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, 20 insertions, 15 deletions

diff --git a/arm/sha1.c b/arm/sha1.c
index 9e3ae038e..c61ad4aff 100644
--- a/arm/sha1.c
+++ b/arm/sha1.c
@@ -8,9 +8,9 @@
 #include <string.h>
 #include "sha1.h"
 
-extern void sha_transform(uint32_t *hash, const unsigned char *data, uint32_t *W);
+extern void arm_sha_transform(uint32_t *hash, const unsigned char *data, uint32_t *W);
 
-void SHA1_Init(SHA_CTX *c)
+void arm_SHA1_Init(arm_SHA_CTX *c)
 {
 	c->len = 0;
 	c->hash[0] = 0x67452301;
@@ -20,7 +20,7 @@ void SHA1_Init(SHA_CTX *c)
 	c->hash[4] = 0xc3d2e1f0;
 }
 
-void SHA1_Update(SHA_CTX *c, const void *p, unsigned long n)
+void arm_SHA1_Update(arm_SHA_CTX *c, const void *p, unsigned long n)
 {
 	uint32_t workspace[80];
 	unsigned int partial;
@@ -32,12 +32,12 @@ void SHA1_Update(SHA_CTX *c, const void *p, unsigned long n)
 		if (partial) {
 			done = 64 - partial;
 			memcpy(c->buffer + partial, p, done);
-			sha_transform(c->hash, c->buffer, workspace);
+			arm_sha_transform(c->hash, c->buffer, workspace);
 			partial = 0;
 		} else
 			done = 0;
 		while (n >= done + 64) {
-			sha_transform(c->hash, p + done, workspace);
+			arm_sha_transform(c->hash, p + done, workspace);
 			done += 64;
 		}
 	} else
@@ -46,7 +46,7 @@ void SHA1_Update(SHA_CTX *c, const void *p, unsigned long n)
 		memcpy(c->buffer + partial, p + done, n - done);
 }
 
-void SHA1_Final(unsigned char *hash, SHA_CTX *c)
+void arm_SHA1_Final(unsigned char *hash, arm_SHA_CTX *c)
 {
 	uint64_t bitlen;
 	uint32_t bitlen_hi, bitlen_lo;
@@ -57,7 +57,7 @@ void SHA1_Final(unsigned char *hash, SHA_CTX *c)
 	bitlen = c->len << 3;
 	offset = c->len & 0x3f;
 	padlen = ((offset < 56) ? 56 : (64 + 56)) - offset;
-	SHA1_Update(c, padding, padlen);
+	arm_SHA1_Update(c, padding, padlen);
 
 	bitlen_hi = bitlen >> 32;
 	bitlen_lo = bitlen & 0xffffffff;
@@ -69,7 +69,7 @@ void SHA1_Final(unsigned char *hash, SHA_CTX *c)
 	bits[5] = bitlen_lo >> 16;
 	bits[6] = bitlen_lo >> 8;
 	bits[7] = bitlen_lo;
-	SHA1_Update(c, bits, 8);
+	arm_SHA1_Update(c, bits, 8);
 
 	for (i = 0; i < 5; i++) {
 		uint32_t v = c->hash[i];
diff --git a/arm/sha1.h b/arm/sha1.h
index 395264634..b61b61848 100644
--- a/arm/sha1.h
+++ b/arm/sha1.h
@@ -7,12 +7,17 @@
 
 #include <stdint.h>
 
-typedef struct sha_context {
+typedef struct {
 	uint64_t len;
 	uint32_t hash[5];
 	unsigned char buffer[64];
-} SHA_CTX;
+} arm_SHA_CTX;
 
-void SHA1_Init(SHA_CTX *c);
-void SHA1_Update(SHA_CTX *c, const void *p, unsigned long n);
-void SHA1_Final(unsigned char *hash, SHA_CTX *c);
+void arm_SHA1_Init(arm_SHA_CTX *c);
+void arm_SHA1_Update(arm_SHA_CTX *c, const void *p, unsigned long n);
+void arm_SHA1_Final(unsigned char *hash, arm_SHA_CTX *c);
+
+#define git_SHA_CTX	arm_SHA_CTX
+#define git_SHA1_Init	arm_SHA1_Init
+#define git_SHA1_Update	arm_SHA1_Update
+#define git_SHA1_Final	arm_SHA1_Final
diff --git a/arm/sha1_arm.S b/arm/sha1_arm.S
index 8c1cb99fb..41e92636e 100644
--- a/arm/sha1_arm.S
+++ b/arm/sha1_arm.S
@@ -10,7 +10,7 @@
  */
 
 	.text
-	.globl	sha_transform
+	.globl	arm_sha_transform
 
 /*
  * void sha_transform(uint32_t *hash, const unsigned char *data, uint32_t *W);
@@ -18,7 +18,7 @@
  * note: the "data" pointer may be unaligned.
  */
 
-sha_transform:
+arm_sha_transform:
 
 	stmfd	sp!, {r4 - r8, lr}