MSVC syntax error with if statement and variable declaration

Question

I can't figure this one out. Plain C compiled with MSVC Compiler on the command-line.

Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation. All rights reserved.

With the if (NULL == string) { return NULL; } block, I get a syntax error.

..\src\drift_charbuffer.c(78) : error C2143: syntax error : missing ';' before 'type'
..\src\drift_charbuffer.c(79) : error C2065: 'index' : undeclared identifier
..\src\drift_charbuffer.c(79) : error C2065: 'index' : undeclared identifier
..\src\drift_charbuffer.c(79) : error C2065: 'index' : undeclared identifier
..\src\drift_charbuffer.c(81) : error C2065: 'index' : undeclared identifier
..\src\drift_charbuffer.c(85) : error C2065: 'index' : undeclared identifier
..\src\drift_charbuffer.c(87) : error C2065: 'index' : undeclared identifier

But it compiles fine without the if-block. I just can't see what's wrong here.

char*
drift_charbuffer_tostring(const drift_charbuffer* buffer)
{
    // todo: UTF-8 encoding for characters outside the ASCII-range.
    char* string = drift_alloc(buffer->count + 1);
    if (NULL == string)
    {
        return NULL;
    }

    int index;     // Line: 78
    for (index = 0; index < buffer->count; ++index)
    {
        int value = *drift_charbuffer_get(buffer, index);
        if (value > 127)
            value = '?';

        string[index] = value;
    }
    string[index] = 0;
    return string;
}

Move `int index;` to top of block? (Old C may not allow variable declarations other than beginning of block. — chux - Reinstate Monica, Aug 18 '14 at 18:59
@chux Ay, that's it. Really didn't think of this. It's the Win7 SDK Compiler (v110 I think?). — Niklas R, Aug 18 '14 at 19:01
@n.m. Now that we know what the issue is, yes :) Thanks for the link btw — Niklas R, Aug 18 '14 at 19:02
BTW: Code can always make a new block level by adding `{}` around `{ int index; for (index = 0; index < buffer->count; ++index) { int value = *drift_char buffer_get(buffer, index); if (value > 127) value = '?'; string[index] = value; } string[index] = 0;}` — chux - Reinstate Monica, Aug 18 '14 at 19:10

score 2 · Accepted Answer · answered Aug 18 '14 at 19:02

2

Well, your "plain C" is actually C99 or post-C99 C. Meanwhile, MSVC compiler only supports the "classic good old plain C" AKA C89/90. In classic C it is illegal to mix statements and declarations. All declarations have to be done at the very top of the block.

answered Aug 18 '14 at 19:02

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MSVC syntax error with if statement and variable declaration

1 Answers1