How to get gcc to compile 16-bit unicode strings - gcc

So I'm trying to compile this project : https://github.com/dmitrystu/libusb_stm32 with Segger Embedded studio which uses gcc. The process is choking on this error :
pasting formed 'u"Open source USB stack for STM32"', an invalid preprocessing token
which is caused by this line :
static const struct usb_string_descriptor manuf_desc_en = USB_STRING_DESC("Open source USB stack for STM32");
So USB_STRING_DESC is a macro :
#define USB_STRING_DESC(s) {.bLength = sizeof(CAT(u,s)),.bDescriptorType = USB_DTYPE_STRING,.wString = {CAT(u,s)}}
And CAT is a macro CAT(x,y) x##y. The intent must be to convert a string of type 8-bit char into a 16-bit Unicode type but the compiler doesn't like it. Is there some #include or compiler setting that may be missing that I have to add here? Clearly the author of this code expects it to work so there must be some fault in my setup.
Also I'm not clear on how the sizeof() operation is supposed to work here. As I understand it there is no way to get the length of a string at compile time so that operation will always return the size of a pointer.


In response to Keith's question, the gcc version is 4.2.1. Poking around the compiler settings the default option is the C99 standard, when I changed it to C11 everything compiled just fine. Thanks!

Related

how to include text file as string at compile time without adding c++11 string literal prefix and suffix in the text file

I'm aware of many similar questions on this site. I really like the solution mention in the following link:
https://stackoverflow.com/a/25021520/884553
with some modification, you can include text file at compile time, for example:
constexpr const char* s =
#include "file.txt"
BUT to make this work you have to add string literal prefix and suffix to your original file, for example
R"(
This is the original content,
and I don't want this file to be modified. but i
don't know how to do it.
)";
My question is: is there a way to make this work but not modifying file.txt?
(I know I can use command line tools to make a copy, prepend and append to the copy, remove the copy after compile. I'm looking for a more elegant solution than this. hopefully no need of other tools)
Here's what I've tried (but not working):
#include <iostream>
int main() {
constexpr const char* s =
#include "bra.txt" // R"(
#include "file.txt" //original file without R"( and )";
#include "ket.txt" // )";
std::cout << s << "\n";
return 0;
}
/opt/gcc8/bin/g++ -std=c++1z a.cpp
In file included from a.cpp:5:
bra.txt:1:1: error: unterminated raw string
R"(
^
a.cpp: In function ‘int main()’:
a.cpp:4:27: error: expected primary-expression at end of input
constexpr const char* s =
^
a.cpp:4:27: error: expected ‘}’ at end of input
a.cpp:3:12: note: to match this ‘{’
int main() {
^

No, this cannot be done.
There is a c++2a proposal to allow inclusion of such resources at compile time called std::embed.
The motivation part of ths p1040r1 proposal:
Motivation
Every C and C++ programmer -- at some point -- attempts to #include large chunks of non-C++ data into their code. Of course, #include expects the format of the data to be source code, and thusly the program fails with spectacular lexer errors. Thusly, many different tools and practices were adapted to handle this, as far back as 1995 with the xxd tool. Many industries need such functionality, including (but hardly limited to):
Financial Development
representing coefficients and numeric constants for performance-critical algorithms;
Game Development
assets that do not change at runtime, such as icons, fixed textures and other data
Shader and scripting code;
Embedded Development
storing large chunks of binary, such as firmware, in a well-compressed format
placing data in memory on chips and systems that do not have an operating system or file system;
Application Development
compressed binary blobs representing data
non-C++ script code that is not changed at runtime; and
Server Development
configuration parameters which are known at build-time and are baked in to set limits and give compile-time information to tweak performance under certain loads
SSL/TLS Certificates hard-coded into your executable (requiring a rebuild and potential authorization before deploying new certificates).
In the pursuit of this goal, these tools have proven to have inadequacies and contribute poorly to the C++ development cycle as it continues to scale up for larger and better low-end devices and high-performance machines, bogging developers down with menial build tasks and trying to cover-up disappointing differences between platforms.
MongoDB has been kind enough to share some of their code below. Other companies have had their example code anonymized or simply not included directly out of shame for the things they need to do to support their workflows. The author thanks MongoDB for their courage and their support for std::embed.
The request for some form of #include_string or similar dates back quite a long time, with one of the oldest stack overflow questions asked-and-answered about it dating back nearly 10 years. Predating even that is a plethora of mailing list posts and forum posts asking how to get script code and other things that are not likely to change into the binary.
This paper proposes <embed> to make this process much more efficient, portable, and streamlined. Here’s an example of the ideal:
#include <embed>
int main (int, char*[]) {
constexpr std::span<const std::byte> fxaa_binary = std::embed( "fxaa.spirv" );
// assert this is a SPIRV file, compile-time
static_assert( fxaa_binary[0] == 0x03 && fxaa_binary[1] == 0x02
&& fxaa_binary[2] == 0x23 && fxaa_binary[3] == 0x07
, "given wrong SPIRV data, check rebuild or check the binaries!" )
auto context = make_vulkan_context();
// data kept around and made available for binary
// to use at runtime
auto fxaa_shader = make_shader( context, fxaa_binary );
for (;;) {
// ...
// and we’re off!
// ...
}
return 0;
}

