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Supported Keil or IAR Language Extensions

Polyspace® analysis can interpret a subset of common C/C++ language constructs and extended keywords by default. For compiler-specific keywords, you must specify your choice of compiler. If you specify keil or iar for Compiler (-compiler), the Polyspace verification allows language extensions specific to the Keil or IAR compilers.

Note

If you use an IAR Embedded Workbench compiler, use the option IAR Embedded Workbench Compiler (-compiler iar-ew) to enable IAR-specific extensions of the C language.

Special Function Register Data Type

Embedded control applications frequently read and write port data, set timer registers, and read input captures. To deal with these requirements without using assembly language, some microprocessor compilers define special data types such as sfr and sbit. Typical declarations are:

sfr A0 = 0x80; 
sfr A1 = 0x81; 
sfr ADCUP = 0xDE; 
sbit EI = 0x80;

The declarations reside in header files such as regxx.h for the basic 80Cxxx micro processor. The declarations customize the compiler to the target processor.

You access a register or a port by using the sfr and sbit data as follows. However, these data types are not part of the C99 Standard.

int status,P0; 

void main (void) { 
  ADCUP = 0x08; /* Write data to register */ 
  A1 = 0xFF; /* Write data to Port */ 
  status = P0; /* Read data from Port */ 
  EI = 1; /* Set a bit (enable all interrupts) */ 
}

To analyze this type of code, use these options:

For example, if you define the sbit data type as:

sbit ADST = ADCUP^7;
Use these options:
-compiler keil -sfr-types sfr=8

The analysis then supports the Keil language extensions even if some structures, keywords, and syntax are not part of the C99 standard.

Support Additional sbit Syntax

If you use a dot (.) or colon (:) as a bit selector in the sbit definition instead of a caret (^), for example:

sbit ADST = ADCUP.7;
// or 
sbit ADST = ADCUP:7;
Run this Perl script after the preprocessing phase of the analysis to replace the dot or colon with a caret in your preprocessed code.
#!/usr/bin/perl
binmode STDOUT;

# Process every line from STDIN until EOF
while ($line = <STDIN>) {
  # Replace bit selector "." in sbit declarations by "^"
  # For example, the following line
  #   sbit readybit = ADC.2;
  # Will be replaced by:
  #   sbit readybit = ADC^2;
  $line =~ s/(sbit\s*[A-Za-z0-9_]+\s*=.*)\.([0-9])/\1^\2/g;

  # Same kind of replacement for the case where the bit selector is ":"
  $line =~ s/(sbit\s*[A-Za-z0-9_]+\s*=.*):([0-9])/\1^\2/g;

  # Print the current processed line to STDOUT
  print $line;
}
For an example of how to run a script on preprocessed files, see Command/script to apply to preprocessed files (-post-preprocessing-command).

Keywords Removed During Preprocessing

Once you specify the Keil or IAR compiler, the analysis recognizes compiler-specific keywords in your code. If a keyword is not relevant for the analysis, it is removed from the source code during preprocessing.

If you disable the keyword and use it as an identifier instead, you can encounter a compilation error when you compile your code with Polyspace. See Fix Polyspace Compilation Errors Related to Keil or IAR Compiler.

These keywords are removed during preprocessing:

  • Keil — bdata, idata, interrupt, reentrant, __interrupt.

    If macro __C51__ is defined, these keywords are also removed during preprocessing: code, data, far, huge, large, pdata, sdata, xdata, xhuge.

  • IAR — bdata, code, idata, interrupt, non_banked, pdata, plm, reentrant, __interrupt, __intrinsic.