Export of internal Abseil changes.

--
7fa1107161a03dac53fb84c2b06d8092616c7b13 by Abseil Team <absl-team@google.com>:

Harden the generic stacktrace implementation for use during early program execution

PiperOrigin-RevId: 226375950

--
079f9969329f5eb66f647dd3c44b17541b1bf217 by Matt Kulukundis <kfm@google.com>:

Workaround platforms that have over-aggressive warnings on -Wexit-time-destructors

PiperOrigin-RevId: 226362948

--
1447943f509be681ca5495add0162c750ef237f1 by Matt Kulukundis <kfm@google.com>:

Switch from 64 to size_t atomics so they work on embedded platforms that do not
have 64 bit atomics.

PiperOrigin-RevId: 226210704

--
d14d49837ae2bcde74051e0c79c18ee0f43866b9 by Tom Manshreck <shreck@google.com>:

Develop initial documentation for API breaking changes process:

PiperOrigin-RevId: 226210021

--
7ea3d7fe0e86979dab83a5fc9cc3bf1d6cb3bd53 by Abseil Team <absl-team@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 226195522

--
7de873e880d7f016a4fa1e08d626f0535cc470af by Abseil Team <absl-team@google.com>:

Make Abseil LICENSE files newline terminated, with a single
trailing blank line.  Also remove line-ending whitespace.

PiperOrigin-RevId: 226182949

--
7d00643fadfad7f0d992c68bd9d2ed2e5bc960b0 by Matt Kulukundis <kfm@google.com>:

Internal cleanup

PiperOrigin-RevId: 226045282

--
c4a0a11c0ce2875271191e477f3d36eaaeca4613 by Matt Kulukundis <kfm@google.com>:

Internal cleanup

PiperOrigin-RevId: 226038273

--
8ee4ebbb1ae5cda119e436e5ff7e3aa966608c10 by Matt Kulukundis <kfm@google.com>:

Adds a global sampler which tracks a fraction of live tables for collecting
telemetry data.

PiperOrigin-RevId: 226032080

--
d576446f050518cd1b0ae447d682d8552f0e7e30 by Mark Barolak <mbar@google.com>:

Replace an internal CaseEqual function with calls to the identical absl::EqualsIgnoreCase.  This closes out a rather old TODO.

PiperOrigin-RevId: 226024779

--
6b23f1ee028a5ffa608c920424f1220a117a8f3d by Abseil Team <absl-team@google.com>:

Add December 2018 LTS branch to list of LTS branches.

PiperOrigin-RevId: 226011333

--
bb0833a43bdaef4c8c059b17bcd27ba9a085a114 by Mark Barolak <mbar@google.com>:

Explicitly state that when the SimpleAtoi family of functions encounter an error, the value of their output parameter is unspecified.

Also standardize the name of the output parameter to be `out`.

PiperOrigin-RevId: 225997035

--
46c1876b1a248eabda7545daa61a74a4cdfe9077 by Abseil Team <absl-team@google.com>:

Remove deprecated CMake function absl_test, absl_library and absl_header_library

PiperOrigin-RevId: 225950041
GitOrigin-RevId: 7fa1107161a03dac53fb84c2b06d8092616c7b13
Change-Id: I2ca9d3aada9292614527d1339a7557494139b806

2 files changed, 37 insertions, 39 deletions

diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc
index 9309f9da..60c8fed1 100644
--- a/absl/strings/numbers.cc
+++ b/absl/strings/numbers.cc
@@ -35,17 +35,18 @@
 #include "absl/strings/ascii.h"
 #include "absl/strings/charconv.h"
 #include "absl/strings/internal/memutil.h"
+#include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
 
 namespace absl {
 
-bool SimpleAtof(absl::string_view str, float* value) {
-  *value = 0.0;
+bool SimpleAtof(absl::string_view str, float* out) {
+  *out = 0.0;
   str = StripAsciiWhitespace(str);
   if (!str.empty() && str[0] == '+') {
     str.remove_prefix(1);
   }
-  auto result = absl::from_chars(str.data(), str.data() + str.size(), *value);
+  auto result = absl::from_chars(str.data(), str.data() + str.size(), *out);
   if (result.ec == std::errc::invalid_argument) {
     return false;
   }
@@ -56,22 +57,22 @@ bool SimpleAtof(absl::string_view str, float* value) {
   // from_chars() with DR 3801's current wording will return max() on
   // overflow.  SimpleAtof returns infinity instead.
   if (result.ec == std::errc::result_out_of_range) {
-    if (*value > 1.0) {
-      *value = std::numeric_limits<float>::infinity();
-    } else if (*value < -1.0) {
-      *value = -std::numeric_limits<float>::infinity();
+    if (*out > 1.0) {
+      *out = std::numeric_limits<float>::infinity();
+    } else if (*out < -1.0) {
+      *out = -std::numeric_limits<float>::infinity();
     }
   }
   return true;
 }
 