Reading an UTF-8 encoded file into std::u32string without intermediate buffering

Having worked quite long time with Unicode and C++ I thought this would be a simple thing to accomplish, especially with the new C++11 std::codecvt_utf8 facet. Though it turned out to be a diffcult task. What I want is to read a file encoded in UTF-8 into a u32string (converting it from UTF-8 to UTF-32 implicitly). Sure, I could load the entire content into a buffer and convert that using std::wstring_convert. But that doubles the memory footprint when loading a file. So I tried to use a std::wifstream and imbue a locale with a utf-8 facet like this:
std::wifstream stream(fileName, std::ios::binary);
stream.imbue(std::locale(stream.getloc(), new std::codecvt_utf8<char32_t, 0x10ffff, std::consume_header>));
std::u32string data;
for (char32_t c; stream >> c; )
data += c;
which looks like a straight forward implementation. It only doesn't compile. wifstream's element type is wchar_t, so you can only use wchar_t in the loop, like this:
std::u32string data;
for (wchar_t c; stream >> c; )
data += c;
(at least with clang, VC++ also accepts char32_t there, but that doesn't change anything). After fixing this several other problems remain, though:
In Visual C++ wchar_t is only 16bit (no UTF-32 then, we don't consider surrogate pairs here).
Using char32_t for the facet essentially disables conversion. The iteration over the stream returns the original UTF-8 content, both in clang and VC++.
Using wchar_t also for the facet makes it work in clang, but not in VC++, because in clang wchar_t is 32bit wide, while (as mentioned already) it is only 16bit in VC++.
So, what is the correct approach here? With the lock into wchar_t for the facet I cannot even use a different data type. I also tried defining a basic_ifstream<char32_t> but that requires additional typedefs, hence I didn't follow that path further.

Seems there is no way using a facet and imbue that in a stream, so I went with an intermediate buffer, which is a very elegant solution too, only that it doubles (more or less) the memory needed to load the content. Use a byte (file) stream in binary mode to call this:
void load(std::istream &stream)
{
static std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> utfConverter;
std::string s((std::istreambuf_iterator<char>(stream)), std::istreambuf_iterator<char>());
_data = utfConverter.from_bytes(s);
}

freeimage 3.17 library build failing on Mac OS X: fails with C++11 narrowing error... any ideas?

