[compiler-rt] r221283 - [TSan] Keep original function and filename in ReportStack.

[Alexey Samsonov]

Author: samsonov
Date: Tue Nov  4 12:41:38 2014
New Revision: 221283

URL: http://llvm.org/viewvc/llvm-project?rev=221283&view=rev
Log:
[TSan] Keep original function and filename in ReportStack.

TSan used to do the following transformations with data obtained
from the symbolizer:
1) Strip "__interceptor_" prefix from function name.
2) Use "strip_path_prefix" runtime flag to strip filepath.

Now these transformations are performed right before the stack trace
is printed, and ReportStack structure contains original information.

This seems like a right thing to do - stripping is a detail of report
formatting implementation, and should belong there. We should, for
example, use original path to source file when we apply suppressions.

This change also make "strip_path_prefix" flag behavior in TSan
consistent with all the other sanitizers - now it should actually
match *the prefix* of path, not some substring. E.g. earlier TSan
would turn "/usr/lib/libfoo.so" into "libfoo.so" even if strip_path_prefix
was "/lib/".

Finally, strings obtained from symbolizer come from internal allocator,
and "stripping" them early by incrementing a "char*" ensures they can
never be properly deallocated, which is a bug.

Modified:
    compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc
    compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc?rev=221283&r1=221282&r2=221283&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc Tue Nov  4 12:41:38 2014
@@ -93,13 +93,25 @@ static const char *ReportTypeString(Repo
   return "";
 }
 
+static const char *StripFunctionName(const char *function, const char *prefix) {
+  if (function == 0) return 0;
+  if (prefix == 0) return function;
+  uptr prefix_len = internal_strlen(prefix);
+  if (0 == internal_strncmp(function, prefix, prefix_len))
+    return function + prefix_len;
+  return function;
+}
+
 void PrintStack(const ReportStack *ent) {
   if (ent == 0) {
     Printf("    [failed to restore the stack]\n\n");
     return;
   }
   for (int i = 0; ent; ent = ent->next, i++) {
-    Printf("    #%d %s %s:%d", i, ent->func, ent->file, ent->line);
+    Printf("    #%d %s %s:%d", i,
+           StripFunctionName(ent->func, "__interceptor_"),
+           StripPathPrefix(ent->file, common_flags()->strip_path_prefix),
+           ent->line);
     if (ent->col)
       Printf(":%d", ent->col);
     if (ent->module && ent->offset) {

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc?rev=221283&r1=221282&r2=221283&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_report.cc Tue Nov  4 12:41:38 2014
@@ -59,18 +59,7 @@ bool WEAK OnReport(const ReportDesc *rep
 static void StackStripMain(ReportStack *stack) {
   ReportStack *last_frame = 0;
   ReportStack *last_frame2 = 0;
-  const char *prefix = "__interceptor_";
-  uptr prefix_len = internal_strlen(prefix);
-  const char *path_prefix = common_flags()->strip_path_prefix;
-  uptr path_prefix_len = internal_strlen(path_prefix);
-  char *pos;
   for (ReportStack *ent = stack; ent; ent = ent->next) {
-    if (ent->func && 0 == internal_strncmp(ent->func, prefix, prefix_len))
-      ent->func += prefix_len;
-    if (ent->file && (pos = internal_strstr(ent->file, path_prefix)))
-      ent->file = pos + path_prefix_len;
-    if (ent->file && ent->file[0] == '.' && ent->file[1] == '/')
-      ent->file += 2;
     last_frame2 = last_frame;
     last_frame = ent;
   }