constexpr helpers to identify core version

cores/esp8266/Arduino.h

@@ -38,6 +38,7 @@ extern "C" {
 #include "esp8266_peri.h"
 #include "twi.h"
 #include "core_esp8266_features.h"
+#include "core_esp8266_version.h"
 
 #define HIGH 0x1
 #define LOW  0x0

cores/esp8266/Esp-version.cpp

@@ -29,9 +29,6 @@
 #define STR(x) STRHELPER(x) // stringifier
 
 static const char arduino_esp8266_git_ver [] PROGMEM = STR(ARDUINO_ESP8266_GIT_DESC);
-#if LWIP_VERSION_MAJOR != 1
-static const char lwip2_version [] PROGMEM = "/lwIP:" STR(LWIP_VERSION_MAJOR) "." STR(LWIP_VERSION_MINOR) "." STR(LWIP_VERSION_REVISION);
-#endif
 static const char bearssl_version [] PROGMEM = "/BearSSL:" STR(BEARSSL_GIT);
 
 String EspClass::getFullVersion()
@@ -40,17 +37,15 @@ String EspClass::getFullVersion()
            + F("/Core:") + FPSTR(arduino_esp8266_git_ver)
 #if LWIP_VERSION_MAJOR == 1
            + F("/lwIP:") + String(LWIP_VERSION_MAJOR) + "." + String(LWIP_VERSION_MINOR) + "." + String(LWIP_VERSION_REVISION)
-#else
-           + FPSTR(lwip2_version)
-#endif
 #if LWIP_VERSION_IS_DEVELOPMENT
              + F("-dev")
 #endif
 #if LWIP_VERSION_IS_RC
              + F("rc") + String(LWIP_VERSION_RC)
 #endif
-#ifdef LWIP_HASH_STR
-             + "(" + F(LWIP_HASH_STR) + ")"
+#else // LWIP_VERSION_MAJOR != 1
+             + F("/lwIP:")
+             + F(LWIP_HASH_STR)
 #endif
              + FPSTR(bearssl_version)
            ;

