cppexp.c tweak
Neil Booth
neil@daikokuya.co.uk
Thu Jul 18 00:14:00 GMT 2002
This patch is preparing for the new diagnostic discussed
in the other thread. It removes the function pointer
indirection in cppexp.c, replacing it with a switch.
Some possibilities were in a switch before, and the
remaining ones were distinguished by a pair of if
statements before dispatch, so this arguably makes the
code a little clearer. It also avoids a bit of contortion
in the operator table.
This has passed the CPP testsuite; I'm now doing a full
bootstrap/test. I'll apply it when it succeeds.
Neil.
* cppexp.c (cpp_num_mul): Remove unused parameter.
(UNARY, BINARY, OTHER, binary_handler): Remove.
(ALWAYS_EVAL): New.
(optab): Update.
(reduce): Refactor to a large switch, don't use a function
pointer.
Index: cppexp.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppexp.c,v
retrieving revision 1.126
diff -u -p -r1.126 cppexp.c
--- cppexp.c 17 Jul 2002 17:27:13 -0000 1.126
+++ cppexp.c 18 Jul 2002 06:35:17 -0000
@@ -30,7 +30,7 @@ Boston, MA 02111-1307, USA. */
struct op
{
- cpp_num value; /* The value logically "right" of op. */
+ cpp_num value; /* The value logically "right" of op. */
enum cpp_ttype op;
};
@@ -52,8 +52,7 @@ static cpp_num num_inequality_op PARAMS
enum cpp_ttype));
static cpp_num num_equality_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
enum cpp_ttype));
-static cpp_num num_mul PARAMS ((cpp_reader *, cpp_num, cpp_num,
- enum cpp_ttype));
+static cpp_num num_mul PARAMS ((cpp_reader *, cpp_num, cpp_num));
static cpp_num num_div_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
enum cpp_ttype));
static cpp_num num_lshift PARAMS ((cpp_num, size_t, size_t));
@@ -631,60 +630,54 @@ The parser assumes all shifted operators
the flag NO_L_OPERAND is set. These semantics are automatic; any
extra semantics need to be handled with operator-specific code. */
-/* Flags. */
+/* Flags. ALWAYS_EVAL is for operators that should be evaluated even
+ if skip_eval is true; perhaps they are invalid and require a
+ diagnostic, or they might modify skip_eval. */
#define NO_L_OPERAND (1 << 0)
#define LEFT_ASSOC (1 << 1)
+#define ALWAYS_EVAL (1 << 2)
-/* Arity. */
-#define UNARY (1 << 0)
-#define BINARY (1 << 1)
-#define OTHER (1 << 2)
-
-typedef cpp_num (*binary_handler) PARAMS ((cpp_reader *, cpp_num, cpp_num,
- enum cpp_ttype));
/* Operator to priority map. Must be in the same order as the first
N entries of enum cpp_ttype. */
static const struct operator
{
uchar prio;
uchar flags;
- uchar arity;
- binary_handler handler;
} optab[] =
{
- /* EQ */ {0, 0, OTHER, NULL}, /* Shouldn't happen. */
- /* NOT */ {16, NO_L_OPERAND, UNARY, NULL},
