Introduction

Sun WorkShop 6 C Compiler Release

This document contains last minute information about the Sun WorkShop 6 C compiler. It describes the software corrections addressed by this release and lists the known problems, limitations, and incompatibilities.

You can view the text version of this document by typing the following at a command prompt:

example% cc -xhelp=readme

To access the HTML version of this document, point your Netscape(TM) Communicator 4 or compatible Netscape version browser to:

   file:/opt/SUNWspro/docs/index.html

Note - If your Sun WorkShop software is not installed in the /opt directory, ask your system administrator for the equivalent path on your system.

For more information about this product, see:

• Sun WorkShop 6 Release Notes -- Describes installation-related and late-breaking information about this Sun WorkShop release. Information in the release notes overrides information in all readme files.

• About Sun WorkShop 6 Documentation -- Describes the documentation available with this Sun WorkShop release and how to access it.

• What's New in Sun WorkShop 6 -- Describes the new features in this release.

Contents 

About Sun WorkShop 6 C Compiler

New Features

Software Corrections 

Problems and Workarounds 

Limitations and Incompatibilities 

Documentation Errata 

The Sun WorkShop 6 C compiler (cc) runs on the Solaris(TM) Operating Environment (SPARC(TM) Platform Edition) and Solaris(TM) Operating Environment (Intel Platform Edition) versions 2.6, 7, and 8. Information unique to one or more platforms is identified as "(SPARC)" or "(IA)." 

This compiler is fully compliant with the ANSI/ISO C language and environment standard (ANSI/ISO 9899-1990), and it also supports traditional K&R C.

The 64-bit SPARC architecture features in this release provide support for the C International Standard and for -xarch=v9. 

This release of the Sun WorkShop 6 C compiler supports the following new features:

• Incremental Link Editor Chapter

  This version of the C User's Guide includes a full chapter about the incremental link editor.

• __func__

  The C compiler now predefines a static, constant, char array named __func__ for every function definition. The array is initialized with the name of the function and can be used anywhere a static function scope array can be used, such as when printing the name of the enclosing function.

• Variable argument macro

  You can now issue a #define preprocessor directive in the following form:

  #define <identifier> (...) <replacement-list> new-line
  #define <identifier> (<identifier-list> , ...) <replacement-list> new-line

  The C preprocessor accepts a variable number of arguments for a #define preprocessor directive. If the macro definition includes an ellipsis as part of the identifier list, then there will be more arguments when the macro is invoked then there were parameters in the macro definition.

• SUNW_MP_THR_IDLE

  You can now use the SUNW_MP_THR_IDLE environment variable to control whether a thread continues to use system resources after it finishes its task or it "sleeps."

• Large arrays

  The C compiler now supports significantly larger array objects. For specifics, see Appendix A of the C User's Guide.

• -errchk=locfmtchk

  lint now accepts a new flag, -errchk=locfmtchk, that checks for printf-like format strings during lint's first pass.

• New lint directive (PRINTFLIKE(n))

  lint now accepts a new directive that identifies all calls to the printf() family through a pointer. All such calls through the pointer can now be checked for argument consistency by lint.

• -errwarn=t

  The C compiler and the lint source code checker now support a new option -errwarn=t, which causes the compiler to exit with a failure status if any of the specified warnings are issued.

• -errchk

  The -errchk option of lint now has a new value signext that you can use in conjunction with the longptr64 option: -errchk=longptr64,signext. This new option warns about sign extension in order to facilitate migration to the 64-bit development environment.

• -xchar_byte_order

  The -xchar_byte_order option produces an integer constant by placing the characters of a multi-character character-constant in the specified byte order.

• -xinline

  The -xinline option now accepts two new values: %auto and no%function_name. The %auto value takes effect at the -x04 level of optimization and allows the compiler to automatically inline functions in addition to those listed in -xinline. The no%function_name value tells the compiler to not inline the function function_name.

• -xmemalign

  The C compiler now offers a new option called -xmemalign. This option controls code generated for potentially misaligned memory accesses and controls program behavior in the event of a misaligned access.

• -xprefetch

  SPARC only - You can use the new option -xprefetch, in conjunction with the header file, sun_prefetch.h to specify prefetch instructions on those architectures that support prefetch, such as UltraSPARC II.

• -xvector

  The -xvector option enables automatic generation of calls to the vector library functions.

There is no new information at this time. 

This section discusses the following software bugs that could not be fixed in time for this release. Check Hot News for Sun WorkShop 6 (http://www.sun.com/workshop/users/ws.html) for updated information. 

Intel Only

On Solaris 2.6 and 7, you need a patch to correctly divide two values of type long long. Visit http://sunsolve.Sun.COM and search for a patch that fixes any of these bugs: 4291587, 4170068.

• Example 1 of this problem:

  #include 
  
  main(int argc, char **argv)
  {
  	unsigned long long a, b, c;
  
  	b = 14767657705731979164;
  	c = 8930435072;
  
  	a = b % c;
  	printf("%llu %llu %lld\n", a, b, c);
  }
  
  /opt/SunWSpro/bin/cc:
  outputs: 18446567979202000796 14767657705731979164 8930435072
  

  Here is the correct output:

  outputs : 4741633948 14767657705731979164 8930435072
  

• Example 2 of this problem:

  ----------------------
  test.c
  ----------------------
  #include 
  #include 
  
  #define A (15683869288531500908ULL)
  #define B (193107421370ULL)
  #define C (81218366ULL)
  
  unsigned long long get_a() { return A;   }
  unsigned long long get_b() { return B;   }
  unsigned long long getresult() { return get_a()/get_b(); }
  
  int main()
  {
    printf("%llu / %llu : compiler evaluation: %llu run-time evaluation: %llu expected: %llu\n",
  	A,
     	B,
  	A / B,                 /* evaluated at compile time */
  	getresult(),           /* evaluated at run-time when we compile w/o optimization */
      C);
  }
  

  Output from Intel compiler:

  15683869288531500908 / 193107421370 : compiler evaluation: 81218404 run-time evaluation: 81218404 expected: 81218366
  

  Here is the correct output:

  15683869288531500908 / 193107421370 : compiler evaluation: 81218366 run-time evaluation: 81218366 expected: 81218366
  

There is no new information at this time. 

• The description for #pragma opt level (funcname[, funcname]) should read as follows:

  The value of level specifies the optimization level for the funcname subprograms. You can assign the following value to level: 0, 1, 2, 3, 4, 5. You can turn off optimization by setting level to 0. The funcname subprograms must be prototyped prior to the pragma. The level of optimization for any function listed in the pragma is reduced to the value of -xmaxopt. The pragma is ignored when -xmaxopt=off.  

 

• The C User's Guide does not mention generic64 and native64 as possible settings for -xtarget, -xarch, and -xchip. See the cc(1) man page for details.

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