interpret lines that look like

	//line 10 units.y
which is equiv to c
	#line 10 units.y
the purpose is to generate diagnostics
that correctly point to preprocessed source.

R=rsc
CC=golang-dev
https://golang.org/cl/1863042

diff --git a/src/cmd/gc/lex.c b/src/cmd/gc/lex.c
index 4399e28bd642c4017e8fc8cb641dfe9fc9bda59c..88f53b48c5ca3215f2ef7e032c61d1076ee1ce02 100644 (file)
--- a/src/cmd/gc/lex.c
+++ b/src/cmd/gc/lex.c
@@ -25,6 +25,7 @@ static void   ungetc(int);
 static int32   getr(void);
 static int     escchar(int, int*, vlong*);
 static void    addidir(char*);
+static int     getlinepragma(void);
 
 static char *goos, *goarch, *goroot;
 
@@ -658,8 +659,8 @@ l0:
                        }
                }
                if(c1 == '/') {
+                       c = getlinepragma();
                        for(;;) {
-                               c = getr();
                                if(c == '\n') {
                                        ungetc(c);
                                        goto l0;
@@ -668,6 +669,7 @@ l0:
                                        yyerror("eof in comment");
                                        errorexit();
                                }
+                               c = getr();
                        }
                }
                if(c1 == '=') {
@@ -1106,6 +1108,63 @@ caseout:
        return LLITERAL;
 }
 
+/*
+ * read and interpret syntax that looks like
+ * //line 15 parse.y
+ * as a discontenuity in sequential line numbers.
+ * the next line of input comes from parse.y:15
+ */
+static int
+getlinepragma(void)
+{
+       int i, c, n;
+       char *cp, *ep;
+       Hist *h;
+
+       for(i=0; i<5; i++) {
+               c = getr();
+               if(c != "line "[i])
+                       return c;
+       }
+
+       n = 0;
+       for(;;) {
+               c = getr();
+               if(!isdigit(c))
+                       break;
+               n = n*10 + (c-'0');
+       }
+
+       if(c != ' ' || n == 0)
+               return c;
+
+       cp = lexbuf;
+       ep = lexbuf+sizeof(lexbuf)-5;
+       for(;;) {
+               c = getr();
+               if(c == ' ')
+                       continue;
+               if(c == '\n')
+                       break;
+               *cp++ = c;
+               if(cp >= ep)
+                       break;
+       }
+       *cp = 0;
+//     n--;    // weve already seen the newline
+       if(n > 0) {
+               // try to avoid allocating file name over and over
+               for(h=hist; h!=H; h=h->link) {
+                       if(h->name != nil && strcmp(h->name, lexbuf) == 0) {
+                               linehist(h->name, n, 0);
+                               return c;
+                       }
+               }
+               linehist(strdup(lexbuf), n, 0);
+       }
+       return c;
+}
+
 int32
 yylex(void)
 {

diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 65b56dee62d76a9d34b9c02715c61a9e6e132b55..6af406be86dda0f03a2dd8b2529f3e8ae08f15dc 100644 (file)
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -228,11 +228,14 @@ linehist(char *file, int32 off, int relative)
        if(debug['i']) {
                if(file != nil) {
                        if(off < 0)
-                               print("pragma %s at line %L\n", file, lineno);
+                               print("pragma %s at line %L\n", file, lexlineno);
                        else
-                               print("import %s at line %L\n", file, lineno);
+                       if(off > 0)
+                               print("line %s at line %L\n", file, lexlineno);
+                       else
+                               print("import %s at line %L\n", file, lexlineno);
                } else
-                       print("end of import at line %L\n", lineno);
+                       print("end of import at line %L\n", lexlineno);
        }
 
        if(off < 0 && file[0] != '/' && !relative) {
@@ -894,12 +897,21 @@ Lconv(Fmt *fp)
                if(lno < h->line)
                        break;
                if(h->name) {
-                       if(n < HISTSZ) {        /* beginning of file */
-                               a[n].incl = h;
-                               a[n].idel = h->line;
-                               a[n].line = 0;
+                       if(h->offset > 0) {
+                               // #line directive
+                               if(n > 0 && n < HISTSZ) {
+                                       a[n-1].line = h;
+                                       a[n-1].ldel = h->line - h->offset + 1;
+                               }
+                       } else {
+                               // beginning of file
+                               if(n < HISTSZ) {
+                                       a[n].incl = h;
+                                       a[n].idel = h->line;
+                                       a[n].line = 0;
+                               }
+                               n++;
                        }
-                       n++;
                        continue;
                }
                n--;
@@ -921,12 +933,12 @@ Lconv(Fmt *fp)
                }
                if(a[i].line)
                        fmtprint(fp, "%s:%ld[%s:%ld]",
-                               a[i].line->name, lno-a[i].ldel+1,
-                               a[i].incl->name, lno-a[i].idel+1);
+                               a[i].line->name, lno-a[i].ldel,
+                               a[i].incl->name, lno-a[i].idel);
                else
                        fmtprint(fp, "%s:%ld",
                                a[i].incl->name, lno-a[i].idel+1);
-               lno = a[i].incl->line - 1;      /* now print out start of this file */
+               lno = a[i].incl->line - 1;      // now print out start of this file
        }
        if(n == 0)
                fmtprint(fp, "<epoch>");

diff --git a/src/cmd/goyacc/goyacc.go b/src/cmd/goyacc/goyacc.go
index a5da5f0a1d54cd97b082a4cba1850581b9c3e6e4..bc867fccf3eed5a62b03a7b4e6ac352817d8e567 100644 (file)
--- a/src/cmd/goyacc/goyacc.go
+++ b/src/cmd/goyacc/goyacc.go
@@ -675,7 +675,7 @@ outer:
        //
        if t == MARK {
                if !lflag {
-                       fmt.Fprintf(ftable, "\n//line %v:%v\n", infile, lineno)
+                       fmt.Fprintf(ftable, "\n//line %v %v\n", lineno, infile)
                }
                for {
                        c := getrune(finput)
@@ -2066,6 +2066,7 @@ nextk:
 func output() {
        var c, u, v int
 
+       fmt.Fprintf(ftable, "\n//line 1 yacctab\n")
        fmt.Fprintf(ftable, "var\tyyExca = []int {\n")
 
        noset := mkset()
@@ -2825,8 +2826,10 @@ func others() {
                c = getrune(finput)
        }
 
-       parts := strings.Split(yaccpar, "yyrun()", 2)
        // copy yaccpar
+       fmt.Fprintf(ftable, "\n//line 1 yaccpar\n")
+
+       parts := strings.Split(yaccpar, "yyrun()", 2)
        fmt.Fprintf(ftable, "%v", parts[0])
        ftable.Write(fcode.Bytes())
        fmt.Fprintf(ftable, "%v", parts[1])