With not having any understanding of C++ (I'm teaching myself Swift), I'm struggling a bit to get around this one - but ideally would love to be able to expose some of the functionality in the FreeImage library in my project.
It appears that only one module is generating any errors: dcraw_common.cpp - and the lines in error are those from the following entry list where there is a value of 0x80 or above. From the investigations I've done, it would appear that these values are too large for a signed char (max 128?), yet the list also includes negative numbers, and so it can't use an unsigned char.
Any help would be most gratefully received.
Here's an example of the error message generated by the make process:
Source/LibRawLite/./internal/dcraw_common.cpp:4543:19: error: constant expression evaluates to 136 which cannot be narrowed to type 'signed char'
[-Wc++11-narrowing]
+1,-1,+1,+1,0,0x88, +1,+0,+1,+2,0,0x08, +1,+0,+2,-1,0,0x40,
^~~~
And here's the code:
void CLASS vng_interpolate()
{
static const signed char *cp, terms[] = {
-2,-2,+0,-1,0,0x01, -2,-2,+0,+0,1,0x01, -2,-1,-1,+0,0,0x01,
-2,-1,+0,-1,0,0x02, -2,-1,+0,+0,0,0x03, -2,-1,+0,+1,1,0x01,
-2,+0,+0,-1,0,0x06, -2,+0,+0,+0,1,0x02, -2,+0,+0,+1,0,0x03,
-2,+1,-1,+0,0,0x04, -2,+1,+0,-1,1,0x04, -2,+1,+0,+0,0,0x06,
-2,+1,+0,+1,0,0x02, -2,+2,+0,+0,1,0x04, -2,+2,+0,+1,0,0x04,
-1,-2,-1,+0,0,0x80, -1,-2,+0,-1,0,0x01, -1,-2,+1,-1,0,0x01,
-1,-2,+1,+0,1,0x01, -1,-1,-1,+1,0,0x88, -1,-1,+1,-2,0,0x40,
-1,-1,+1,-1,0,0x22, -1,-1,+1,+0,0,0x33, -1,-1,+1,+1,1,0x11,
-1,+0,-1,+2,0,0x08, -1,+0,+0,-1,0,0x44, -1,+0,+0,+1,0,0x11,
-1,+0,+1,-2,1,0x40, -1,+0,+1,-1,0,0x66, -1,+0,+1,+0,1,0x22,
-1,+0,+1,+1,0,0x33, -1,+0,+1,+2,1,0x10, -1,+1,+1,-1,1,0x44,
-1,+1,+1,+0,0,0x66, -1,+1,+1,+1,0,0x22, -1,+1,+1,+2,0,0x10,
-1,+2,+0,+1,0,0x04, -1,+2,+1,+0,1,0x04, -1,+2,+1,+1,0,0x04,
+0,-2,+0,+0,1,0x80, +0,-1,+0,+1,1,0x88, +0,-1,+1,-2,0,0x40,
+0,-1,+1,+0,0,0x11, +0,-1,+2,-2,0,0x40, +0,-1,+2,-1,0,0x20,
+0,-1,+2,+0,0,0x30, +0,-1,+2,+1,1,0x10, +0,+0,+0,+2,1,0x08,
+0,+0,+2,-2,1,0x40, +0,+0,+2,-1,0,0x60, +0,+0,+2,+0,1,0x20,
+0,+0,+2,+1,0,0x30, +0,+0,+2,+2,1,0x10, +0,+1,+1,+0,0,0x44,
+0,+1,+1,+2,0,0x10, +0,+1,+2,-1,1,0x40, +0,+1,+2,+0,0,0x60,
+0,+1,+2,+1,0,0x20, +0,+1,+2,+2,0,0x10, +1,-2,+1,+0,0,0x80,
+1,-1,+1,+1,0,0x88, +1,+0,+1,+2,0,0x08, +1,+0,+2,-1,0,0x40,
+1,+0,+2,+1,0,0x10
}, chood[] = { -1,-1, -1,0, -1,+1, 0,+1, +1,+1, +1,0, +1,-1, 0,-1 };
...

C++11 prevents 'narrowing conversions' like that. Early versions of C++ would accept them. I think this patch to the source of dcraw_common.cpp should fix it.
https://gist.github.com/conchurnavid/ac19c8e882f1835f0310
There's a duplicate question here. Building FreeImage 3.16.0 for Android

The most usable solution I found to this issue was the following GitHub posting: https://github.com/danoli3/FreeImage. Here some kind soul appears to have successfully built the 3.17.0 library and uploaded it. I've found that works just fine.
Please bear in mind however that it's been built with a hard-coded path of /opt/local/lib - which may be an issue when you come to implementation, since your app will be looking for it there, not bundled with the app. I did find this LiveCode post aided my understanding in that regard a lot.
Hope this helps.

