Fix version with NULLPTR in JSON output

global._version has been changed at some point to an
null-terminated string. However, its type was still a D string. Some
parts of the code base were updated to do `.length - 1`, but other like
the `compilerInfo` were forgotten. This change remedies this and:
- removes null terminator from the D string of _version
- initializes versionNumber directly and avoid the use of a __gshared
  global

src/dmd/backend/elfobj.d

@@ -1500,8 +1500,9 @@ void Obj_compiler()
  enum n = compilerHeader.length;
  char[n + maxVersionLength] compiler = compilerHeader;
 
- assert(config._version.length < maxVersionLength);
- const newLength = n + config._version.length;
+ // _version is a null-terminated D string
+ assert(config._version.length +1 < maxVersionLength);
+ const newLength = n + config._version.length + 1;
  compiler[n .. newLength] = config._version;
  comment_data.write(compiler[0 .. newLength]);
  //dbg_printf("Comment data size %d\n",comment_data.length());

src/dmd/globals.d

@@ -316,6 +316,7 @@ extern (C++) struct Global
  Array!(const(char)*)* filePath; // Array of char*'s which form the file import lookup path
 
  string _version;
+ uint _versionNumber;
  const(char)[] vendor; // Compiler backend name
 
  Param params;
@@ -370,7 +371,10 @@ extern (C++) struct Global
 
  extern (C++) void _init()
  {
+ // add NULL for the backend, but retain _version as dstring for the frontend
  _version = import("VERSION") ~ '\0';
+ _version = _version[0 .. $-1];
+ _versionNumber = calcVersionNumber();
 
  version (MARS)
  {
@@ -459,41 +463,44 @@ extern (C++) struct Global
  }
 
  /**
- Returns: the version as the number that would be returned for __VERSION__
- */
- extern(C++) uint versionNumber()
+  * Computes the version number __VERSION__ from the compiler version string.
+  */
+ private uint calcVersionNumber()
  {
- import core.stdc.ctype;
- __gshared uint cached = 0;
- if (cached == 0)
+ import core.stdc.ctype : isdigit;
+ //
+ // parse _version
+ //
+ uint major = 0;
+ uint minor = 0;
+ bool point = false;
+ // skip initial 'v'
+ foreach (const c; _version[1..$])
  {
- //
- // parse _version
- //
- uint major = 0;
- uint minor = 0;
- bool point = false;
- for (const(char)* p = _version.ptr + 1;; p++)
+ if (isdigit(cast(char)c))
  {
- const c = *p;
- if (isdigit(cast(char)c))
- {
- minor = minor * 10 + c - '0';
- }
- else if (c == '.')
- {
- if (point)
- break; // ignore everything after second '.'
- point = true;
- major = minor;
- minor = 0;
- }
- else
- break;
+ minor = minor * 10 + c - '0';
+ }
+ else if (c == '.')
+ {
+ if (point)
+ break; // ignore everything after second '.'
+ point = true;
+ major = minor;
+ minor = 0;
  }
- cached = major * 1000 + minor;
+ else
+ break;
  }
- return cached;
+ return major * 1000 + minor;
+ }
+
+ /**
+ Returns: the version as the number that would be returned for __VERSION__
+ */
+ extern(C++) uint versionNumber()
+ {
+ return _versionNumber;
  }
 
  /**

src/dmd/globals.h

@@ -281,6 +281,7 @@ struct Global
  Array<const char *> *filePath; // Array of char*'s which form the file import lookup path
 
  DString version; // Compiler version string
+ const unsigned _versionNumber; // Compiler __VERSION__ number
  DString vendor; // Compiler backend name
 
  Param params;

src/dmd/mars.d

@@ -73,7 +73,7 @@ private void logo()
 {
  printf("DMD%llu D Compiler %.*s\n%.*s %.*s\n",
  cast(ulong)size_t.sizeof * 8,
- cast(int) global._version.length - 1, global._version.ptr,
+ cast(int) global._version.length, global._version.ptr,
  cast(int)global.copyright.length, global.copyright.ptr,
  cast(int)global.written.length, global.written.ptr
  );
@@ -93,7 +93,7 @@ extern(C) void printInternalFailure(FILE* stream)
  "with, preferably, a reduced, reproducible example and the information below.\n" ~
  "DustMite (https://github.com/CyberShadow/DustMite/wiki) can help with the reduction.\n" ~
  "---\n").ptr, stream);
- stream.fprintf("DMD %.*s\n", cast(int) global._version.length - 1, global._version.ptr);
+ stream.fprintf("DMD %.*s\n", cast(int) global._version.length, global._version.ptr);
  stream.printPredefinedVersions;
  stream.printGlobalConfigs();
  fputs("---\n".ptr, stream);
@@ -1310,7 +1310,7 @@ private void printPredefinedVersions(FILE* stream)
 extern(C) void printGlobalConfigs(FILE* stream)
 {
  stream.fprintf("binary %.*s\n", cast(int)global.params.argv0.length, global.params.argv0.ptr);
- stream.fprintf("version %.*s\n", cast(int) global._version.length - 1, global._version.ptr);
+ stream.fprintf("version %.*s\n", cast(int) global._version.length, global._version.ptr);
  const iniOutput = global.inifilename ? global.inifilename : "(none)";
  stream.fprintf("config %.*s\n", cast(int)iniOutput.length, iniOutput.ptr);
  // Print DFLAGS environment variable