This is what is required by the C standards.
This partially reverts a change in ORCA/C 2.1.0, which should only have been applied to hexadecimal escape sequences.
For example, the following is now allowed:
typedef void v;
void foo(v) {}
This appears to be permitted under at least C99 and C11 (the C89 wording is less clear), and is accepted by other modern compilers.
This is based on a patch from Kelvin Sherlock, and in turn on code from MPW IIgs ORCA/C, but with modifications to be more standards-compliant.
Bit 1 in #pragma ignore controls a new option to (non-standardly) treat character constants with three or more characters as having type long, so they can contain up to four bytes.
Note that this patch orders the bytes the opposite way from MPW IIgs ORCA/C, but the same way as GCC and Clang.
These are enabled when bit 15 is set in the #pragma debug directive.
Support is still needed to ensure these work properly with pre-compiled headers.
This patch is from Kelvin Sherlock.
Previously, the structure load would be treated as a common subexpression eligible for elimination, but the structure would always be treated as if it had a size of 4 bytes. If it did not, this would generally lead to a crash. (I'm also not sure if dependency analysis was being performed properly for these structures.)
The following program illustrates the problem:
#pragma optimize 17
struct mystruct { char x; } ms;
static void foo(struct mystruct pk) {}
int main(void)
{
struct mystruct *p = &ms;
foo(*p);
foo(*p);
}
This could happen in certain cases where the destination is not considered "simple" (e.g. because it is a local array location that does not fit in the direct page).
The following program demonstrates the problem:
#pragma optimize 1
int main(void) {
long temp1 = 1, temp2 = 2, A[64];
long B[2] = {0};
B[1] = temp1 + temp2;
return B[1]; /* should return 3 */
}
This could occur because a temporary location might be used both in the l-value and r-value computations, but the final assignment code assumed it still had the value from the l-value computation.
The following function demonstrates this problem (*ip is not updated, and *p is trashed):
int badinc(char **p, int *ip)
{
*ip += *(*p)++;
}
Previously, several optimizations would be disabled for the rest of the translation unit whenever the keyword 'volatile' appeared. Now, if 'volatile' is used within a function, it only reduces optimization for that function, since whatever was declared as 'volatile' will be out of scope after the function is over. Uses of 'volatile' outside functions still behave as before.
This bug could both cause accesses to volatile variables to be omitted, and also cause other expressions to be erroneously optimized out in certain circumstances.
As an example, both the access of x and the call to bar() would be erroneously removed in the following program:
#pragma optimize 1
volatile int x;
int bar(void);
void foo(void)
{
if(x) ;
if(bar()) ;
}
Note that this patch disables even more optimizations than previously if the 'volatile' keyword is used anywhere in a translation unit. This is necessary for correctness given the current design of ORCA/C, but it means that care should be taken to avoid unnecessary use of 'volatile'.
This bug occurred because the generated code tried to store part of the return address to a direct page offset of 256, but instead an offset of 0 was used, resulting in an invalid return address and (typically) a crash. It could occur if the function took one or more parameters, and the total size of parameters and local variables (including compiler-generated ones) was 254 bytes.
The following program demonstrates the problem:
int main(int argc, char **argv) {
char x[244];
}
Global structs and unions with the const qualifier were not being generated in object files. This occurred because they were represented as having "defined types" and the code was not handling those types properly.
The following example demonstrated this problem:
const struct x { int i; } X = {9};
int main(void) {
return X.i;
}
This problem could cause "duplicate symbol" and "undeclared identifier" errors, for example in the following program:
typedef int f1( void );
void bar( void ) {
int i;
f1 *foo;
int baz;
i = 10;
}
int foo;
long baz;
The C standards define "pp-number" tokens handled by the preprocessor using a syntax that encompasses various things that aren't valid integer or floating constants, or are constants too large for ORCA/C to handle. These cases would previously give errors even in code skipped by the preprocessor. With this patch, most such errors in skipped code are now ignored.
This is useful, e.g., to allow for #ifdefed-out code containing 64-bit constants.
There are still some cases involving pp-numbers that should be allowed but aren't, particularly in the context of macros.
This should give C99-compatible behavior, as far as it goes. The functions aren't actually inlined, but that's just a quality-of-implementation issue. No C standard requires actual inlining.
Non-static inline functions are still not supported. The C99 semantics for them are more complicated, and they're less widely used, so they're a lower priority for now.