Stringify Endpoint for Xcode LLVM Processor Macros

In the "Apple LLVM 7.0 - Preprocessing" section under the "Build Settings" tab, I've defined a Preprocessor Macros as:
STR(arg)=#arg
HUBNAME=STR("myhub")
HUBLISTENACCESS=STR("Endpoint=sb://abc-xyz.servicebus.windows.net/;SharedAccessKeyName=DefaultListenSharedAccessSignature;SharedAccessKey=JKLMNOP=")
In my code, I'm trying to refer to the value of HUBLISTENACCESS as a string:
SBNotificationHub* hub = [[SBNotificationHub alloc] initWithConnectionString:#HUBLISTENACCESS notificationHubPath:#HUBNAME];
But I'm getting errors from Xcode for the initialization of "hub":
Expected ';' at end of declaration
Unterminated function-like macro invocation
Unexpected '#' in program
I suspect that the definition of HUBLISTENACCESS in the Preprocessor Macros needs to be properly escaped but I've tried a few things and can't seem to get it right. Can somebody help me understand what I'm doing wrong?

There's one very obvious reason why you were trying to do failed: you use // in the HUBLISTENACCESS. As in C, things after // were commented out so in the aspect of the compiler, the last line of yours is actually:
HUBLISTENACCESS=STR("Endpoint=sb:
To test it, just remove one slash and it will work again. What you were doing like trying to define things as such:
#define FOO //
which I don't think it's possible. I honestly have no idea how you can do that within the Build Settings, but there are other ways to do it globally via a PCH file (prefix header).
A simple line within the PCH will will save all those troubles:
#define HUBLISTENACCESS #"Endpoint=sb://abc-xyz.servicebus.windows.net/;SharedAccessKeyName=DefaultListenSharedAccessSignature;SharedAccessKey=JKLMNOP="
Then use it as below: (no more # needed!)
NSLog(#"%#", HUBLISTENACCESS);

