fix openssl headers conflicting with custom SHA1 implementations

On ARM I have the following compilation errors:

    CC fast-import.o
In file included from cache.h:8,
                 from builtin.h:6,
                 from fast-import.c:142:
arm/sha1.h:14: error: conflicting types for 'SHA_CTX'
/usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here
arm/sha1.h:16: error: conflicting types for 'SHA1_Init'
/usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here
arm/sha1.h:17: error: conflicting types for 'SHA1_Update'
/usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here
arm/sha1.h:18: error: conflicting types for 'SHA1_Final'
/usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here
make: *** [fast-import.o] Error 1

This is because openssl header files are always included in
git-compat-util.h since commit 684ec6c63c whenever NO_OPENSSL is not
set, which somehow brings in <openssl/sha1.h> clashing with the custom
ARM version.  Compilation of git is probably broken on PPC too for the
same reason.

Turns out that the only file requiring openssl/ssl.h and openssl/err.h
is imap-send.c.  But only moving those problematic includes there
doesn't solve the issue as it also includes cache.h which brings in the
conflicting local SHA1 header file.

As suggested by Jeff King, the best solution is to rename our references
to SHA1 functions and structure to something git specific, and define those
according to the implementation used.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

3 files changed, 21 insertions, 16 deletions

diff --git a/ppc/sha1.c b/ppc/sha1.c
index 738e36c1e8..ec6a1926d4 100644
--- a/ppc/sha1.c
+++ b/ppc/sha1.c
@@ -10,10 +10,10 @@
 #include <string.h>
 #include "sha1.h"
 
-extern void sha1_core(uint32_t *hash, const unsigned char *p,
-		      unsigned int nblocks);
+extern void ppc_sha1_core(uint32_t *hash, const unsigned char *p,
+			  unsigned int nblocks);
 
-int SHA1_Init(SHA_CTX *c)
+int ppc_SHA1_Init(ppc_SHA_CTX *c)
 {
 	c->hash[0] = 0x67452301;
 	c->hash[1] = 0xEFCDAB89;
@@ -25,7 +25,7 @@ int SHA1_Init(SHA_CTX *c)
 	return 0;
 }
 
-int SHA1_Update(SHA_CTX *c, const void *ptr, unsigned long n)
+int ppc_SHA1_Update(ppc_SHA_CTX *c, const void *ptr, unsigned long n)
 {
 	unsigned long nb;
 	const unsigned char *p = ptr;
@@ -38,12 +38,12 @@ int SHA1_Update(SHA_CTX *c, const void *ptr, unsigned long n)
 				nb = n;
 			memcpy(&c->buf.b[c->cnt], p, nb);
 			if ((c->cnt += nb) == 64) {
-				sha1_core(c->hash, c->buf.b, 1);
+				ppc_sha1_core(c->hash, c->buf.b, 1);
 				c->cnt = 0;
 			}
 		} else {
 			nb = n >> 6;
-			sha1_core(c->hash, p, nb);
+			ppc_sha1_core(c->hash, p, nb);
 			nb <<= 6;
 		}
 		n -= nb;
@@ -52,7 +52,7 @@ int SHA1_Update(SHA_CTX *c, const void *ptr, unsigned long n)
 	return 0;
 }
 
-int SHA1_Final(unsigned char *hash, SHA_CTX *c)
+int ppc_SHA1_Final(unsigned char *hash, ppc_SHA_CTX *c)
 {
 	unsigned int cnt = c->cnt;
 
@@ -60,13 +60,13 @@ int SHA1_Final(unsigned char *hash, SHA_CTX *c)
 	if (cnt > 56) {
 		if (cnt < 64)
 			memset(&c->buf.b[cnt], 0, 64 - cnt);
-		sha1_core(c->hash, c->buf.b, 1);
+		ppc_sha1_core(c->hash, c->buf.b, 1);
 		cnt = 0;
 	}
 	if (cnt < 56)
 		memset(&c->buf.b[cnt], 0, 56 - cnt);
 	c->buf.l[7] = c->len;
-	sha1_core(c->hash, c->buf.b, 1);
+	ppc_sha1_core(c->hash, c->buf.b, 1);
 	memcpy(hash, c->hash, 20);
 	return 0;
 }
diff --git a/ppc/sha1.h b/ppc/sha1.h
index c3c51aa4d4..c405f734c2 100644
--- a/ppc/sha1.h
+++ b/ppc/sha1.h
@@ -5,7 +5,7 @@
  */
 #include <stdint.h>
 
-typedef struct sha_context {
+typedef struct {
 	uint32_t hash[5];
 	uint32_t cnt;
 	uint64_t len;
@@ -13,8 +13,13 @@ typedef struct sha_context {
 		unsigned char b[64];
 		uint64_t l[8];
 	} buf;
-} SHA_CTX;
+} ppc_SHA_CTX;
 
-int SHA1_Init(SHA_CTX *c);
-int SHA1_Update(SHA_CTX *c, const void *p, unsigned long n);
-int SHA1_Final(unsigned char *hash, SHA_CTX *c);
+int ppc_SHA1_Init(ppc_SHA_CTX *c);
+int ppc_SHA1_Update(ppc_SHA_CTX *c, const void *p, unsigned long n);
+int ppc_SHA1_Final(unsigned char *hash, ppc_SHA_CTX *c);
+
+#define git_SHA_CTX	ppc_SHA_CTX
+#define git_SHA1_Init	ppc_SHA1_Init
+#define git_SHA1_Update	ppc_SHA1_Update
+#define git_SHA1_Final	ppc_SHA1_Final
diff --git a/ppc/sha1ppc.S b/ppc/sha1ppc.S
index f132696ee7..1711eef6e7 100644
--- a/ppc/sha1ppc.S
+++ b/ppc/sha1ppc.S
@@ -162,8 +162,8 @@ add RE(t),RE(t),%r0;  rotlwi RB(t),RB(t),30
 	STEPUP4(fn, (t)+12, (s)+12,);	\
 	STEPUP4(fn, (t)+16, (s)+16, loadk)
 
-	.globl	sha1_core
-sha1_core:
+	.globl	ppc_sha1_core
+ppc_sha1_core:
 	stwu	%r1,-80(%r1)
 	stmw	%r13,4(%r1)