[coreboot] romcc segfault

[Russell Whitaker]

On Tue, 12 Apr 2011, Stefan Reinauer wrote:

> Hi,
>
> just a heads up, I got romcc to segfault with the following sample program:
>
>
> --------------------- 8< snip 8< --------------------------------------
> typedef unsigned int u32;
> #define DEFAULT_RCBA 0xfed1c000
> #define GCS 0x3410
> #define RCBA32(x) *((volatile u32 *)(DEFAULT_RCBA + x))
>
> void test(void)
> {
>        RCBA32(GCS) &= (~0x04);
> }
> --------------------- >8 snip >8 --------------------------------------
>
> I tried to simplify this further and this construct is still crashing romcc:
>
> --------------------- 8< snip 8< --------------------------------------
>        u32 *gcs = (u32 *)(DEFAULT_RCBA + GCS);
>        *gcs &= (~0x04);
> --------------------- >8 snip >8 --------------------------------------
>
> while this one is working
>
> --------------------- 8< snip 8< --------------------------------------
>        u32 *gcs = (u32 *)(DEFAULT_RCBA + GCS);
>        u32 temp = *gcs;
>        temp &= (~0x04);
>        *gcs = temp;
> --------------------- >8 snip >8 --------------------------------------
>
> Is that a construct that we just can't/don't want to support in romcc?
> Or is there a chance we can fix that?
>
> Stefan

Just for comparison used gcc -S to compile the 3 snippets.
The first compiled without error.

2nd:
testc2.c:1:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
testc2.c:2:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&=' token

3rd:
testc3.c:1:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
testc3.c:2:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'temp'
testc3.c:3:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&=' token
testc3.c:4:9: warning: data definition has no type or storage class
testc3.c:4:16: error: 'temp' undeclared here (not in a function)
testc3.c:5:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
testc3.c:6:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'temp'
testc3.c:7:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&=' token
testc3.c:8:9: warning: data definition has no type or storage class
testc3.c:8:10: error: redefinition of 'gcs'
testc3.c:4:10: note: previous definition of 'gcs' was here
testc3.c:9:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
testc3.c:10:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'temp'
testc3.c:11:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&=' token
testc3.c:12:10: warning: data definition has no type or storage class
testc3.c:12:11: error: redefinition of 'gcs'
testc3.c:4:10: note: previous definition of 'gcs' was here

   Russ