VS2008 to VS2010 - Problematic Configuration and Upgrade - Newbie

I have updated this question with an executive summary at the start below. Then, extensive details follow, if needed. Thanks for the suggestions.
Exec Summary:
I am a novice with VS. I have a problem with some inherited code. Code builds and executes fine on VS2008 (XP64). Same code will either build and not run, or fail to build on XP64 or W7 with VS2008 and/or VS2010. After changing some compiler options, I managed to get it to run without an issue on VS2010 on XP64; however, on W7, no luck.
I eventually discovered that the heap is getting corrupted.
Unhandled exception at 0x76e540f2 (ntdll.dll) in ae312i3.3.exe: 0xC0000374: A heap has been corrupted.
I am not familiar with how to consider fixing a heap problem; perhaps there is an issue with the pointers in the existing code that points to memory in use by another thread or program, corrupted ntdll.dll file, other?
Rebooting PC to check if ntdll.dll was corrupted didn't help. Changed debug settings, and received the following feedback:
HEAP[ae312i3.3.exe]: Invalid address specified to RtlSizeHeap( 0000000000220000, 000000002BC8BE58 )
Windows has triggered a breakpoint in ae312i3.3.exe.
This may be due to a corruption of the heap, which indicates a bug in ae312i3.3.exe or any of the DLLs it has loaded. This may also be due to the user pressing F12 while ae312i3.3.exe has focus.
It appears that when it crashes, C++ is returning a boolean variable to an expression of the form
While (myQueryFcn(inputvars))
QUESTIONS:
So, is it not returning a C++ boolean to a VB boolean? I do believe that the two are different representations (one uses True/False, the other an integer?) Could this be an issue? If so, why was it NOT an issue in VB2008?**
Or, perhaps it is that the C++ code has written to allocated memory, and upon returning to VB, it crashes???
** I have recently learned of 'Insure++', and will be trying to use it to track down the issue. Any suggestions on its use, other possible insight? **
I would appreciate any suggestions. Thanks again.
.
.
.
.
.
DETAILS THAT LED TO THE ABOVE SUMMARY (below):
I am a novice with VS2010; familiar with programming at an engineering application level (Python, Fortran, but been decades since I used C++ extensively), but not a professional programmer.
I have a solution that consists of multiple projects, all in VS2008. Projects are:
Reader (C++ project; utilizes 3rd party DLLs)
Query (C++ project; depends upon Reader)
Main (VB; depends upon Reader and Query).
The following applies to XP64 OS.
The solution and projects were written, built, and released by someone other than myself.
I have taken the existing files, and made a copy, placed in a directory of my choice, and simply opened in VS2010 (VS2008 is not installed on my PC). I was able to successfully build (with many warnings though - more on that later) ; but when I ran the executable, it would reach a point and crash. After much trial and error, I discovered that modification of compiler settings resolved the issue for me as follows:
It would build and execute in DEBUG configuration, but no the Release. I found that the in the Query project Property Page / Configuration Properties / C++ / Optimization / Optimization --> the Release (x64) configuration utilized 'Maximize Speed (/O2) while the Debug used 'Disabled (/Od)' --> so I switched to 'Disabled (/Od).
Also, Query's project Property Page / Configuration Properties / General / Whole Program Optimization --> needed to be set to 'Use Link Time Code Generation'.
The above build and ran successfully on XP64 in VS2010.
Next, I simply copied the files and placed a copy on a W7 machine with VS2010. Opened the solution via 2010, and it 'upgraded' the files automatically. When I launch VS2010, it automatically indicates the 4 following warnings. They are:
Operands of type Object used for operator '&'; runtime errors could occur. In file 'CobraIFile.vb', Line 1845, Column 37.
identical error completely
Accesss of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated. In file 'FileWriter.vb', Lines 341, Columns 51
Operands of type Object used for operator '='; use the 'Is' operator to test object identity. In file 'FormMain.vb'; Line 4173, Column 32.
Code for warnings in 1 & 2 are as follows
ValueStr = String.Empty
For iCols = 0 To DGrid.Columns.Count - 1
ValueStr &= DGrid.Item(iCols, iRows).Value & ";" // THIS IS WARNING LINE!!!
Next
Code for warning 3:
With FormMain
WriteComment("")
WriteComment("Generated by :")
WriteComment("")
WriteComment(" Program : " & .PROGRAM.ToUpper) // THIS IS WARNING LINE!!!
Code for warning 4:
' Compare material against the material table
For iRowMat As Integer = 0 To matCount - 1
' Ignore new row
If Not .Rows(iRowMat).IsNewRow Then
' Check material description
// LINE BELOW IS WARNING LINE!!!
If .Item("ColMatDesc", iRowMat).Value = matDesc Then
DataGridMatProp.Item("ColMatIdx", iRow).Value = .Item("ColMatFile", iRowMat).Value
