Make most of the C/C++ examples truly C compatible.

Some of the examples use C++ data structures like `std::ifstream`, `std::vector` etc. Leave them as is for now. Update docs. This addresses bug #484 "Example is not C".
skvadrik · Nov 23, 2024 · 3a40b3d · 3a40b3d
1 parent a75eb2b
commit 3a40b3d
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Showing 25 changed files with 421 additions and 432 deletions.
diff --git a/bootstrap/doc/re2c.1 b/bootstrap/doc/re2c.1
diff --git a/build/split_man.py b/build/split_man.py
@@ -26,7 +26,7 @@
     src_ext = b'c'
     hdr_ext = b'h'
     lang_name = b'C/C++'
-    disclaimer = b'Note: examples are in C++ (but can be easily adapted to C).'
+    disclaimer = b'Note: some examples are in C++ (but can be adapted to C).'
 elif lang == b'd':
     src_ext = b'd'
     lang_name = b'D'

diff --git a/examples/c/01_basic.c b/examples/c/01_basic.c
@@ -2,7 +2,7 @@
 // re2c $INPUT -o $OUTPUT -i --case-ranges
 #include <assert.h>
 
-bool lex(const char *s) {
+int lex(const char *s) {
     const char *YYCURSOR = s;
 
 {
@@ -14,20 +14,20 @@ bool lex(const char *s) {
 	}
 yy1:
 	++YYCURSOR;
-	{ return false; }
+	{ return 1; }
 yy2:
 	yych = *++YYCURSOR;
 	switch (yych) {
 		case '0' ... '9': goto yy2;
 		default: goto yy3;
 	}
 yy3:
-	{ return true; }
+	{ return 0; }
 }
 
 }
 
 int main() {
-    assert(lex("1234"));
+    assert(lex("1234") == 0);
     return 0;
 }
diff --git a/examples/c/01_basic.re b/examples/c/01_basic.re
@@ -1,18 +1,18 @@
 // re2c $INPUT -o $OUTPUT -i --case-ranges
 #include <assert.h>
 
-bool lex(const char *s) {
+int lex(const char *s) {
     const char *YYCURSOR = s;
     /*!re2c
         re2c:yyfill:enable = 0;
         re2c:define:YYCTYPE = char;
 
-        [1-9][0-9]* { return true; }
-        *           { return false; }
+        [1-9][0-9]* { return 0; }
+        *           { return 1; }
     */
 }
 
 int main() {
-    assert(lex("1234"));
+    assert(lex("1234") == 0);
     return 0;
 }
diff --git a/examples/c/conditions/parse_u32_blocks.c b/examples/c/conditions/parse_u32_blocks.c
@@ -6,10 +6,7 @@
 
 static const uint64_t ERROR = UINT64_MAX;
 
-static void add(uint32_t base, uint64_t &number, char digit) {
-    number = number * base + digit;
-    if (number > UINT32_MAX) number = ERROR;
-}
+#define CHECK(n) if (n > UINT32_MAX) return ERROR;
 
 static uint64_t parse_u32(const char *s) {
     const char *YYCURSOR = s, *YYMARKER;
@@ -116,7 +113,7 @@ static uint64_t parse_u32(const char *s) {
 	{ return ERROR; }
 yy13:
 	++YYCURSOR;
-	{ add(2, u, YYCURSOR[-1] - '0'); goto bin; }
+	{ u = u * 2 + (YYCURSOR[-1] - '0'); CHECK(u); goto bin; }
 }
 
 oct:
@@ -144,7 +141,7 @@ static uint64_t parse_u32(const char *s) {
 	{ return ERROR; }
 yy17:
 	++YYCURSOR;
-	{ add(8, u, YYCURSOR[-1] - '0'); goto oct; }
+	{ u = u * 8 + (YYCURSOR[-1] - '0'); CHECK(u); goto oct; }
 }
 
 dec:
@@ -174,7 +171,7 @@ static uint64_t parse_u32(const char *s) {
 	{ return ERROR; }
 yy21:
 	++YYCURSOR;
-	{ add(10, u, YYCURSOR[-1] - '0'); goto dec; }
+	{ u = u * 10 + (YYCURSOR[-1] - '0'); CHECK(u); goto dec; }
 }
 
