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Warnings
Warnings produce information about potential problems which may occur during the execution of the resulting program. Warnings do not hinder compilation of the source file.
Warnings produce a message in the list file. These warning messages are in the following format:
*** WARNING number IN LINE line OF file: warning message
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is the error number. |
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corresponds to the line number in the source file or include |
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file. |
file |
is the name of the source or include file in which the error |
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was detected. |
warning message is descriptive text that is dependent upon the type of warning encountered.
The following table lists warnings by number. The warning message displayed is listed along with a brief description and possible cause and correction.
Number Warning Message and Description
173Missing return-expression
A function which returns a value of any type but int, must contain a return statement including an expression. Because of compatibility to older programs, no check is done on functions which return an int value.
182 |
Pointer to different objects |
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A pointer was assigned the address of a different type. |
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185 |
Different memory space |
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The memory space of an object declaration differs from the memory space of a |
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prior declaration for the same object. |
196Mspace probably invalid
This warning is caused by the assignment of an invalid constant value to a pointer. Valid pointer constants are long or unsigned long. The compiler uses 24 bits
(3 bytes) for pointer objects. The low-order 16 bits represent the offset. The high-order 8 bits represent the memory space selector.
198Sizeof returns zero
The calculation of the size of an object yields zero. This value may be wrong if the object is external or if not all dimension sizes of an array are known.
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Number |
Warning Message and Description |
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206 |
Missing function prototype |
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The called function is unknown because no prototype declaration exists. Calls to |
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unknown functions are always at risk that the number of parameters does not |
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correspond to the actual requirements. If this is the case, the function is called |
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incorrectly. |
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Without function prototypes, the compiler has no way to check for missing or |
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excessive parameters or their types. To avoid this warning, include prototypes of |
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the functions used in your program. |
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Function prototypes must be specified before the function is called. Note that |
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function definitions automatically produce prototypes. |
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209 |
Too few actual parameters |
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Too few actual parameters were included in a function call. |
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219 |
Long constant truncated to int |
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The value of a constant expression must be capable of being represented by an int |
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type. |
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245 |
Unknown pragma, line ignored |
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The #pragma statement is unknown, so the entire pragma line is ignored. |
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258 |
Mspace illegal on struct/union member |
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Mspace on parameter ignored |
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A member of a structure or a parameter may not contain the specification of a |
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memory type. The object to which the pointer refers may, however, contain a |
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memory type. For example: |
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struct vp { char code c; int xdata i; }; |
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generates error 258. |
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struct v1 { char c; int xdata *i; }; |
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is the correct declaration for the struct. |
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259 |
Pointer: different mspace |
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This warning is generated when two pointers that do not refer to the same memory |
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type of object are compared. |
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260 |
Pointer truncation |
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This error or warning occurs when converting a pointer to a pointer with a smaller |
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offset area. The conversion takes place, but the offset of the larger pointer is |
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truncated to fit into the smaller pointer. |
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261 |
Bit in reentrant function |
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A reentrant function cannot contain bits because bit scalars cannot be stored on |
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the virtual stack. |
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265 |
‘name’: recursive call to non-reentrant function |
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A direct recursion to a non-reentrant function was discovered. This can be |
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intentional but should be functionally checked (through the generated code) for |
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each individual case. Indirect recursions are discovered by the linker/locator. |
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Number |
Warning Message and Description |
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271Misplaced ‘asm/endasm’ control
The asm and endasm statements may not be nested. Endasm requires that an asm block be opened by a previous asm statement. For example:
#pragma asm
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assembler instruction(s)
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#pragma endasm
275Expression with possibly no effect
The compiler detected an expression which does not generate code. For example:
void test |
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{ |
int i1, |
i2, i3; |
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i1, i2, |
i3; |
/* dead expression */ |
i1 << 3; |
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/* result is not used */ |
} |
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276Constant in condition expression
The compiler detected a conditional expression with a constant value. In most cases this is a typing mistake. For example:
void test (void) { int i1, i2, i3;
if (i1 = 1) i2 = 3; /* const assigned with = */ while (i3 = 2); /* const assigned with = */
}
277Different mspaces to pointer
A typedef declaration has a conflict of the memory spaces. For example:
typedef |
char xdata XCC; |
/* |
mspace |
xdata */ |
typedef |
XCC idata PICC; |
/* |
mspace |
collision */ |
280Unreferenced symbol/label
This message identifies a symbol or label which has been defined but not used.
307Macro ‘name’: parameter count mismatch
The number of actual parameters in a macro call does not match the number of
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parameters of the macro definition. This warning indicates that too many |
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parameters were used. Excess parameters are ignored. |
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317 |
Macro ‘name’: invalid redefinition |
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A predefined macro cannot be redefined or removed. Refer to “Predefined Macro |
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Constants” on page 138 for more information. |
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322Unknown identifier
The identifier in an #if directive line is undefined (evaluates to FALSE).
323Newline expected, extra characters found
A #directive line is correct but contains extra non commented characters. For example:
#include <stdio.h> foo
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Chapter 7. Error Messages |
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Number |
Warning Message and Description |
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324Preprocessor token expected
A preprocessor token was expected but a newline character was found in input. For example: #line where the arguments to the #line directive are missing.
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