The "inline" function specifier can currently only come after the "static" storage class specifier. This relates to a broader issue where not all legal orderings of declaration specifiers are supported.
Since "inline" was already treated as a keyword in ORCA/C, this shouldn't create any extra compatibility issues for C89 code.
This allows code like the following to compile:
#if 0
#if some bogus stuff !
#endif
#endif
This is what the C standards require. The change affects #if, #ifdef, and #ifndef directives.
This may be needed to handle code targeted at other compilers that allow pseudo-functions such as "__has_feature" in preprocessor expressions.
This is necessary to make the "compile" command halt and not process additional source files, as well as to make occ stop and not run the linker.
Previously, this was not happening when the #error directive was used, or when an undefined label was used in a goto.
This addressed the issue with the compco07.c test case.
Previously the result type was based on the operand types (using the arithmetic conversions), which is incorrect. The following program illustrates the issue:
#include <stdio.h>
int main(void)
{
/* should print "1 0 2 2" */
printf("%i %i %lu %lu\n", 0L || 2, 0.0 && 2,
sizeof(1L || 5), sizeof(1.0 && 2.5));
}
The following is an example of a program that requires this:
#include <stdio.h>
int main(void)
{
int true = !0.0;
int false = !1.1;
printf("%i %i\n", true, false);
}
This is as required by C90. C99 and later require (u)intmax_t, which must be 64-bit or greater.
The following example shows problems with the previous behavior:
#if (30000 + 30000 == 60000) && (1 << 16 == 0x10000)
int main(void) {}
#else
#error "preprocessor error"
#endif
This avoids various problems with inappropriately processing these elements, which should not be recognized as such at preprocessing time. For example, the following program should compile without errors, but did not:
typedef long foo;
#if int+1
#if foo-1
int main(void) {}
#endif
#endif
The following is an example that would give a compile error before this patch:
int main(void)
{
unsigned long i = 1 % 3000000000;
}
The remainder operation still does not work properly for signed types when either operand is negative. It gives either errors or incorrect values in various cases, both when evaluated at compile time and run time. Fully addressing this (including the run-time cases) would require library updates.
The following example shows cases that were mis-evaluated:
/* Should print "3 10000" */
#include <stdio.h>
int main(void)
{
printf("%lu %lu\n", 100000ul / 30000ul, 100000ul % 30000ul);
}
This is a problem introduced by the scanner changes between ORCA/C 2.1.0 and ORCA/C 2.1.1 B3.
The following examples demonstrate the problem:
#define m m
m
#define f(x) f(x)
f(a)
This occurred because the values were being rounded rather than truncated when converted to long, unsigned long, or unsigned int.
This was causing problems in the C6.2.3.5.CC test case when compiled with optimization.
The below program demonstrates the problem:
#pragma optimize 1
#include <stdio.h>
int main (void)
{
long L;
unsigned int ui;
unsigned long ul;
L = -1.5;
ui = 1.5;
ul = 1.5;
printf("%li %u %lu\n", L, ui, ul); /* should print "-1 1 1" */
}
This fixes the compco09.c test case.
This implementation permits duplicate copies of type qualifiers to appear. This is technically illegal in C90, but it’s legal in C99 and later, and ORCA/C already allows this in other contexts.
This allows functions that require an OMF segment byte count of up to 128K to be compiled, although the length in memory at run time is still limited to 64K. (The OMF segment byte count is usually larger, due to the size of relocation records, etc.)
This is useful for compiling large functions, e.g. the main interpreter loop in git. It also fixes the bug shown in the compca23 test case, where functions that require a segment of over 64K may appear to compile correctly but generate corrupted OMF segment headers. This related to tracking sizes with 16-bit values that could roll over.
This patch increases the memory needed at run time by 64K. This shouldn’t generally be a problem on systems with sufficient memory, although it does increase the minimum memory requirement a bit. If behavior in low-memory configurations is a concern, buffSize could be made into a run-time option.
This would occur if ORCA/C remained in memory and was restarted after a previous execution, because the 'pc' value was not reinitialized. The ORCA linker seems to ignore the too-long segment length value, but ORCA/C should generate a correct value that actually corresponds to the length of the segment.
This is necessary to compile some very large functions, such as the main interpreter loop in Git.
This consumes about 8K of extra memory for the additional label records.
