[sanitizer] Include inlined frames into __sanitizer_symbolize_pc output

[vitalybuka]

Summary

Behavior for existing used is not changing as the first line is going
to be the same, and it was invalid to try to read more lines.

New clients can read until they get empty string.

[vitalybuka]

documentation

[vitalybuka]

typo

[eugenis]

compiler-rt/include/sanitizer/common_interface_defs.h

127 ↗

(On Diff #167826)

Mention that the frames are printed in the order from most-inlined to least-inlined.

129 ↗

(On Diff #167826)

typo: inlined

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc

126

what does this condition do?

[vitalybuka]

Updated doc

[vitalybuka]

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc

126

you can provide weird "fmt" which will result in empty strings.
Having that empty string is terminator we'd like to avoid them in the middle.

[eugenis]

LGTM

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc

void __sanitizer_symbolize_pc(uptr pc, const char *fmt, char *out_buf,
   pc = StackTrace::GetPreviousInstructionPc(pc);
   SymbolizedStack *frame = Symbolizer::GetOrInit()->SymbolizePC(pc);
   if (!frame) {
     internal_strncpy(out_buf, "<can't symbolize>", out_buf_size);
     out_buf[out_buf_size - 1] = 0;
     return;
   }
   InternalScopedString frame_desc(GetPageSizeCached());
-  RenderFrame(&frame_desc, fmt, 0, frame->info,
+  uptr frame_num = 0;
+  // Reserve one byte for the final 0.
+  char *out_end = out_buf + out_buf_size - 1;
+  for (SymbolizedStack *cur = frame; cur && out_buf < out_end;
+       cur = cur->next) {
+    frame_desc.clear();
+    RenderFrame(&frame_desc, fmt, frame_num++, cur->info,
                 common_flags()->symbolize_vs_style,
                 common_flags()->strip_path_prefix);
-  internal_strncpy(out_buf, frame_desc.data(), out_buf_size);
-  out_buf[out_buf_size - 1] = 0;
+    if (!frame_desc.length())
+      continue;
+    // Reserve one byte for the terminating 0.
+    uptr n = out_end - out_buf - 1;
+    internal_strncpy(out_buf, frame_desc.data(), n);
+    out_buf += __sanitizer::Min<uptr>(n, frame_desc.length());
+    *out_buf++ = 0;
+  }
+  CHECK(out_buf <= out_end);
+  *out_buf = 0;
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void __sanitizer_symbolize_global(uptr data_addr, const char *fmt,
                                   char *out_buf, uptr out_buf_size) {
   if (!out_buf_size) return;
   out_buf[0] = 0;
   DataInfo DI;

compiler-rt/test/sanitizer_common/TestCases/symbolize_pc_inline.cc

+// RUN: %clangxx -O3  %s -o %t
+// RUN: %env_tool_opts=strip_path_prefix=/TestCases/ %run %t 2>&1 | FileCheck %s
+// RUN: %env_tool_opts=strip_path_prefix=/TestCases/:symbolize_inline_frames=0 \
+// RUN:   %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK-NOINLINE
+
+#include <sanitizer/common_interface_defs.h>
+#include <stdio.h>
+#include <string.h>
+
+char buffer[10000];
+
+__attribute__((noinline)) static void Symbolize() {
+  __sanitizer_symbolize_pc(__builtin_return_address(0), "%p %F %L", buffer,
+                           sizeof(buffer));
+  for (char *p = buffer; strlen(p); p += strlen(p) + 1)
+    printf("%s\n", p);
+}
+
+// CHECK-NOINLINE: {{0x[0-9a-f]+}} in main symbolize_pc_inline.cc:[[@LINE+2]]
+// CHECK: [[ADDR:0x[0-9a-f]+]] in C2 symbolize_pc_inline.cc:[[@LINE+1]]
+static inline void C2() { Symbolize(); }
+
+// CHECK: [[ADDR]] in C3 symbolize_pc_inline.cc:[[@LINE+1]]
+static inline void C3() { C2(); }
+
+// CHECK: [[ADDR]] in C4 symbolize_pc_inline.cc:[[@LINE+1]]
+static inline void C4() { C3(); }
+
+// CHECK: [[ADDR]] in main symbolize_pc_inline.cc:[[@LINE+1]]
+int main() { C4(); }