7 files changed, 29 insertions, 5 deletions
diff --git a/absl/base/config.h b/absl/base/config.h
index 2a14fe740630..f12f84fde6b2 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -181,6 +181,13 @@
 #endif
 #endif  // defined(__ANDROID__) && defined(__clang__)
 
+// Emscripten doesn't yet support `thread_local` or `__thread`.
+// https://github.com/emscripten-core/emscripten/issues/3502
+#if defined(__EMSCRIPTEN__)
+#undef ABSL_HAVE_TLS
+#undef ABSL_HAVE_THREAD_LOCAL
+#endif  // defined(__EMSCRIPTEN__)
+
 // ABSL_HAVE_INTRINSIC_INT128
 //
 // Checks whether the __int128 compiler extension for a 128-bit integral type is
diff --git a/absl/copts/GENERATED_AbseilCopts.cmake b/absl/copts/GENERATED_AbseilCopts.cmake
index 927ef290f90c..c4948d42d495 100644
--- a/absl/copts/GENERATED_AbseilCopts.cmake
+++ b/absl/copts/GENERATED_AbseilCopts.cmake
@@ -77,6 +77,7 @@ list(APPEND ABSL_CLANG_CL_TEST_FLAGS
     "-Wno-unused-template"
     "-Wno-used-but-marked-unused"
     "-Wno-zero-as-null-pointer-constant"
+    "-Wno-gnu-include-next"
     "-Wno-gnu-zero-variadic-macro-arguments"
 )
 
@@ -180,6 +181,7 @@ list(APPEND ABSL_LLVM_TEST_FLAGS
     "-Wno-unused-template"
     "-Wno-used-but-marked-unused"
     "-Wno-zero-as-null-pointer-constant"
+    "-Wno-gnu-include-next"
     "-Wno-gnu-zero-variadic-macro-arguments"
 )
 
diff --git a/absl/copts/GENERATED_copts.bzl b/absl/copts/GENERATED_copts.bzl
index 58bdfef9378d..422b3a9b1c3a 100644
--- a/absl/copts/GENERATED_copts.bzl
+++ b/absl/copts/GENERATED_copts.bzl
@@ -78,6 +78,7 @@ ABSL_CLANG_CL_TEST_FLAGS = [
     "-Wno-unused-template",
     "-Wno-used-but-marked-unused",
     "-Wno-zero-as-null-pointer-constant",
+    "-Wno-gnu-include-next",
     "-Wno-gnu-zero-variadic-macro-arguments",
 ]
 
@@ -181,6 +182,7 @@ ABSL_LLVM_TEST_FLAGS = [
     "-Wno-unused-template",
     "-Wno-used-but-marked-unused",
     "-Wno-zero-as-null-pointer-constant",
+    "-Wno-gnu-include-next",
     "-Wno-gnu-zero-variadic-macro-arguments",
 ]
 
diff --git a/absl/copts/copts.py b/absl/copts/copts.py
index 4594fda222f4..5bede34cb8e7 100644
--- a/absl/copts/copts.py
+++ b/absl/copts/copts.py
@@ -105,6 +105,8 @@ LLVM_TEST_DISABLE_WARNINGS_FLAGS = [
     "-Wno-unused-template",
     "-Wno-used-but-marked-unused",
     "-Wno-zero-as-null-pointer-constant",
+    # For a libc++ bug fixed in r357267
+    "-Wno-gnu-include-next",
     # gtest depends on this GNU extension being offered.
     "-Wno-gnu-zero-variadic-macro-arguments",
 ]
diff --git a/absl/strings/str_cat.h b/absl/strings/str_cat.h
index 559ee0aa5294..a99aac01ebbf 100644
--- a/absl/strings/str_cat.h
+++ b/absl/strings/str_cat.h
@@ -37,7 +37,8 @@
 // attempt to pass ':' instead of ":" might result in a 58 ending up in your
 // result.
 //
-// Bools convert to "0" or "1".
+// Bools convert to "0" or "1". Pointers to types other than `char *` are not
+// valid inputs. No output is generated for null `char *` pointers.
 //
 // Floating point numbers are formatted with six-digit precision, which is
 // the default for "std::cout <<" or printf "%g" (the same as "%.6g").
diff --git a/absl/strings/str_format.h b/absl/strings/str_format.h
index da3208e10303..0b93c28856e7 100644
--- a/absl/strings/str_format.h
+++ b/absl/strings/str_format.h
@@ -20,7 +20,8 @@
 // The `str_format` library is a typesafe replacement for the family of
 // `printf()` string formatting routines within the `<cstdio>` standard library
 // header. Like the `printf` family, the `str_format` uses a "format string" to
-// perform argument substitutions based on types.
+// perform argument substitutions based on types. See the `FormatSpec` section
+// below for format string documentation.
 //
 // Example:
 //
@@ -67,6 +68,7 @@
 // In addition, the `str_format` library provides extension points for
 // augmenting formatting to new types. These extensions are fully documented
 // within the `str_format_extension.h` header file.
+
 #ifndef ABSL_STRINGS_STR_FORMAT_H_
 #define ABSL_STRINGS_STR_FORMAT_H_
 
@@ -211,6 +213,11 @@ class FormatCountCapture {
 //     written to this point. The resulting value must be captured within an
 //     `absl::FormatCountCapture` type.
 //
+// Implementation-defined behavior:
+//   * A null pointer provided to "%s" or "%p" is output as "(nil)".
+//   * A non-null pointer provided to "%p" is output in hex as if by %#x or
+//     %#lx.
+//
 // NOTE: `o`, `x\X` and `u` will convert signed values to their unsigned
 // counterpart before formatting.
 //
@@ -226,7 +233,7 @@ class FormatCountCapture {
 //     "%e", .01                -> "1.00000e-2"
 //     "%a", -3.0               -> "-0x1.8p+1"
 //     "%g", .01                -> "1e-2"
-//     "%p", *int               -> "0x7ffdeb6ad2a4"
+//     "%p", (void*)&value      -> "0x7ffdeb6ad2a4"
 //
 //     int n = 0;
 //     std::string s = absl::StrFormat(
diff --git a/absl/strings/substitute.h b/absl/strings/substitute.h
index 32dec30b63a0..233e9dcf9386 100644
--- a/absl/strings/substitute.h
+++ b/absl/strings/substitute.h
@@ -35,10 +35,13 @@
 // and single digit positional ids to indicate which substitution arguments to
 // use at that location within the format string.
 //
+// A '$$' sequence in the format string causes a literal '$' character to be
+// output.
+//
 // Example 1:
-//   std::string s = Substitute("$1 purchased $0 $2. Thanks $1!",
+//   std::string s = Substitute("$1 purchased $0 $2 for $$10. Thanks $1!",
 //                              5, "Bob", "Apples");
-//   EXPECT_EQ("Bob purchased 5 Apples. Thanks Bob!", s);
+//   EXPECT_EQ("Bob purchased 5 Apples for $10. Thanks Bob!", s);
 //
 // Example 2:
 //   std::string s = "Hi. ";