Fix strict compiler warnings

.bazelrc

@@ -1,6 +1,9 @@
 # For all builds, use C++17
 build --cxxopt="-std=c++17"
 
+# Strict diagnostics for this repository's C++ sources.
+build:strict --per_file_copt=(co|http_client|http_server)/.*@-Wall,-Wextra,-Wpedantic,-Wconversion,-Wsign-conversion,-Wshadow,-Wnon-virtual-dtor,-Wold-style-cast,-Wcast-align,-Woverloaded-virtual,-Wnull-dereference,-Wdouble-promotion,-Wformat=2,-Wimplicit-fallthrough,-Wundef,-Wextra-semi,-Wcast-qual,-Wmissing-declarations,-Wheader-hygiene,-Wthread-safety,-Wcomma,-Wrange-loop-analysis,-Wdeprecated,-Werror,-Wno-nullability-extension,-Wno-gcc-compat,-Wno-unknown-warning-option
+
 # For Apple Silicon
 build:apple_silicon --cpu=darwin_arm64
 build:apple_silicon --features=oso_prefix_is_pwd

BUILD.bazel

@@ -2,17 +2,23 @@ package(default_visibility = ["//visibility:public"])
 
 config_setting(
   name = "macos_arm64",
-  values = {"cpu": "darwin_arm64"},
+  constraint_values = [
+    "@platforms//cpu:arm64",
+    "@platforms//os:macos",
+  ],
 )
 
 config_setting(
   name = "macos_default",
-  values = {"cpu": "darwin"},
+  constraint_values = ["@platforms//os:macos"],
 )
 
 config_setting(
   name = "macos_x86_64",
-  values = {"cpu": "darwin_x86_64"},
+  constraint_values = [
+    "@platforms//cpu:x86_64",
+    "@platforms//os:macos",
+  ],
 )
 
 alias(

MODULE.bazel

@@ -1,9 +1,10 @@
 module(
     name = "coroutines",
-    version = "3.3.2",
+    version = "3.3.3",
 )
 
 bazel_dep(name = "bazel_skylib", version = "1.9.0")
+bazel_dep(name = "platforms", version = "1.0.0")
 bazel_dep(name = "abseil-cpp", version = "20250814.1")
 bazel_dep(name = "googletest", version = "1.17.0.bcr.2")
-bazel_dep(name = "rules_cc", version = "0.2.16")
+bazel_dep(name = "rules_cc", version = "0.2.17")

co/BUILD.bazel

@@ -2,21 +2,6 @@ package(default_visibility = ["//visibility:public"])
 
 load("@rules_cc//cc:defs.bzl", "cc_library", "cc_binary", "cc_test")
 
-config_setting(
-    name = "macos_arm64",
-    values = {"cpu": "darwin_arm64"},
-)
-
-config_setting(
-    name = "macos_default",
-    values = {"cpu": "darwin"},
-)
-
-config_setting(
-    name = "macos_x86_64",
-    values = {"cpu": "darwin_x86_64"},
-)
-
 cc_library(
     name = "co",
     srcs = [

co/bitset.h

@@ -10,6 +10,8 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstdlib>
+#include <limits>
+#include <stdexcept>
 #include <vector>
 
 namespace co {
@@ -23,7 +25,13 @@ class BitSet {
   BitSet() = default;
   BitSet(int num_bits) { Resize(num_bits); }
 
-  void Resize(int num_bits) { bits_.resize(BitsToWords(num_bits)); }
+  void Resize(int num_bits) {
+    if (num_bits <= 0) {
+      bits_.clear();
+      return;
+    }
+    bits_.resize(BitsToWords(static_cast<size_t>(num_bits)));
+  }
 
   // Allocate the first free bit.
   std::uint32_t Allocate();
@@ -46,7 +54,14 @@ class BitSet {
     }
   }
 
-  int SizeInBits() const { return bits_.size() * 64; }
+  int SizeInBits() const {
+    constexpr size_t kBitsPerWord = 64;
+    if (bits_.size() >
+        static_cast<size_t>(std::numeric_limits<int>::max()) / kBitsPerWord) {
+      return std::numeric_limits<int>::max();
+    }
+    return static_cast<int>(bits_.size() * kBitsPerWord);
+  }
 
 private:
   // Note the use of explicit long long type here because
@@ -58,18 +73,29 @@ class BitSet {
 inline std::uint32_t BitSet::Allocate() {
   size_t start = 0;
   for (;;) {
-    for (std::uint32_t i = start; i < bits_.size(); i++) {
-      size_t bit = static_cast<std::uint32_t>(ffsll(~bits_[i]));
-      if (bit != 0) {
-        bits_[i] |= (1LL << (bit - 1));
-        return i * 64 + (bit - 1);
+    for (size_t i = start; i < bits_.size(); i++) {
+      const int bit_index = ffsll(~bits_[i]);
+      if (bit_index == 0) {
+        continue;
+      }
+      const size_t bit = static_cast<size_t>(bit_index);
+      const size_t allocated = i * 64 + (bit - 1);
+      if (allocated > std::numeric_limits<std::uint32_t>::max()) {
+        throw std::overflow_error("BitSet index exceeds uint32_t");
       }
+      bits_[i] |= (1ULL << (bit - 1));
+      return static_cast<std::uint32_t>(allocated);
     }
     // Expand bit set and allocate again.  There's no point in
     // searching the whole bitset again because we know it won't
     // have any zero bits in it, so start at the newly added
     // word of zeroes.
-    start = static_cast<std::uint32_t>(bits_.size());
+    constexpr size_t kMaxWords =
+        static_cast<size_t>(std::numeric_limits<std::uint32_t>::max()) / 64 + 1;
+    if (bits_.size() >= kMaxWords) {
+      throw std::overflow_error("BitSet exhausted uint32_t index space");
+    }
+    start = bits_.size();
     bits_.push_back(0);
   }
 }