Fix "unsafe narrowing" warnings in absl, 1/n.

Addresses failures with the following, in some files:
-Wshorten-64-to-32
-Wimplicit-int-conversion
-Wsign-compare
-Wsign-conversion
-Wtautological-unsigned-zero-compare

(This specific CL focuses on .h and win32 .inc files.)

Bug: chromium:1292951
PiperOrigin-RevId: 463835431
Change-Id: If8e5f7f651d5cd96035e23e4623bdb08a7fedabe

2 files changed, 12 insertions, 10 deletions

diff --git a/absl/debugging/internal/stacktrace_win32-inl.inc b/absl/debugging/internal/stacktrace_win32-inl.inc
index 1c666c8b..ef2b973e 100644
--- a/absl/debugging/internal/stacktrace_win32-inl.inc
+++ b/absl/debugging/internal/stacktrace_win32-inl.inc
@@ -63,11 +63,12 @@ static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn =
 template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
 static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
                       const void*, int* min_dropped_frames) {
-  int n = 0;
-  if (!RtlCaptureStackBackTrace_fn) {
-    // can't find a stacktrace with no function to call
+  USHORT n = 0;
+  if (!RtlCaptureStackBackTrace_fn || skip_count < 0 || max_depth < 0) {
+    // can't get a stacktrace with no function/invalid args
   } else {
-    n = (int)RtlCaptureStackBackTrace_fn(skip_count + 2, max_depth, result, 0);
+    n = RtlCaptureStackBackTrace_fn(static_cast<ULONG>(skip_count) + 2,
+                                    static_cast<ULONG>(max_depth), result, 0);
   }
   if (IS_STACK_FRAMES) {
     // No implementation for finding out the stack frame sizes yet.
diff --git a/absl/debugging/symbolize_win32.inc b/absl/debugging/symbolize_win32.inc
index c3df46f6..53a099a1 100644
--- a/absl/debugging/symbolize_win32.inc
+++ b/absl/debugging/symbolize_win32.inc
@@ -65,14 +65,15 @@ bool Symbolize(const void* pc, char* out, int out_size) {
   if (!SymFromAddr(process, reinterpret_cast<DWORD64>(pc), nullptr, symbol)) {
     return false;
   }
-  strncpy(out, symbol->Name, out_size);
-  if (out[out_size - 1] != '\0') {
+  const size_t out_size_t = static_cast<size_t>(out_size);
+  strncpy(out, symbol->Name, out_size_t);
+  if (out[out_size_t - 1] != '\0') {
     // strncpy() does not '\0' terminate when it truncates.
     static constexpr char kEllipsis[] = "...";
-    int ellipsis_size =
-        std::min<int>(sizeof(kEllipsis) - 1, out_size - 1);
-    memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size);
-    out[out_size - 1] = '\0';
+    size_t ellipsis_size =
+        std::min(sizeof(kEllipsis) - 1, out_size_t - 1);
+    memcpy(out + out_size_t - ellipsis_size - 1, kEllipsis, ellipsis_size);
+    out[out_size_t - 1] = '\0';
   }
   return true;
 }