AN3350 datasheet(165/185 Pages) STMICROELECTRONICS

165 / 185 page

AN3350

Pragmas for code generation

Doc ID 018512 Rev 2

165/185

const char* str1 = "cat";

char* str2 = "cat";

char str3[] = "cat";

*str2 = 'h'; /* str1 and str2 point to "hat"! */

str3[0] = 'b';

/* OK: str3 contains "bat", *str1 and *str2 unchanged.

}

21.3

enumsalwaysint

Specifies the size of enumerated types.

Syntax

#pragma enumsalwaysint on | off | reset

Remarks

If you enable this pragma, the C/C++ compiler makes an enumerated type the same size as

an int. If an enumerated constant is larger than int, the compiler generates an error

message. Otherwise, the compiler makes an enumerated type the size of any integral type.

It chooses the integral type with the size that most closely matches the size of the largest

enumerated constant. The type could be as small as a char or as large as a long long.

Example 116 shows an example.

Example 116 Example of enumerations the same as size as int

enum SmallNumber { One = 1, Two = 2 };

/* If you enable enumsalwaysint, this type is

the same size as an int. Otherwise, this type is

the same size as a char. */

enum BigNumber

{ ThreeThousandMillion = 3000000000 };

/* If you enable enumsalwaysint, the compiler might

generate an error message. Otherwise, this type is

the same size as a long long. */

By default, this pragma is off.

21.4

errno_name

Tells the optimizer how to find the errno identifier.

Syntax

#pragma errno_name id | ...

AN3350 Datasheet(PDF) 165 Page - STMicroelectronics