Exit For
End If ' Check description
End If ' Check new row
Next iRowMat
When I build the solution, it will successfully build without errors (but many warnings), and when I run the executable, it successfully loads the GUI, but at some point crashes while executing either the Query or Reader projects (after taking actions with gui buttons) with the following information:
C:\Users\mcgrete\AppData\Local\Temp\WER5D31.tmp.WERInternalMetadata.xml
C:\Users\mcgrete\AppData\Local\Temp\WER68E6.tmp.appcompat.txt
C:\Users\mcgrete\AppData\Local\Temp\WER722A.tmp.mdmp
I was unable to utilize the information in the three files above (ignorant of how to consider to do so).
The warnings I receive in W7 are very similar / if not identical to that in XP64; they are along the lines of the following types, and there are over 1,600 of them. Add to the warning types below the original 4 warnings listed ealier above. With my success in running on XP64, and not in W7, I was assuming/hoping that these would not require to individually be addressed, but are only warnings.
Warning C4267: 'argument' : conversion from 'size_t' to 'int', possible loss of data. C:\Users\mcgrete\Documents\iCOBRA\pts\p312\exec\win64\6111\include\atr_StringBase.h 351 1 Reader
Warning C4018: '<' : signed/unsigned mismatch C:\Users\mcgrete\Documents\iCOBRA\pts\p312\exec\win64\6111\include\omi_BlkBitVectTrav.h 69 1 Reader
Warning C4244: 'initializing' : conversion from 'double' to 'float', possible loss of data. C:\Users\mcgrete\Documents\iCOBRA\pts\p312\exec\win64\6111\include\g3d_Vector.h 76 1 Reader
Warning C4244: 'initializing' : conversion from 'double' to 'float', possible loss of data. C:\Users\mcgrete\Documents\iCOBRA\pts\p312\exec\win64\6111\include\g3d_Vector.h 76 1 Reader
Warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning). C:\Users\mcgrete\Documents\iCOBRA\pts\p312\exec\win64\6111\include\rgnC_Region.h 219 1 Reader
Warning LNK4006: "public: class ddr_ShortcutImpl const & __cdecl cow_COW,struct cow_Virtual > >::ConstGet(void)const " (?ConstGet#?$cow_COW#V?$ddr_ShortcutImpl#VkmaC_Material####U?$cow_Virtual#V?$ddr_ShortcutImpl#VkmaC_Material########QEBAAEBV?$ddr_ShortcutImpl#VkmaC_Material####XZ) already defined in ABQDDB_Odb_import.lib(ABQDDB_Odb.dll); second definition ignored C:\Users\mcgrete\Documents\iCOBRA\pts\p312\source\312i3.3\Reader\ABQSMAOdbCore_import.lib(ABQSMAOdbCore.dll) Reader
Warning LNK4221: This object file does not define any previously undefined public symbols, so it will not be used by any link operation that consumes this library. C:\Users\mcgrete\Documents\iCOBRA\pts\p312\source\312i3.3\Reader\ABQSMAOdbCore_import.lib(ABQSMAOdbCore.dll) Reader
Warning C4996: 'sprintf': This function or variable may be unsafe. Consider using sprintf_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. C:\Users\mcgrete\Documents\iCOBRA\pts\p312\source\312i3.3\Query\Query.cpp 271 1 Query
Warning MSB8004: Output Directory does not end with a trailing slash. This build instance will add the slash as it is required to allow proper evaluation of the Output Directory. C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\Microsoft.CppBuild.targets 299 6 Query
Now to my request for help:
I must clarify, I am willing to dig into the warnings above in detail; however, I have not done so as before investing that effort and not having written code to begin with, I am simply trying to understand what might be the true root cause, then focus efforts in that direction.
I was disappointed with the XP64 issues I experienced, and was unsure if the changes required to the configuration were required, or if the changes that I made were only actually a 'work-around' to an unidentified problem?
I expected that once the XP64 VS2010 version of the solution was operable, that it would transfer to W7 without an issue, as the software build and ran fine with VS2008 and XP64. Is that a poor assumption? What might I be missing?
Should I consider attempting to modify the configurations again, or is the root cause likely associatd with the warnings indicated above? If the warnings, why were they apparently non-issues in VS2008 - did changes in VS2010 effectively lead to generation of actual runtime errors where in VS2008 I was luckily 'spared' the pain?
I appreciate any guidance and insight on how to proceed, as from my limited experience, it appears from searches on the web that there were numerous compiler bugs or related in VS2010. Not sure if any are related to my issues, if the numerous warnings are actually a problem and the code needs quite a bit of cleaning up, or if there are simply some configuration issues that I may have to deal with.
FYI - The latest update/SP to VS2010 that I have installed is VS10SP1-KB2736182.exe. I have also trid to use the debugger, but was unable to get it to stop at breakpoints in my Query or Reader project codes, even while running VS2010 as administrator. W7 does have .NET Framework 4.0 Multi-Targeting Pack installed, and my solution is configured to use .NET Framework 4.0 Client Profile.
