Common: Add build_timestamp.h

src/common/CMakeLists.txt

@@ -4,6 +4,7 @@ add_library(common
   assert.h
   bitfield.h
   bitutils.h
+  build_timestamp.h
   byte_stream.cpp
   byte_stream.h
   crash_handler.cpp

src/common/build_timestamp.h

@@ -0,0 +1,97 @@
+/* 
+ *
+ * Created: 29.03.2018
+ *
+ * Authors:
+ * 
+ * Assembled from the code released on Stackoverflow by:
+ *   Dennis (instructable.com/member/nqtronix)    |   https://stackoverflow.com/questions/23032002/c-c-how-to-get-integer-unix-timestamp-of-build-time-not-string
+ * and
+ *   Alexis Wilke                                 |   https://stackoverflow.com/questions/10538444/do-you-know-of-a-c-macro-to-compute-unix-time-and-date
+ *
+ * Assembled by Jean Rabault
+ * 
+ * BUILD_UNIX_TIMESTAMP gives the UNIX timestamp (unsigned long integer of seconds since 1st Jan 1970) of compilation from macros using the compiler defined __TIME__ macro.
+ * This should include Gregorian calendar leap days, in particular the 29ths of February, 100 and 400 years modulo leaps.
+ * 
+ * Careful: __TIME__ is the local time of the computer, NOT the UTC time in general!
+ * 
+ */
+
+#ifndef COMPILE_TIME_H_
+#define COMPILE_TIME_H_
+
+// Some definitions for calculation
+#define SEC_PER_MIN             60UL
+#define SEC_PER_HOUR            3600UL
+#define SEC_PER_DAY             86400UL
+#define SEC_PER_YEAR            (SEC_PER_DAY*365)
+
+// extracts 1..4 characters from a string and interprets it as a decimal value
+#define CONV_STR2DEC_1(str, i)  (str[i]>'0'?str[i]-'0':0)
+#define CONV_STR2DEC_2(str, i)  (CONV_STR2DEC_1(str, i)*10 + str[i+1]-'0')
+#define CONV_STR2DEC_3(str, i)  (CONV_STR2DEC_2(str, i)*10 + str[i+2]-'0')
+#define CONV_STR2DEC_4(str, i)  (CONV_STR2DEC_3(str, i)*10 + str[i+3]-'0')
+
+// Custom "glue logic" to convert the month name to a usable number
+#define GET_MONTH(str, i)      (str[i]=='J' && str[i+1]=='a' && str[i+2]=='n' ? 1 :     \
+                                str[i]=='F' && str[i+1]=='e' && str[i+2]=='b' ? 2 :     \
+                                str[i]=='M' && str[i+1]=='a' && str[i+2]=='r' ? 3 :     \
+                                str[i]=='A' && str[i+1]=='p' && str[i+2]=='r' ? 4 :     \
+                                str[i]=='M' && str[i+1]=='a' && str[i+2]=='y' ? 5 :     \
+                                str[i]=='J' && str[i+1]=='u' && str[i+2]=='n' ? 6 :     \
+                                str[i]=='J' && str[i+1]=='u' && str[i+2]=='l' ? 7 :     \
+                                str[i]=='A' && str[i+1]=='u' && str[i+2]=='g' ? 8 :     \
+                                str[i]=='S' && str[i+1]=='e' && str[i+2]=='p' ? 9 :     \
+                                str[i]=='O' && str[i+1]=='c' && str[i+2]=='t' ? 10 :    \
+                                str[i]=='N' && str[i+1]=='o' && str[i+2]=='v' ? 11 :    \
+                                str[i]=='D' && str[i+1]=='e' && str[i+2]=='c' ? 12 : 0)
+
+// extract the information from the time string given by __TIME__ and __DATE__
+#define __TIME_SECONDS__        CONV_STR2DEC_2(__TIME__, 6)
+#define __TIME_MINUTES__        CONV_STR2DEC_2(__TIME__, 3)
+#define __TIME_HOURS__          CONV_STR2DEC_2(__TIME__, 0)
+#define __TIME_DAYS__           CONV_STR2DEC_2(__DATE__, 4)
+#define __TIME_MONTH__          GET_MONTH(__DATE__, 0)
+#define __TIME_YEARS__          CONV_STR2DEC_4(__DATE__, 7)
+
+// Days in February
+#define _UNIX_TIMESTAMP_FDAY(year) \
+    (((year) % 400) == 0UL ? 29UL : \
+        (((year) % 100) == 0UL ? 28UL : \
+            (((year) % 4) == 0UL ? 29UL : \
+                28UL)))
+
+// Days in the year
+#define _UNIX_TIMESTAMP_YDAY(year, month, day) \
+    ( \
+        /* January */    day \
+        /* February */ + (month >=  2 ? 31UL : 0UL) \
+        /* March */    + (month >=  3 ? _UNIX_TIMESTAMP_FDAY(year) : 0UL) \
+        /* April */    + (month >=  4 ? 31UL : 0UL) \
+        /* May */      + (month >=  5 ? 30UL : 0UL) \
+        /* June */     + (month >=  6 ? 31UL : 0UL) \
+        /* July */     + (month >=  7 ? 30UL : 0UL) \
+        /* August */   + (month >=  8 ? 31UL : 0UL) \
+        /* September */+ (month >=  9 ? 31UL : 0UL) \
+        /* October */  + (month >= 10 ? 30UL : 0UL) \
+        /* November */ + (month >= 11 ? 31UL : 0UL) \
+        /* December */ + (month >= 12 ? 30UL : 0UL) \
+    )
+
+// get the UNIX timestamp from a digits representation
+#define _UNIX_TIMESTAMP(year, month, day, hour, minute, second) \
+    ( /* time */ second \
+                + minute * SEC_PER_MIN \
+                + hour * SEC_PER_HOUR \
+    + /* year day (month + day) */ (_UNIX_TIMESTAMP_YDAY(year, month, day) - 1) * SEC_PER_DAY \
+    + /* year */ (year - 1970UL) * SEC_PER_YEAR \
+                + ((year - 1969UL) / 4UL) * SEC_PER_DAY \
+                - ((year - 1901UL) / 100UL) * SEC_PER_DAY \
+                + ((year - 1601UL) / 400UL) * SEC_PER_DAY \
+    )
+
+// the UNIX timestamp
+#define BUILD_UNIX_TIMESTAMP (_UNIX_TIMESTAMP(__TIME_YEARS__, __TIME_MONTH__, __TIME_DAYS__, __TIME_HOURS__, __TIME_MINUTES__, __TIME_SECONDS__))
+
+#endif

src/common/common.vcxproj

@@ -6,6 +6,7 @@
     <ClInclude Include="assert.h" />
     <ClInclude Include="bitfield.h" />
     <ClInclude Include="bitutils.h" />
+    <ClInclude Include="build_timestamp.h" />
     <ClInclude Include="byte_stream.h" />
     <ClInclude Include="crash_handler.h" />
     <ClInclude Include="d3d11\shader_cache.h" />

src/common/common.vcxproj.filters

@@ -137,6 +137,7 @@
     <ClInclude Include="memory_settings_interface.h" />
     <ClInclude Include="threading.h" />
     <ClInclude Include="scoped_guard.h" />
+    <ClInclude Include="build_timestamp.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="gl\program.cpp">