-bool SimpleAtod(absl::string_view str, double* value) {
-  *value = 0.0;
+bool SimpleAtod(absl::string_view str, double* out) {
+  *out = 0.0;
   str = StripAsciiWhitespace(str);
   if (!str.empty() && str[0] == '+') {
     str.remove_prefix(1);
   }
-  auto result = absl::from_chars(str.data(), str.data() + str.size(), *value);
+  auto result = absl::from_chars(str.data(), str.data() + str.size(), *out);
   if (result.ec == std::errc::invalid_argument) {
     return false;
   }
@@ -82,10 +83,10 @@ bool SimpleAtod(absl::string_view str, double* value) {
   // from_chars() with DR 3801's current wording will return max() on
   // overflow.  SimpleAtod returns infinity instead.
   if (result.ec == std::errc::result_out_of_range) {
-    if (*value > 1.0) {
-      *value = std::numeric_limits<double>::infinity();
-    } else if (*value < -1.0) {
-      *value = -std::numeric_limits<double>::infinity();
+    if (*out > 1.0) {
+      *out = std::numeric_limits<double>::infinity();
+    } else if (*out < -1.0) {
+      *out = -std::numeric_limits<double>::infinity();
     }
   }
   return true;
@@ -93,14 +94,6 @@ bool SimpleAtod(absl::string_view str, double* value) {
 
 namespace {
 
-// TODO(rogeeff): replace with the real released thing once we figure out what
-// it is.
-inline bool CaseEqual(absl::string_view piece1, absl::string_view piece2) {
-  return (piece1.size() == piece2.size() &&
-          0 == strings_internal::memcasecmp(piece1.data(), piece2.data(),
-                                            piece1.size()));
-}
-
 // Writes a two-character representation of 'i' to 'buf'. 'i' must be in the
 // range 0 <= i < 100, and buf must have space for two characters. Example:
 //   char buf[2];
@@ -136,18 +129,18 @@ inline void PutTwoDigits(size_t i, char* buf) {
 
 }  // namespace
 
-bool SimpleAtob(absl::string_view str, bool* value) {
-  ABSL_RAW_CHECK(value != nullptr, "Output pointer must not be nullptr.");
-  if (CaseEqual(str, "true") || CaseEqual(str, "t") ||
-      CaseEqual(str, "yes") || CaseEqual(str, "y") ||
-      CaseEqual(str, "1")) {
-    *value = true;
+bool SimpleAtob(absl::string_view str, bool* out) {
+  ABSL_RAW_CHECK(out != nullptr, "Output pointer must not be nullptr.");
+  if (EqualsIgnoreCase(str, "true") || EqualsIgnoreCase(str, "t") ||
+      EqualsIgnoreCase(str, "yes") || EqualsIgnoreCase(str, "y") ||
+      EqualsIgnoreCase(str, "1")) {
+    *out = true;
     return true;
   }
-  if (CaseEqual(str, "false") || CaseEqual(str, "f") ||
-      CaseEqual(str, "no") || CaseEqual(str, "n") ||
-      CaseEqual(str, "0")) {
-    *value = false;
+  if (EqualsIgnoreCase(str, "false") || EqualsIgnoreCase(str, "f") ||
+      EqualsIgnoreCase(str, "no") || EqualsIgnoreCase(str, "n") ||
+      EqualsIgnoreCase(str, "0")) {
+    *out = false;
     return true;
   }
   return false;
diff --git a/absl/strings/numbers.h b/absl/strings/numbers.h
index f9b2ccef..dc02bc30 100644
--- a/absl/strings/numbers.h
+++ b/absl/strings/numbers.h
@@ -44,7 +44,8 @@ namespace absl {
 // Converts the given string into an integer value, returning `true` if
 // successful. The string must reflect a base-10 integer (optionally followed or
 // preceded by ASCII whitespace) whose value falls within the range of the
-// integer type.
+// integer type. If any errors are encountered, this function returns `false`,
+// leaving `out` in an unspecified state.
 template <typename int_type>
 ABSL_MUST_USE_RESULT bool SimpleAtoi(absl::string_view s, int_type* out);
 
@@ -53,24 +54,28 @@ ABSL_MUST_USE_RESULT bool SimpleAtoi(absl::string_view s, int_type* out);
 // Converts the given string (optionally followed or preceded by ASCII
 // whitespace) into a float, which may be rounded on overflow or underflow.
 // See http://en.cppreference.com/w/c/string/byte/strtof for details about the
-// allowed formats for `str`.
-ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* value);
+// allowed formats for `str`. If any errors are encountered, this function
+// returns `false`, leaving `out` in an unspecified state.
+ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* out);
 
 // SimpleAtod()
 //
 // Converts the given string (optionally followed or preceded by ASCII
 // whitespace) into a double, which may be rounded on overflow or underflow.
 // See http://en.cppreference.com/w/c/string/byte/strtof for details about the
-// allowed formats for `str`.
-ABSL_MUST_USE_RESULT bool SimpleAtod(absl::string_view str, double* value);
+// allowed formats for `str`. If any errors are encountered, this function
+// returns `false`, leaving `out` in an unspecified state.
+ABSL_MUST_USE_RESULT bool SimpleAtod(absl::string_view str, double* out);
 
 // SimpleAtob()
 //
 // Converts the given string into a boolean, returning `true` if successful.
 // The following case-insensitive strings are interpreted as boolean `true`:
 // "true", "t", "yes", "y", "1". The following case-insensitive strings
-// are interpreted as boolean `false`: "false", "f", "no", "n", "0".
-ABSL_MUST_USE_RESULT bool SimpleAtob(absl::string_view str, bool* value);
+// are interpreted as boolean `false`: "false", "f", "no", "n", "0". If any
+// errors are encountered, this function returns `false`, leaving `out` in an
+// unspecified state.
+ABSL_MUST_USE_RESULT bool SimpleAtob(absl::string_view str, bool* out);
 
 }  // namespace absl