- /* GREATER */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
- /* LESS */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
- /* PLUS */ {14, LEFT_ASSOC, BINARY, num_binary_op},
- /* MINUS */ {14, LEFT_ASSOC, BINARY, num_binary_op},
- /* MULT */ {15, LEFT_ASSOC, BINARY, num_mul},
- /* DIV */ {15, LEFT_ASSOC, BINARY, num_div_op},
- /* MOD */ {15, LEFT_ASSOC, BINARY, num_div_op},
- /* AND */ {9, LEFT_ASSOC, BINARY, num_bitwise_op},
- /* OR */ {7, LEFT_ASSOC, BINARY, num_bitwise_op},
- /* XOR */ {8, LEFT_ASSOC, BINARY, num_bitwise_op},
- /* RSHIFT */ {13, LEFT_ASSOC, BINARY, num_binary_op},
- /* LSHIFT */ {13, LEFT_ASSOC, BINARY, num_binary_op},
-
- /* MIN */ {10, LEFT_ASSOC, BINARY, num_binary_op},
- /* MAX */ {10, LEFT_ASSOC, BINARY, num_binary_op},
-
- /* COMPL */ {16, NO_L_OPERAND, UNARY, NULL},
- /* AND_AND */ {6, LEFT_ASSOC, OTHER, NULL},
- /* OR_OR */ {5, LEFT_ASSOC, OTHER, NULL},
- /* QUERY */ {3, 0, OTHER, NULL},
- /* COLON */ {4, LEFT_ASSOC, OTHER, NULL},
- /* COMMA */ {2, LEFT_ASSOC, BINARY, num_binary_op},
- /* OPEN_PAREN */ {1, NO_L_OPERAND, OTHER, NULL},
- /* CLOSE_PAREN */ {0, 0, OTHER, NULL},
- /* EOF */ {0, 0, OTHER, NULL},
- /* EQ_EQ */ {11, LEFT_ASSOC, BINARY, num_equality_op},
- /* NOT_EQ */ {11, LEFT_ASSOC, BINARY, num_equality_op},
- /* GREATER_EQ */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
- /* LESS_EQ */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
- /* UPLUS */ {16, NO_L_OPERAND, UNARY, NULL},
- /* UMINUS */ {16, NO_L_OPERAND, UNARY, NULL}
+ /* EQ */ {0, 0}, /* Shouldn't happen. */
+ /* NOT */ {16, NO_L_OPERAND},
+ /* GREATER */ {12, LEFT_ASSOC},
+ /* LESS */ {12, LEFT_ASSOC},
+ /* PLUS */ {14, LEFT_ASSOC},
+ /* MINUS */ {14, LEFT_ASSOC},
+ /* MULT */ {15, LEFT_ASSOC},
+ /* DIV */ {15, LEFT_ASSOC},
+ /* MOD */ {15, LEFT_ASSOC},
+ /* AND */ {9, LEFT_ASSOC},
+ /* OR */ {7, LEFT_ASSOC},
+ /* XOR */ {8, LEFT_ASSOC},
+ /* RSHIFT */ {13, LEFT_ASSOC},
+ /* LSHIFT */ {13, LEFT_ASSOC},
+
+ /* MIN */ {10, LEFT_ASSOC},
+ /* MAX */ {10, LEFT_ASSOC},
+
+ /* COMPL */ {16, NO_L_OPERAND},
+ /* AND_AND */ {6, LEFT_ASSOC | ALWAYS_EVAL},
+ /* OR_OR */ {5, LEFT_ASSOC | ALWAYS_EVAL},
+ /* QUERY */ {3, ALWAYS_EVAL},
+ /* COLON */ {4, LEFT_ASSOC | ALWAYS_EVAL},
+ /* COMMA */ {2, LEFT_ASSOC},
+ /* OPEN_PAREN */ {1, NO_L_OPERAND | ALWAYS_EVAL},
+ /* CLOSE_PAREN */ {0, 0},
+ /* EOF */ {0, 0},
+ /* EQ_EQ */ {11, LEFT_ASSOC},
+ /* NOT_EQ */ {11, LEFT_ASSOC},
+ /* GREATER_EQ */ {12, LEFT_ASSOC},
+ /* LESS_EQ */ {12, LEFT_ASSOC},
+ /* UPLUS */ {16, NO_L_OPERAND},
+ /* UMINUS */ {16, NO_L_OPERAND}
};
/* Parse and evaluate a C expression, reading from PFILE.
