Function attributes for pure and const

Author: terryburton

src/c-lib/ai.c

@@ -102,7 +102,7 @@ static bool populateAIlengthByPrefix(gs1_encoder* const ctx) {
 	return true;
 }
 
-static inline uint8_t aiLengthByPrefix(const gs1_encoder* const ctx, const char *ai) {
+static inline __ATTR_PURE uint8_t aiLengthByPrefix(const gs1_encoder* const ctx, const char *ai) {
 	assert(ai[0] >= '0' && ai[0] <= '9' && ai[1] >= '0' && ai[1] <= '9');
 	return ctx->aiLengthByPrefix[(ai[0] - '0') * 10 + (ai[1] - '0')];
 }
@@ -200,7 +200,7 @@ static const uint8_t fixedAIprefixLengths[100] = {
 	VL, VL, VL, VL, VL, VL, VL, VL, VL, VL,
 };
 
-static inline uint8_t valLengthByPrefix(const char* const ai) {
+static inline __ATTR_PURE uint8_t valLengthByPrefix(const char* const ai) {
 	assert(ai[0] >= '0' && ai[0] <= '9' && ai[1] >= '0' && ai[1] <= '9');
 	return fixedAIprefixLengths[(ai[0] - '0') * 10 + (ai[1] - '0')];
 }
@@ -411,13 +411,13 @@ static size_t validate_ai_val(gs1_encoder* const ctx, const char* const ai, cons
  * Return the overall minimum and maximum lengths for an AI, by summing the components.
  *
  */
-static inline size_t aiEntryMinLength(const struct aiEntry* const entry) {
+static inline __ATTR_PURE size_t aiEntryMinLength(const struct aiEntry* const entry) {
 	const struct aiComponent *part;
 	size_t l;
 	for (part = entry->parts, l = 0; part->cset; l+= (part->opt == MAN ? part->min : 0), part++);
 	return l;
 }
-static inline size_t aiEntryMaxLength(const struct aiEntry* const entry) {
+static inline __ATTR_PURE size_t aiEntryMaxLength(const struct aiEntry* const entry) {
 	const struct aiComponent *part;
 	size_t l;
 	for (part = entry->parts, l = 0; part->cset; l+= part->max, part++);

src/c-lib/enc-private.h

@@ -38,7 +38,16 @@
 #define strdup _strdup
 #endif
 
-#define SIZEOF_ARRAY(x) (sizeof(x) / sizeof(x[0]))
+#if defined(__GNUC__) || defined(__clang__)
+#define __ATTR_CONST __attribute__ ((__const__))
+#define __ATTR_PURE __attribute__ ((__pure__))
+#elif _MSC_VER
+#define __ATTR_CONST __declspec(noalias)
+#define __ATTR_PURE
+#else
+#define __ATTR_CONST
+#define __ATTR_PURE
+#endif
 
 #if defined(__clang__)
 #  define DIAG_PUSH _Pragma("clang diagnostic push")
@@ -54,6 +63,7 @@
 #  define DIAG_DISABLE_DEPRECATED_DECLARATIONS __pragma(warning(disable: 4996))
 #endif
 
+#define SIZEOF_ARRAY(x) (sizeof(x) / sizeof(x[0]))
 
 
 #include "ai.h"

src/c-lib/gs1encoders-test.c

@@ -24,14 +24,20 @@
  *  Don't perform code analysis of third-party code that is only used for testing.
  *
  */
-#if defined(_MSC_VER)
-#include <CodeAnalysis/warnings.h>
-#pragma warning(push)
-#pragma warning(disable: ALL_CODE_ANALYSIS_WARNINGS)
+#if defined(__clang__)
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
+#elif defined(_MSC_VER)
+#  include <CodeAnalysis/warnings.h>
+#  pragma warning(push)
+#  pragma warning(disable: ALL_CODE_ANALYSIS_WARNINGS)
 #endif
 #include "acutest.h"
-#if defined(_MSC_VER)
-#pragma warning(pop)
+#if defined(__clang__)
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic pop
+#elif defined(_MSC_VER)
+#  pragma warning(pop)
 #endif
 
 #include <stddef.h>

src/c-lib/gs1encoders.c

@@ -42,12 +42,12 @@ static inline void reset_error(gs1_encoder* const ctx) {
 }
 
 
-size_t gs1_encoder_instanceSize(void) {
+__ATTR_CONST size_t gs1_encoder_instanceSize(void) {
 	return sizeof(struct gs1_encoder);
 }
 
 
-int gs1_encoder_getMaxDataStrLength(void) {
+__ATTR_CONST int gs1_encoder_getMaxDataStrLength(void) {
 	return MAX_DATA;
 }
 
@@ -109,7 +109,7 @@ void gs1_encoder_free(gs1_encoder* const ctx) {
 }
 
 
-char* gs1_encoder_getVersion(void) {
+__ATTR_CONST char* gs1_encoder_getVersion(void) {
 	return __DATE__;
 }
 
@@ -582,14 +582,14 @@ void gs1_encoder_copyDLignoredQueryParams(gs1_encoder* const ctx, void* const bu
 }
 
 
-char* gs1_encoder_getErrMsg(gs1_encoder* const ctx) {
+__ATTR_PURE char* gs1_encoder_getErrMsg(gs1_encoder* const ctx) {
 	assert(ctx);
 	assert((!ctx->errFlag) ^ *ctx->errMsg);
 	return ctx->errMsg;
 }
 
 
-char* gs1_encoder_getErrMarkup(gs1_encoder* const ctx) {
+__ATTR_PURE char* gs1_encoder_getErrMarkup(gs1_encoder* const ctx) {
 	assert(ctx);
 	return ctx->linterErrMarkup;
 }
@@ -600,7 +600,7 @@ char* gs1_encoder_getErrMarkup(gs1_encoder* const ctx) {
  *
  */
 
-bool gs1_allDigits(const uint8_t* const str, size_t len) {
+__ATTR_PURE bool gs1_allDigits(const uint8_t* const str, size_t len) {
 
 	size_t i;
 

src/c-lib/scandata.c

@@ -88,7 +88,7 @@ static const struct symIdEntry symIdTable[] = {
 #define CC_SYM_ID "]e0"
 
 
-static const char* lookupSymId(const gs1_encoder* const ctx) {
+static const __ATTR_PURE char* lookupSymId(const gs1_encoder* const ctx) {
 
 	size_t i;
 	const char *symId = NULL;