X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fglsl%2Fs_expression.cpp;h=1a28e1d5248c637b3dd2b8cc01851e388f28c49a;hb=0779f37e1589b0ba4f1443a889f34dd83607c117;hp=4c8829fea9ac62e90d617c01feb81387bb2a1f13;hpb=195bbe8ce218533569dde1368d04da0fd229913d;p=mesa.git diff --git a/src/glsl/s_expression.cpp b/src/glsl/s_expression.cpp index 4c8829fea9a..1a28e1d5248 100644 --- a/src/glsl/s_expression.cpp +++ b/src/glsl/s_expression.cpp @@ -22,96 +22,128 @@ * DEALINGS IN THE SOFTWARE. */ -#include -#include -#include #include +#include #include "s_expression.h" -s_symbol::s_symbol(const char *tmp, size_t n) +s_symbol::s_symbol(const char *str, size_t n) { - this->str = talloc_strndup (this, tmp, n); - assert(this->str != NULL); + /* Assume the given string is already nul-terminated and in memory that + * will live as long as this node. + */ + assert(str[n] == '\0'); + this->str = str; } s_list::s_list() { } -unsigned -s_list::length() const +static void +skip_whitespace(const char *&src, char *&symbol_buffer) { - unsigned i = 0; - foreach_iter(exec_list_iterator, it, this->subexpressions) { - i++; + size_t n = strspn(src, " \v\t\r\n"); + src += n; + symbol_buffer += n; + /* Also skip Scheme-style comments: semi-colon 'til end of line */ + if (src[0] == ';') { + n = strcspn(src, "\n"); + src += n; + symbol_buffer += n; + skip_whitespace(src, symbol_buffer); } - return i; } static s_expression * -read_atom(void *ctx, const char *& src) +read_atom(void *ctx, const char *&src, char *&symbol_buffer) { s_expression *expr = NULL; - // Skip leading spaces. - src += strspn(src, " \v\t\r\n"); + skip_whitespace(src, symbol_buffer); - size_t n = strcspn(src, "( \v\t\r\n)"); + size_t n = strcspn(src, "( \v\t\r\n);"); if (n == 0) return NULL; // no atom - // Check if the atom is a number. - char *float_end = NULL; - double f = strtod(src, &float_end); - if (float_end != src) { - char *int_end = NULL; - int i = strtol(src, &int_end, 10); - // If strtod matched more characters, it must have a decimal part - if (float_end > int_end) - expr = new(ctx) s_float(f); - else - expr = new(ctx) s_int(i); + // Check for the special symbol '+INF', which means +Infinity. Note: C99 + // requires strtof to parse '+INF' as +Infinity, but we still support some + // non-C99-compliant compilers (e.g. MSVC). + if (n == 4 && strncmp(src, "+INF", 4) == 0) { + expr = new(ctx) s_float(std::numeric_limits::infinity()); } else { - // Not a number; return a symbol. - expr = new(ctx) s_symbol(src, n); + // Check if the atom is a number. + char *float_end = NULL; + float f = glsl_strtof(src, &float_end); + if (float_end != src) { + char *int_end = NULL; + int i = strtol(src, &int_end, 10); + // If strtof matched more characters, it must have a decimal part + if (float_end > int_end) + expr = new(ctx) s_float(f); + else + expr = new(ctx) s_int(i); + } else { + // Not a number; return a symbol. + symbol_buffer[n] = '\0'; + expr = new(ctx) s_symbol(symbol_buffer, n); + } } src += n; + symbol_buffer += n; return expr; } -s_expression * -s_expression::read_expression(void *ctx, const char *&src) +static s_expression * +__read_expression(void *ctx, const char *&src, char *&symbol_buffer) { - assert(src != NULL); - - s_expression *atom = read_atom(ctx, src); + s_expression *atom = read_atom(ctx, src, symbol_buffer); if (atom != NULL) return atom; - // Skip leading spaces. - src += strspn(src, " \v\t\r\n"); + skip_whitespace(src, symbol_buffer); if (src[0] == '(') { ++src; + ++symbol_buffer; s_list *list = new(ctx) s_list; s_expression *expr; - while ((expr = read_expression(ctx, src)) != NULL) { + while ((expr = __read_expression(ctx, src, symbol_buffer)) != NULL) { list->subexpressions.push_tail(expr); } - src += strspn(src, " \v\t\r\n"); + skip_whitespace(src, symbol_buffer); if (src[0] != ')') { printf("Unclosed expression (check your parenthesis).\n"); return NULL; } ++src; + ++symbol_buffer; return list; } return NULL; } +s_expression * +s_expression::read_expression(void *ctx, const char *&src) +{ + assert(src != NULL); + + /* When we encounter a Symbol, we need to save a nul-terminated copy of + * the string. However, ralloc_strndup'ing every individual Symbol is + * extremely expensive. We could avoid this by simply overwriting the + * next character (guaranteed to be whitespace, parens, or semicolon) with + * a nul-byte. But overwriting non-whitespace would mess up parsing. + * + * So, just copy the whole buffer ahead of time. Walk both, leaving the + * original source string unmodified, and altering the copy to contain the + * necessary nul-bytes whenever we encounter a symbol. + */ + char *symbol_buffer = ralloc_strdup(ctx, src); + return __read_expression(ctx, src, symbol_buffer); +} + void s_int::print() { printf("%d", this->val); @@ -130,8 +162,7 @@ void s_symbol::print() void s_list::print() { printf("("); - foreach_iter(exec_list_iterator, it, this->subexpressions) { - s_expression *expr = (s_expression*) it.get(); + foreach_in_list(s_expression, expr, &this->subexpressions) { expr->print(); if (!expr->next->is_tail_sentinel()) printf(" "); @@ -139,3 +170,48 @@ void s_list::print() printf(")"); } +// -------------------------------------------------- + +bool +s_pattern::match(s_expression *expr) +{ + switch (type) + { + case EXPR: *p_expr = expr; break; + case LIST: if (expr->is_list()) *p_list = (s_list *) expr; break; + case SYMBOL: if (expr->is_symbol()) *p_symbol = (s_symbol *) expr; break; + case NUMBER: if (expr->is_number()) *p_number = (s_number *) expr; break; + case INT: if (expr->is_int()) *p_int = (s_int *) expr; break; + case STRING: + s_symbol *sym = SX_AS_SYMBOL(expr); + if (sym != NULL && strcmp(sym->value(), literal) == 0) + return true; + return false; + }; + + return *p_expr == expr; +} + +bool +s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial) +{ + s_list *list = SX_AS_LIST(top); + if (list == NULL) + return false; + + unsigned i = 0; + foreach_in_list(s_expression, expr, &list->subexpressions) { + if (i >= n) + return partial; /* More actual items than the pattern expected */ + + if (expr == NULL || !pattern[i].match(expr)) + return false; + + i++; + } + + if (i < n) + return false; /* Less actual items than the pattern expected */ + + return true; +}