[compiler-rt] [sanitizer] Change return type of __sanitizer_symbolize_demangle to bool (PR #65991)

[Vitaly Buka via llvm-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/65991:

To match other internal symbolizer functions.

This makes harder to distighush small buffer from a different failure,
but we has the same problem for the rest of the lib.

Still we use 16k buffer so it should be enough most of the time.
We can fix all function togerher if future, if needed.


>From c7a94f8a82d05244eb8353652f2a6bf33b155e1f Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Sun, 10 Sep 2023 08:41:50 -0700
Subject: [PATCH] [sanitizer] Change return type of
 __sanitizer_symbolize_demangle to bool

To match other internal symbolizer functions.

This makes harder to distighush small buffer from a different failure,
but we has the same problem for the rest of the lib.

Still we use 16k buffer so it should be enough most of the time.
We can fix all function togerher if future, if needed.
---
 .../sanitizer_symbolizer_posix_libcdep.cpp    | 29 +++++++------------
 .../symbolizer/sanitizer_symbolize.cpp        |  6 ++--
 2 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
index 1317facec170416..5cba86e39fa2839 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
@@ -326,7 +326,7 @@ __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
                            char *Buffer, int MaxLength);
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void
 __sanitizer_symbolize_flush();
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE int
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool
 __sanitizer_symbolize_demangle(const char *Name, char *Buffer, int MaxLength);
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool
 __sanitizer_symbolize_set_demangle(bool Demangle);
@@ -349,7 +349,7 @@ class InternalSymbolizer final : public SymbolizerTool {
 
   bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
     bool result = __sanitizer_symbolize_code(
-        stack->info.module, stack->info.module_offset, buffer_, kBufferSize);
+        stack->info.module, stack->info.module_offset, buffer_, sizeof(buffer_));
     if (result)
       ParseSymbolizePCOutput(buffer_, stack);
     return result;
@@ -357,7 +357,7 @@ class InternalSymbolizer final : public SymbolizerTool {
 
   bool SymbolizeData(uptr addr, DataInfo *info) override {
     bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
-                                             buffer_, kBufferSize);
+                                             buffer_, sizeof(buffer_));
     if (result) {
       ParseSymbolizeDataOutput(buffer_, info);
       info->start += (addr - info->module_offset);  // Add the base address.
@@ -371,28 +371,19 @@ class InternalSymbolizer final : public SymbolizerTool {
   }
 
   const char *Demangle(const char *name) override {
-    if (__sanitizer_symbolize_demangle) {
-      for (uptr res_length = 1024;
-           res_length <= InternalSizeClassMap::kMaxSize;) {
-        char *res_buff = static_cast<char *>(InternalAlloc(res_length));
-        uptr req_length =
-            __sanitizer_symbolize_demangle(name, res_buff, res_length);
-        if (req_length > res_length) {
-          res_length = req_length + 1;
-          InternalFree(res_buff);
-          continue;
-        }
-        return res_buff;
-      }
+    if (&__sanitizer_symbolize_demangle &&
+        __sanitizer_symbolize_demangle(name, buffer_, sizeof(buffer_))) {
+      char *res_buff = nullptr;
+      ExtractToken(buffer_, "", &res_buff);
+      return res_buff;
     }
-    return name;
+    return nullptr;
   }
 
  private:
   InternalSymbolizer() {}
 
-  static const int kBufferSize = 16 * 1024;
-  char buffer_[kBufferSize];
+  char buffer_[16 * 1024];
 };
 #  else  // SANITIZER_SUPPORTS_WEAK_HOOKS
 
diff --git a/compiler-rt/lib/sanitizer_common/symbolizer/sanitizer_symbolize.cpp b/compiler-rt/lib/sanitizer_common/symbolizer/sanitizer_symbolize.cpp
index 2bc0444050f80e4..6ca4b9835bf3acd 100644
--- a/compiler-rt/lib/sanitizer_common/symbolizer/sanitizer_symbolize.cpp
+++ b/compiler-rt/lib/sanitizer_common/symbolizer/sanitizer_symbolize.cpp
@@ -115,14 +115,12 @@ void __sanitizer_symbolize_flush() {
     Symbolizer->flush();
 }
 
-int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
+bool __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
                                    int MaxLength) {
   std::string Result =
       llvm::symbolize::LLVMSymbolizer::DemangleName(Name, nullptr);
   return __sanitizer::internal_snprintf(Buffer, MaxLength, "%s",
-                                        Result.c_str()) < MaxLength
-             ? static_cast<int>(Result.size() + 1)
-             : 0;
+                                        Result.c_str()) < MaxLength;
 }
 
 bool __sanitizer_symbolize_set_demangle(bool Value) {