cmd/ld: populate pe symbol table with Go symbols

Fixes #6936

LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/87770048

diff --git a/src/cmd/ld/pe.c b/src/cmd/ld/pe.c
index 4419471240d9f53786a849743b8de7e40e3c28ce..cd1dd036831099c90b5ac5a1475ff04b96b978b4 100644 (file)
--- a/src/cmd/ld/pe.c
+++ b/src/cmd/ld/pe.c
@@ -32,15 +32,11 @@ static char dosstub[] =
        0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
-// Note: currently only up to 8 chars plus \0.
-static char *symlabels[] = {
-       "symtab", "esymtab", "pclntab", "epclntab"
-};
-
 static LSym *rsrcsym;
 
-static char symnames[256]; 
-static int  nextsymoff;
+static char* strtbl;
+static int strtblnextoff;
+static int strtblsize;
 
 int32 PESECTHEADR;
 int32 PEFILEHEADR;
@@ -50,6 +46,7 @@ static int nsect;
 static int nextsectoff;
 static int nextfileoff;
 static int textsect;
+static int datasect;
 
 static IMAGE_FILE_HEADER fh;
 static IMAGE_OPTIONAL_HEADER oh;
@@ -81,6 +78,17 @@ static Dll* dr;
 static LSym *dexport[1024];
 static int nexport;
 
+typedef struct COFFSym COFFSym;
+struct COFFSym
+{
+       LSym* sym;
+       int strtbloff;
+       int sect;
+};
+
+static COFFSym* coffsym;
+static int ncoffsym;
+
 static IMAGE_SECTION_HEADER*
 addpesection(char *name, int sectsize, int filesize)
 {
@@ -421,6 +429,24 @@ dope(void)
        initdynexport();
 }
 
+static int
+strtbladd(char *name)
+{
+       int newsize, thisoff;
+
+       newsize = strtblnextoff + strlen(name) + 1;
+       if(newsize > strtblsize) {
+               strtblsize = 2 * (newsize + (1<<18));
+               strtbl = realloc(strtbl, strtblsize);
+       }
+       thisoff = strtblnextoff+4; // first string starts at offset=4
+       strcpy(&strtbl[strtblnextoff], name);
+       strtblnextoff += strlen(name);
+       strtbl[strtblnextoff] = 0;
+       strtblnextoff++;
+       return thisoff;
+}
+
 /*
  * For more than 8 characters section names, name contains a slash (/) that is 
  * followed by an ASCII representation of a decimal number that is an offset into 
@@ -433,20 +459,13 @@ newPEDWARFSection(char *name, vlong size)
 {
        IMAGE_SECTION_HEADER *h;
        char s[8];
+       int off;
 
        if(size == 0)
                return nil;
 
-       if(nextsymoff+strlen(name)+1 > sizeof(symnames)) {
-               diag("pe string table is full");
-               errorexit();
-       }
-
-       strcpy(&symnames[nextsymoff], name);
-       sprint(s, "/%d\0", nextsymoff+4);
-       nextsymoff += strlen(name);
-       symnames[nextsymoff] = 0;
-       nextsymoff ++;
+       off = strtbladd(name);
+       sprint(s, "/%d\0", off);
        h = addpesection(s, size, size);
        h->Characteristics = IMAGE_SCN_MEM_READ|
                IMAGE_SCN_MEM_DISCARDABLE;
@@ -454,36 +473,84 @@ newPEDWARFSection(char *name, vlong size)
        return h;
 }
 
+static void
+addsym(LSym *s, char *name, int type, vlong addr, vlong size, int ver, LSym *gotype)
+{
+       USED(name);
+       USED(addr);
+       USED(size);
+       USED(ver);
+       USED(gotype);
+
+       if(s == nil)
+               return;
+
+       if(s->sect == nil)
+               return;
+
+       switch(type) {
+       default:
+               return;
+       case 'D':
+       case 'B':
+       case 'T':
+               break;
+       }
+
+       if(coffsym) {
+               coffsym[ncoffsym].sym = s;
+               if(strlen(s->name) > 8)
+                       coffsym[ncoffsym].strtbloff = strtbladd(s->name);
+               if(type == 'T')
+                       coffsym[ncoffsym].sect = textsect;
+               else
+                       coffsym[ncoffsym].sect = datasect;
+       }
+       ncoffsym++;
+}
+
 static void
 addsymtable(void)
 {
        IMAGE_SECTION_HEADER *h;
        int i, size;
-       LSym *s;
-       
-       fh.NumberOfSymbols = sizeof(symlabels)/sizeof(symlabels[0]);
-       size = nextsymoff + 4 + 18*fh.NumberOfSymbols;
+       COFFSym *s;
+
+       if(!debug['s']) {
+               genasmsym(addsym);
+               coffsym = mal(ncoffsym * sizeof coffsym[0]);
+               ncoffsym = 0;
+               genasmsym(addsym);
+       }
+
+       size = strtblnextoff + 4 + 18*ncoffsym;
        h = addpesection(".symtab", size, size);
        h->Characteristics = IMAGE_SCN_MEM_READ|
                IMAGE_SCN_MEM_DISCARDABLE;
        chksectoff(h, cpos());
        fh.PointerToSymbolTable = cpos();
+       fh.NumberOfSymbols = ncoffsym;
        
        // put COFF symbol table
-       for (i=0; i<fh.NumberOfSymbols; i++) {
-               s = linkrlookup(ctxt, symlabels[i], 0);
-               strnput(s->name, 8);
-               lputl(datoff(s->value));
-               wputl(textsect);
+       for (i=0; i<ncoffsym; i++) {
+               s = &coffsym[i];
+               if(s->strtbloff == 0)
+                       strnput(s->sym->name, 8);
+               else {
+                       lputl(0);
+                       lputl(s->strtbloff);
+               }
+               lputl(datoff(s->sym->value));
+               wputl(s->sect);
                wputl(0x0308);  // "array of structs"
                cput(2);        // storage class: external
                cput(0);        // no aux entries
        }
 
        // put COFF string table
-       lputl(nextsymoff + 4);
-       for (i=0; i<nextsymoff; i++)
-               cput(symnames[i]);
+       lputl(strtblnextoff + 4);
+       for (i=0; i<strtblnextoff; i++)
+               cput(strtbl[i]);
        strnput("", h->SizeOfRawData - size);
 }
 
@@ -557,6 +624,7 @@ asmbpe(void)
        d->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
                IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
        chksectseg(d, &segdata);
+       datasect = nsect;
 
        if(!debug['s'])
                dwarfaddpeheaders();