[compiler-rt] ASan debugging API for report info extraction and locating addresses

Reviewed at http://reviews.llvm.org/D4527

This patch is part of an effort to implement a more generic debugging API, as proposed in http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074656.html, with first part reviewed at http://reviews.llvm.org/D4466. Now adding several new APIs: __asan_report_present, __asan_get_report_{pc,bp,sp,address,type,size,description}, __asan_locate_address. These return whether an asan report happened yet, the PC, BP, SP, address, access type (read/write), access size and bug description (e.g. "heap-use-after-free"), __asan_locate_address takes a pointer and tries to locate it, i.e. say whether it is a heap pointer, a global or a stack, or whether it's a pointer into the shadow memory. If global or stack, tries to also return the variable name, address and size. If heap, tries to return the chunk address and size. Generally these should serve as an alternative to "asan_describe_address", which only returns all the data in text form. Having an API to get these data could allow having debugging scripts/extensions that could show additional information about a variable/expression/pointer. Test cases in test/asan/TestCases/debug_locate.cc and test/asan/TestCasea/debug_report.cc.




git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@218481 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/include/sanitizer/asan_interface.h b/include/sanitizer/asan_interface.h
index db0d1f5d3..8ae434008 100644
--- a/include/sanitizer/asan_interface.h
+++ b/include/sanitizer/asan_interface.h
@@ -62,6 +62,32 @@ extern "C" {
   // Print the description of addr (useful when debugging in gdb).
   void __asan_describe_address(void *addr);
 
+  // Useful for calling from a debugger to get information about an ASan error.
+  // Returns 1 if an error has been (or is being) reported, otherwise returns 0.
+  int __asan_report_present();
+
+  // Useful for calling from a debugger to get information about an ASan error.
+  // If an error has been (or is being) reported, the following functions return
+  // the pc, bp, sp, address, access type (0 = read, 1 = write), access size and
+  // bug description (e.g. "heap-use-after-free"). Otherwise they return 0.
+  void *__asan_get_report_pc();
+  void *__asan_get_report_bp();
+  void *__asan_get_report_sp();
+  void *__asan_get_report_address();
+  int __asan_get_report_access_type();
+  size_t __asan_get_report_access_size();
+  const char *__asan_get_report_description();
+
+  // Useful for calling from the debugger to get information about a pointer.
+  // Returns the category of the given pointer as a constant string.
+  // Possible return values are "global", "stack", "stack-fake", "heap",
+  // "heap-invalid", "shadow-low", "shadow-gap", "shadow-high", "unknown".
+  // If global or stack, tries to also return the variable name, address and
+  // size. If heap, tries to return the chunk address and size. 'name' should
+  // point to an allocated buffer of size 'name_size'.
+  const char *__asan_locate_address(void *addr, char *name, size_t name_size,
+                                    void **region_address, size_t *region_size);
+
   // Useful for calling from the debugger to get the allocation stack trace
   // and thread ID for a heap address. Stores up to 'size' frames into 'trace',
   // returns the number of stored frames or 0 on error.