Necessary changes were made in the aws-c-common module to support AIX…

CMakeLists.txt

@@ -129,6 +129,10 @@ else ()
         list(APPEND AWS_COMMON_OS_SRC "${ANDROID_SRC}")
         list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/system_info.c")
         list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/file_direct_io.c")
+    elseif(CMAKE_SYSTEM_NAME STREQUAL "AIX")
+        list(APPEND AWS_COMMON_OS_SRC "source/aix/*.c")
+        list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/system_info.c")
+        list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/file_direct_io.c")
     else()
         list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/system_info.c")
         list (APPEND AWS_COMMON_OS_SRC "source/platform_fallback_stubs/file_direct_io.c")

cmake/AwsCFlags.cmake

@@ -167,7 +167,9 @@ function(aws_set_common_properties target)
         # loaded at runtime which happens to use libcrypto.so from OpenSSL.
         # If the symbols from libcrypto.a aren't hidden, then SOME function calls use the libcrypto.a implementation
         # and SOME function calls use the libcrypto.so implementation, and this mismatch leads to weird crashes.
-        if (UNIX AND NOT APPLE)
+        if (CMAKE_SYSTEM_NAME STREQUAL "AIX")
+            target_link_options(${PROJECT_NAME} PRIVATE -lm -lbsd)
+        elseif (UNIX AND NOT APPLE)
             # If we used target_link_options() (CMake 3.13+) we could make these flags PUBLIC
             set_property(TARGET ${target} APPEND_STRING PROPERTY LINK_FLAGS " -Wl,--exclude-libs,libcrypto.a")
         endif()

include/aws/common/platform.h

@@ -29,6 +29,8 @@
 #    endif
 #elif __linux__
 #    define AWS_OS_LINUX
+#elif _AIX
+#    define AWS_OS_AIX
 #endif
 
 #if defined(__ANDROID__)

source/aix/time.c

@@ -0,0 +1,76 @@
+/* time.c
+   timegm() implementation for AIX platform.
+*/
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+time_t timegm (struct tm *tm);
+time_t timegm (struct tm *tm)
+{
+    static const int msum [2][12] = {
+        { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},        /* normal years */
+        { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}        /* leap years */
+    };
+    static const int mlen [2][12] = {
+        { 31, 28, 31, 30,  31,  30,  31,  31,  30,  31,  30, 31},
+        { 31, 29, 31, 30,  31,  30,  31,  31,  30,  31,  30, 31}
+    };
+    static const int tmstr_year= 1900; /* base of 'tm_year' in 'struct tm' */
+    static const int epoch_year= 1970; /* unix timestamp epoch */
+    static const int base_year=  -9999;  /* start of a 400-year period: used to be 1601,
+                                            but this allows larger range (in 64 bit)
+                                            mind you, this is proleptic Gregorian */
+    int year, ytmp, dtmp, ytmpe, dtmpe;
+    int isleapyear;
+    long long t;
+
+    if (!tm) return -1;
+
+    year = tm->tm_year + tmstr_year;
+    isleapyear= (year%4==0) - (year%100==0) + (year%400==0);
+
+    if (year<-9999    || year>9999  ||
+        tm->tm_mon<0  || tm->tm_mon>11 ||
+        tm->tm_mday<1 || tm->tm_mday>mlen[isleapyear][tm->tm_mon] ||
+        tm->tm_hour<0 || tm->tm_hour>23 ||
+        tm->tm_min<0  || tm->tm_min>59 ||
+        tm->tm_min<0  || tm->tm_sec>59) return -1;
+
+/* days between 'current year' and 'epoch_year' has to be calculated
+   in three steps: */
+
+/* 1. days between current year and 'base_year' */
+    ytmp = year - base_year;
+    dtmp = ytmp*365 + ytmp/4 - ytmp/100 + ytmp/400;
+
+/* 2. days between 'epoch year' and 'base_year' */
+    ytmpe = epoch_year - base_year;
+    dtmpe = ytmpe*365 + ytmpe/4 - ytmpe/100 + ytmpe/400;
+
+/* 3. days between 'current year' and 'epoch_year' */
+    t  = dtmp - dtmpe;
+
+    t += msum[isleapyear][tm->tm_mon];
+    t += tm->tm_mday-1;
+
+    tm->tm_wday = (t+4)%7;/* 0..6=Sun..Sat; adding 4 to adjust 1970.01.01.=Thursday; */
+    if (tm->tm_wday<0) tm->tm_wday += 7;
+    tm->tm_yday = msum[isleapyear][tm->tm_mon] + tm->tm_mday-1;
+    tm->tm_isdst= 0;
+
+    t  = t*24 + tm->tm_hour;
+    t  = t*60 + tm->tm_min;
+    t  = t*60 + tm->tm_sec;
+
+#if LONG_MAX == 2147483647L
+    if (t<LONG_MIN || t>LONG_MAX) {
+        t= -1;
+    }
+#endif
+
+    return t;
+}

source/posix/clock.c

@@ -7,6 +7,12 @@
 
 #include <time.h>
 
+/* In AIX, time.h provided NS_PER_SEC as macro, which causes compilation
+ * error, so need to undefine it.
+ */
+#if defined (AWS_OS_AIX) && defined (NS_PER_SEC)
+#undef NS_PER_SEC
+#endif
 static const uint64_t NS_PER_SEC = 1000000000;
 
 #if defined(CLOCK_BOOTTIME)