From 93c112c587269e778494e828b23e63ae70bd451e Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Wed, 9 Apr 2025 13:32:34 -0700
Subject: [PATCH] Fix "unsafe narrowing" in absl for Emscripten

Addresses failures with -Wsign-compare.

PiperOrigin-RevId: 745713553
Change-Id: I8053c3cc097355ce3606a30a7546d92594438d37
---
 absl/base/internal/low_level_alloc.cc                 | 2 +-
 absl/debugging/internal/stacktrace_emscripten-inl.inc | 8 +++++---
 absl/debugging/symbolize_emscripten.inc               | 5 +++--
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index 2e30701e..158b6098 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -330,7 +330,7 @@ size_t GetPageSize() {
   GetSystemInfo(&system_info);
   return std::max(system_info.dwPageSize, system_info.dwAllocationGranularity);
 #elif defined(__wasm__) || defined(__asmjs__) || defined(__hexagon__)
-  return getpagesize();
+  return static_cast<size_t>(getpagesize());
 #else
   return static_cast<size_t>(sysconf(_SC_PAGESIZE));
 #endif
diff --git a/absl/debugging/internal/stacktrace_emscripten-inl.inc b/absl/debugging/internal/stacktrace_emscripten-inl.inc
index 6689300f..2f39c705 100644
--- a/absl/debugging/internal/stacktrace_emscripten-inl.inc
+++ b/absl/debugging/internal/stacktrace_emscripten-inl.inc
@@ -24,6 +24,7 @@
 #include <stdint.h>
 
 #include <atomic>
+#include <cstddef>
 #include <cstring>
 
 #include "absl/base/attributes.h"
@@ -77,7 +78,8 @@ static int UnwindImpl(void **result, uintptr_t *frames, int *sizes,
 
   int size;
   uintptr_t pc = emscripten_stack_snapshot();
-  size = emscripten_stack_unwind_buffer(pc, stack, kStackLength);
+  size =
+      static_cast<int>(emscripten_stack_unwind_buffer(pc, stack, kStackLength));
 
   int result_count = size - skip_count;
   if (result_count < 0) result_count = 0;
@@ -87,10 +89,10 @@ static int UnwindImpl(void **result, uintptr_t *frames, int *sizes,
   if (IS_STACK_FRAMES) {
     // No implementation for finding out the stack frames yet.
     if (frames != nullptr) {
-      memset(frames, 0, sizeof(*frames) * result_count);
+      memset(frames, 0, sizeof(*frames) * static_cast<size_t>(result_count));
     }
     if (sizes != nullptr) {
-      memset(sizes, 0, sizeof(*sizes) * result_count);
+      memset(sizes, 0, sizeof(*sizes) * static_cast<size_t>(result_count));
     }
   }
   if (min_dropped_frames != nullptr) {
diff --git a/absl/debugging/symbolize_emscripten.inc b/absl/debugging/symbolize_emscripten.inc
index a0f344dd..f6da0ac2 100644
--- a/absl/debugging/symbolize_emscripten.inc
+++ b/absl/debugging/symbolize_emscripten.inc
@@ -58,12 +58,13 @@ bool Symbolize(const void* pc, char* out, int out_size) {
     return false;
   }
 
-  strncpy(out, func_name, out_size);
+  strncpy(out, func_name, static_cast<size_t>(out_size));
 
   if (out[out_size - 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);
+    size_t ellipsis_size =
+        std::min(sizeof(kEllipsis) - 1, static_cast<size_t>(out_size) - 1);
     memcpy(out + out_size - ellipsis_size - 1, kEllipsis, ellipsis_size);
     out[out_size - 1] = '\0';
   }