@@ -870,70 +863,112 @@ reduce (pfile, top, op)
prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
while (prio < optab[top->op].prio)
{
- if (optab[top->op].arity == UNARY)
- {
- if (!pfile->state.skip_eval)
+ if (!pfile->state.skip_eval || optab[top->op].flags & ALWAYS_EVAL)
+ switch (top->op)
+ {
+ case CPP_UPLUS:
+ case CPP_UMINUS:
+ case CPP_NOT:
+ case CPP_COMPL:
top[-1].value = num_unary_op (pfile, top->value, top->op);
- top--;
- }
- else if (optab[top->op].arity == BINARY)
- {
- if (!pfile->state.skip_eval)
- top[-1].value = (* (binary_handler) optab[top->op].handler)
- (pfile, top[-1].value, top->value, top->op);
- top--;
- }
- /* Anything changing skip_eval has to be handled here. */
- else switch (top--->op)
- {
- case CPP_OR_OR:
- if (!num_zerop (top->value))
- pfile->state.skip_eval--;
- top->value.low = !num_zerop (top->value) || !num_zerop (top[1].value);
- top->value.high = 0;
- top->value.unsignedp = false;
- top->value.overflow = false;
- break;
+ break;
- case CPP_AND_AND:
- if (num_zerop (top->value))
- pfile->state.skip_eval--;
- top->value.low = !num_zerop (top->value) && !num_zerop (top[1].value);
- top->value.high = 0;
- top->value.unsignedp = false;
- top->value.overflow = false;
- break;
+ case CPP_PLUS:
+ case CPP_MINUS:
+ case CPP_RSHIFT:
+ case CPP_LSHIFT:
+ case CPP_MIN:
+ case CPP_MAX:
+ case CPP_COMMA:
+ top[-1].value = num_binary_op (pfile, top[-1].value,
+ top->value, top->op);
+ break;
- case CPP_OPEN_PAREN:
- if (op != CPP_CLOSE_PAREN)
- {
- cpp_error (pfile, DL_ERROR, "missing ')' in expression");
- return 0;
- }
- top->value = top[1].value;
- return top;
+ case CPP_GREATER:
+ case CPP_LESS:
+ case CPP_GREATER_EQ:
+ case CPP_LESS_EQ:
+ top[-1].value
+ = num_inequality_op (pfile, top[-1].value, top->value, top->op);
+ break;
- case CPP_COLON:
- top--;
- if (!num_zerop (top->value))
- {
- pfile->state.skip_eval--;
- top->value = top[1].value;
- }
- else
- top->value = top[2].value;
- top->value.unsignedp = (top[1].value.unsignedp
- || top[2].value.unsignedp);
- break;
+ case CPP_EQ_EQ:
+ case CPP_NOT_EQ:
+ top[-1].value
+ = num_equality_op (pfile, top[-1].value, top->value, top->op);
+ break;
- case CPP_QUERY:
- cpp_error (pfile, DL_ERROR, "'?' without following ':'");
- return 0;
+ case CPP_AND:
+ case CPP_OR:
+ case CPP_XOR:
+ top[-1].value
+ = num_bitwise_op (pfile, top[-1].value, top->value, top->op);
+ break;
- default:
- goto bad_op;
- }
+ case CPP_MULT:
+ top[-1].value = num_mul (pfile, top[-1].value, top->value);
+ break;
+
+ case CPP_DIV:
+ case CPP_MOD:
+ top[-1].value = num_div_op (pfile, top[-1].value,
+ top->value, top->op);
+ break;
+
+ case CPP_OR_OR:
+ top--;
+ if (!num_zerop (top->value))
+ pfile->state.skip_eval--;
+ top->value.low = (!num_zerop (top->value)
+ || !num_zerop (top[1].value));
+ top->value.high = 0;
+ top->value.unsignedp = false;
+ top->value.overflow = false;
+ continue;
+
+ case CPP_AND_AND:
+ top--;
+ if (num_zerop (top->value))
+ pfile->state.skip_eval--;
+ top->value.low = (!num_zerop (top->value)
+ && !num_zerop (top[1].value));
+ top->value.high = 0;
+ top->value.unsignedp = false;
+ top->value.overflow = false;
+ continue;
+
+ case CPP_OPEN_PAREN:
+ if (op != CPP_CLOSE_PAREN)
+ {
+ cpp_error (pfile, DL_ERROR, "missing ')' in expression");
+ return 0;
+ }
+ top--;
+ top->value = top[1].value;
+ return top;
+
+ case CPP_COLON:
+ top -= 2;
+ if (!num_zerop (top->value))
+ {
+ pfile->state.skip_eval--;
+ top->value = top[1].value;
+ }
+ else
+ top->value = top[2].value;
+ top->value.unsignedp = (top[1].value.unsignedp
+ || top[2].value.unsignedp);
+ continue;
+
+ case CPP_QUERY:
+ cpp_error (pfile, DL_ERROR, "'?' without following ':'");
+ return 0;
+
+ default:
+ goto bad_op;
+ }
+ top--;
if (top->value.overflow && !pfile->state.skip_eval)
cpp_error (pfile, DL_PEDWARN,
"integer overflow in preprocessor expression");
@@ -1383,10 +1418,9 @@ num_part_mul (lhs, rhs)
/* Multiply two preprocessing numbers. */
static cpp_num
-num_mul (pfile, lhs, rhs, op)
+num_mul (pfile, lhs, rhs)
cpp_reader *pfile;
cpp_num lhs, rhs;
- enum cpp_ttype op ATTRIBUTE_UNUSED;
{
cpp_num result, temp;
bool unsignedp = lhs.unsignedp || rhs.unsignedp;
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