 hex:
@@ -216,13 +213,13 @@ static uint64_t parse_u32(const char *s) {
 	{ return ERROR; }
 yy25:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - '0');      goto hex; }
+	{ u = u * 16 + (YYCURSOR[-1] - '0');      CHECK(u); goto hex; }
 yy26:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - 'A' + 10); goto hex; }
+	{ u = u * 16 + (YYCURSOR[-1] - 'A' + 10); CHECK(u); goto hex; }
 yy27:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - 'a' + 10); goto hex; }
+	{ u = u * 16 + (YYCURSOR[-1] - 'a' + 10); CHECK(u); goto hex; }
 }
 
 }

diff --git a/examples/c/conditions/parse_u32_blocks.re b/examples/c/conditions/parse_u32_blocks.re
@@ -5,10 +5,7 @@
 
 static const uint64_t ERROR = UINT64_MAX;
 
-static void add(uint32_t base, uint64_t &number, char digit) {
-    number = number * base + digit;
-    if (number > UINT32_MAX) number = ERROR;
-}
+#define CHECK(n) if (n > UINT32_MAX) return ERROR;
 
 static uint64_t parse_u32(const char *s) {
     const char *YYCURSOR = s, *YYMARKER;
@@ -29,27 +26,27 @@ static uint64_t parse_u32(const char *s) {
 bin:
     /*!re2c
         end   { return u; }
-        [01]  { add(2, u, YYCURSOR[-1] - '0'); goto bin; }
+        [01]  { u = u * 2 + (YYCURSOR[-1] - '0'); CHECK(u); goto bin; }
         *     { return ERROR; }
     */
 oct:
     /*!re2c
         end   { return u; }
-        [0-7] { add(8, u, YYCURSOR[-1] - '0'); goto oct; }
+        [0-7] { u = u * 8 + (YYCURSOR[-1] - '0'); CHECK(u); goto oct; }
         *     { return ERROR; }
     */
 dec:
     /*!re2c
         end   { return u; }
-        [0-9] { add(10, u, YYCURSOR[-1] - '0'); goto dec; }
+        [0-9] { u = u * 10 + (YYCURSOR[-1] - '0'); CHECK(u); goto dec; }
         *     { return ERROR; }
     */
 hex:
     /*!re2c
         end   { return u; }
-        [0-9] { add(16, u, YYCURSOR[-1] - '0');      goto hex; }
-        [a-f] { add(16, u, YYCURSOR[-1] - 'a' + 10); goto hex; }
-        [A-F] { add(16, u, YYCURSOR[-1] - 'A' + 10); goto hex; }
+        [0-9] { u = u * 16 + (YYCURSOR[-1] - '0');      CHECK(u); goto hex; }
+        [a-f] { u = u * 16 + (YYCURSOR[-1] - 'a' + 10); CHECK(u); goto hex; }
+        [A-F] { u = u * 16 + (YYCURSOR[-1] - 'A' + 10); CHECK(u); goto hex; }
         *     { return ERROR; }
     */
 }

diff --git a/examples/c/conditions/parse_u32_conditions.c b/examples/c/conditions/parse_u32_conditions.c
@@ -14,11 +14,6 @@ enum YYCONDTYPE {
 };
 
