From: ggn <ggn.dbug@gmail.com>
Date: Sat, 8 Aug 2020 14:17:56 +0000 (+0300)
Subject: Fix for bug #170 - ELF output module exports global,defined symbols as undefined
X-Git-Tag: v2.1.0~5
X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=commitdiff_plain;h=ceab9325bdbffccecf61ba26387ed03f4ab0591e

Fix for bug #170 - ELF output module exports global,defined symbols as undefined

Signed-off-by: ggn <ggn.dbug@gmail.com>
---

diff --git a/object.c b/object.c
index 0b7df7e..fe10743 100644
--- a/object.c
+++ b/object.c
@@ -224,7 +224,7 @@ uint8_t * AddELFSymEntry(uint8_t * buf, SYM * sym, int globflag)
 	if (w1 & DEFINED)
 	{
 		if (globflag)		// Export the symbol
-			st_info |= 16;   //STB_GLOBAL (1<<4)
+			st_info |= 16;  // STB_GLOBAL (1<<4)
 	}
 	else if (w1 & (GLOBAL | REFERENCED))
 		st_info |= 16;
@@ -232,7 +232,7 @@ uint8_t * AddELFSymEntry(uint8_t * buf, SYM * sym, int globflag)
 	D_byte(st_info);
 	D_byte(0);				// st_other
 
-	uint16_t st_shndx = 0xFFF1;	// Assume absolute (equated) number
+	uint16_t st_shndx = SHN_ABS;	// Assume absolute (equated) number
 
 	if (w1 & TEXT)
 		st_shndx = elfHdrNum[ES_TEXT];
@@ -240,8 +240,13 @@ uint8_t * AddELFSymEntry(uint8_t * buf, SYM * sym, int globflag)
 		st_shndx = elfHdrNum[ES_DATA];
 	else if (w1 & BSS)
 		st_shndx = elfHdrNum[ES_BSS];
-	else if (globflag)
-		st_shndx = 0;		// Global, not absolute
+	else if (globflag && !(w1 & DEFINED) && (w1 & REFERENCED))
+	{
+		st_shndx = SHN_UNDEF;
+	}		                       // If the symbol is global then probably we
+                                    // don't need to do anything (probably)
+                                    // since we set STB_GLOBAL in st_info above.
+                                    // Unless we need to set it to SHN_COMMON?
 
 	D_word(st_shndx);
 
diff --git a/object.h b/object.h
index f871457..fe5997c 100644
--- a/object.h
+++ b/object.h
@@ -33,6 +33,14 @@ enum ELFSectionNames
 	ES_SYMTAB, ES_STRTAB
 };
 
+//
+// ELF special section indices (field st_shndx)
+// Lifted from glibc (https://sourceware.org/git/?p=glibc.git;a=blob;f=elf/elf.h)
+//
+#define SHN_UNDEF       0               /* Undefined section */
+#define SHN_ABS         0xFFF1          /* Associated symbol is absolute */
+#define SHN_COMMON      0xFFF2          /* Associated symbol is common */
+
 // Exported variables.
 extern uint8_t * objImage;
 extern int elfHdrNum[];