Parse input #line directives.

1 files changed, 70 insertions, 6 deletions

diff --git a/xenv.l b/xenv.l
index 3c0ad30..446b305 100644
--- a/xenv.l
+++ b/xenv.l
@@ -19,11 +19,13 @@
 #include <unistd.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <sysexits.h>
 #include <assert.h>
 
 char const *progname;       /* Program name */
-char const *filename;       /* Name of the input file. */     
+char *filename;             /* Name of the input file. */
+size_t filename_size;       /* Size of memory allocated for filename. */
 unsigned lineno;            /* Line number in the input file. */
 int undef_error_option;     /* Treat undefined variables as error. */
 int synclines_option;       /* Generate `#line NUM "FILE"' lines. */
@@ -52,6 +54,8 @@ static void expand_inline_flop(void);
 static int cond_peek(void);
 static void cond_push(int result);
 static int cond_pop(void);
+
+static int parse_line_directive(char *text);
 
 /*
  * Given a '$$' preprocessor statement TEXT, find the variable identifier
@@ -101,6 +105,26 @@ xstrdup(char *str)
 		enomem();
 	return p;
 }
+
+char *
+xrealloc(char *ptr, size_t size)
+{
+	char *p = realloc(ptr, size);
+	if (!p)
+		enomem();
+	return p;
+}
+	
+static void
+set_filename(char const *name, size_t len)
+{
+	if (len + 1 > filename_size) {
+		filename_size = len + 1;
+		filename = xrealloc(filename, filename_size);
+	}
+	memcpy(filename, name, len);
+	filename[len] = 0;
+}
 %}
 IDENT [a-zA-Z_][a-zA-Z_0-9]*
 WS [ \t][ \t]*
@@ -133,7 +157,13 @@ OWS [ \t]*
 
 <SQ>"'" { BEGIN(save_state); ECHO; }
 "'"   { save_state = YYSTATE; BEGIN(SQ); ECHO; }
-	
+
+<INITIAL>^"#line ".*\n {
+	if (parse_line_directive(yytext)) {
+		ECHO;
+		lineno++;
+	}
+ }
 <INITIAL>"${*" { save_state = YYSTATE; BEGIN(COMMENT); }
 <COMMENT>[^*\n]*        /* eat anything that's not a '*' */
 <COMMENT>"*"+[^*}\n]*   /* eat up '*'s not followed by '}'s */
@@ -349,7 +379,7 @@ struct expand_inline {
 		char *varname; /* type == EXP_ASSIGN - assign the expansion
 				  to that variable */
 		struct {       /* type == EXP_ERROR - location of the error */
-			char const *filename;
+			char *filename;
 			unsigned lineno;
 		} loc;
 	};
@@ -382,7 +412,7 @@ expand_inline_push(int type, char *varname, int varlen, int suppress)
 		memcpy(ep->varname, varname, varlen);
 		ep->varname[varlen] = 0;
         } else if (type == EXP_ERROR) {
-  	        ep->loc.filename = filename;
+  	        ep->loc.filename = xstrdup(filename);
 		ep->loc.lineno = lineno;
         }
 	ep->fp = yyout;
@@ -467,6 +497,7 @@ expand_inline_pop(void)
 
 			fprintf(stderr, "%s:%u: ", ep->loc.filename,
 				ep->loc.lineno);
+			free(ep->loc.filename);
 			rewind(yyout);
 			while ((c = fgetc(yyout)) != EOF)
 				fputc(c, stderr);
@@ -481,7 +512,10 @@ expand_inline_pop(void)
 					emit_syncline = 1;
 			}
 		}
-	}
+	} else
+		/* FIXME: Emit syncline only if there were newlines in the
+		   suppressed text. */
+		emit_syncline = 1;
 	
 	if (ep->type == EXP_ASSIGN)
 		free(ep->varname);
@@ -549,6 +583,36 @@ cond_pop(void)
 	return cond_stack[cond_tos--].result;
 }
 
+static int
+parse_line_directive(char *text)
+{
+	unsigned long n;
+	char *fname, *p;
+	
+	text += sizeof("#line ")-1;
+
+	n = strtoul(text, &p, 10);
+	if ((n == 0 && errno == ERANGE) || n > INT_MAX ||
+	    !(*p == 0 || *p == ' ' || *p == '\t' || *p == '\n'))
+		return 1;
+	while (*p == ' ' || *p == '\t')
+		p++;
+	if (*p == '\n' || *p == 0) {
+		lineno = (int) n;
+		return 0;
+	}
+	if (*p != '"')
+		return 1;
+	p++;
+	fname = p;
+	p = strchr(fname, '"');
+	if (!p)
+		return 1;
+	set_filename(fname, p - fname);
+	lineno = n;
+	return 0;
+}
+
 /*
  * Input file handling.
  */
@@ -568,7 +632,7 @@ open_input(char const *name)
 		exit(errno == ENOENT ? EX_NOINPUT : EX_OSERR);
 	}
 	yyin = fp;
-	filename = name;
+	set_filename(name, strlen(name));
 	lineno = 1;
 	if (synclines_option)
 		fprintf(yyout, "#line %u \"%s\"\n", lineno, filename);