Add a platform-independent implementation of box_strtoui64

Replaces strtoull(), which doesn't exist on older Windows compilers (MSVC < 12), and in any case doesn't necessarily return a uint64_t, so this is a better interface.
boxbackup · Jul 23, 2017 · 5da656c · 5da656c
1 parent 0458cd3
commit 5da656c
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Showing 3 changed files with 60 additions and 5 deletions.
diff --git a/lib/win32/emu.cpp b/lib/win32/emu.cpp
@@ -2,9 +2,14 @@
 
 #include "emu.h"
 
+#include <assert.h>
+#include <string.h> // for strlen()
+
+#include <iomanip>
+#include <sstream>
+
 #ifdef WIN32
 
-#include <assert.h>
 #include <fcntl.h>
 #include <process.h>
 #include <windows.h>
@@ -15,7 +20,6 @@
 
 #include <string>
 #include <list>
-#include <sstream>
 
 // message resource definitions for syslog()
 #include "messages.h"
@@ -2036,3 +2040,31 @@ bool ConvertTime_tToFileTime(const time_t from, FILETIME *pTo)
 
 #endif // WIN32
 
+// MSVC < 12 (2013) does not have strtoull(), and _strtoi64 is signed only (truncates all values
+// greater than 1<<63 to _I64_MAX, so we roll our own using std::istringstream
+// <http://stackoverflow.com/questions/1070497/c-convert-hex-string-to-signed-integer>
+uint64_t box_strtoui64(const char *nptr, const char **endptr, int base)
+{
+	std::istringstream iss((std::string(nptr)));
+	uint64_t result;
+
+	assert(base == 0 || base == 8 || base == 10 || base == 16);
+	iss >> std::setbase(base);
+	iss >> result;
+
+	if(endptr != NULL)
+	{
+		if(iss.eof())
+		{
+			*endptr = nptr + strlen(nptr);
+		}
+		else
+		{
+			assert(iss.tellg() >= 0);
+			*endptr = nptr + iss.tellg();
+		}
+	}
+
+	return result;
+}
+
diff --git a/lib/win32/emu.h b/lib/win32/emu.h
@@ -2,6 +2,12 @@
 
 #include "emu_winver.h"
 
+#include <stdint.h> // for uint64_t
+#include <stdlib.h> // for strtoull()
+
+#if ! defined EMU_INCLUDE
+#define EMU_INCLUDE
+
 #ifdef WIN32
 	#define EMU_STRUCT_STAT struct emu_stat
 	#define EMU_STAT  emu_stat
@@ -14,8 +20,7 @@
 	#define EMU_LSTAT ::lstat
 #endif
 
-#if ! defined EMU_INCLUDE && defined WIN32
-#define EMU_INCLUDE
+#ifdef WIN32
 
 // Need feature detection macros below
 #if defined BOX_CMAKE
@@ -450,4 +455,11 @@ int console_read(char* pBuffer, size_t BufferSize);
 	#pragma warning(disable:4996)		// POSIX name for this item is deprecated
 #endif // _MSC_VER
 
-#endif // !EMU_INCLUDE && WIN32
+#endif // WIN32
+
+// MSVC < 12 (2013) does not have strtoull(), and _strtoi64 is signed only (truncates all values
+// greater than 1<<63 to _I64_MAX, so we roll our own using std::istringstream
+// <http://stackoverflow.com/questions/1070497/c-convert-hex-string-to-signed-integer>
+uint64_t box_strtoui64(const char *nptr, const char **endptr, int base);
+
+#endif // !EMU_INCLUDE
diff --git a/test/common/testcommon.cpp b/test/common/testcommon.cpp
@@ -920,5 +920,16 @@ int test(int argc, const char *argv[])
 		}
 	}
 
+	// Test that box_strtoui64 works properly
+	TEST_EQUAL(1234567890123456, box_strtoui64("1234567890123456", NULL, 10));
+	TEST_EQUAL(0x1234567890123456, box_strtoui64("1234567890123456", NULL, 16));
+	TEST_EQUAL(0xd9385a13c3842ba0, box_strtoui64("d9385a13c3842ba0", NULL, 16));
+	const char *input = "12a34";
+	const char *endptr;
+	TEST_EQUAL(12, box_strtoui64(input, &endptr, 10));
+	TEST_EQUAL(input + 2, endptr);
+	TEST_EQUAL(0x12a34, box_strtoui64(input, &endptr, 16));
+	TEST_EQUAL(input + 5, endptr);
+
 	return 0;
 }