cores/esp8266/core_esp8266_version.h

@@ -0,0 +1,157 @@
+
+/*
+ core_esp8266_version.h - parse "git describe" at compile time
+ Copyright (c) 2018 david gauchard. All rights reserved.
+ This file is part of the esp8266 core for Arduino environment.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef __CORE_ESP8266_VERSION_H
+#define __CORE_ESP8266_VERSION_H
+
+#include <core_version.h>
+
+#define STRHELPER(x) #x
+#define STR(x) STRHELPER(x)
+
+#ifdef __cplusplus
+extern "C++"
+{
+
+// Following constexpr functions are compiled and executed
+// *after* pre-processing and *during* compilation
+//
+// Their result is treated like a numeric constant in final binary code.
+// git tags must be in the form:
+// - <major>.<minor>.<revision>       (2.4.2) (2.5.0)
+// - <major>.<minor>.<revision>-rc<rc> (2.5.0-rc1) (2.5.0-rc2)
+//
+// "git describe" = ARDUINO_ESP8266_GIT_DESC will thus be in the form:
+// - <tag> (2.4.2) (2.5.0)
+// - <tag>-<numberOfCommits>-g<git-hash> (2.4.2-91-gcb05b86d) (2.5.0-rc3-1-gcb05b86d)
+//
+// Examples:
+// case 2.4.2 (fresh version/tag)
+//     esp8266CoreVersionSubRevision() is 0   Numeric is: 20402000
+// case 2.4.2-91-gcb05b86d:
+//     esp8266CoreVersionSubRevision() is -91 Numeric is: 20402091
+// case 2.5.0-rc3-1-gcb05b86d:
+//     esp8266CoreVersionSubRevision() is 3   Numeric is: 20499903
+// case 2.5.0:
+//     esp8266CoreVersionSubRevision() is 0   Numeric is: 20500000
+
+constexpr
+bool constexpr_isDecimal (const char c)
+{
+    return c >= '0' && c <= '9';
+}
+
+template<unsigned N> constexpr
+bool constexpr_isMinus (const char (&arr) [N], unsigned i)
+{
+    return arr[i] == '-' && constexpr_isDecimal(arr[i+1]);
+}
+
+template<unsigned N> constexpr
+int constexpr_atoi (const char (&arr) [N], unsigned i)
+{
+    return ({ // <= c++11 requires a "return statement"
+        int ret = 0;
+        int sign = 1;
+        if (arr[i] == '-')
+        {
+            sign = -1;
+            i++;
+        }
+        while (constexpr_isDecimal(arr[i]))
+            ret = 10*ret + arr[i++] - '0';
+        ret * sign;
+    });
+}
+
+template<unsigned N> constexpr
+int constexpr_extract_int (const char (&arr) [N], unsigned f)
+{
+    return ({ // <= c++11 requires a "return statement"
+        unsigned i = 0;
+        while (f && arr[i])
+        {
+            if (constexpr_isMinus(arr, i))
+                i++;
+            for (; constexpr_isDecimal(arr[i]); i++);
+            f--;
+            for (; arr[i] && !constexpr_isMinus(arr, i) && !constexpr_isDecimal(arr[i]); i++);
+        }
+        constexpr_atoi(arr, i);
+    });
+}
+
+/*
+ * version major
+ */
+constexpr
+int esp8266CoreVersionMajor ()
+{
+    return constexpr_extract_int(STR(ARDUINO_ESP8266_GIT_DESC), 0);
+}
+
+/*
+ * version minor
+ */
+constexpr
+int esp8266CoreVersionMinor ()
+{
+    return constexpr_extract_int(STR(ARDUINO_ESP8266_GIT_DESC), 1);
+}
+
+/*
+ * version revision
+ */
+constexpr
+int esp8266CoreVersionRevision ()
+{
+    return constexpr_extract_int(STR(ARDUINO_ESP8266_GIT_DESC), 2);
+}
+
+/*
+ * git commit number since last tag (negative)
+ * or RC-number (positive)
+ */
+constexpr
+int esp8266CoreVersionSubRevision ()
+{
+    return constexpr_extract_int(STR(ARDUINO_ESP8266_GIT_DESC), 3);
+}
+
+/*
+ * unique revision indentifier (never decreases)
+ */
+constexpr
+int esp8266CoreVersionNumeric ()
+{
+    return   esp8266CoreVersionMajor()    * 10000000
+           + esp8266CoreVersionMinor()    *   100000
+           + esp8266CoreVersionRevision() *     1000
+           + (esp8266CoreVersionSubRevision() < 0 ?
+               -esp8266CoreVersionSubRevision() :
+               esp8266CoreVersionSubRevision() ?
+                   esp8266CoreVersionSubRevision() - 100 :
+                   0);
+}
+
+} // extern "C++"
+#endif // __cplusplus
+#endif // __CORE_ESP8266_ESP8266_VERSION_H

libraries/esp8266/keywords.txt

@@ -77,4 +77,11 @@ WAKE_RFCAL	LITERAL1
 WAKE_NO_RFCAL	LITERAL1
 WAKE_RF_DISABLED	LITERAL1
 ADC_VCC	LITERAL1
-ADC_TOUT	LITERAL1
+ADC_TOUT	LITERAL1
+
+# constexpr
+esp8266CoreVersionMajor	LITERAL1
+esp8266CoreVersionMinor	LITERAL1
+esp8266CoreVersionRevision	LITERAL1
+esp8266CoreVersionSubRevision	LITERAL1
+esp8266CoreVersionNumeric	LITERAL1

package/README.md

@@ -57,6 +57,8 @@ Here is an overview of the release process. See the section below for detailed i
 
    * When done, put release notes into a private Gist and send the link to other maintainers for review.
 
+   * Update `version` to the release in platform.txt and commit. E.g. `2.5.0`.
+
 2. Tag the latest commit on the master branch. In this project, tags have form `X.Y.Z`, e.g. `2.4.0`, or `X.Y.Z-rcN` for release versions. Notice that there's no `v`at the beginning of the tag. Tags must be annotated, not lightweight tags. To create a tag, use git command (assuming that the master branch is checked out):
 
    ```