Oh, I see. You're right, that's another bug in the old code, but easy
enough to fix. Here's the fixed patch and a test case.
If you want to optimize things, it would be great if we wouldn't end
up storing each VLA pointer twice—having it on the stack once should
be enough. I think we should be able to get away with simply setting
*vla_sp_loc to c in the initializers...
On Tue, Apr 28, 2015 at 6:52 AM, Sergey Korshunoff <[email protected]> wrote:
> Hi, Philip! A nice work :-)
>
>> PS: patch 4 can be wrong for the case of the multiple VLA declaration
>> As I understand, SP will be saved only after vla1.
>
> Let's continue. Testing a current mob tcc with 1..4 patches added.
> A test program:
>
> void test2()
> {
> unsigned long our_sp;
> int count = 10;
> void *addr[count];
> void *addr2[count];
> void *addr3[count];
>
> __asm__ ("\t movl %%esp,%0" : "=m"(our_sp));
> fprintf(stderr,"1: SP=%p\n", (void *)our_sp);
>
> for(;count--;) {
> int a[f()];
>
> addr[count] = a;
>
> continue;
> }
>
> __asm__ ("\t movl %%esp,%0" : "=m"(our_sp));
> fprintf(stderr,"2: SP=%p\n", (void *)our_sp);
>
> if(addr[9] == addr[0]) {
> printf("OK\n");
> } else {
> printf("NOT OK\n");
> }
> }
>
> A test compiled by gcc:
> 1: SP=0xbf896260
> 2: SP=0xbf896260
> OK
>
> A test compiled by tcc:
> 1: SP=0xbff62dc0
> 2: SP=0xbff62e20
> OK
>
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> Tinycc-devel mailing list
> [email protected]
> https://lists.nongnu.org/mailman/listinfo/tinycc-devel
diff --git a/tccgen.c b/tccgen.c
index 88b8c72..8c1165f 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -3480,7 +3480,7 @@ static void post_type(CType *type, AttributeDef *ad)
vla_runtime_type_size(type, &align);
gen_op('*');
- vset(&int_type, VT_LOCAL|VT_LVAL, loc);
+ vset(&int_type, VT_LOCAL|VT_LVAL, n);
vswap();
vstore();
}
@@ -4809,7 +4809,7 @@ static void block(int *bsym, int *csym, int *case_sym,
int *def_sym,
gsym_addr(b, d);
} else if (tok == '{') {
Sym *llabel;
- int block_vla_sp_loc, *saved_vla_sp_loc, saved_vla_flags;
+ int block_vla_sp_loc, *saved_vla_sp_loc, saved_vla_flags,
*orig_vla_sp_loc;
next();
/* record local declaration stack position */
@@ -4822,7 +4822,8 @@ static void block(int *bsym, int *csym, int *case_sym,
int *def_sym,
/* save VLA state */
block_vla_sp_loc = *(saved_vla_sp_loc = vla_sp_loc);
if (saved_vla_sp_loc != &vla_sp_root_loc)
- vla_sp_loc = &block_vla_sp_loc;
+ vla_sp_loc = &block_vla_sp_loc;
+ orig_vla_sp_loc = vla_sp_loc;
saved_vla_flags = vla_flags;
vla_flags |= VLA_NEED_NEW_FRAME;
@@ -4878,10 +4879,10 @@ static void block(int *bsym, int *csym, int *case_sym,
int *def_sym,
/* Pop VLA frames and restore stack pointer if required */
if (saved_vla_sp_loc != &vla_sp_root_loc)
*saved_vla_sp_loc = block_vla_sp_loc;
- if (vla_sp_loc != (saved_vla_sp_loc == &vla_sp_root_loc ?
&vla_sp_root_loc : &block_vla_sp_loc)) {
- vla_sp_loc = saved_vla_sp_loc;
- gen_vla_sp_restore(*vla_sp_loc);
+ if (vla_sp_loc != orig_vla_sp_loc) {
+ gen_vla_sp_restore(*saved_vla_sp_loc);
}
+ vla_sp_loc = saved_vla_sp_loc;
vla_flags = (vla_flags & ~VLA_SCOPE_FLAGS) | (saved_vla_flags &
VLA_SCOPE_FLAGS);
next();
@@ -5482,6 +5483,8 @@ static void decl_initializer(CType *type, Section *sec,
unsigned long c,
vla_runtime_type_size(type, &a);
gen_vla_alloc(type, a);
+ vla_flags = VLA_IN_SCOPE;
+ vla_sp_save();
vset(type, VT_LOCAL|VT_LVAL, c);
vswap();
vstore();
diff --git a/tests/tests2/79_vla_continue.c b/tests/tests2/79_vla_continue.c
index 9c48c1d..19301e0 100644
--- a/tests/tests2/79_vla_continue.c
+++ b/tests/tests2/79_vla_continue.c
@@ -81,12 +81,36 @@ void test4()
}
}
+void test5()
+{
+ int count = 10;
+ int a[f()];
+ int c[f()];
+
+ c[0] = 42;
+
+ for(;count--;) {
+ int b[f()];
+ int i;
+ for (i=0; i<f(); i++) {
+ b[i] = count;
+ }
+ }
+
+ if (c[0] == 42) {
+ printf("OK\n");
+ } else {
+ printf("NOT OK\n");
+ }
+}
+
int main(void)
{
test1();
test2();
test3();
test4();
+ test5();
return 0;
}
diff --git a/tests/tests2/79_vla_continue.expect
b/tests/tests2/79_vla_continue.expect
index b462a5a..21da4d2 100644
--- a/tests/tests2/79_vla_continue.expect
+++ b/tests/tests2/79_vla_continue.expect
@@ -2,3 +2,4 @@ OK
OK
OK
OK
+OK
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