linux - dlsym()'ing a global variable in C++ -

-

I want to create a program which is a series of dlopen () (written by itself ) And a omnibox variable is stored in it, which is named a valid variable name called test_suite , which is a null-terminated array of function pointers (the signature of the function is predefined by me , No need to worry about that)

The problem is that the G + library has been compiled as: 

  G ++ -Wall-Shared - Radi IP-FPIC foo.cpp -o foo. So   
 and "Function Index" have been declared and allocated:  
  const testunit_testcase test_suite = {...}   
 yet  
  objdump - t foo.so | Grep test_suite   
 Shows:  
  0000000000200940L O.Data.rel.ro 0000000000000020 _ZL10test_suite   
 Do me  
  0000000000200940Lo Data .rel.ro 0000000000000020 test_suite   
 so I can do  dlsym (dlh, "test_suite")  program  dllupen ()  '  foo.so   
 Thanks  
 
  Appendix   
 Yes,  Extern "c" I first tried:  
  extern "c" {const testunit_testcase test_suite [] = {// TESTUNIT_DEF_TESTCASE (doTest), {NULL, NULL}} }; }   
 I am using:  
 
  G ++ - V  Using a built-in app COLLECT_GCC = g ++ COLLECT_LTO_WRAPPER = / usr / lib / gcc / x86_64-unknown-linux-gnu / 4.5.2 / lto-wrapper Target: x86_64-unknown-linux-gnu is configured with: /build/src/gcc-4.5 -20110127  /configure --prefix = / usr --enable-languages ​​= c, c ++, fortran, objc, obj-c ++, ada -enable-share - enabled-thread = Posix --enable -__ cxa_atexit --enable-clocale = gnu --enable-gnu-unique-object --enable-lto --enable-plugin --enable-gold --with-plugin-ld = ld.gold - -disable-multilib --disable -libstdcxx-pch --with-system-zlib -with-ppl --with-cloog - Include-clog - / usr / include / cloog-ppl --libdir = / Usr / lib --libexecdir = / thread model: Pausix  GCC version 4.5.2  20110127 (Prerelease) (GCC)      < / P>  
  
 
  Appendix 2   
 For whatever reason  
  Extern "C" {const testit_testcase test_suite = {. ..}}   
 does  no  works, but it does one:  
  extern "c" const Estunit_testcase test_suite = {...}   
  My question now : As I can see in some of your replies,  extern "C" {. ..}  works for you Is there any compiler flag that I can use to make sure that  test_suite  will never match, even if any 4. X (at least) g ++ version not used?  
 
 
 
 The name of the problem is not one of the confused (or perhaps it is not: public variable name usually Is not confused.) The real problem is that "const" means steady constant, rendering invisible temporary outside the translation unit. To avoid this, the variable should be declared clearly. And "Includes Brace-Attached Announcement-seq as Linkage-Specification, does not affect whether the implied announcements are definitions or not (3.1); In the form of a linkage-specification, the same declaration will be given to an external specifier (7.1.1) For the purpose of determining that the implied declaration is a definition. "That, while it does not directly solve your problem (the presence of an initiator Ensures that the declaration is a definition), it would seem to indicate intention: are within a brace attached enclosure specifier, apply the general rule; If the link specifier is directly applicable for declaration, then it seems that the announcement was clearly excluded. You can either write:  
  extern "c" {testunit_testcase const test_suite [] // ...}   
 or  
  extern "c" testunit_testcase const test_suite [] // ...   
 but to explicitly define which should be an extern Built-in "override static" "Const key"

Comments

Post a Comment

Popular posts from this blog

qt - switch/case statement in C++ with a QString type -

-
I want to use switch-case in my program but the compiler generates an error. How can I use the switch statement with QString ? The compiler gives me this error: The expression of the switch type 'QString' is invalid My code is as follows : boolStopWord (the word QString) {bool flag = false; Switch (word) {case "the": flag = true; break ; "On" case: flag = true; break ; Case "in": flag = true; break ; Case "your": flag = true; break ; Case "near": flag = true; break ; Case "all": flag = true; break ; Case "this": flag = true; break ; } Return flag; } How do I use the switch statement with a Caststring ? You can not use the switch statement in C ++ language with integral or enum types. You can formally enter the square type of object in the switch statement, but this means that the compiler will look for a user-defined conversion to convert it to an integral or enum type.
Read more

python - sqlite3.OperationalError: near "REFERENCES": syntax error - foreign key creating -

-
I'm trying to create a predefined key after checking the manual and I wrote it: Db.execute ("create table" Table 2 (id, integer primary key, somedata integer) "db.execute" (table creation table 2 does not exist (name text, maintain reference (id) ") and found this: sqlite 3. Operation error: near" references ": syntax error Your second ligne is wrong db.execute ("create table if table does not exist 2 (name text, my_id integer, foreign key (my_id) reference Maintenance (ID)) ") as explained
Read more

Python's equivalent for Ruby's define_method? -

-
What is a Python equivalent for Ruby's define_method , which is the dynamic generation of class methods will allow? (As can be seen in Wikipedia) Functions are first-class objects in Python and assign them The properties of a class or an example can be a way of doing the same thing as a Wikipedia example: colors = {"black": "000", "red": "F00", "green": "0f0", "yellow": "ff0", "blue": "00f", "magenta": "fff", "cyan": "0ff", "white": " FFF "} Class MyStream (ARR): Pass for Name, Code in colors.iteritems (): def _in_colour ( W code = code): return '& lt; Span style = "color:% s" & gt;% s & lt; / Span & gt; ' % (Code, self) setter (histrive, "in_" + name, _in_ color)
Read more