[libsanitizer] Add descriptions for the common flags.

Use new(allocator_for_flags) instead of allocator_for_flags.Allocate()
Fix the description output format a bit.

llvm-svn: 204484

2 files changed, 60 insertions, 61 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc b/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
index e612fa6f8c2..2fd5d2643fd 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_flags.cc
@@ -56,31 +56,66 @@ void SetCommonFlagsDefaults(CommonFlags *f) {
 }
 
 void ParseCommonFlagsFromString(CommonFlags *f, const char *str) {
-  ParseFlag(str, &f->symbolize, "symbolize", "");
-  ParseFlag(str, &f->external_symbolizer_path, "external_symbolizer_path", "");
-  ParseFlag(str, &f->allow_addr2line, "allow_addr2line", "");
-  ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix", "");
-  ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal", "");
-  ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc", "");
-  ParseFlag(str, &f->handle_ioctl, "handle_ioctl", "");
-  ParseFlag(str, &f->malloc_context_size, "malloc_context_size", "");
-  ParseFlag(str, &f->log_path, "log_path", "");
-  ParseFlag(str, &f->verbosity, "verbosity", "");
-  ParseFlag(str, &f->detect_leaks, "detect_leaks", "");
-  ParseFlag(str, &f->leak_check_at_exit, "leak_check_at_exit", "");
+  ParseFlag(str, &f->symbolize, "symbolize",
+      "If set, use the online symbolizer from common sanitizer runtime to turn "
+      "virtual addresses to file/line locations.");
+  ParseFlag(str, &f->external_symbolizer_path, "external_symbolizer_path",
+      "Path to external symbolizer. If empty, the tool will search $PATH for "
+      "the symbolizer.");
+  ParseFlag(str, &f->allow_addr2line, "allow_addr2line",
+      "If set, allows online symbolizer to run addr2line binary to symbolize "
+      "stack traces (addr2line will only be used if llvm-symbolizer binary is "
+      "unavailable.");
+  ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix",
+      "Strips this prefix from file paths in error reports.");
+  ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal",
+      "If available, use the fast frame-pointer-based unwinder on fatal "
+      "errors.");
+  ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc",
+      "If available, use the fast frame-pointer-based unwinder on "
+      "malloc/free.");
+  ParseFlag(str, &f->handle_ioctl, "handle_ioctl",
+      "Intercept and handle ioctl requests.");
+  ParseFlag(str, &f->malloc_context_size, "malloc_context_size",
+      "Max number of stack frames kept for each allocation/deallocation.");
+  ParseFlag(str, &f->log_path, "log_path",
+      "Write logs to \"log_path.pid\". The special values are \"stdout\" and "
+      "\"stderr\". The default is \"stderr\".");
+  ParseFlag(str, &f->verbosity, "verbosity",
+      "Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).");
+  ParseFlag(str, &f->detect_leaks, "detect_leaks",
+      "Enable memory leak detection.");
+  ParseFlag(str, &f->leak_check_at_exit, "leak_check_at_exit",
+      "Invoke leak checking in an atexit handler. Has no effect if "
+      "detect_leaks=false, or if __lsan_do_leak_check() is called before the "
+      "handler has a chance to run.");
   ParseFlag(str, &f->allocator_may_return_null, "allocator_may_return_null",
-            "");
-  ParseFlag(str, &f->print_summary, "print_summary", "");
-  ParseFlag(str, &f->check_printf, "check_printf", "");
-  ParseFlag(str, &f->handle_segv, "handle_segv", "");
-  ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler", "");
-  ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack", "");
-  ParseFlag(str, &f->detect_deadlocks, "detect_deadlocks", "");
+      "If false, the allocator will crash instead of returning 0 on "
+      "out-of-memory.");
+  ParseFlag(str, &f->print_summary, "print_summary",
+      "If false, disable printing error summaries in addition to error "
+      "reports.");
+  ParseFlag(str, &f->check_printf, "check_printf",
+      "Check printf arguments.");
+  ParseFlag(str, &f->handle_segv, "handle_segv",
+      "If set, registers the tool's custom SEGV handler (both SIGBUS and "
+      "SIGSEGV on OSX).");
+  ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler",
+      "If set, allows user to register a SEGV handler even if the tool "
+      "registers one.");
+  ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack",
+      "If set, uses alternate stack for signal handling.");
+  ParseFlag(str, &f->detect_deadlocks, "detect_deadlocks",
+      "If set, deadlock detection is enabled.");
   ParseFlag(str, &f->clear_shadow_mmap_threshold,
-            "clear_shadow_mmap_threshold", "");
-  ParseFlag(str, &f->color, "color", "");
-  ParseFlag(str, &f->legacy_pthread_cond, "legacy_pthread_cond", "");
-  ParseFlag(str, &f->help, "help", "");
+            "clear_shadow_mmap_threshold",
+      "Large shadow regions are zero-filled using mmap(NORESERVE) instead of "
+      "memset(). This is the threshold size in bytes.");
+  ParseFlag(str, &f->color, "color",
+      "Colorize reports: (always|never|auto).");
+  ParseFlag(str, &f->legacy_pthread_cond, "legacy_pthread_cond",
+      "Enables support for dynamic libraries linked with libpthread 2.2.5.");
+  ParseFlag(str, &f->help, "help", "Print the flag descriptions.");
 