 
-static void add(uint32_t base, uint64_t &number, char digit) {
-    number = number * base + digit;
-    if (number > UINT32_MAX) number = ERROR;
-}
-
 static uint64_t parse_u32(const char *s) {
     const char *YYCURSOR = s, *YYMARKER;
     int c = yycinit;
@@ -52,6 +47,7 @@ static uint64_t parse_u32(const char *s) {
 	}
 yy1:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return ERROR; }
 yy2:
 	yych = *(YYMARKER = ++YYCURSOR);
@@ -128,13 +124,16 @@ static uint64_t parse_u32(const char *s) {
 	}
 yy11:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return u; }
 yy12:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return ERROR; }
 yy13:
 	++YYCURSOR;
-	{ add(2,  u, YYCURSOR[-1] - '0');      goto yyc_bin; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 2  + (YYCURSOR[-1] - '0');      goto yyc_bin; }
 /* *********************************** */
 yyc_dec:
 	yych = *YYCURSOR;
@@ -154,13 +153,16 @@ static uint64_t parse_u32(const char *s) {
 	}
 yy15:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return u; }
 yy16:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return ERROR; }
 yy17:
 	++YYCURSOR;
-	{ add(10, u, YYCURSOR[-1] - '0');      goto yyc_dec; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 10 + (YYCURSOR[-1] - '0');      goto yyc_dec; }
 /* *********************************** */
 yyc_hex:
 	yych = *YYCURSOR;
@@ -192,19 +194,24 @@ static uint64_t parse_u32(const char *s) {
 	}
 yy19:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return u; }
 yy20:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return ERROR; }
 yy21:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - '0');      goto yyc_hex; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 16 + (YYCURSOR[-1] - '0');      goto yyc_hex; }
 yy22:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - 'A' + 10); goto yyc_hex; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 16 + (YYCURSOR[-1] - 'A' + 10); goto yyc_hex; }
 yy23:
 	++YYCURSOR;
-	{ add(16, u, YYCURSOR[-1] - 'a' + 10); goto yyc_hex; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 16 + (YYCURSOR[-1] - 'a' + 10); goto yyc_hex; }
 /* *********************************** */
 yyc_oct:
 	yych = *YYCURSOR;
@@ -222,13 +229,16 @@ static uint64_t parse_u32(const char *s) {
 	}
 yy25:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return u; }
 yy26:
 	++YYCURSOR;
+	{ if (u > UINT32_MAX) return ERROR; }
 	{ return ERROR; }
 yy27:
 	++YYCURSOR;
-	{ add(8,  u, YYCURSOR[-1] - '0');      goto yyc_oct; }
+	{ if (u > UINT32_MAX) return ERROR; }
+	{ u = u * 8  + (YYCURSOR[-1] - '0');      goto yyc_oct; }
 }
 
 }

diff --git a/examples/c/conditions/parse_u32_conditions.re b/examples/c/conditions/parse_u32_conditions.re
@@ -6,11 +6,6 @@
 static const uint64_t ERROR = UINT64_MAX;
 /*!conditions:re2c*/
 
-static void add(uint32_t base, uint64_t &number, char digit) {
-    number = number * base + digit;
-    if (number > UINT32_MAX) number = ERROR;
-}
-
 static uint64_t parse_u32(const char *s) {
     const char *YYCURSOR = s, *YYMARKER;
     int c = yycinit;
@@ -32,12 +27,13 @@ static uint64_t parse_u32(const char *s) {
 
         <bin, oct, dec, hex> "\x00" { return u; }
 
-        <bin> [01]  { add(2,  u, YYCURSOR[-1] - '0');      goto yyc_bin; }
-        <oct> [0-7] { add(8,  u, YYCURSOR[-1] - '0');      goto yyc_oct; }
-        <dec> [0-9] { add(10, u, YYCURSOR[-1] - '0');      goto yyc_dec; }
-        <hex> [0-9] { add(16, u, YYCURSOR[-1] - '0');      goto yyc_hex; }
-        <hex> [a-f] { add(16, u, YYCURSOR[-1] - 'a' + 10); goto yyc_hex; }
-        <hex> [A-F] { add(16, u, YYCURSOR[-1] - 'A' + 10); goto yyc_hex; }
+        <bin> [01]  { u = u * 2  + (YYCURSOR[-1] - '0');      goto yyc_bin; }
+        <oct> [0-7] { u = u * 8  + (YYCURSOR[-1] - '0');      goto yyc_oct; }
+        <dec> [0-9] { u = u * 10 + (YYCURSOR[-1] - '0');      goto yyc_dec; }
+        <hex> [0-9] { u = u * 16 + (YYCURSOR[-1] - '0');      goto yyc_hex; }
+        <hex> [a-f] { u = u * 16 + (YYCURSOR[-1] - 'a' + 10); goto yyc_hex; }
+        <hex> [A-F] { u = u * 16 + (YYCURSOR[-1] - 'A' + 10); goto yyc_hex; }
+        <!*> { if (u > UINT32_MAX) return ERROR; }
     */
 }