Added buffer in get_ch() for line continuation lookahead

pnut.c

@@ -55,6 +55,9 @@
 #define OPTIMIZE_CONSTANT_PARAM_not
 #define SUPPORT_ADDRESS_OF_OP_not
 
+// Make get_ch() use a length-1 character buffer to lookahead and skip line continuations
+#define SUPPORT_LINE_CONTINUATION_not
+
 // Shell backend codegen options
 #ifndef SH_AVOID_PRINTF_USE_NOT
 #define SH_AVOID_PRINTF_USE
@@ -747,8 +750,44 @@ void output_declaration_c_code(bool no_header) {
 }
 #endif
 
+#ifdef SUPPORT_LINE_CONTINUATION
+// get_ch_ is reponsible for reading the next character from the input file,
+// switching to the next file if necessary and updating the line number.
+// get_ch is then responsible for skipping line continuations.
+void get_ch_();
+
+int line_continutation_prev_char = -2; // -1 is EOF, -2 is uninitialized
 void get_ch() {
+  if (line_continutation_prev_char == -2) {
+    while (1) {      // Loop as long as we're reading line continuations
+      get_ch_();     // Read the next character
+      if (ch == '\\') {
+        get_ch_();   // Skip backslash
+        if (ch == '\n') {
+          continue; // Loop again to read the next character
+        } else {
+          // '\' is not followed by newline, so we save the current character
+          // and make '\' the current character
+          line_continutation_prev_char = ch;
+          ch = '\\';
+          break;
+        }
+      } else {
+        break;
+      }
+    }
+  } else {
+    ch = line_continutation_prev_char;
+    line_continutation_prev_char = -2;
+  }
+}
+
+void get_ch_() {
+#else
+void get_ch() {
+#endif
   ch = fgetc(fp);
+
   if (ch == EOF) {
     // If it's not the last file on the stack, EOF means that we need to switch to the next file
     if (include_stack->next != 0) {

sh.c

@@ -281,6 +281,7 @@ void print_escaped_text(text t, bool for_printf) {
     putchar('0'); putchar('x');
     puthex_unsigned(TEXT_TO_INT(text_pool[t + 1]));
   } else if (text_pool[t] == TEXT_FROM_INT(TEXT_INTEGER_OCT)) {
+    putchar('0'); // Note: This is not supported by zsh by default
     putoct_unsigned(TEXT_TO_INT(text_pool[t + 1]));
   } else if (text_pool[t] == TEXT_FROM_INT(TEXT_STRING)) {
     print_escaped_string((char*) text_pool[t + 1],  (char*) text_pool[t + 2], for_printf);
@@ -315,6 +316,7 @@ void print_text(text t) {
     putchar('0'); putchar('x');
     puthex_unsigned(TEXT_TO_INT(text_pool[t + 1]));
   } else if (text_pool[t] == TEXT_FROM_INT(TEXT_INTEGER_OCT)) {
+    putchar('0'); // Note: This is not supported by zsh by default
     putoct_unsigned(TEXT_TO_INT(text_pool[t + 1]));
   } else if (text_pool[t] == TEXT_FROM_INT(TEXT_STRING)) {
     if (TEXT_TO_INT(text_pool[t + 2]) == 0) { // null-terminated string

tests/_all/line_continuation.c

@@ -0,0 +1,36 @@
+// comp_pnut_opt: -DSUPPORT_LINE_CONTINUATION
+#include <stdio.h>
+
+void putint_aux(int n) {
+  if (n >= 10) putint_aux(n / 10);
+  putchar('0' + (n % 10));
+}
+
+void putint(int n) {
+  if (n < 0) {
+    putchar('-');
+    putint_aux(-n);
+  } else {
+    putint_aux(n);
+  }
+}
+
+int main() {
+
+/**/
+int foo = 0;
+
+/\
+*
+*/ fo\
+\
+\
+o +\
+= 1\
+\
+10\
+200;
+
+    putint(foo);
+    return 0;
+}

tests/_all/line_continuation.golden

@@ -0,0 +1 @@
+110200