   // Do a sanity check for certain flags.
   if (f->malloc_context_size < 1)
@@ -149,8 +184,7 @@ bool FlagInDescriptionList(const char *name) {
 void AddFlagDescription(const char *name, const char *description) {
   if (FlagInDescriptionList(name)) return;
   FlagDescription *new_description =
-      (FlagDescription*)allocator_for_flags.Allocate(
-          sizeof(FlagDescription));
+      new(allocator_for_flags) FlagDescription();
   new_description->name = name;
   new_description->description = description;
   flag_descriptions.push_back(new_description);
@@ -162,7 +196,7 @@ void PrintFlagDescriptions() {
   Printf("Available flags for %s:\n", SanitizerToolName);
   while (it.hasNext()) {
     FlagDescription *descr = it.next();
-    Printf("\t%s - %s\n", descr->name, descr->description);
+    Printf("\t%s\n\t\t- %s\n", descr->name, descr->description);
   }
 }
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_flags.h b/compiler-rt/lib/sanitizer_common/sanitizer_flags.h
index 670428ba395..627040173d6 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_flags.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_flags.h
@@ -28,63 +28,28 @@ void ParseFlag(const char *env, const char **flag,
     const char *name, const char *descr);
 
 struct CommonFlags {
-  // If set, use the online symbolizer from common sanitizer runtime to turn
-  // virtual addresses to file/line locations.
   bool symbolize;
-  // Path to external symbolizer. If it is NULL, symbolizer will be looked for
-  // in PATH. If it is empty (or if "symbolize" is false), external symbolizer
-  // will not be started.
   const char *external_symbolizer_path;
-  // If set, allows online symbolizer to run addr2line binary to symbolize
-  // stack traces (addr2line will only be used if llvm-symbolizer binary is not
-  // available.
   bool allow_addr2line;
-  // Strips this prefix from file paths in error reports.
   const char *strip_path_prefix;
-  // Use fast (frame-pointer-based) unwinder on fatal errors (if available).
   bool fast_unwind_on_fatal;
-  // Use fast (frame-pointer-based) unwinder on malloc/free (if available).
   bool fast_unwind_on_malloc;
-  // Intercept and handle ioctl requests.
   bool handle_ioctl;
-  // Max number of stack frames kept for each allocation/deallocation.
   int malloc_context_size;
-  // Write logs to "log_path.pid".
-  // The special values are "stdout" and "stderr".
-  // The default is "stderr".
   const char *log_path;
-  // Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).
   int  verbosity;
-  // Enable memory leak detection.
   bool detect_leaks;
-  // Invoke leak checking in an atexit handler. Has no effect if
-  // detect_leaks=false, or if __lsan_do_leak_check() is called before the
-  // handler has a chance to run.
   bool leak_check_at_exit;
-  // If false, the allocator will crash instead of returning 0 on out-of-memory.
   bool allocator_may_return_null;
-  // If false, disable printing error summaries in addition to error reports.
   bool print_summary;
-  // Check printf arguments.
   bool check_printf;
-  // If set, registers the tool's custom SEGV handler (both SIGBUS and SIGSEGV
-  // on OSX).
   bool handle_segv;
-  // If set, allows user to register a SEGV handler even if the tool registers
-  // one.
   bool allow_user_segv_handler;
-  // If set, uses alternate stack for signal handling.
   bool use_sigaltstack;
-  // If set, deadlock detection is enabled.
   bool detect_deadlocks;
-  // Large shadow regions are zero-filled using mmap(NORESERVE) instead of
-  // memset. This is the threshold size in bytes.
   uptr clear_shadow_mmap_threshold;
-  // Colorize reports: (always|never|auto).
   const char *color;
-  // Enables support for dynamic libraries linked with libpthread 2.2.5.
   bool legacy_pthread_cond;
-  // Print help and exit.
   bool help;
 };