Thanks in advance!
UPDATE March 18, 2013
I didn't know how to reply to my own question, so here is an update.
I still could not manage to get the debugger working; so, I did it the old fashioned way - added various MessageBoxs to find where it was crashing.
A. The Main.vb program calls a function in the 'Query' project
OdbQueryGetIncrement(str_out, vec_ptr)
B. Then, the function executes through 100%, attempting to return a boolean...here is code with some old fashioned debugging code added...
//Gets the next item in a list.
// Returns false if there is the vector is empty.
// NOTE: Once an element is returned it is removed from the list.
bool __stdcall OdbQueryGetItem(
char* &str_out, // RETURN Next item in list.
void * vec_ptr, // Pointer to the vector of pointers.
int index) // Index of pointers vector to return next item of.
{
// Cast the point into an array of pointers
std::vector<std::string>* *vec_temp = (std::vector<std::string>* *) vec_ptr;
bool bool_out = false;
char vectempsize[1000];
int TEM1;
char temp[1000];
TEM1 = vec_temp[index]->size();
// Check vector is valid
if (vec_temp) {
if(vec_temp[index]->size() >= index)
{
sprintf(temp,"value: %d\n",(int)bool_out);
::MessageBoxA(0, (LPCSTR) temp, (LPCSTR) "OdbQuery.dll - bool_out", MB_ICONINFORMATION);
sprintf(temp,"value: %d\n",(int)index);
::MessageBoxA(0, (LPCSTR) temp, (LPCSTR) "OdbQuery.dll - index", MB_ICONINFORMATION);
sprintf(vectempsize,"value: %d\n",(int)TEM1);
::MessageBoxA(0, (LPCSTR) temp, (LPCSTR) "OdbQuery.dll - index", MB_ICONINFORMATION);
}
if (!vec_temp[index]->empty()) {
// Get the next item in the list
std::string item = vec_temp[index]->front();
// Initialise ouput string
str_out = (char*)malloc( item.size()*sizeof(char) );
sprintf(str_out, "%s", item.c_str());
::MessageBoxA(0,(LPCSTR) str_out, (LPCSTR) "hello", 0);
// Remove first item from the vector
vec_temp[index]->erase(vec_temp[index]->begin());
bool_out = true;
}
}
sprintf(temp,"value: %d\n",(int)bool_out);
::MessageBoxA(0, (LPCSTR) temp, (LPCSTR) "OdbQuery.dll - bool_out", MB_ICONINFORMATION);
return bool_out;
}
The code starts out with bool_out=false as expected (verified with MessageBox value=0 output)
The code reads and outputs index = 2 with the MessageBox...
The code reads and outputs TEM1=vec_temp[index]->size() as a value=2 with the MessageBox...
The code outputs bool_out as true (value=1) with the MessageBox...
Then, the code crashes. A MessageBox that was placed immediately after the line that calls the code above never is executed.
The output from VS2010 is "The program '[6892] ae312i3.3.exe: Managed (v4.0.30319)' has exited with code -2147483645 (0x80000003)."
I am lost as to why the execution would die while returning from this function.
Is there some possible issue with compiler settings or bugs?
Any help is appreciated!
MORE INFORMATION
Hello, I modified some settings on the Properties Page to attempt to get the debugger to give me more information. This has resulted in more information as follows:
Unhandled exception at 0x76e540f2 (ntdll.dll) in ae312i3.3.exe: 0xC0000374: A heap has been corrupted.
I am not familiar with how to consider fixing a heap problem; perhaps there is an issue with the pointers in the existing code that points to memory in use by another thread or program, corrupted ntdll.dll file, other?
I will try rebooting PC to see if that helps, though I have little hope for that...didn't help.
Found option in Debugger to 'Enable unmanaged code debugging', checked it; cleaned; rebuild; run with debug...
Output more descriptive --
HEAP[ae312i3.3.exe]: Invalid address specified to RtlSizeHeap( 0000000000220000, 000000002BC8BE58 )
Windows has triggered a breakpoint in ae312i3.3.exe.
This may be due to a corruption of the heap, which indicates a bug in ae312i3.3.exe or any of the DLLs it has loaded. This may also be due to the user pressing F12 while ae312i3.3.exe has focus.
It appears that when it crashes, C++ is returning a boolean variable to an expression of the form
While (myQueryFcn(inputvars))
So, is it not returning a C++ boolean to a VB boolean? I do believe that the two are different representations (one uses True/False, the other an integer?) Could this be an issue? If so, why was it NOT an issue in VB2008?

I solved my own problem; the root cause of the problem was as follows.
Root Cause:
VisualBasic (VB) called C++.
VB created a string and sent to C++. Previous developer/coder allocated memory in C++ for the same string.
When execution of C++ code ended, C++ appears to have terminated the memory allocation established by VB and C++.
Solution:
1. Removed memory allocation in C++ code (below).
str_out=(char*)malloc( (item.size()+1)*sizeof(char) );
Modified VB code to use a StringBuilder type, rather than string.
Dim str_out As StringBuilder = New StringBuilder(5120)
See: return string from c++ function to VB .Net

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