diff options
Diffstat (limited to 'linker')
| -rw-r--r-- | linker/README.TXT | 89 | ||||
| -rw-r--r-- | linker/linker_debug.h | 12 |
2 files changed, 9 insertions, 92 deletions
diff --git a/linker/README.TXT b/linker/README.TXT deleted file mode 100644 index e75823e24..000000000 --- a/linker/README.TXT +++ /dev/null @@ -1,89 +0,0 @@ -Android Dynamic Linker Design Notes -=================================== - -Introduction: -------------- - -This document provides several notes related to the design of the Android -dynamic linker. - - -Initialization and Termination functions: ------------------------------------------ - -The Unix Sys V Binary Interface standard states that an -executable can have the following entries in its .dynamic -section: - - DT_INIT - Points to the address of an initialization function - that must be called when the file is loaded. - - DT_INIT_ARRAY - Points to an array of function addresses that must be - called, in-order, to perform initialization. Some of - the entries in the array can be 0 or -1, and should - be ignored. - - Note: this is generally stored in a .init_array section - - DT_INIT_ARRAYSZ - The size of the DT_INITARRAY, if any - - DT_FINI - Points to the address of a finalization function which - must be called when the file is unloaded or the process - terminated. - - DT_FINI_ARRAY - Same as DT_INITARRAY but for finalizers. Note that the - functions must be called in reverse-order though - - Note: this is generally stored in a .fini_array section - - DT_FINI_ARRAYSZ - Size of FT_FINIARRAY - - DT_PREINIT_ARRAY - An array similar to DT_INIT_ARRAY which must *only* be - present in executables, not shared libraries, which contains - a list of functions that need to be called before any other - initialization function (i.e. DT_INIT and/or DT_INIT_ARRAY) - in the executable or any of its libraries. - - Note: this is generally stored in a .preinit_array section - - DT_PREINIT_ARRAYSZ - The size of DT_PREINIT_ARRAY - -If both a DT_INIT and DT_INITARRAY entry are present, the DT_INIT -function must be called before the DT_INITARRAY functions. - -Consequently, the DT_FINIARRAY must be parsed in reverse order before -the DT_FINI function, if both are available. - -Note that the implementation of static C++ constructors is very -much processor dependent, and may use different ELF sections. - -On the ARM (see "C++ ABI for ARM" document), the static constructors -must be called explicitly from the DT_INIT_ARRAY, and each one of them -shall register a destructor by calling the special __eabi_atexit() -function (provided by the C library). The DT_FINI_ARRAY is not used -by static C++ destructors. - -On x86, the lists of constructors and destructors are placed in special -sections named ".ctors" and ".dtors", and the DT_INIT / DT_FINI functions -are in charge of calling them explicitly. - - -Debugging: ----------- - -You can increase the verbosity of debug traces by defining the LD_DEBUG -environment variable to a numeric value from 0 to 2 (corresponding to -INFO, TRACE, and DEBUG calls in the source). This will only -affect new processes being launched. - -By default, traces are sent to logcat, with the "linker" tag. You can -change this to go to stdout instead by setting the definition of -LINKER_DEBUG_TO_LOG to 0 in "linker_debug.h". diff --git a/linker/linker_debug.h b/linker/linker_debug.h index bf9ef921f..6aeb9ac1e 100644 --- a/linker/linker_debug.h +++ b/linker/linker_debug.h @@ -31,10 +31,16 @@ #include <stdio.h> -/* set LINKER_DEBUG_TO_LOG to 1 to send the logs to logcat, - * or 0 to use stdout instead. - */ +// You can increase the verbosity of debug traces by defining the LD_DEBUG +// environment variable to a numeric value from 0 to 2 (corresponding to +// INFO, TRACE, and DEBUG calls in the source). This will only +// affect new processes being launched. + +// By default, traces are sent to logcat, with the "linker" tag. You can +// change this to go to stdout instead by setting the definition of +// LINKER_DEBUG_TO_LOG to 0. #define LINKER_DEBUG_TO_LOG 1 + #define TRACE_DEBUG 1 #define DO_TRACE_LOOKUP 1 #define DO_TRACE_RELO 1 |