1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> 5 <link href="style.css" rel="stylesheet" type="text/css" /> 6 <title>LLDB FAQ</title> 7 </head> 8 9 <body> 10 <div class="www_title"> 11 Troubleshooting <strong>LLDB</strong> 12 </div> 13 14 <div id="container"> 15 <div id="content"> 16 <!--#include virtual="sidebar.incl"--> 17 <div class="postfooter"></div> 18 <div id="middle"> 19 <div class="post"> 20 <h1 class ="postheader">File and line breakpoints are not getting hit</h1> 21 <div class="postcontent"> 22 <p>First you must make sure that your source files were compiled with 23 debug information. Typically this means passing <code>-g</code> to the 24 compiler when compiling your source file. 25 </p> 26 <p>When setting breakpoints in <b>implementation</b> source files 27 (.c, cpp, cxx, .m, .mm, etc), LLDB by default will only search for compile units whose filename matches. If your 28 code does tricky things like using <font color=purple>#include</font> to include source files: 29 <code><pre><tt>% <b>cat foo.c</b> 30 <font color=purple>#include</font> "bar.c" 31 <font color=purple>#include</font> "baz.c" 32 ... 33 </tt></pre></code> 34 <p> This will cause breakpoints in "bar.c" to be inlined into the compile unit for "foo.c". 35 If your code does this, or if your build system combines multiple files in some way such 36 that breakpoints from one implementation file will be compiled into another implementation file, 37 you will need to tell LLDB to always search for inlined breakpoint locations 38 by adding the following line to your <code>~/.lldbinit</code> file: 39 </p> 40 <code><pre><tt>% <b>echo "settings set target.inline-breakpoint-strategy always" >> ~/.lldbinit</b></tt></pre></code> 41 <p> This tells LLDB to always look in all compile units and search for breakpoint 42 locations by file and line even if the implementation file doesn't match. Settings breakpoints 43 in header files always searches all compile units because inline functions are commonly defined 44 in header files and often cause multiple breakpoints to have source line information that matches 45 the header files paths. 46 </p> 47 <p> If you set a file and line breakpoint using a full path to the source file, like Xcode does when setting a 48 breakpoint in its GUI on Mac OS X when you click in the gutter of the source view, this path must match 49 the full paths in the debug information. If the paths mismatch, possibly due to 50 passing in a resolved source file path that doesn't match an unresolved path in the debug 51 information, this can cause breakpoints to not be resolved. Try setting breakpoints using the file 52 basename only. 53 <p> If you are using an IDE and you move your project in your file system and build again, sometimes doing a 54 clean then build will solve the issue.This will fix the issue if some .o files didn't get rebuilt 55 after the move as the .o files in the build folder might still contain stale debug information with 56 the old source locations. 57 </p> 58 </div> 59 <div class="postfooter"></div> 60 </div> 61 </div> 62 <div class="postfooter"></div> 63 <div id="middle"> 64 <div class="post"> 65 <h1 class ="postheader">How do I check if I have debug symbols?</h1> 66 <div class="postcontent"> 67 <p> Checking if a module has any compile units (source files) is a good way to check 68 if there is debug information in a module: 69 <code><pre><tt> 70 (lldb) <b>file /tmp/a.out</b> 71 (lldb) <b>image list</b> 72 [ 0] 71E5A649-8FEF-3887-9CED-D3EF8FC2FD6E 0x0000000100000000 /tmp/a.out 73 /tmp/a.out.dSYM/Contents/Resources/DWARF/a.out 74 [ 1] 6900F2BA-DB48-3B78-B668-58FC0CF6BCB8 0x00007fff5fc00000 /usr/lib/dyld 75 .... 76 (lldb) <b>script lldb.target.module['/tmp/a.out'].GetNumCompileUnits()</b> 77 1 78 (lldb) <b>script lldb.target.module['/usr/lib/dyld'].GetNumCompileUnits()</b> 79 0 80 </tt></pre></code> 81 <p> Above we can see that "/tmp/a.out" does have a compile unit, and "/usr/lib/dyld" does not. 82 </div> 83 <div class="postfooter"></div> 84 </div> 85 </div> 86 </div> 87 </div> 88 </body> 89 </html> 90
