished executing, it is popped. This also did not work, as there was no way to reliably determine once the file had finished executing.
It seems that the loadModule function does just that: loads. It does not execute, so I cannot pop after the module has loaded, as the imports are not fully resolved. The checkModule/execModule functions are only invoked on dynamic imports, making them useless to determining the completion of a static import.
I'm at a loss. I'm not familiar with v8 enough to know where to look, although I have dug through some NodeJS source code looking for an implementation, to no avail.
Any pointers are greatly appreciated.
Thanks.
Jake.
I don't know much about module resolution, but looking at V8's sources, I can see an example mapping a v8::Module to a std::string absolute_path, which sounds like what you're looking for. I'm not copying the whole code here, because the way it uses custom metadata is a bit involved; the short story is that it keeps a std::unordered_map to keep data about each module's source on the side. (I wonder if it would be possible to use Module::ScriptId() as that map's key, for simplification.)
Code search finds a bunch more example uses of InstantiateModule, mostly in tests. Tests often serve as useful examples/documentation :-)
I want to build a control flow graph diagram in llvm in one of my passes. I currently use the following to show the CFG
block->getParent()->viewCFG(); //block is a basic block
The problem is that it pops up a windows. I just want to dump the cfg at that particular program point, as a dot file (or jpg if possible), not to show up in a window. How can I do the same? I am using llvm 3.1.
NOTE: I am modifying the cfg in my pass, before that program point. Hence I cannot use the opt -view-cfg.
Update:
Thanks to Mishr, I was able to draw to graph with this
WriteGraph(File, (const llvm::Function*) &fun, true, "test"); //I have also tired with false
The CFG is shown. But the nodes are blank. How can I show the contents of the node
Take a look at this, read the comment before the viewCFG() function.
http://llvm.org/docs/doxygen/html/CFGPrinter_8cpp_source.html
The viewCFG() function is intended for printing the CFG in a new window. To dump the CFG in a file you have to use CFGPrinter pass which can be invoked by the handle dot-cfg.
Let me add something to ssubbotin's answer.
The question is about
DOTGraphTraits<const Function*>
provided by CFGPrinter.
In my case I had to use the call like that:
WriteGraph<const llvm::Function*>(...)
to make it work.
The function template definition is like the following:
template<typename GraphType>
raw_ostream &WriteGraph(raw_ostream &O, const GraphType &G,
bool ShortNames = false,
const Twine &Title = "")
so GraphType gets non-const with implicit template call.
You need to add include:
#include <llvm\Analysis\CFGPrinter.h>
It has getEdgeSourceLabel implementation inside which provides correct node labels.
In the same time, make sure you don't have <llvm\Support\CFG.h> file included since it provides empty labels by default.
I ran into a problem with the Eclipse formatter. It won't format my code correctly when declaring methods within a class declaration. It puts a new line after the method's return type.
I already exported the style xml file and examined the settings in it, but none of the settings have any apparent connection to this problem, and the settings editor in Eclipse didn't show the same problem happening in it's sample code for method declarations.
Here is an example bit of code for what I want to have happen:
class MyClass
{
public:
MyClass();
void myMethod();
};
However, this is what I get:
class MyClass
{
public:
MyClass();
void
myMethod();
};
Again, in the styles editor, the code doesn't have this problem and looks just how I want it to, but in the actual code, the story is different.
I'm using version 3.8.0. Any help is appreciated.
Edit: I deleted those source files that were formatted incorrectly (after formatting the code several times to no avail) and replaced them with "identical" files with the same methods, same structure, etc. I formatted the code this time and it worked. This is probably a bug, but I'm leaving it up just in case anyone else encounters a similar problem or has a solution to avoiding this problem in the first place.
I hand edited two files under the main eclipse projects directory
.metadata\.plugins\org.eclipse.core.runtime\.settings
The two files:
file 1: org.eclipse.cdt.core.prefs, change this line from "insert" to "do not insert"
org.eclipse.cdt.core.formatter.insert_new_line_before_identifier_in_function_declaration=do not insert
file 2: org.eclipse.cdt.ui.prefs,
scan this file for "insert_new_line_before_identifier_in_function_declaration" and make a similar change from insert to do not insert next to it, should be obvious
Note I seen this problem on indigo and juno, the fix described above was in juno.
If you have a custom formatter config, export it first (settings>C/C++ General>Formatter>Edit>Export). Then change the following line to "do not insert". Save the XML.
<setting id="org.eclipse.cdt.core.formatter.insert_new_line_before_identifier_in_function_declaration" value="do not insert"/>
Delete the current config and import the one you changed.
There's a specific preference in the formatter options starting from cdt 9.8 included in Eclipse 2019-06.
I need to replace all WinAPI calls of the
CreateFile,
ReadFile,
SetFilePointer,
CloseHandle
with my own implementation (which use low-level file reading via Bluetooth).
The code, where functions will be replaced, is Video File Player and it already works with the regular hdd files.
It is also needed, that Video Player still can play files from HDD, if the file in the VideoPlayer input is a regular hdd file.
What is the best practice for such task?
I suggest that you follow these steps:
Write a set of wrapper functions, e.g MyCreateFile, MyReadFile, etc, that initially just call the corresponding API and pass the same arguments along, unmodified.
Use your text editor to search for all calls to the original APIs, and replace these with calls to your new wrapper functions.
Test that the application still functions correctly.
Modify the wrapper functions to suit your own purposes.
Note that CreateFile is a macro which expands to either CreateFileW or CreateFileA, depending on whether UNICODE is defined. Consider using LPCTSTR and the TCHAR functions so that your application can be built as either ANSI or Unicode.
Please don't use #define, as suggested in other responses here, as this will just lead to maintenance problems, and as Maximilian correctly points out, it's not a best-practice.
You could just write your new functions in a custom namespace. e.g.
namespace Bluetooth
{
void CreateFile(/*params*/);
void etc...
}
Then in your code, the only thing you would have to change is:
if (::CreateFile(...))
{
}
to
if (Bluetooth::CreateFile(...))
{
}
Easy! :)
If you're trying to intercept calls to these APIs from another application, consider Detours.
If you can edit the code, you should just re-write it to use a custom API that does what you want. Failing that, use Maximilian's technique, but be warned that it is a maintenance horror.
If you cannot edit the code, you can patch the import tables to redirect calls to your own code. A description of this technique can be found in this article - search for the section titled "Spying by altering of the Import Address Table".
This is dangerous, but if you're careful you can make it work. Also check out Microsoft Detours, which does the same sort of thing but doesn't require you to mess around with the actual patching.
If you really want to hijack the API, look at syringe.dll (L-GPL).
I don't think this is best practice but it should work if you put it in an include file that's included everywhere the function you want to change is called:
#define CreateFile MyCreateFile
HRESULT MyCreateFile(whatever the params are);
Implementation of MyCreateFile looks something like this:
#undef CreateFile
HRESULT MyCreateFile(NobodyCanRememberParamListsLikeThat params)
{
if (InputIsNormalFile())
CreateFile(params);
else
// do your thing
}
You basically make every CreateFile call a MyCreateFile call where you can decide if you want need to use your own implementation or the orginal one.
Disclaimer: I think doing this is ugly and I wouldn't do it. I'd rather search and replace all occurences or something.