Working with libraries

(2 intermediate revisions by the same user not shown)

Line 16:

==Building with libraries==

* If the library supports [~~http://pkg-config.freedesktop.org~~ pkg-config], and you're willing to depend on that tool being installed, proper compilation flags can be lifted from it:

* If the library supports [[pkg-config]], and you're willing to depend on that tool being installed, proper compilation flags can be lifted from it:

** <tt>pkg-config --cflags ''pkgname''</tt> will pull the preprocessor and compilation flags

** <tt>pkg-config --libs ''pkgname''</tt> will pull the linking flags

Line 24:

===Environment variables that control ld.so===

===Files that control ld.so===

* The presence of <tt>/etc/ld.so.nohwcap</tt> precludes use of optimized library versions

===Interpositioning===

* Using the GNU linker, a particular object can wrap a symbol via <tt>-Wl,--wrap,symbolname</tt>. This will result in calls to <tt>symbolname</tt> resolving to <tt>__wrap_symbolname</tt>, and calls to <tt>__real_symbolname</tt> to resolve <tt>symbolname</tt>.

Line 30:

Line 32:

===What the hell is linux-gate.so.1?===

The SYSENTER/SYSEXIT instructions of some Pentium processors provides a faster way to switch rings (a callgate, hence the name). [http://www.trilithium.com/johan/2005/08/linux-gate/ This page] explains pretty well what's going on.

The [[MSR|SYSENTER/SYSEXIT]] instructions of some Pentium processors provides a faster way to switch rings (a callgate, hence the name). [http://www.trilithium.com/johan/2005/08/linux-gate/ This page] explains pretty well what's going on.

==Quality Assurance==

Working with libraries: Difference between revisions

Dank (talk | contribs)

@@ Line 16: / Line 16: @@
 ==Building with libraries==
-* If the library supports [http://pkg-config.freedesktop.org pkg-config], and you're willing to depend on that tool being installed, proper compilation flags can be lifted from it:
+* If the library supports [[pkg-config]], and you're willing to depend on that tool being installed, proper compilation flags can be lifted from it:
 ** <tt>pkg-config --cflags ''pkgname''</tt> will pull the preprocessor and compilation flags
 ** <tt>pkg-config --libs ''pkgname''</tt> will pull the linking flags
@@ Line 24: / Line 24: @@
 ===Environment variables that control ld.so===
 ===Files that control ld.so===
+* The presence of <tt>/etc/ld.so.nohwcap</tt> precludes use of optimized library versions
 ===Interpositioning===
 * Using the GNU linker, a particular object can wrap a symbol via <tt>-Wl,--wrap,symbolname</tt>. This will result in calls to <tt>symbolname</tt> resolving to <tt>__wrap_symbolname</tt>, and calls to <tt>__real_symbolname</tt> to resolve <tt>symbolname</tt>.
@@ Line 30: / Line 32: @@
 ===What the hell is linux-gate.so.1?===
-The SYSENTER/SYSEXIT instructions of some Pentium processors provides a faster way to switch rings (a callgate, hence the name). [http://www.trilithium.com/johan/2005/08/linux-gate/ This page] explains pretty well what's going on.
+The [[MSR|SYSENTER/SYSEXIT]] instructions of some Pentium processors provides a faster way to switch rings (a callgate, hence the name). [http://www.trilithium.com/johan/2005/08/linux-gate/ This page] explains pretty well what's going on.
 ==Quality Assurance==