constexpr helpers to identify core version (#5269)

Author: d-a-v

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

@@ -35,6 +35,7 @@ String EspClass::getFullVersion()
 {
     return   String(F("SDK:")) + system_get_sdk_version()
            + F("/Core:") + FPSTR(arduino_esp8266_git_ver)
+           + F("=") + String(esp8266::coreVersionNumeric())
 #if LWIP_VERSION_MAJOR == 1
            + F("/lwIP:") + String(LWIP_VERSION_MAJOR) + "." + String(LWIP_VERSION_MINOR) + "." + String(LWIP_VERSION_REVISION)
 #if LWIP_VERSION_IS_DEVELOPMENT
@@ -47,9 +48,9 @@ String EspClass::getFullVersion()
              + F("/lwIP:")
 #if LWIP_IPV6
              + F("IPv6+")
-#endif
+#endif // LWIP_IPV6
              + F(LWIP_HASH_STR)
-#endif
+#endif // LWIP_VERSION_MAJOR != 1
              + FPSTR(bearssl_version)
            ;
 }

cores/esp8266/core_esp8266_version.h

@@ -0,0 +1,165 @@
+
+/*
+ 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
+
+namespace conststr {
+
+constexpr
+bool isDecimal (const char c)
+{
+    return c >= '0' && c <= '9';
+}
+
+template<unsigned N> constexpr
+bool isMinus (const char (&arr) [N], unsigned i)
+{
+    return arr[i] == '-' && isDecimal(arr[i+1]);
+}
+
+template<unsigned N> constexpr
+int 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 (isDecimal(arr[i]))
+            ret = 10*ret + arr[i++] - '0';
+        ret * sign;
+    });
+}
+
+template<unsigned N> constexpr
+int parseNthInteger (const char (&arr) [N], unsigned f)
+{
+    return ({ // <= c++11 requires a "return statement"
+        unsigned i = 0;
+        while (f && arr[i])
+        {
+            if (isMinus(arr, i))
+                i++;
+            for (; isDecimal(arr[i]); i++);
+            f--;
+            for (; arr[i] && !isMinus(arr, i) && !isDecimal(arr[i]); i++);
+        }
+        atoi(arr, i);
+    });
+}
+
+}; // namespace conststr
+
+namespace esp8266 {
+
+/*
+ * version major
+ */
+constexpr
+int coreVersionMajor ()
+{
+    return conststr::parseNthInteger(STR(ARDUINO_ESP8266_GIT_DESC), 0);
+}
+
+/*
+ * version minor
+ */
+constexpr
+int coreVersionMinor ()
+{
+    return conststr::parseNthInteger(STR(ARDUINO_ESP8266_GIT_DESC), 1);
+}
+
+/*
+ * version revision
+ */
+constexpr
+int coreVersionRevision ()
+{
+    return conststr::parseNthInteger(STR(ARDUINO_ESP8266_GIT_DESC), 2);
+}
+
+/*
+ * git commit number since last tag (negative)
+ * or RC-number (positive)
+ */
+constexpr
+int coreVersionSubRevision ()
+{
+    return conststr::parseNthInteger(STR(ARDUINO_ESP8266_GIT_DESC), 3);
+}
+
+/*
+ * unique revision indentifier (never decreases)
+ */
+constexpr
+int coreVersionNumeric ()
+{
+    return   coreVersionMajor()    * 10000000
+           + coreVersionMinor()    *   100000
+           + coreVersionRevision() *     1000
+           + (coreVersionSubRevision() < 0 ?
+               -coreVersionSubRevision() :
+               coreVersionSubRevision() ?
+                 coreVersionSubRevision() - 100 :
+                 0);
+}
+
+}; // namespace esp8266
+
+} // extern "C++"
+#endif // __cplusplus
+#endif // __CORE_ESP8266_ESP8266_VERSION_H

libraries/esp8266/keywords.txt

@@ -77,4 +77,13 @@ WAKE_RFCAL	LITERAL1
 WAKE_NO_RFCAL	LITERAL1
 WAKE_RF_DISABLED	LITERAL1
 ADC_VCC	LITERAL1
-ADC_TOUT	LITERAL1
+ADC_TOUT	LITERAL1
+
+#######################################
+# namespace esp8266
+#######################################
+coreVersionMajor	LITERAL1
+coreVersionMinor	LITERAL1
+coreVersionRevision	LITERAL1
+coreVersionSubRevision	LITERAL1
+coreVersionNumeric	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):
 
    ```